CN117720382A - Agricultural compound phosphate fertilizer and preparation method thereof - Google Patents

Abstract

The invention discloses an agricultural compound phosphate fertilizer and a preparation method thereof, and relates to the technical field of fertilizers. The method comprises the steps of carrying out super aeration flotation on extraction slurry obtained by crystal growth in a wet phosphoric acid process, introducing super aeration micro-bubbles into the extraction slurry through super aeration flotation, and grading to obtain air flotation layer slurry and floating residual layer slurry, wherein the air flotation layer slurry is used as a base material, straw matters, coal slime, layered silicate, phosphorite and straw fast-decay microbial inoculum are directly matched without filtration to obtain the agricultural composite phosphate fertilizer, the phosphorite can utilize low-grade phosphorite, the purpose of comprehensively utilizing phosphogypsum waste and low-grade mineral is realized, and the technical problem that waste accumulation is easy to occur in the existing phosphoric acid production process can be further solved.

Description

Agricultural compound phosphate fertilizer and preparation method thereof

Technical Field

The invention relates to the technical field of fertilizers, in particular to an agricultural compound phosphate fertilizer and a preparation method thereof.

Background

Fig. 1 is a prior art phosphoric acid production line, in which phosphorite, acid and water are put into reaction, liquid-solid reaction is sequentially carried out in a multistage reaction tank, the process is generally called extraction reaction in the field of phosphorus chemical industry, the process is essentially liquid-solid reaction process, extraction slurry is obtained after the extraction reaction, then crystal growth process (crystal growth slurry) and filtering equipment are used for filtering the crystal growth slurry to obtain liquid product phosphoric acid and solid waste phosphogypsum, and whether flash evaporation cooling is carried out or not is determined according to the temperature of the slurry to be filtered. The route can generate a large amount of phosphogypsum, and the phosphogypsum is mainly used as a building material, however, the application of the phosphogypsum on the building material is restricted due to the fact that the phosphogypsum contains organic matters, indissolvable phosphorus, fluoride and other impurities, so the phosphogypsum generated by the wet-process phosphoric acid process is difficult to recycle as an effective building material.

The phosphogypsum with higher impurity content generated by the wet-process phosphoric acid process is not provided with a better recovery method at present, so that a large amount of phosphogypsum increment is generated each year, and the whole phosphoric acid industry faces a great development difficulty because of the generation of phosphogypsum.

In view of this, the present invention has been made.

Disclosure of Invention

The invention aims to provide an agricultural compound phosphate fertilizer and a preparation method thereof, and aims to improve the economic benefit of phosphogypsum by utilizing phosphogypsum with higher impurity content generated by a wet-process phosphoric acid process.

The invention is realized in the following way:

in a first aspect, the invention provides an agricultural compound phosphate fertilizer, which comprises, by mass, 10-35% of phosphogypsum slurry, 10-55% of straw materials, 5-30% of coal slime, 5-30% of layered silicate, 5-15% of phosphorite and 0.1-0.5% of straw quick-rot fungus agent;

wherein, the phosphogypsum slurry comprises the following components in percentage by mass: 25-30% of phosphorus, 3-4% of total impurities of magnesium, aluminum and iron, 5-8% of MER value and the balance of water;

the phosphogypsum slurry is produced by wet phosphoric acid, the extraction slurry obtained by crystal growth is subjected to super aeration flotation, super aeration microbubbles are introduced into the extraction slurry through super aeration flotation, and the air flotation layer slurry and the floating residual layer slurry are obtained after classification, wherein the phosphogypsum slurry is the air flotation layer slurry.

In an alternative embodiment, the straw rapid-decay microbial agent is selected from the group consisting of Jin Kuizi straw rapid-decay microbial agents;

preferably, the phosphorite is a low grade phosphorite.

In an alternative embodiment, the agricultural compound phosphate fertilizer is a desertification land improvement material, and comprises, by mass, 20-25% of phosphogypsum slurry, 30-35% of straw matters, 5-10% of coal slime, 20-30% of layered silicate, 5-10% of phosphorite and 0.3-0.5% of straw quick-rot fungus agent.

In an alternative embodiment, the agricultural compound phosphate fertilizer is a saline-alkali soil improvement material and comprises, by mass, 30-35% of phosphogypsum slurry, 25-35% of straw, 15-20% of coal slime, 5-10% of layered silicate, 5-8% of phosphorite and 0.1-0.3% of straw quick-rot microbial agent.

In an alternative embodiment, the agricultural composite phosphate fertilizer is a repair material for heavy metal or pesticide residue pollution, and comprises, by mass, 10-15% of phosphogypsum slurry, 15-20% of straw matters, 10-15% of coal slime, 15-20% of layered silicate, 10-15% of phosphorite and 0.1-0.5% of straw quick-decay microbial agent.

In an alternative embodiment, the agricultural compound phosphate fertilizer is a degraded sand improvement material, and comprises, by mass, 10-15% of phosphogypsum slurry, 35-55% of straw matters, 10-15% of coal slime, 5-10% of layered silicate, 10-15% of phosphorite and 0.1-0.3% of straw quick-rot fungus agent.

In an alternative embodiment, the composite material comprises 25-35% of phosphogypsum slurry, 40-55% of straw matter, 20-30% of coal slime, 5-10% of layered silicate, 10-15% of phosphorite and 0.1-0.5% of straw quick-decay microbial agent by mass percent.

In a second aspect, the present invention provides a method for preparing an agricultural compound phosphate fertilizer according to any one of the foregoing embodiments, where the preparation is performed according to a formulation composition of the agricultural compound phosphate fertilizer.

In an alternative embodiment, the method comprises: mixing phosphogypsum slurry, straw matters, coal slime, layered silicate, phosphorite and straw quick-decay microbial inoculum for reaction at the temperature of 30-65 ℃ for 8-12 days;

preferably, the humidity of the mixture is controlled between 30% and 48% during the reaction.

In an alternative embodiment, the phosphogypsum slurry is prepared by the steps of: mixing phosphorite and inorganic acid, performing extraction and crystal growth to obtain extraction slurry, performing super-aeration flotation on the extraction slurry, introducing super-aeration microbubbles into the extraction slurry through super-aeration flotation, and grading to obtain air flotation layer slurry and floating residual layer slurry, wherein phosphogypsum slurry is air flotation layer slurry; wherein, the ultra-aeration micro-bubble contains a surfactant;

preferably, the ultra-aeration micro-bubbles are introduced in the form of a gas-liquid mixed phase, the gas is introduced into the liquid phase with pressure to form the gas-liquid mixed phase, and the gas-liquid mixed phase is introduced into the extraction slurry through an aeration disc; the pressure of the gas-liquid mixed phase is 0.1MPa-1.0MPa, the gas phase comprises microbubbles with the diameter of 0.1 mu m-50 mu m, and the gas phase accounts for 1wt% to 30wt% of the gas-liquid mixed phase; the mass ratio of the gas-liquid mixed phase to the extraction slurry is (5-30): 100;

Preferably, adding a surfactant into the liquid phase, wherein the adding amount of the surfactant is 1.0mg/L-4.0mg/L, and the surfactant is at least one selected from cetyltrimethylammonium bromide, polydimethyldiallyl ammonium chloride and quaternary ammonium chitosan;

preferably, the extraction slurry is sequentially subjected to multistage super-aeration flotation, wherein each stage of super-aeration flotation is to introduce super-aeration micro-bubbles into the extraction slurry, and the extraction slurry enters a classification channel for classification after multistage super-aeration flotation; in the multistage super-aeration floating process, controlling the treatment time of the extraction slurry in the super-aeration micro-bubbles to be 15-60 min; the classification is to use a dynamic settler to process in a classification channel, output air floating layer slurry above the dynamic settler and output floating residual layer slurry below the dynamic settler.

The invention has the following beneficial effects: the method comprises the steps of carrying out super aeration flotation on extraction slurry obtained by crystal growth in a wet phosphoric acid process, introducing super aeration micro-bubbles into the extraction slurry through super aeration flotation, and grading to obtain air flotation layer slurry and floating residual layer slurry, wherein the air flotation layer slurry is used as a base material, straw matters, coal slime, layered silicate, phosphorite and straw fast-decay microbial inoculum are directly matched without filtration to obtain the agricultural composite phosphate fertilizer, the phosphorite can utilize low-grade phosphorite, the purpose of comprehensively utilizing phosphogypsum waste and low-grade mineral is realized, and the technical problem that waste accumulation is easy to occur in the existing phosphoric acid production process can be further solved.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings that are needed in the embodiments will be briefly described below, it being understood that the following drawings only illustrate some embodiments of the present invention and therefore should not be considered as limiting the scope, and other related drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.

FIG. 1 is a flow chart of a wet process phosphoric acid process provided in the prior art;

FIG. 2 is a flow chart of a wet process phosphoric acid process provided by an embodiment of the invention;

FIG. 3 is a diagram of a super-aeration air floatation device according to an embodiment of the present invention;

FIG. 4 is a schematic view of the aeration structure of FIG. 3;

FIG. 5 is a dimensional illustration of the super aeration floatation device of FIG. 3;

FIG. 6 is a diagram of a super-aeration air floatation device according to another embodiment of the present invention;

FIG. 7 is a schematic diagram of a super-exposure generator according to an embodiment of the present invention;

FIG. 8 is a comparative plot of beet-H10099 samples; in the drawings, (a) represents a group of embodiments; (b) represents a control group;

FIG. 9 is a graph showing a comparison of North Chinese cabbage-Jinfeng samples; in the drawings, (a) represents a group of embodiments; (b) represents a control group;

FIG. 10 is a comparison of samples of castor-Zicastor No. 5; in the drawings, (a) represents a group of embodiments; (b) represents a control group;

FIG. 11 is a comparative plot of tobacco leaf tests in saline-alkali soil; in the figure, (a) and (c) represent experimental groups (i.e., example groups); (b) and (d) represent a comparative group;

FIG. 12 is a comparative chart of the cold resistance of zucchini; in the figure, (a) represents a comparison of the comparative group and the experimental group at the first viewing angle; (b) A comparison of the comparative and experimental groups at the second viewing angle;

FIG. 13 is a graph showing a comparison of plant heights of different fertilization treatments for sunflower;

fig. 14 is a graph showing comparison of plant heights of different fertilization treatments for leguminous crops.

Icon is 100-first super aeration floatation device; 001-a feed inlet; 002-fractionation of channels; 003-a discharge hole of the air floatation layer; 004-a floating residue layer discharge port; 005-a third discharge port; 006-fourth discharge port; 007-overflow port; 110-an outer shell; 121-outermost layer of tubing; 122-an intermediate line; 1221-a second communication hole; 123-inner layer pipeline; 1231-a first communication hole; 130-aeration structure; 131-connecting pipes; 132-aeration disc; 133-an aeration generator; 134-primary aeration structure; 135-a secondary aeration structure; 136-three-stage aeration structure; 140-a bottom plate; 151-a first dynamic settler; 152-a second dynamic settler;

200-a second super aeration floatation device; 210-bin number one; 220-bin number two; 230-bin number three; 211-a first through window; 221-a second through window; 231-a third through window;

400-super-exposure generator; 401-a pressurized zone; 410-an occurrence container; 420-a liquid transfer line; 421-fifth valve; 430-compressed gas transfer line; 431-top transfer line; 432-bottom transfer line; 433-a first valve; 434-a second valve; 435-a third valve; 440-gas-liquid mixture output line; 441-fourth valves; 450-safety valve; 460-pressure detection mechanism.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present invention more clear, the technical solutions of the embodiments of the present invention will be clearly and completely described below. The specific conditions are not noted in the examples and are carried out according to conventional conditions or conditions recommended by the manufacturer. The reagents or apparatus used were conventional products commercially available without the manufacturer's attention.

The embodiment of the invention provides an agricultural compound phosphate fertilizer, which comprises, by mass, 10-35% of phosphogypsum slurry, 10-55% of straw matters, 5-30% of coal slime, 5-30% of layered silicate, 5-15% of phosphorite and 0.1-0.5% of straw quick-decay microbial inoculum.

The phosphogypsum slurry can be derived from phosphogypsum slurry with higher impurity content generated by wet phosphoric acid, and the phosphogypsum slurry comprises the following components in percentage by mass: the phosphorus content is 25-30%, the total content of magnesium-aluminum-iron impurities is 3-4%, the MER value is 5-8%, and the balance is water.

The straw may be crop straw commonly used for fertilizer, such as corn straw, but is not limited thereto. The straw contains more nutrient elements, and can improve soil fertility and crop yield.

The coal slime is a semisolid formed by water contained in coal dust, and is a product in the coal production process. The coal slurry may be a commercially available material. The coal slime contains a large amount of organic matters, inorganic salts and mineral matters, and is beneficial to soil restoration.

The layered silicate is silicate mineral with layered structure, and through introducing silicon element, the soil is improved, so that the photosynthesis efficiency of crops is improved, and the disease and pest resistance of crops is improved.

The straw quick-rot microbial agent is also called as straw quick-rot microbial agent, and can quickly decompose organic wastes such as straw, so that organic matters, phosphorus, potassium and other elements contained in the straw become nutrition required by plant growth, generate a large amount of beneficial microorganisms, stimulate crop production, improve soil organic matters, enhance plant stress resistance, reduce the use amount of chemical fertilizers, improve crop quality and realize sustainable development of agriculture. The straw quick-rot microbial agent is not limited in type and can be selected from Jin Kuizi straw quick-rot microbial agents.

The phosphorite can be low-grade phosphorite, the grade refers to the content of phosphorite phosphorus, the low-grade phosphorite refers to the low content of phosphorite phosphorus, and the phosphorus content is 18-20%.

Specifically, the phosphogypsum slurry can be 10%, 15%, 20%, 25%, 30%, 35% and the like by mass, the straw can be 10%, 20%, 30%, 40%, 50%, 55% and the like by mass, the coal slurry can be 5%, 10%, 15%, 20%, 25%, 30% and the like by mass, the layered silicate can be 5%, 10%, 15%, 20%, 25%, 30% and the like by mass, the phosphorite can be 5%, 10%, 15% and the like by mass, and the straw quick-rot microbial inoculum can be 0.1%, 0.2%, 0.3%, 0.4%, 0.5% and the like by mass.

Aiming at different purposes of the agricultural compound phosphate fertilizer, the inventor carries out targeted adjustment on the formula:

in some embodiments, the agricultural composite phosphate fertilizer is a desertification land improvement material, and comprises, by mass, 20-25% of phosphogypsum slurry, 30-35% of straw, 5-10% of coal slime, 20-30% of layered silicate, 5-10% of phosphorite and 0.3-0.5% of straw fast-rot microbial agent. The quality ratio of phosphogypsum slurry, straw matters, coal slime, layered silicate, phosphorite and straw fast-decay microbial inoculum is regulated, so that the prepared agricultural compound phosphate fertilizer is suitable for improving sandy land.

In some embodiments, the agricultural compound phosphate fertilizer is a saline-alkali soil improvement material, and comprises, by mass, 30-35% of phosphogypsum slurry, 25-35% of straw, 15-20% of coal slime, 5-10% of layered silicate, 5-8% of phosphorite and 0.1-0.3% of straw quick-rot microbial agent. The mass ratio of phosphogypsum slurry, straw matters, coal slime, layered silicate, phosphorite and straw quick-decay microbial inoculum is controlled within the above range, so that the prepared agricultural compound phosphate fertilizer is suitable for improving saline-alkali soil.

In some embodiments, the agricultural composite phosphate fertilizer is a repair material for heavy metal or pesticide residue pollution, and comprises, by mass, 10-15% of phosphogypsum slurry, 15-20% of straw matters, 10-15% of coal slime, 15-20% of layered silicate, 10-15% of phosphorite and 0.1-0.5% of straw quick-rot fungus agent. The prepared agricultural compound phosphate fertilizer can repair soil, reduce the heavy metal content and pesticide residue in the soil and has good market application value by regulating and controlling the dosage of phosphogypsum slurry, straw matters, coal slime, layered silicate, phosphorite and straw fast-decay microbial inoculum.

In some embodiments, the agricultural composite phosphate fertilizer is a degraded sand improvement material, and comprises, by mass, 10-15% of phosphogypsum slurry, 35-55% of straw, 10-15% of coal slime, 5-10% of layered silicate, 10-15% of phosphorite and 0.1-0.3% of straw fast-rot microbial agent. The mass ratio of phosphogypsum slurry, straw matters, coal slime, layered silicate, phosphorite and straw quick-decay microbial inoculum is controlled within the above range, so that the prepared agricultural compound phosphate fertilizer has the effect of improving degraded sand.

In some embodiments, if the agricultural compound phosphate fertilizer is used as other improving materials, namely not used as desertification improving materials, saline-alkali soil improving materials, heavy metal or restoration materials for pesticide residue pollution and degraded sand improving materials, the agricultural compound phosphate fertilizer can be optimized according to the following formula: the quick-corrosion straw-stalk composite fertilizer comprises, by mass, 25-35% of phosphogypsum slurry, 40-55% of straw matters, 20-30% of coal slime, 5-10% of layered silicate, 10-15% of phosphorite and 0.1-0.5% of quick-corrosion straw-stalk bacterial agent. The mass ratio of phosphogypsum slurry, straw matters, coal slime, layered silicate, phosphorite and straw quick-decay microbial inoculum is controlled within the above range, so that the comprehensive performance of the agricultural composite phosphate fertilizer is better, and the application range is wider.

The embodiment of the invention also provides a preparation method of the agricultural composite phosphate fertilizer for realizing the low-carbon interface, which is prepared according to the formula composition of the agricultural composite phosphate fertilizer, and phosphogypsum slurry is obtained from wet-process phosphoric acid production and is phosphogypsum with higher impurity content generated in the wet-process phosphoric acid production. Specifically, the preparation method comprises the following steps:

s1, preparing phosphogypsum slurry

The phosphogypsum slurry is prepared through extraction and crystal growth, super aeration floatation and classification, and flash evaporation can be added after the extraction and crystal growth as required. Referring to fig. 2, the specific steps are as follows:

(1) Extraction crystal growing

Mixing phosphorite and inorganic acid for extraction and crystal growth to obtain extraction slurry, the process of extracting and crystal growth can refer to the prior process, mixing phosphorite and inorganic acid for extraction and crystal growth, the extraction and crystal growth can be respectively carried out in two tanks, and the slurry after extraction can overflow to a crystal growth tank for crystal growth.

In some embodiments, the inorganic acid is selected from at least one of sulfuric acid, nitric acid and hydrochloric acid, and may be any one or more of the above. Can be used forFirstly, inorganic acid is mixed with water to be dissolved to obtain inorganic acid aqueous solution, phosphorite and sulfuric acid aqueous solution are mixed to be extracted and cultured, SO is contained in sulfuric acid aqueous solution ₃ The concentration is 0.03g/mL-0.05g/mL, the liquid-solid mass ratio is controlled to be 1.5-3.0, and the extraction effect is further improved by regulating and controlling the dosage ratio of phosphorite and sulfuric acid aqueous solution. Specifically, SO in sulfuric acid aqueous solution ₃ The concentration may be 0.03g/mL, 0.04g/mL, 0.05g/mL, etc., and the liquid-to-solid mass ratio may be 1.5:1, 2.0:1, 2.5:1, 3.0:1, etc.

In some embodiments, at least one of the extraction stage and the crystal growing stage is filled with ultra-aeration microbubbles generated by a high-pressure aeration device, and an aeration disc is added in the existing extraction and/or crystal growing device, wherein the aeration disc can be an existing aeration device, such as available from Shengtai environmental protection filler Co. The formation of the ultra-aeration micro-bubbles can be described with reference to the content of step (3).

In the extraction reaction, a great amount of heat is released in the extraction, so that the process of enhancing crystallization conditions by introducing a great deal of heat transfer and vortex mixing in the original extraction and crystal growth stirring tank is greatly facilitated, the process conditions of phosphoric acid extraction and phosphogypsum grain growth are greatly optimized, the yield of phosphorus and the phosphogypsum filtration strength are improved, high-quality phosphogypsum is obtained, and further, the filtration energy consumption is lower. Meanwhile, the super exposure also enables the slurry to be layered, so that the phosphogypsum classification application is realized; the forced gas-liquid microcirculation stirring system is added, the reaction condition is optimized, the quality of the product and the use value of byproducts are greatly improved, and a low-carbon interface, high efficiency and energy conservation in the production process are realized. In addition, after the bubbles burst, an emulsion layer is generated at the gas-liquid-solid interface, substances with high viscosity such as organic matters, aluminum and the like can float on the emulsion layer, the residual phosphorus can be divided into an air floatation layer and a floating residual layer, the air floatation layer can be filtered, impurity components (such as organic matters, fluorides, iron aluminum and the like) are mainly concentrated on the air floatation layer, and the impurities are useful for phosphogypsum for agriculture and are suitable for further preparing agricultural fertilizers.

(2) Flash evaporation

The flash evaporation can reduce the temperature of the slurry, is not an essential step in the wet phosphoric acid process, and the method provided by the embodiment of the invention is improved on the existing device, and if the existing process is provided with a flash evaporation stage, the flash evaporation stage is reserved.

In some embodiments, the ultra-aeration micro-bubbles generated by the high-pressure aeration device are introduced in at least one of the extraction stage, the crystal growing stage and the flash evaporation stage, and the ultra-aeration micro-bubbles generated by the high-pressure aeration device are introduced in at least one of the extraction stage, the crystal growing stage and the flash evaporation stage, so that the impurity removal effect is improved, the impurities are concentrated on the upper layer more, the flash evaporation energy can be reduced, and the flash evaporation effect is improved. The formation of the ultra-aeration micro-bubbles can be described with reference to the content of step (3).

(3) Super aeration floatation and classification

The extracted slurry is subjected to super-aeration flotation, wherein the extracted slurry refers to the slurry obtained in the step (1), and if the wet-process phosphoric acid process with a flash evaporation stage refers to the slurry obtained in the step (2). The extraction slurry is subjected to super aeration flotation and classification to obtain air-floating layer slurry and residual layer slurry, wherein the air-floating layer slurry is phosphogypsum slurry in the formula provided by the embodiment of the invention.

Specifically, super aeration flotation is carried out in extraction slurry, super aeration micro bubbles containing surfactant are introduced, in the process of floating up the bubbles, the pressure of the slurry is gradually reduced, so that the pressure inside and outside the super aeration micro bubbles is gradually unbalanced, the super aeration micro bubbles can be broken to generate smaller bubbles, the surfactant can be used for enhancing the adhesion of impurities, thereby taking away the impurities, finally, the slurry is in the slurry distribution state of an upper air flotation layer and a lower floating residual layer, the slurry of the upper air flotation layer and the slurry of the lower floating residual layer are graded and subjected to solid-liquid separation, a filter cake obtained by filtering the floating residual layer accords with the relevant standard of building materials, the property of phosphogypsum building materials is greatly improved, and the slurry of the air flotation layer can be directly used as a base material of ingredients.

Further, the ultra-aeration micro-bubbles are introduced in the form of a gas-liquid mixed phase, the gas-liquid mixed phase is formed by pressurizing the gas introduced into the liquid phase, and the gas-liquid mixed phase is introduced into the extraction slurry through an aeration disc. The pressure of the gas-liquid mixed phase is 0.1MPa-1.0MPa, the gas phase comprises microbubbles with the diameter of 0.1 mu m-50 mu m, the gas phase accounts for 1wt% -30wt% of the gas-liquid mixed phase, and the mass ratio of the gas-liquid mixed phase to the extraction slurry is (5-30): 100. the specific operation parameters of the ultra-aeration micro-bubbles are optimized, so that impurities beneficial to crops are positioned on the air floatation layer as much as possible.

Specifically, the pressure of the gas-liquid mixed phase may be 0.1MPa, 0.2MPa, 0.3MPa, 0.4MPa, 0.5MPa, 0.6MPa, 0.7MPa, 0.8MPa, 0.9MPa, 1.0MPa, etc. The gas phase may be composed of microbubbles having diameters of 0.1 μm to 50. Mu.m, specifically 0.1 μm, 0.5 μm, 1.0 μm, 3.0 μm, 5.0 μm, 10.0 μm, 20.0 μm, 30.0 μm, 40.0 μm, 50.0 μm, etc. The proportion of the gas phase to the gas-liquid mixed phase can be 1wt%, 3wt%, 5wt%, 8wt%, 10wt%, 15wt%, 20wt%, 25wt%, 30wt%, etc. The mass ratio of the gas-liquid mixed phase to the extraction slurry may be 5:100, 10:100, 15:100, 20:100, 25:100, 30:100, etc.

In some embodiments, the liquid phase is at least one of a system slurry, wash water, and return acid, the system slurry being an extraction slurry in a wet-process phosphoric acid system; the washing water is washing water obtained by washing the solid after filtering the floating layer; the acid return refers to dilute phosphoric acid obtained after filtration of an air floatation layer and a surplus layer.

In some embodiments, the surfactant may be added to the liquid phase in an amount of 1.0mg/L to 4.0mg/L. The adhesive effect of the impurities can be enhanced by adding the surfactant, so that the impurities are taken away, and finally, the slurry is in a slurry distribution state of the upper air flotation layer and the lower floating residual layer, and the slurry of the upper air flotation layer and the slurry of the lower floating residual layer are separated. The inventor finds that the filtrate obtained by filtering the air floatation layer and the residual layer is a phosphoric acid product with better quality, and the filter cake obtained by filtering the residual layer accords with the relevant standards of building materials, so that the property of phosphogypsum building materials is greatly improved, and the air floatation layer can be directly used as the base material of the phosphate fertilizer without filtering.

Further, the surfactant is at least one selected from anionic surfactant, cationic surfactant, zwitterionic surfactant, nonionic surfactant and natural surfactant with unknown property, and can be any one or more of the above surfactants. The natural surfactant with unknown properties is a natural surfactant which is not anionic, cationic, zwitterionic or nonionic.

Anionic surfactants are those in which the surface-active ions generated upon dissociation in aqueous solution are negatively charged and generally consist of an ionic hydrophilic group and an oil-soluble lipophilic group. The specific classification is as follows: (1) carboxylates. Such as alkali metal soap, and has a molecular structure of R-COONa (K). It is made up by using animal and vegetable oil and sodium hydroxide (potassium) through the process of saponification. Soap surfactants are not hard water resistant and most contain free base and therefore are not suitable for use with alkaline earth containing pesticides such as bordeaux mixture to avoid calcium soap formation and loss of surface activity in water. (2) sulfate salts. The molecular structure is expressed as R-OSO ₃ Na is the sulfated product of fatty alcohols. Such as turkish red oil obtained by reacting castor oil with concentrated sulfuric acid at a lower temperature and neutralizing with sodium hydroxide. (3) sulfonates. The molecular structure is simply R-SO ₃ Na (Ca), R is alkylaryl. This is currently the most important and common class of surfactants. The composite emulsifier has quite strong resistance to hard water and acid and alkali, wide application and various varieties, wherein sodium dodecyl benzene sulfonate and alkyl naphthalene sulfonate such as nekal are wetting agents commonly used in wettable powder, and calcium dodecyl benzene sulfonate is an important component of the existing composite emulsifier.

Cationic surfactants are capable of generating hydrophobic cations, such as quaternary ammonium ions, in water, mostly nitrogen-containing organic compounds, and rarely phosphorous-or sulfur-containing organic compounds. Mainly quaternary ammonium compounds. Such as cetyl trimethyl quaternary ammonium bromide and stearyl dimethyl benzyl quaternary ammonium chloride.

The amphoteric surfactant is a cationic surfactant or an anionic surfactant, which has both positive and negative charge groups in the molecule, depending on the pH value of the medium. The amphoteric surfactant can be natural products and artificial products, and lecithin is common in natural products; in the synthetic amphoteric surfactant, the cationic part is ammonium salt or quaternary ammonium salt, and the anionic part is mainly carboxylate, sulfate, sulfonate and the like.

The nonionic surfactant is not dissociated in water, has stable property, is resistant to hard water, has good emulsifying, wetting, dispersing and dissolving assisting performances, and is a main emulsifier for processing pesticides. The chemical structure of the main species is divided into two categories of esters and ethers. (1) esters. For example, polyoxyethylene fatty acid esters, having the molecular structural formula RCOO (CH ₂ CH ₂ O） _n H. The fatty acid moiety is an oleophilic moiety, mostly lauric acid, oleic acid, stearic acid or ricinoleic acid. The polyoxyethylene moiety is a hydrophilic moiety, and the more the number of molecules (n) polymerized, the more hydrophilic it is, and the more the polyoxyethylene moiety is, the more the hydrophilic it is, and the polyoxyethylene moiety is, as needed, adjusted, and is generally 5 to 15 polyoxyethylene moieties. (2) ethers. The surfactant is mainly prepared by the addition reaction of hydrophobic compounds containing-OH groups, such as alcohol or phenol, and ethylene oxide or propylene oxide. This is a polymerization reaction in which the number of molecules of ethylene oxide or propylene oxide can be artificially adjusted to control the hydrophilic-lipophilic balance of such surfactants. The main variety types are alkyl polyoxyethylene ether, alkyl aryl polyoxyethylene ether, poly aryl nuclear polyoxyethylene ether and the like.

In a preferred embodiment, the surfactant is at least one selected from cetyltrimethylammonium bromide, polydimethyldiallylammonium chloride and quaternary ammonium chitosan, and may be any one or more of the above. The above surfactants can further improve the impurity removal effect, and the raw materials are easy to obtain.

In some embodiments, an extraction aid may be added to the liquid phase, and the extraction aid may be added in an amount of 1mg/L to 20mg/L (e.g., 1mg/L, 5mg/L, 10mg/L, 15mg/L, 20mg/L, etc.), so that the impurity removal effect can be further improved by further adding the extraction aid. The extraction auxiliary agent is at least one selected from fatty alcohols, ethers, ketones, esters and phosphates, and can be any one or more of the above.

Specifically, fatty alcohols are the most used solvents for various research institutions, such as n-butanol, isobutanol, isoamyl alcohol, etc. The aliphatic alcohol solvent has low price, can be repeatedly used, has very little toxicity and corrosiveness, has poor purifying effect on anions, is easy to be mutually dissolved with water, has high recovery cost in the later period, and is not thorough for purifying high-concentration phosphoric acid.

The ethers are usually isopropyl ether and isobutyl ether, which hardly extract phosphoric acid with low concentration, but have outstanding extraction effect on phosphoric acid with high concentration, and have better selectivity on metal ions and sulfate ions, but have poorer purification effect on anions, are improper to store, are easy to cause fire and cause explosion, and threaten personal safety.

The most commonly used ketones and esters are methyl isobutyl ketone (MIBK), and in addition to propyl acetate, butyl acetate, and the like. The advantages and disadvantages are similar to ethers.

The phosphate is mainly tributyl phosphate (TBP), the TBP is insoluble in water, and after extraction, phosphate radical, fluorine and metal impurities contained in an extraction phase are less, but the TBP has high price, high density and viscosity and difficult layering. TBP is often used with a small amount of diluent added to reduce viscosity to accelerate phase separation, and is easier to recycle.

Similar to the method for purifying wet phosphoric acid, each extraction aid has different optimal application ranges for purifying phosphoric acid, and for crude phosphoric acid, the extraction effect of the composite extraction aid is much better than that of a single kind of extraction aid, and how to select the extraction aid is selected specifically by referring to objective conditions such as the impurity types, the impurity amounts, the concentration of crude phosphoric acid and the like in the phosphoric acid.

In a preferred embodiment, the extraction aid is at least one selected from n-butanol, isobutanol, isoamyl alcohol, isopropyl ether, isobutyl ether, methyl isobutyl ketone, propyl acetate, butyl acetate and tributyl phosphate, and can be any one or more of the above, and the above extraction aids have easily available raw materials and better impurity removal effect.

In some embodiments, the extraction slurry is sequentially subjected to multi-stage super-aeration flotation, wherein each stage of super-aeration flotation is to introduce super-aeration micro-bubbles into the extraction slurry, and the extraction slurry enters a classification channel for classification after multi-stage super-aeration flotation, so as to obtain air-flotation layer slurry and floating residue layer slurry after classification. In the multistage super aeration floating process, the treatment time of the extraction slurry in the super aeration micro-bubbles is controlled to be 1min-15min (such as 1min, 3min, 5min, 8min, 10min, 13min, 15min and the like), and the quality of phosphogypsum is improved by optimizing the treatment time so that impurities are more fully removed.

In some embodiments, classification may be performed in a classification tunnel using a dynamic settler, with the air bed slurry being output above the dynamic settler and the retentate bed slurry being output below the dynamic settler, but is not limited to classification using a dynamic settler.

The process of super-aeration flotation and classification can be operated by using the first super-aeration flotation device 100 shown in fig. 3 to 5, and the specific structure is as follows:

referring to fig. 3, the first super-aeration air-floating device 100 includes an outer housing 110, a sleeve structure is disposed in the outer housing 110, the sleeve structure is formed by sequentially sleeving a plurality of pipelines, and communication holes are disposed between two adjacent pipelines, so that materials in an inner pipeline can enter an outer pipeline. An aeration structure 130 is arranged between two adjacent pipelines, the aeration structure 130 is obtained according to the number of the pipelines in the sleeve structure, and the specific number is not limited.

Further, a feed port 001 is provided at the bottom of the first super aeration air floatation device 100, a classification channel 002 is formed between the outermost layer pipeline 121 in the sleeve structure and the outer shell 110, an air floatation layer discharge port 003 is provided at the top side wall of the classification channel 002, and a floating layer discharge port 004 is provided at the bottom of the classification channel 002. The extraction slurry enters the sleeve structure from the feed inlet 001, is subjected to aeration treatment by the plurality of aeration structures 130, so that impurities float upwards along with bubbles, and are finally classified in the classification channel 002, the slurry with relatively more impurities is output from the air floatation layer discharge port 003 at the top, and the slurry with less impurities is output from the floating residual layer discharge port 004 at the bottom.

The slurry output from the bottom of the classification channel 002 can be filtered to obtain high-purity phosphogypsum products, the phosphogypsum products have little impurity content, and the phosphogypsum products are beneficial to being directly used as phosphogypsum for construction (namely industrial phosphogypsum); the phosphogypsum with higher impurity content is obtained after the slurry output from the top is filtered, but the impurities such as organic matters, fluoride, residual phosphorus and the like are beneficial to crops, and can be output as an agricultural phosphogypsum product.

In some embodiments, the sleeve structure may be a tertiary sleeve structure, mated with a tertiary aeration structure. The sleeve structure is formed by sequentially sleeving an inner pipeline 123, a middle pipeline 122 and an outermost pipeline 121, wherein a plurality of first communication holes 1231 are distributed on the pipe wall of the inner pipeline 123, and a plurality of second communication holes 1221 are distributed on the pipe wall of the middle pipeline 122. After entering from the inner layer piping 123, the extraction slurry enters the intermediate piping 122 from the first communication hole 1231, and then enters the outermost layer piping 121 from the second communication hole 1221. The top of the inner pipe 123, the intermediate pipe 122 and the outermost pipe 121 may be closed or open.

Further, a primary aeration structure 134 is provided in the inner pipe 123, a secondary aeration structure 135 is provided between the inner pipe 123 and the middle pipe 122, and a tertiary aeration structure 136 is provided between the middle pipe 122 and the outermost pipe 121, and the installation heights of the primary aeration structure 134, the secondary aeration structure 135 and the tertiary aeration structure 136 are gradually increased. The primary aeration structure 134, the secondary aeration structure 135 and the tertiary aeration structure 136 are all connected with the external aeration generator 133, that is, the tertiary aeration generator is mounted on the outer housing 110, the primary aeration structure 134 corresponds to the primary aeration generator, the secondary aeration structure 135 corresponds to the secondary aeration generator, and the tertiary aeration structure 136 corresponds to the tertiary aeration generator.

Specifically, referring to fig. 3 and 4, the aeration structures 130 each include a connection pipe 131 and a plurality of aeration disks 132, the plurality of aeration disks 132 are spaced apart on the connection pipe 131, and the connection pipe 131 is connected to an external aeration generator 133. The aeration disc 132 is structured like a shower head, and sprays out the gas-liquid mixture through a plurality of water outlet holes. The aeration generator 133 may be configured to pressurize the liquid and to introduce a gas into the pressurized liquid to form a gas-liquid mixture. The liquid filling device comprises a container, wherein a transfusion pipeline and a gas transmission pipeline are arranged on the container, liquid is firstly filled into the container, gas is filled into the top of the container through the gas transmission pipeline for pressurization, and then gas is filled into the bottom of the container through the gas transmission pipeline to form a gas-liquid mixed phase; and finally, introducing gas into the top of the container, opening an outlet valve, and outputting the gas-liquid mixed phase.

Further, the first communication holes 1231 are distributed from the top to the bottom of the inner pipeline 123, that is, the whole of the first communication holes 1231 is porous. The second communication holes 1221 are distributed in the region of the intermediate pipe 122 above the secondary aeration structure 135 so that the aerated slurry enters the outermost pipe 121 from above. The outermost pipe 121 may be provided with no communication hole, and the top of the outermost pipe 121 may be spaced from the top of the outer casing 110 to form an overflow port 007 that overflows from the outermost pipe 121 to the classification channel 002, so that slurry enters the classification channel 002 from the overflow port 007. Specifically, the opening ratio of the inner pipe 123 may be about 36%, and the opening ratio of the intermediate pipe 122 may be about 30%.

In some embodiments, the first super aeration device 100 further includes a bottom plate 140, the bottom plate 140 is disposed at the bottom of the sleeve structure, the feed port 001 is disposed on the bottom plate 140, and the position of the feed port 001 corresponds to the inner layer pipeline 123, and the feed can be from the center of the inner layer pipeline 123.

Further, a third outlet 005 is provided in the bottom plate 140 between the inner pipe 123 and the middle pipe 122, and a fourth outlet 006 is provided in the bottom plate 140 between the middle pipe 122 and the outermost pipe 121. The slurries output by the third discharge port 005 and the fourth discharge port 006 are the slurries with relatively low impurity content, and can be output as industrial phosphogypsum.

In some embodiments, the outermost pipe 121 is higher than the inner pipe 123 and the middle pipe 122, and a first dynamic settler 151 is disposed on top of the outermost pipe 121, and impurities are concentrated more in the slurry of the upper layer by using the first dynamic settler 151 to promote classification effect.

Similarly, a second dynamic settler 152 is arranged on the classification channel 002, the air-floating layer discharge outlet 003 is positioned above the second dynamic settler 152, and the dynamic settler is also arranged on the classification channel 002, so that the classification effect is further improved, and impurities are more concentrated on the upper-layer slurry.

Specifically, the first dynamic settler 151 and the second dynamic settler 152 are existing dynamic settlers, such as may be used in solving sludge settling in a sewage treatment process. As shown, the first dynamic settler 151 may be installed by means of a plate-like structure having upper and lower holes, and the second dynamic settler 152 may be installed by means of a plate-like structure having upper and lower holes, and the opening ratio may be 30%.

Specifically, the dimensions of each portion of the first super aeration air floatation device 100 are not limited, and may be designed according to the process requirements. The diameter of the outer housing 110 may be 900-1100mm, such as 1000mm; the diameter of the outermost tube 121 may be 600-800mm, such as 700mm; the diameter of the intermediate conduit 122 may be 400-600mm, such as 500mm; the diameter of the inner conduit may be 100-200mm, such as 150mm. The diameter of the feed inlet 001 can be 80mm, and the diameter of the discharge outlet can be 100mm.

As shown in FIG. 5, the height a of each part is 303mm; b, 180mm; c, 120mm; d, 230mm; e, 250mm; f, 230mm; g is 230mm; h, 330mm. The dimensions of the first dynamic settler 151 and the second dynamic settler 152 are shown in figure 5 in mm.

Specifically, the material of the first super aeration air floatation device 100 needs to resist corrosion of 20-45% phosphoric acid and 16-60% sulfuric acid, has the characteristics of high temperature resistance and high pressure resistance, is suitable for working under the working condition of 100 ℃ and 0.1MPa, and is recommended to be PC material, and PC pipe is selected as far as possible.

The super aeration float device is not limited to the structure of fig. 3, and may be operated by using the device of fig. 6. The second super-aeration air floatation device 200 comprises a first bin 210, a second bin 220 and a third bin 230, wherein a first through window 211 communicated with the second bin 220 is arranged at the top of the first bin 210, a second through window 221 communicated with the third bin 230 is arranged on the side wall of the second bin 220, and a third through window 231 communicated with the first bin 210 is arranged on the side wall of the third bin 230. After entering from the first bin 210, the extraction slurry circulates back to the first bin 210 after passing through the second bin 220 and the third bin 230, ultra-exposure microbubbles are introduced into the first bin 210, agricultural phosphogypsum slurry is output from the top of the third bin 230, and building phosphogypsum slurry is output from the lower part of the ultra-exposure bin.

In some embodiments, the structure of the super-exposure generator 400 in fig. 3 may be as shown in fig. 7, and the super-exposure generator 400 in fig. 7 operates as follows: (1) Opening the fifth valve 421, feeding liquid or slurry into the generating vessel 410 using the liquid transfer line 420, and closing the fifth valve 421; (2) Opening the third valve 435 and the first valve 433 to pressurize the liquid in the generating vessel 410 through the compressed gas delivery line 430 and the top delivery line 431 to form a pressurizing area 401 at the top, and closing the first valve 433 after the pressure reaches the process requirement; (3) Opening the third valve 435 and the second valve 434, performing pressurized aeration into the pressurized liquid in the generating vessel 410 through the compressed gas delivery line 430 and the bottom delivery line 432 to form a pressurized gas-liquid mixture, and closing the third valve 435 and the second valve 434 after the process requirements are met; (4) The third valve 435, the first valve 433 and the fourth valve 441 are opened, compressed gas is pressurized to the top of the generation container 410 through the compressed gas delivery line 430 and the top delivery line 431, the pressurized gas-liquid mixture is outputted from the gas-liquid mixture output line 440, and the super-exposed liquid is delivered to the target area. The whole process utilizes the pressure detection mechanism 460 to detect the pressure, and the safety valve 450 alarms when the pressure exceeds a specified range.

By "overexposure" is meant that a gas-liquid mixture with pressure is formed, which differs from conventional bubbling mainly in pressurization.

S2, mixing materials

Phosphogypsum slurry, straw matters, coal slime, layered silicate, phosphorite and straw fast-decay microbial inoculum are subjected to blending reaction, wherein the reaction temperature is 30-65 ℃, the reaction pressure is normal pressure, and the reaction time is 8-12 days.

In the actual operation process, the separated air-float layer slurry is put into a reactor, straw matters, coal slime, layered silicate, phosphorite and straw quick-corrosion microbial agent are added according to the proportion to carry out a blending reaction, and the straw quick-corrosion microbial agent can quickly decompose organic wastes such as straw and the like in the reaction process, so that organic matters, phosphorus, potassium and other elements contained in the straw become nutrition required by plant growth, and a large number of beneficial microorganisms are generated.

Specifically, the reaction temperature may be 30 ℃, 35 ℃, 40 ℃, 45 ℃, 50 ℃, 55 ℃, 60 ℃, 65 ℃, or the like.

In some embodiments, the humidity of the mixture is controlled to be 30% -48% during the reaction to promote the reaction to proceed fully. Specifically, the mixture humidity may be 30%, 35%, 40%, 45%, 48%, etc.

It should be noted that, the "low-carbon interface" in the embodiment of the invention is to realize the preposed separation of harmful components affecting the use value of phosphogypsum and the quality of phosphoric acid in the traditional phosphoric acid extraction process, and achieve the goals of low energy consumption, low pollution and low emission in the interface of the whole production process, and the goal of graded comprehensive utilization of phosphogypsum, thereby realizing the comprehensive benefits of energy conservation, emission reduction, environmental protection and solid waste resource utilization.

The features and capabilities of the present invention are described in further detail below in connection with the examples.

Example 1

The embodiment provides an agricultural compound phosphate fertilizer, which comprises, by mass, 30% of phosphogypsum slurry, 20% of straw matters, 20% of coal slime, 15% of layered silicate (calcium bentonite, the same applies below), 14.7% of low-grade phosphorite and 0.3% of straw quick-corrosion microbial agent (Jin Kuizi straw quick-corrosion microbial agent, the same applies below).

The embodiment of the invention also provides a preparation method of the agricultural compound phosphate fertilizer for realizing the low-carbon interface, which comprises the following specific steps:

(1) Preparation of phosphogypsum slurry

Mixing phosphorite with SO ₃ Mixing sulfuric acid water solution with the concentration of 0.05g/mL, entering an extraction tank, controlling the liquid-solid ratio to be 3.0, controlling the temperature in the extraction tank to be 85-90 ℃, entering a crystal growing tank after the extraction time in the extraction tank is 1.5h, and growing crystals in the crystal growing tank for 2.5h to obtain extraction slurry.

The extracted slurry is subjected to super aeration flotation by using the device shown in fig. 3 to obtain air-floating layer slurry and floating residual layer slurry, wherein the air-floating layer slurry is phosphogypsum slurry.

The method comprises the steps of floating in extraction slurry through super aeration, and introducing super aeration micro-bubbles generated by a high-pressure aeration device, wherein the super aeration micro-bubbles form a gas-liquid mixed phase in a liquid phase with pressure, the aeration pressure is 0.5MPa, the gas phase consists of micro-bubbles with the diameter of 2 mu m, the gas phase accounts for 8wt% of the gas-liquid mixed phase, and the mass ratio of the gas-liquid mixed phase to the extraction slurry is 12:100. the liquid phase is extraction slurry, and meanwhile, surfactant (C4-HTCC, HTCC represents chitosan quaternary ammonium salt and is a commercially available material) is added into the liquid phase, wherein the adding amount of the surfactant is 1.0mg/L.

In the embodiment, a conveying pipeline is also arranged in the extraction tank, a high-pressure aeration device is connected with the conveying pipeline, high-pressure aeration is carried out in the extraction tank, and the aeration composition is the same as that of the super-aeration floating stage.

(2) Mixing material

Phosphogypsum slurry is put into a reactor, straw matters, coal slime, phyllosilicate, low-grade phosphorite and straw fast-decay microbial inoculum are added according to the proportion, and the mixing reaction is carried out, wherein the reaction condition is that the temperature is 40 ℃, the humidity of the mixture is controlled at 35%, and the reaction time is 10 days.

Examples 2 to 6

The only difference from example 1 is that: the amounts of the bubble surface modifier C4-HTCC added were different, and the amounts of the C4-HTCC added in examples 2 to 6 were 0.5mg/L, 2.0mg/L, 3.0mg/L, 4.0mg/L, and 5.0mg/L, respectively.

Examples 7 to 10

The only difference from example 1 is that: the types of the bubble surface modifiers used in examples 7 to 10 were C8-HTCC, C12-HTCC, cetyltrimethylammonium bromide and polydimethyldiallylammonium chloride in that order.

Examples 11 to 14

The only difference from example 1 is that: the pressures of the liquid phases were different, and the pressures of the liquid phases corresponding to examples 11 to 14 were 0.3MPa, 0.4MPa, 0.8MPa, and 1.0MPa in this order.

Examples 15 to 18

The only difference from example 1 is that: the proportions of the gas phase and the gas-liquid mixed phase are different, and the proportions of the examples 15-18 are 5%wt, 10%wt, 15%wt and 20%wt in sequence.

Comparative example 1

The only difference from example 1 is that: the super aeration flotation is changed into common micro-bubble flotation, namely, the liquid is not pressurized.

Comparative example 2

The only difference from example 1 is that: the process of fig. 1 is used for treatment.

Example 19

The only difference from example 1 is that: the agricultural compound phosphate fertilizer has different dosage of each component. The method comprises the following steps:

the embodiment of the invention provides an agricultural compound phosphate fertilizer for realizing a low-carbon interface, which comprises 14.9% of phosphogypsum slurry, 50% of straw, 5% of coal slime, 20% of layered silicate, 10% of low-grade phosphorite and 0.1% of straw quick-corrosion microbial agent (Jin Kuizi straw quick-corrosion microbial agent) by mass percent.

Example 20

The only difference from example 1 is that: the agricultural compound phosphate fertilizer has different dosage of each component. The method comprises the following steps:

the embodiment of the invention provides an agricultural compound phosphate fertilizer for realizing a low-carbon interface, which comprises, by mass, 35% of phosphogypsum slurry, 10% of straw matters, 30% of coal slime, 10% of layered silicate, 14.5% of low-grade phosphorite and 0.5% of straw quick-corrosion microbial agent (Jin Kuizi straw quick-corrosion microbial agent).

Comparative example 3

The comparative example provides a common commercial phosphate fertilizer, which comprises the following components: the microelement 22810-25KG in the 40% compound fertilizer of the stone-placard.

Comparative example 4

The only difference from example 1 is that: the layered silicate is replaced by low-grade phosphorite with the phosphorus content of less than 12% and 120-200 meshes.

Test example 1

The results of the filtration of the supernatant slurry and the air-floating layer slurry in examples 1 to 18 and comparative examples 1 to 2 were shown in Table 1.

TABLE 1 relevant index of the filtration products of the air bearing layer and the surplus layer

Comparative example 1 general bubbling air flotation layer filtrate index: magnesium aluminum iron content 4.53wt%, phosphorus content 25.8wt%, MER value 6.13wt%; comparative example 1 common bubbling air flotation layer filter cake index: the phosphorus content is 3.03 weight percent, and the whiteness of the paste is 41 percent; comparative example 1 general bubbling float layer filtrate index: 1.12wt% of magnesium-aluminum-iron impurity, 28.9wt% of phosphorus and 2.98wt% of MER value; comparative example 1 general bubbling float layer filter cake index: 84.50wt% of calcium sulfate dihydrate, 0.61wt% of water-soluble magnesium oxide and 85% of phosphogypsum whiteness.

Comparative example 2 the traditional process failed to delaminate, and the phosphogypsum product prepared had the following indices: 78. 78 wt percent of calcium sulfate dihydrate, 1.8. 1.8 wt percent of water-soluble magnesium oxide and 66 percent of phosphogypsum whiteness; the prepared phosphoric acid contains 3.98 percent wt percent of magnesium aluminum iron, 25.2 percent wt percent of phosphorus and 5.86 percent of MER value.

It can be seen that phosphogypsum obtained from the air-floating layer contains impurities useful for agriculture, and is suitable for being used as phosphogypsum for agriculture.

Test example 2

The composite phosphate fertilizer prepared by the embodiment of the invention is subjected to field test, and the effect of the composite phosphate fertilizer is verified.

(1) The composite phosphate fertilizer obtained in example 1 was applied to a field test of the open agricultural sciences, the test crop was beet-H10099, 160 kg/mu of fertilizer was applied, and the result was shown in FIG. 8 by using the application of a common phosphate fertilizer as a comparison. The result shows that the plant height of the compound fertilizer provided by the embodiment of the invention is 53cm, and the chlorophyll ratio is 57.1; the plant height of the control group is 44cm, and the chlorophyll ratio is 44.9.

(2) The compound phosphate fertilizer obtained in example 1 was applied to the North Chinese cabbage-Jinfeng, 160 kg/mu was fertilized, and the result was shown in FIG. 9 with the application of the ordinary phosphate fertilizer as a comparison. The result shows that the development degree of the compound fertilizer provided by the embodiment of the invention is 53cm, and the chlorophyll ratio is 54.8; the control group had a degree of development of 44cm and a chlorophyll ratio of 43.2.

(3) The composite phosphorus fertilizer obtained in example 1 was applied to castor-Zi castor No. 5, 160 kg/mu and the result was shown in FIG. 10 with the application of a conventional phosphorus fertilizer as comparison. The result shows that the plant height of the compound fertilizer provided by the embodiment of the invention is 45.5cm, and the chlorophyll ratio is 50.2; the plant height of the control group is 28.5cm, and the chlorophyll ratio is 45.2.

Experiments also prove that the fruit bearing rate of the castor can be improved by using the compound phosphate fertilizer provided by the embodiment 1 of the invention, and the fruit bearing rate can be improved by 15.81-33.71% compared with that of a control group. The seeds of the castor capsules in the control group are 3 chambers, each chamber is 1 seed, and after the compound phosphate fertilizer provided in the embodiment 1 of the invention is applied, 12.3 percent of capsules are increased to 4-8 chambers, and each chamber is provided with 1 seed.

(4) The composite phosphate fertilizer obtained in example 1 was applied to tobacco leaf test in saline-alkali soil, 160 kg/mu was fertilized, and the result was shown in fig. 11 by comparing with the application of a common phosphate fertilizer. The results show that the tobacco leaf growing condition of the composite phosphate fertilizer applied by the embodiment of the invention on the saline-alkali soil is obviously superior to that of a comparison group.

(5) The compound phosphate fertilizer obtained in example 1 was applied to a cold-resistant stress-resistant test of mountain zucchini, 160 kg/mu was fertilized, and the result is shown in fig. 12 with the application of a normal phosphate fertilizer as a comparison. The results show that the pumpkin with the composite phosphate fertilizer prepared by the embodiment of the invention shows excellent cold resistance.

Test example 3

The compound biological fertilizer prepared in the example 1 is tested in the open market to test the effects of controlling and preventing sand.

1. Purpose of test

And (3) checking fertilizer effects of the desertification control and soil moisture prevention compound biological fertilizer on various crops in different ecological types of areas in Zhangkou city, and fertilizer application technical indexes such as optimal fertilizer application amount and economic fertilizer application amount of different crops.

2. Test site and area

The test is developed in three different ecological types of areas of Zhangjia city, and a test point 15 is arranged, wherein the plateau area on the dam is arranged at a test point 8 by taking Zhangbei county as the center, and the north-seeking management area and the northbound management area are respectively 1; the dam hypotenuse is provided with a test point 5 with a Ucounty as a center, wherein 1 part of each county is Chong to the county and the Chicheng county; the under-dam plain area was centered at trial point 2 at \280951, deer county (see Table 2).

Table 2 test layout of compound biological fertilizer for controlling desertification and preventing soil moisture in Jiakou city

3. Crop species

The test involves more than 80 varieties of 51 crops such as corn, millet, sorghum, potato, sunflower, soybean, small bean, mung bean, cowpea, kidney bean, broad bean, pea, chickpea, oat, flax, sweet potato, beet, peanut, pumpkin, white radish, green onion, tobacco leaf, castor and the like.

4. Method and procedure

The test is to set two comprehensive tests on the dam and under the dam respectively, to set different fertilization gradients according to different fertilization habits of crops and local places by taking the local fertilization amount and the fertilization method as comparison, and to set general comparison tests in different ecological types of areas.

4.1 comprehensive test area on dam

The experimental place is set in the county of Zhongbei province, the county of steamed bread, and the county of Zhangxiang, the great western ditch village. The lime soil is produced by using the light chestnut, the elevation is 1390 meters, the annual precipitation is 350mm, the effective accumulated temperature is 2300 ℃ or more at 10 ℃, and the cultivated crops are mainly oat, flax, forage maize, potato and beet.

14 different varieties of 8 different crops such as oat, flax, millet, corn, beet, cabbage, chinese cabbage, castor and the like are tested for fertilizer efficiency, and the test occupies 10 mu of land area. The test had 5 treatments: the fertilizing amount is 240 kg/mu, 200 kg/mu, 160 kg/mu, 120 kg/mu and 80 kg/mu, and the fertilizing amounts are sequentially arranged without repetition. The fertilization mode is that a base fertilizer is applied before sowing and ploughing is carried out after broadcasting, and a test Tian Jun is applied with a 'Wuzhoufeng' ternary compound fertilizer of 10 kg/mu as the base fertilizer. Sowing time is 6 months, 7 days to 19 days.

4.2 comprehensive test area under dam

The test area is arranged in a village with a well in the county of the fruit of Chinese character Chen. The chestnut brown soil, the elevation is 1060 meters, the annual precipitation is 380mm, the effective accumulated temperature is 2800 ℃ which is equal to or higher than 10 ℃, the cultivated crops are mainly millet, millet and beans, and the cultivated land is under the condition of no water irrigation, thus being a typical dry farming agricultural area. The rainfall conditions in the spring and summer of the current year are shown in Table 3.

TABLE 3 test of rainfall conditions at 10/11/04/10/08/10/11/year

And performing fertilizer efficiency tests on 53 different varieties of 49 different crops such as millet, corn, millet, sorghum, potato, sunflower, beans, buckwheat, green Chinese onion, tobacco leaf, castor and the like, wherein the test land area is 25 mu. The test had 5 treatments: the fertilizing amount is 80 kg/mu, 100 kg/mu, 120 kg/mu, 140 kg/mu and 160 kg/mu, and 100kg of ammonium bicarbonate is applied to mu as a control, and the fertilizer is repeated for 3 times and sequentially arranged. And (5) applying the base fertilizer in a fertilizing mode. Sowing time is 5 months 2 days to 7 months 9 days.

5. Field performance

Serious drought is encountered in the opening of the home market in 2009, rainfall-free weather is sustained, air is dried, and water becomes a first factor for limiting the growth of crops, so that the exertion of fertilizer effect is relatively influenced.

It is observed that most of the test points show remarkable fertilization effect, and compared with the control, the treated area has dark green leaf color, developed root system and vigorous plant growth.

5.1 Flax test on dam

Sowing flax for 5 months and 26 days, emergence of seedlings for 6 months and 10 days, sprinkling irrigation for 3 times for 6 months and 8 days, sprinkling irrigation for 23 days for 6 months and sprinkling irrigation for 8 days for 7 months, and flowering for 14 days for 7 months, and urea for 10kg for 21 days for 7 months. The indexes such as plant height and the like have little difference, the indexes such as branch number, fresh weight, single plant peach number and root length and the like have obvious difference, and the test results are shown in tables 4-5.

Table 4 data of field test for flax dam sub-No. 7 test on dam

Table 5 field test data for flax dam sub-No. 9 test on dam

5.2 oat on dam test

Sowing the 'Yuan you No. 1' for 5 months and 26 days, emergence of seedlings for 6 months and 4 days, sprinkling irrigation for 3 times for 6 months and 8 days, sprinkling irrigation for 7 months and 8 days respectively for 7 months and 20 days, heading for 7 months and 2 days, and chasing for 10kg of urea for 7 months and 21 days. The plant fresh weight, leaf area and other indexes have little difference, the plant height, individual plant tillering number and other indexes have obvious difference, and the test results are shown in Table 6.

Table 6 field test data for oat dam hulless oat 1 test on dam

5.3 beet on dam test

Planting beet HI0099 for 26 months, emergence of seedlings for 6 months and 4 days, sprinkling irrigation for 2 times for 5 months and 27 days and 21 days for 7 months, and adding 25kg of urea for 7 months and 2 days and 20kg of urea for 7 months and 21 days. The plant height, leaf number, leaf area, sugar degree and other indexes are obviously different, and the test results are shown in Table 7.

TABLE 7 field test data for beet HI0099 test on dam

5.4 Castor test on dam

Sowing castor-oil plants for 5 months and 26 days, wherein the sowing quantity is 1 kg/mu, seedlings emerge for 6 months and 20 days, sprinkling irrigation is carried out for 3 times for 6 months and 6 days, 23 days and 21 days, and urea is added for 12.5kg for 21 days. The difference of plant height, stem thickness, leaf area and other indexes is obvious, and the test results are shown in tables 8-9.

Table 8 Castor-on-dam test field test data for No. 5 test

Table 9 Castor crop lucky No. 2 test field test data on dam

5.5 cabbage test on dam

Planting Chinese cabbage No. 6, 4, 29, 6, 4, 7, 21, 2 times, 7, 2 days and 12.5kg of urea. The difference in the degree of development was evident at 7 months and 14 days, as shown in Table 10.

Table 10 field test data of chinese cabbage on dam

5.6 test of hybrid millet on dam

5 days of 6 months of seedling raising and field planting of Zhang Zagu, 25 days of 7 months of heading, 8 days of 6 months, 23 days of 6 months, 8 days of 7 months of sprinkling irrigation for 3 times, and 21 days of 7 months of urea 15kg; sowing on the 5 month 29 days, emergence on the 18 days, sprinkling 2 times on the 23 days, 7 months and 21 days of the 'Zhang Zagu No. 6'. 12.5kg of urea is chased after 21 days in 7 months, and the difference of measured plant heights is obvious, as shown in Table 11.

Table 11 field test data for hybrid millet on dam

The test conditions of all main cultivated crops on the dam are integrated, and the fertilizer effect difference of the fertilizer application treatment is obvious compared with that of the control.

5.7 under dam sunflower test

The sunflower is irrigated on the ground for 6 months and sowed for 5 months, 9 varieties are all planted, the seedlings emerge for 13 months and the seedlings are fixed for 7 months and 10 days. 7.5kg of urea is added after 7 months and 15 days of sprinkling irrigation. The plant height difference is obvious, and the test results are shown in Table 12 and FIG. 13.

Table 12 contrast of plant heights of different varieties and different fertilization treatments for under-dam sunflower experiments

5.8 under dam crop trials

Sowing the potatoes 5 months and 8 days, taking out seedlings 5 months and 28 days, picking up buds of the potatoes 6 months and 17 days by mulching films, and flowering the potatoes 6 months and 22 days; bud emergence of the potatoes is carried out on 24 days of 6 months, and flowering is carried out on 30 days of 6 months. Watering the land for 6 months and 15 days, and sprinkling and chasing 7.5kg of urea for 7 months. The plant height difference is obvious, and the test results are shown in Table 13.

Sowing castor on 12 months, taking out seedlings on 21 months, intertillage on 29 months, setting seedlings on 10 months, bud emergence on 30 months, and flowering on 2 months. 7.5kg of urea is added after 7 months and 16 days of sprinkling irrigation. The plant height difference is obvious, and the test results are shown in Table 13.

Waxy corns are sowed on the 13 th month, seedlings are discharged on the 22 th month, intertillage is carried out on the 29 th month, and seedlings are fixed on the 10 th month. The plant height difference is obvious, and the test results are shown in Table 13.

Table 13 contrast of different fertilizing treatment heights of crops such as potatoes under a dam (7 months and 9 days)

5.9 under dam legume crop test

The leguminous crops are sowed on the ground for 6 months and 5 days, sown for 6 months and 13 days, 8 varieties are totally used, chickpeas, kidney beans and beans are sequentially emerged for 6 months and 22 days, and peas, broad beans, cowpeas and small red beans are sequentially emerged for 6 months and 25 days. And 7 months and 10 days for final singling. 10kg of urea is recovered after 7 months and 21 days. The plant height difference was obvious, and the test results are shown in Table 14 and FIG. 14.

Table 14 comparison of different varieties of leguminous crops with different heights (7 months and 9 days)

5.10 oat, flax and buckwheat test

Sowing oat for 6 months and 12 days, emergence of seedlings for 6 months and 17 days, heading for 7 months and 15 days. Flax is sown for 6 months and 12 days, seedlings emerge for 6 months and buds appear for 7 months and 19 days. Sowing buckwheat at 7 months and 9 days, emergence at 7 months and 12 days, and flowering at 8 months and 9 days. 7.5kg of urea is added to each mu of the fertilizer for 7 months and 15 days. The fresh weight difference of the plants measured on day 8 and 9 is obvious, and the test results are shown in Table 15.

Table 15 fresh weight contrast of plants treated by different fertilizer application of crops such as oat under dam (8 months 9 days)

5.11 tobacco fertilization test

The number of leaves subjected to fertilization treatment is large, the internodes are short, the leaf area is large, the leaf color is uniform and consistent, the flowering is late, and the growth vigor is vigorous; the number of leaves in the contrast area without fertilization is small, the internode is long, the leaf area is small, the leaf color is uneven, the flowering is early, and the growth vigor is poor.

Table 16 comparison of under-dam tobacco fertilized with field test data without fertilized (7 month 28 day)

And by combining the test conditions of various crops under the dam, the fertilizer effect difference of the fertilizer application treatment compared with the control is obvious.

The above is only a preferred embodiment of the present invention, and is not intended to limit the present invention, but various modifications and variations can be made to the present invention by those skilled in the art. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims (10)

1. The agricultural compound phosphate fertilizer is characterized by comprising, by mass, 10-35% of phosphogypsum slurry, 10-55% of straw materials, 5-30% of coal slime, 5-30% of layered silicate, 5-15% of phosphorite and 0.1-0.5% of straw quick-rot microbial agent;

wherein, the phosphogypsum slurry comprises the following components in percentage by mass: 25-30% of phosphorus, 3-4% of total impurities of magnesium, aluminum and iron, 5-8% of MER value and the balance of water;

the phosphogypsum slurry is produced by wet phosphoric acid, the extraction slurry obtained by crystal growth is subjected to super aeration flotation, super aeration microbubbles are introduced into the extraction slurry through the super aeration flotation, and the air flotation layer slurry and the floating residual layer slurry are obtained after classification, wherein the phosphogypsum slurry is the air flotation layer slurry.

2. The agricultural composite phosphate fertilizer according to claim 1, wherein the straw quick-rot fungicide is selected from Jin Kuizi straw quick-rot fungicides;

the phosphorite is low-grade phosphorite.

3. The agricultural compound phosphate fertilizer according to claim 1 or 2, which is a desertification land improvement material and comprises, by mass, 20-25% of phosphogypsum slurry, 30-35% of straw matter, 5-10% of coal slime, 20-30% of layered silicate, 5-10% of phosphorite and 0.3-0.5% of straw quick-rot fungicide.

4. The agricultural compound phosphate fertilizer according to claim 1 or 2, which is a saline-alkali soil improvement material and comprises, by mass, 30-35% of phosphogypsum slurry, 25-35% of straw matter, 15-20% of coal slime, 5-10% of layered silicate, 5-8% of phosphorite and 0.1-0.3% of straw quick-rot fungicide.

5. The agricultural compound phosphate fertilizer according to claim 1 or 2, wherein the agricultural compound phosphate fertilizer is a repair material for heavy metal or pesticide residue pollution, and comprises, by mass, 10-15% of phosphogypsum slurry, 15-20% of straw matter, 10-15% of coal slime, 15-20% of layered silicate, 10-15% of phosphorite and 0.1-0.5% of straw quick-rot microbial agent.

6. The agricultural compound phosphate fertilizer according to claim 1 or 2, which is a degraded sand improvement material and comprises, by mass, 10-15% of phosphogypsum slurry, 35-55% of straw matters, 10-15% of coal slime, 5-10% of layered silicate, 10-15% of phosphorite and 0.1-0.3% of straw quick-rot bacteria.

7. The agricultural compound phosphate fertilizer according to claim 1 or 2, characterized by comprising, by mass, 25-35% of phosphogypsum slurry, 40-55% of straw matter, 20-30% of coal slime, 5-10% of layered silicate, 10-15% of phosphorite and 0.1-0.5% of straw fast-rot fungus agent.

8. A method for preparing an agricultural compound phosphate fertilizer according to any one of claims 1 to 7, wherein the preparation is performed according to the formulation composition of the agricultural compound phosphate fertilizer.

9. The method of manufacturing according to claim 8, comprising: blending and reacting the phosphogypsum slurry, the straw matters, the coal slime, the layered silicate, the phosphorite and the straw quick-decay microbial inoculum, wherein the reaction temperature is 30-65 ℃ and the reaction time is 8-12 days;

the humidity of the mixture is controlled to be 30-48% in the reaction process.

10. The method of preparing according to claim 9, wherein the phosphogypsum slurry is prepared by: mixing phosphorite and inorganic acid, performing extraction and crystal growth processes to obtain extraction slurry, performing super-aeration flotation on the extraction slurry, introducing super-aeration microbubbles into the extraction slurry through the super-aeration flotation, and grading to obtain air-floating layer slurry and floating residual layer slurry, wherein phosphogypsum slurry is air-floating layer slurry; wherein the ultra-aeration micro-bubbles contain a surfactant;

The ultra-aeration micro-bubbles are introduced in a gas-liquid mixed phase form, gas is introduced into a liquid phase with pressure to form the gas-liquid mixed phase, and the gas-liquid mixed phase is introduced into the extraction slurry through an aeration disc; the pressure of the gas-liquid mixed phase is 0.1MPa-1.0MPa, the gas phase comprises microbubbles with the diameter of 0.1-50 mu m, and the gas phase accounts for 1-30wt% of the gas-liquid mixed phase; the mass ratio of the gas-liquid mixed phase to the extraction slurry is (5-30): 100;

adding the surfactant into a liquid phase, wherein the adding amount of the surfactant is 1.0mg/L-4.0mg/L, and the surfactant is at least one of cetyltrimethylammonium bromide, polydimethyldiallyl ammonium chloride and quaternary ammonium chitosan;

sequentially carrying out multistage super-aeration flotation on the extraction slurry, wherein each stage of super-aeration flotation is to introduce super-aeration micro-bubbles into the extraction slurry, and then enter a classification channel for classification after multistage super-aeration flotation; in the multistage super-aeration floating process, controlling the treatment time of the extraction slurry in the super-aeration micro-bubbles to be 15-60 min; the classification is to treat the slurry in a classification channel by using a dynamic settler, output air floating layer slurry above the dynamic settler and output floating residual layer slurry below the dynamic settler.