CN111574268A - Simple and easy new method for producing compound (mixed) fertilizer directly by urea device - Google Patents

Abstract

The invention comprises the following steps: a simple and easy new method for directly producing compound (mixed) fertilizer by using a urea device belongs to the technical field of compound (mixed) fertilizer production. The prior compound (mixed) fertilizer production equipment has large investment, high cost and no environmental protection. Directly using small particles of market fertilizer or nutrient material as fine seeds, and using a urea large particle device to wrap the urea large particles layer by layer to produce the large particle composite (mixed) fertilizer. Or preparing fertilizer or nutrient material into aqueous solution, pumping into urine of large granule system by metering pump, and making into large granule compound (mixed) fertilizer. Or the fertilizer is thrown into urine in production, evaporated in each section, put into a granulation tower or a large-particle granulator to respectively manufacture large and small particle composite (mixed) fertilizers or multiple element fertilizers. Or the mixed solution is connected to a split charging workshop from the first-stage evaporator by a pipeline to be canned or barreled without evaporating water; or adding urine or finished urea granules in production into a mixed solution containing phosphorus, potassium or other materials to prepare the liquid compound (mixed) fertilizer.

Description

Simple and easy new method for producing compound (mixed) fertilizer directly by urea device

The technical field is as follows: the present invention belongs to the field of compound fertilizer producing technology.

Background art: the prior production processes of the compound (mixed) fertilizer comprise a slurry method, a solid aggregate method, a melting method, a blending method, an extrusion method and the like, all of which specially require a complete set of equipment, have complex processes and are not environment-friendly, generate pollution such as waste water, waste gas and the like, and have large equipment labor investment and high cost.

The invention content is as follows: the invention provides a new method for producing compound (mixed) fertilizer by directly utilizing the existing urea device, which is simple and easy to operate, can produce various compound (mixed) fertilizers with little investment, greatly improves the profit and has environment-friendly process.

The large-particle compound (mixed) fertilizer is produced by directly using the existing particles (mainly medium and small particles) on the market or using uniform mixed materials of monoammonium phosphate or diammonium phosphate and K2SO4 (or KCl) which are proportioned and stirred uniformly or using monopotassium phosphate or potassium pyrophosphate or other potassium phosphate salts or small particles of materials containing other nutrient elements as seeds (one can be used independently), and using a large-particle device to wrap the large-particle compound (mixed) fertilizer layer by urine through a rotary drum fluidized bed granulator (the temperature is about 90 ℃ in a micro-negative pressure environment).

The adjustment of the proportion and the content of each nutrient component can be controlled by adjusting the adding amount of the seed crystal, the spraying amount of urine, the particle size of the seed crystal and the size of a sieve pore of a screen mesh for finished products and returned materials. Wherein, when selecting materials with low particle strength as seeds, selecting the product particles with small seeds as much as possible and controlling the size of the product particles as much as possible to ensure the particle strength.

If monopotassium phosphate is selected, monopotassium phosphate with proper crystal size and monopotassium phosphate is a highly-efficient and popular fertilizer, monopotassium phosphate with the particle size of about 0.8-1.3 mm is mostly used as a seed, the mass ratio of materials is 1: 9.1, 80 tons of finished seeds per hour of a shift product is uniformly added on a seed crystal belt at an inlet of a granulation rotary drum according to the fact that the side length of a seed cube is 1.3mm and the diameter of a finished product is 4 mm. The total nutrient content of N, P2O5 and k2O is 42 percent, 5.1 percent and 3.4 percent, and the total nutrient content is 50.5 percent. At this time, the content of phosphorus and potassium, especially potassium, in the finished product is low, so that potassium salt or phosphorus potassium salt solution can be added into urine by a metering pump according to a required proportion to increase the content of potassium (monoammonium phosphate or diammonium phosphate can be selected to increase the content of phosphorus by the same method when required). The seed crystal can be prepared by other proportions or by potassium phosphate or other materials, and each production unit can be self-mastered and flexibly adjusted according to the market and the condition of the unit.

For example, K2SO4 or a material added with a small amount of KCl and uniformly mixed is used as a fine seed to produce a urea-based potash fertilizer, monoammonium phosphate or diammonium phosphate is used as a fine seed to produce a urea-based phosphorus compound fertilizer, and a compound (mixed) fertilizer is used as a fine seed to produce a compound (mixed) fertilizer with various proportions.

At the moment, the low-end compound (mixed) fertilizer particles which are produced by small factories and mainly have low loose strength and medium and small particle size are coated with urea granules layer by layer, so that the particle strength is improved, the storage and the transportation are convenient, the slow release performance of the fertilizer is improved, and meanwhile, as the external nitrogen fertilizer is firstly dissolved and firstly acts on crops (seedlings are lifted), then the compound (mixed) fertilizer fine cores containing nitrogen, phosphorus and potassium are slowly formed in the compound (mixed) fertilizer fine cores, and long-acting and comprehensive middle and later period nutrition is given to the crops, so that the compound (mixed) fertilizer is very suitable for the growth requirements and the agricultural fertilization habits of wheat, corn, rice and the like of field crops and the like and. Saves the fertilization link and labor cost, and is a very popular novel compound (mixed) fertilizer.

The other production scheme 1 is that water soluble material or fertilizer containing P, K and other nutrients or elements required by plant is first mixed with water to form solution or mixed solution, which is then mixed with urine in the first stage evaporator in production via metering pump and pressurized in the second stage evaporator at 140 deg.c and 0.0033MPa and 25mmHg in the first stage evaporator to produce composite fertilizer or water soluble fertilizer in large and small size.

The mixed liquid is directly taken out from the outlet of the first-stage evaporator (the evaporator can be filled with proper amount of steam condensate or desalted water or natural water for dilution so as to ensure that urine is not easy to crystallize and block the pipeline), and then the mixed liquid is prepared into different concentrations according to the requirements of customers and then is canned into corresponding liquid compound (mixed) fertilizer by using corresponding plastic containers.

The high solubility of the materials is beneficial to reducing the mixing working hours, flexibly controlling and adjusting the proportion, facilitating the production and meeting various requirements of customers. For example, potassium pyrophosphate (when the concentration of potassium dihydrogen phosphate aqueous solution is small, is applied to the production of fertilizers with smaller phosphorus-potassium ratio, a plurality of elements or nutrient components such as full water-soluble materials containing calcium, sulfur and magnesium, or humic acid, alginic acid, polypeptide, fulvic acid and the like can be added to produce various high-quality nutrient fertilizers, and other full water-soluble materials or fertilizers containing phosphorus, potassium or other nutrient components required by plants or elements can be selected to be mixed according to the required proportion) is added into the system, potassium pyrophosphate is prepared into saturated solution, 187 grams of potassium pyrophosphate can be dissolved in 100 grams of water at 25 ℃, the solution is prepared at 25 ℃, the mass percentage concentration reaches 65 percent (the solution is prepared when the temperature of the 100 grams of water is adjusted to 25 ℃ in the environment with the condition in winter in the northern heating, and the solution is conveyed and added by a heat-preserving pipeline).

The potassium pyrophosphate and urine are uniformly mixed according to the mass ratio of 1: 9 and are uniformly pumped into a system (an inlet of a first-stage evaporator) by a metering pump, for example, 80 tons of products in one shift, about 8 tons of potassium pyrophosphate in one shift, about 4.3 square water and about four-five square potassium pyrophosphate solution are required, and the system is suitable for a plurality of small tanks, has low requirement on the volume of a container and is convenient for preparation and production. (the facility matching production capacity is high, the yield and the unit with large single-shift production capacity are in proportion conversion), the N: p2O 5: k2O in the finished product is 42 percent to 4.2 percent to 5.6 percent, and the total nutrient content reaches 51.8 percent (each plant can select to add different materials and adjust the distribution ratio of the components and the total nutrient content according to market requirements and production conditions).

After the mixture is pumped into a section of evaporator, the mixture is in an environment with the temperature of about 130 ℃ higher and the pressure of about 0.033MPa lower and about 250mmHg, the molecular motion of the material is fast, the liquid flows and turbulences, and the urine and the material are uniformly mixed. After the water is removed by two-stage evaporation (temperature is about 140 ℃ and pressure is about 0.0033MPa and about 25mmHg column), the solid particle compound (mixed) fertilizer is obtained by granulation. Wherein the fertilizer is sprayed out from the top of the upper granulation tower through a granulation nozzle and is scattered into small-particle composite (mixed) fertilizer; the urine mixed with the materials enters a large-particle device for production, and then the large-particle compound (mixed) fertilizer is generated by a large-particle granulator (the temperature is about 90 ℃ in a micro-negative pressure environment). At the moment, the fine seeds can be selected from common small particles and small particle compound (mixed) fertilizers, and other compound (mixed) fertilizers with proper granularity, such as various compound (mixed) fertilizers of other material (fertilizer) examples, monoammonium phosphate, diammonium phosphate, KCl and K2SO4 can be selected as fine seeds to produce large particle compound (mixed) fertilizers with different varieties and proportions.

The small particles are uniformly spread in the field and are easy to be infiltrated and absorbed by the root system of the crops when meeting water. Large granule strength, slow release, long fertilizer effect period and delayed effect. Humic acid, polypeptide, alginic acid or high-potassium high-phosphorus full-water-soluble materials or various elements can be added additionally (various plants can add or subtract different kinds of nutrient components according to market demands) to increase or decrease the content of N, adjust the content of other nutrients and relatively adjust the water content in the fertilizer.

The variety can be replaced according to the requirement, wherein monopotassium phosphate is used for replacing high-potassium phosphate, the phosphorus and potassium content of the same material is reduced, the solution concentration is low, the evaporation capacity of an evaporation system is limited, the driving amount is reduced, and the phosphorus and potassium content of the fertilizer is reduced. But the production of the liquid fertilizer with lower concentration is not limited and is more flexible; the mixed solution can be pumped into a system for preparation, and the urine or finished urea granules can also be added into the solution or the mixed solution containing phosphorus and potassium or other materials and uniformly stirred for preparation. If the water is not evaporated after mixing, the mixture is directly connected to a subpackaging workshop for canning or barreling (if necessary, in order to prevent crystallization and caking and keep the liquid state, a proper amount of water can be added for dilution) by a pipeline, namely the liquid compound fertilizer with higher concentration, and the concentration and the proportion can be adjusted according to market demands.

2. The mixed solution of monoammonium phosphate, diammonium phosphate, K2SO4 and the like or the mixed solution prepared by potassium pyrophosphate or other full water-soluble materials according to the required formula proportion is pumped into a special evaporator for large particles by a metering pump (a urea-like two-stage evaporator needs to be specially added on a urine pipeline before urine enters a large particle granulator), and the mixed solution is fully mixed with the urine, and after excessive moisture is evaporated, the mixed solution enters a large particle granulation rotary drum, and the large particle composite (mixed) fertilizer is prepared according to the normal production process of large particle urea.

Adding potassium pyrophosphate solution into large-particle urine. The proportion is 1: 9, the water content is 3.5 percent and is lower than the national index high limit of the blended fertilizer by 4.5 percent, but the granulated particle has small strength and does not meet the requirement of the composite (blended) fertilizer. The water is evaporated by an evaporator (like a urea two-stage evaporator) and then enters a large-particle granulator for granulation to meet the requirement. As the proportion is the same as above, the ratio of the nutrients is the same as above, the N to p2O5 to k2O in the finished product is 42 percent to 4.2 percent to 5.6 percent, the total nutrient content reaches 51.8 percent (each factory can increase and decrease materials according to market demands and adjust the distribution ratio of the components and the total nutrient content), and the proportion can be reduced to reduce water without an evaporator.

The above modes basically utilize the existing process devices, and the mixture ratio is flexible, simple and easy to implement. The existing device can be utilized to promote and change the operation condition of single urea production variety and extremely low profit into the production of various novel compound (mixed) fertilizers, so that enterprises develop new vitality, the profit and the benefit of the enterprises are greatly improved, and the operation condition is greatly changed.

Claims (4)

1. The production method of the compound (mixed) fertilizer is different from all the production methods of the compound (mixed) fertilizer at present. The method is characterized in that a urea device is directly utilized to produce the compound (mixed) fertilizer, and the main special evidence of the method is that the existing particle (mainly medium and small particles) compound (mixed) fertilizer or medium and small particle organic fertilizer on the market is directly used as the fine seed, or the uniform mixed material of monoammonium phosphate or diammonium phosphate and K2SO4 (or KCl) which are proportioned and stirred uniformly or the fine seed (one kind can be used independently) is prepared by monopotassium phosphate or potassium pyrophosphate or other potassium phosphate salts or small particles of materials containing other nutrient elements, and the large particle device is utilized to wrap the fine seed layer by urine through a rotary drum fluidized bed granulator to produce the large particle compound (mixed) fertilizer.

2. The method for producing compound fertilizer by directly using urea device as claimed in claim 1, wherein the other characteristic is that the mixed solution of monoammonium phosphate, diammonium phosphate, K2sO4, or potassium pyrophosphate or other fully water-soluble material or various fertilizers is directly prepared according to the required formulation ratio, and the mixed solution is pumped into the evaporator special for large granules by the metering pump (special addition is needed on the urine pipeline before the urine enters the large granule granulator), and is fully mixed with the urine to evaporate the excess water, and then the mixture enters the large granule granulator, and the large granule compound fertilizer is produced according to the normal large granule urea production process.

3. The method for producing compound (mixed) fertilizer directly with urea device as claimed in claim 1, wherein the method comprises adding water-soluble material or fertilizer containing phosphorus, potassium or other nutrients or elements required by plants according to required variety and ratio into water, stirring to obtain solution or mixed solution, adding into urea first-stage evaporator, mixing with urine in first-stage evaporator, evaporating water with first-stage and second-stage evaporators, pressurizing with urea melting pump, spraying onto top of granulating tower or granulating with large-granule granulator, and making into compound (mixed) fertilizer or multiple element fertilizer and water-soluble fertilizer.

4. The method for producing compound fertilizer directly by using urea device according to claim 1 is characterized by that the fully water-soluble material containing phosphorus, potassium or other nutrient components or elements required by plant or fertilizer can be added into water according to the required variety and proportion, and uniformly stirred to obtain solution or mixed solution, then the mixed solution can be uniformly added into the urine in the first-stage evaporator of urea by means of metering pump according to the quantity converted according to the required production proportion, and then the mixed solution can be directly taken out from outlet of first-stage evaporator and connected into split workshop to make canning or barreling, and the evaporation action of first-stage evaporator can be cancelled; or the urine in production is added into the solution or mixed solution containing phosphorus, potassium or other materials or fertilizers through a pipeline (or finished urea granules), the mixture is stirred evenly, and the mixture is barreled or canned by corresponding plastic containers after being prepared into different concentrations. Producing the corresponding liquid compound (mixed) fertilizer.