CN117735486A - Method for strengthening sulfur hot melting separation by pretreatment of metal sulfur slag - Google Patents

Abstract

The invention discloses a method for preprocessing and strengthening sulfur by hot melting, filtering and separating metal sulfur slag, which comprises the following steps: 1) Crushing and grinding the metal sulfur slag, adding water and acid to carry out slurry mixing to obtain metal sulfur slag slurry; 2) After carrying out aeration treatment on the metal sulfur slag slurry, adding a impurity removal regulating agent to remove impurities to obtain a leaching solution; the impurity removal regulating and controlling agent comprises ferric sulfate, sodium chloride and ammonium chloride; 3) Filtering the leaching solution to separate a solid product, washing and dehydrating the solid product, and separating sulfur liquid through hot melt filtration; the method can realize viscosity reduction of molten metal sulfur slag so as to improve the sulfur recovery rate in the process of hot melting and filtering the metal sulfur slag.

Description

A method for pretreatment of metal sulfur slag to strengthen hot-melt separation of sulfur

Technical field

The invention relates to a method for treating metal sulfur slag, in particular to a method for pre-treating metal sulfur slag to strengthen the hot-melt separation of sulfur, and belongs to the field of comprehensive recycling and utilization of non-ferrous metal smelting waste slag.

Background technique

The zinc smelting process is divided into fire method and wet method. Fire method zinc smelting has the disadvantages of high energy consumption and the production of harmful gases, while wet method zinc smelting unit has relatively low energy consumption, is relatively friendly to the environment, and has a high degree of comprehensive utilization of resources. At present, hydrometallurgical zinc smelting has become the mainstream of zinc metallurgical technology development, and hydrometallurgical zinc smelting output accounts for more than 80% of the world's total zinc. In the zinc sulfide concentrate oxygen pressure leaching wet zinc smelting process, most of the sulfur enters the acid leaching residue in the form of elemental sulfur, and a small amount exists in the form of sulfide, sulfate or sulfate double salt. In addition to sulfur, the acid leaching residue Slag often also contains valuable metals such as zinc, iron, silicon, and silver, which have high recycling value. If these polymetallic sulfur slags are not processed and recycled in time, it will cause a huge waste of resources and also cause environmental problems of waste slag accumulation.

There are many methods to recover elemental sulfur from sulfur residue, including chemical methods and physical methods. The chemical method dissolves the sulfur by adding organic/inorganic solvents, and then extracts and processes it to obtain sulfur products. However, the solvents used have problems such as being toxic and volatile. , cannot be applied to actual production on a large scale. Physical methods mainly include vacuum distillation, high-pressure decantation, flotation, thermal filtration, etc. Vacuum distillation and high-pressure decantation have expensive equipment, complex processes, and are not suitable for large-scale production; flotation uses substances in the slag to The difference in water properties is used to separate elemental sulfur from other materials. The process is simple. The thermal filtration method uses the low melting point of sulfur to heat the polymetallic sulfur slag to a certain temperature (130~160℃) and filter to achieve the separation of sulfur from other elements. The cost of the method is low, and the higher the sulfur content in the sulfur residue, the better the thermal filtration separation effect. It has significant advantages in handling sulfur-containing materials in actual production. Currently, domestic enterprises such as Chihong Zinc and Germanium, Zhongjin Lingnan, and Western Mining use flotation. —Hot filtration method for treating polymetallic sulfur slag.

However, due to its complex composition, polymetallic sulfur slag has a high viscosity after direct melting. It is difficult to separate liquid sulfur from other materials during hot filtration, resulting in a low sulfur separation recovery rate and not conducive to further separation and recovery of valuable metals in the filter cake. At present, researchers focus more on improving the melting process and pay less attention to the raw material pretreatment process. Therefore, it is necessary to provide a method for pretreatment of metal sulfur slag to enhance the hot-melt filtration separation of sulfur to solve or at least alleviate the technical defect of difficult separation of sulfur and metal impurities in the prior art.

Contents of the invention

In view of the defects existing in the treatment process of multi-metallic sulfur slag in the prior art, the purpose of the present invention is to provide a method for pretreatment of metal sulfur slag to strengthen the hot-melt sulfur filtration separation, which method can achieve the reduction of molten metal sulfur slag. Sticky to improve the sulfur recovery rate during hot melt filtration of metal sulfur slag, and the operation process is simple to avoid adding toxic reagents, which is conducive to industrial production.

In order to achieve the above technical objectives, the present invention provides a method for pretreatment of metal sulfur slag to strengthen sulfur hot melt filtration separation, which method includes the following steps:

1) After crushing and grinding the metal sulfur slag, add water and acid to adjust the slurry to obtain a metal sulfur slag slurry;

2) After aeration treatment of the metal sulfur slag slurry, an impurity removal regulator is added to remove impurities to obtain a leaching solution; the impurity removal regulator includes ferric sulfate, sodium chloride and ammonium chloride;

3) The leaching solution is filtered to separate the solid product. After the solid product is washed and dehydrated, the sulfur liquid is separated by hot melt filtration.

The key to the present invention is to perform a special pretreatment process on metal sulfur slag, which can efficiently remove impurity metal ions from metal ions, thereby effectively reducing the viscosity of molten metal sulfur slag, improving the hot-melt filtration effect, and increasing the sulfur recovery efficiency. . More specifically, acid is first used to mix the pulp, and oxygen is introduced to oxidize and leach some metals and metal salts. On this basis, special impurity removal regulators are used to remove difficult-to-leach impurity metals through chemical reactions. Sulfides (such as zinc sulfide, etc.) are converted into easily soluble compounds, thereby achieving the purpose of deeply removing metal impurities. The special impurity-removing regulators used in the present invention include ferric sulfate, sodium chloride and ammonium chloride. Ferric sulfate mainly provides iron ions for inducing zinc sulfide and other insoluble metal sulfides to form soluble zinc salts, while sodium chloride and chloride Ammonium mainly provides chloride ions and ammonium ions, which promote the reaction between iron ions and poorly soluble metal sulfides, synergistically accelerating the process.

As a preferred solution, the metal sulfur slag is ground to a particle size of ≤106 μm. Grinding the metal sulfur slag to an appropriate particle size is conducive to the dissolution of impurities in it.

As a preferred solution, the solid-liquid mass ratio of the metal sulfur slag slurry is 1:2 to 1:5, and the pH is 1 to 3. Adjusting the pH can be achieved using dilute sulfuric acid.

As a preferred solution, the aeration adopts stirring-assisted blast aeration, with a stirring rate of 300 to 700 rpm and a time of 0.5 to 2 hours. The temperature is room temperature, for example, 20 to 35°C. The gas used for aeration is air or other oxygen-containing gas.

As a preferred solution, the impurity removal regulator includes the following mass percentage components: 20% to 80% iron sulfate, 2% to 20% sodium chloride, and 10% to 60% ammonium chloride. The impurity-removing regulator uses iron sulfate as the main component, which mainly provides soluble iron ions to induce the formation of soluble zinc salts from poorly soluble metal sulfides such as zinc sulfide, while chloride ions and ammonium ions serve as secondary components to synergistically accelerate the reaction. process.

As a preferred solution, the amount of the impurity removal regulator is measured based on the total concentration of iron ions, chloride ions and ammonium ions in the metal sulfur slag slurry of 0.1 to 0.6M.

As a preferred option, the impurity removal conditions are: reaction at room temperature for 10 to 24 hours.

As a preferred solution, during the hot melt filtration process, the melting temperature is 140-150°C, the duration is 60-180 minutes, and the filtration pressure is 0.6-0.8MPa.

As a preferred option, the metal sulfur slag contains at least one impurity metal element such as Fe, Zn, and Pb. More specifically, the sulfur element content in the metal sulfur slag is ≥55wt%, the zinc element content is ≤10wt%, the iron element content is ≤20wt%, and the lead element content is ≤3wt%.

As a preferred solution, the washing adopts a multi-stage washing method until the washing liquid becomes neutral. A more specific washing process includes: suction filtration of the leachate, stirring and washing the filter residue with deionized water and suction filtration again until the pH of the filtrate is neutral.

As a preferred option, the dehydration is carried out until the moisture content is less than 10%. More specific dehydration treatment includes: using a belt dehydrator to dehydrate the metal sulfur slag that has been washed with water, so that the moisture content of the metal sulfur slag is less than 10wt%.

As a preferred option, the sulfur liquid is granulated to obtain sulfur products.

Compared with the existing technology, the technical solution of the present invention brings beneficial technical effects:

By performing pickling and aeration treatment on metal sulfur slag and using a regulating reagent, the present invention can effectively remove impurities in metal sulfur slag, reduce the viscosity of molten metal sulfur slag and effectively increase the sulfur separation recovery rate.

The method for pretreating metal sulfur slag and strengthening sulfur hot-melt filtration and separation provided by the present invention has a simple operation process, avoids the use of toxic reagents, and is conducive to industrial application.

Description of drawings

In order to explain the embodiments of the present invention or the technical solutions in the prior art more clearly, the drawings needed to be used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings in the following description are only These are some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on the contents shown in these drawings without exerting creative efforts.

Figure 1 is a schematic flow chart of the method for pretreatment of metal sulfur slag to enhance sulfur hot melt filtration separation in the present invention.

Figure 2 shows the viscosity and separation rate of polymetallic sulfur slag after pretreatment.

Detailed ways

The technical solution of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts fall within the scope of protection of the present invention.

Moreover, the technical solutions in the various embodiments of the present invention can be combined with each other, but it must be based on the realization by those of ordinary skill in the art. When the combination of technical solutions appears to be contradictory or cannot be realized, such combination of technical solutions should be considered. It does not exist and is not within the protection scope required by the present invention.

When the examples give numerical ranges, it should be understood that, unless otherwise stated in the present invention, both endpoints of each numerical range and any value between the two endpoints can be selected. Unless otherwise defined, all technical and scientific terms used in the present invention are consistent with the knowledge of the prior art and the description of the present invention by those skilled in the art. They can also use the methods, equipment, and materials described in the embodiments of the present invention. Any methods, equipment and materials similar or equivalent to those in the prior art may be used to implement the present invention.

The content of the present invention will be further elaborated in detail below. The method for pretreatment of metal sulfur slag and enhanced sulfur hot-melt filtration separation provided by the present invention includes the following steps:

(1) Crush and grind the metal sulfur slag to a size of ≤106 μm; the sulfur content in the metal sulfur slag is ≥55wt%; the zinc content is ≤10wt%; the iron content is ≤20wt%; the lead content is ≤3wt%; polymetallic sulfur The slag size is ≤106μm, specifically it can be 1.3~106μm. It should be noted that the metal sulfur slag can be a polymetallic sulfur slag, that is, there can be a variety of metal impurities; the metal impurities can contain heavy metal elements, that is, the metal elements in the metal impurities can include or be heavy metal elements. , the heavy metal elements can also be multiple; the heavy metal elements can include or be one or more of Zn, Pb; of course, the heavy metal elements can also include or be other heavy metal elements such as Hg, Cu, etc., which are not mentioned here. List them one by one.

The sulfur (S) contained in the metal sulfur slag in the present invention refers to the S element that exists in the form of S ₈ . The existence form of Fe includes or is FeS ₂ , the existence form of Zn includes or is ZnS, and the existence form of Pb includes or is PbSO ₄ ; In addition to the above substances, the metal sulfur slag can generally also contain CaSO ₄ . In terms of mass fraction, the metal sulfur slag includes: sulfur (S) ≥ 55%, Fe ≤ 20%, Zn ≤ 10%, and Pb ≤ 3%. Specifically, the S content can be 55% to 85%, the Fe content can be 1% to 20%, the Zn content can be 1% to 10%, and the Pb content can be 0.1% to 3%. It should be emphasized that since the S element in S-containing materials such as FeS ₂ , ZnS, PbSO ₄ and CaSO ₄ does not exist in the form of sulfur, it does not need to be included in the proportion of sulfur (S).

(2) Mix the metal sulfur slag obtained by the treatment in step (1) with water. The mass ratio of metal sulfur slag to water is 1:2 to 1:5; and use dilute sulfuric acid to adjust the pH to 1 to 3;

(3) The slurry obtained in step (2) is stirred (500 rpm) and aerated for 0.5 to 2 hours; the ambient temperature for blast aeration of metal sulfur slag is 20 to 35°C, and the time is 0.5 to 2 hours, and Stir simultaneously at a speed of 500 rpm.

(4) Stop aeration of the slurry obtained in step (3) with continuous stirring, add regulating reagents to prepare a leaching solution, and react at room temperature for 10 to 24 hours; regulating reagents include ferric sulfate, sodium chloride and ammonium chloride, by mass In terms of fractions, its composition ratio is 20-80% iron sulfate, 2-20% sodium chloride, 10-60% ammonium chloride, and the total concentration of iron ions and ammonium ions is 0.1-0.6M;

(5) The slurry obtained in step (4) is filtered and washed multiple times until the pH is neutral, and vacuum dried until the moisture content is <10%; the water washing treatment is a conventional method, and only the metal sulfur slag needs to be washed to neutral It is sufficient to be neutral or close to neutral and will not be described in detail here. The dehydration treatment includes: dehydrating the metal sulfur slag that has been washed with water so that the moisture content of the metal sulfur slag is less than 10%.

Specifically, the metal sulfur slag after the water washing treatment can be filtered and dehydrated through a vacuum belt filter, and after dehydration, a dehydrated sulfur slag with a moisture content of less than 10% can be obtained.

(6) The metal sulfur slag obtained in step (5) is heated to 140-150°C to melt, and the molten slag to be separated is filtered and separated to obtain a separated sulfur liquid, which contains sulfur.

Among them, the melting temperature can be 140~150℃, and the melting time can be 60~180 minutes

Specifically, it can be as follows: the metal sulfur slag after the dehydration treatment is entered into a crude sulfur melting cyclone through a belt conveyor. The temperature in the crude sulfur melting cyclone is 140-150°C. The heat preservation time is 60 to 180 minutes to completely melt the metal sulfur slag; after the melting is completed, the molten slag to be separated is filtered and separated to obtain the metal filter slag and the separated sulfur liquid, and then the sulfur liquid is prepared. grains to obtain sulfur products. The metal filter residue (which may also be called heavy metal filter residue) contains metal elements (metal impurities) and may also contain other impurities; the sulfur liquid mainly contains sulfur.

The filter diameter of the filtration separation can be <10 μm, specifically 1 to 8 μm; the filtration separation can be pressure filtration, that is, during the filtration separation process, 0.6 to 0.8 MPa can be applied to the residue to be separated. Pressure; during the filtration and separation process, the temperature of the slag to be separated can be kept at 140-150°C, or the slag can be filtered while it is hot.

The specific method of filtering and separating the molten slag to be separated may be: pumping the molten slag to be separated into a filter press or pumping it in batches into a filter press; and then filtering in the filter press. The obtained sulfur liquid (high-purity sulfur liquid) is sent to a granulator to be granulated into sulfur products, and is packaged and stored.

It should be noted that, in view of the problems of high viscosity of molten metal sulfur slag and low efficiency of sulfur recovery by hot-melt filtration, the present invention further removes certain metal impurities in polymetallic sulfur slag through pretreatment and reduces the content of molten polymetallic sulfur slag. The degree of sulfur polymerization thereby improves the recovery rate of sulfur thermal filtration separation. The method provided by the invention is simple in process and easy to operate without adding toxic and harmful chemical reagents. It not only improves the recovery rate of sulfur resources in polymetallic sulfur slag and increases economic benefits, but also reduces the environmental risks caused by sulfur slag.

Specifically, in the present invention, the polymetallic sulfur slag is first crushed and ground, dissolved in deionized water, and the pH is adjusted to 1 to 3 with concentrated sulfuric acid; then the obtained slurry is stirred (500 rpm) and aerated for 0.5 to 2 hours; After aeration, add a regulating reagent to prepare a leaching solution, and react at room temperature for 10 to 24 hours; the obtained slurry is filtered and washed multiple times until the pH is neutral, and vacuum dried until the moisture content is <10%; the dehydrated metal sulfur slag is It is sent to the melting cyclone, and the temperature is maintained at 140-150°C in the crude sulfur melting cyclone. Finally, the molten slag to be separated is filtered and separated. After cooling the filtrate or granulating, a high-purity sulfur product can be obtained.

The technical solutions provided by the present invention will be described in detail below with reference to specific examples, but they should not be understood as limiting the scope of the present invention.

Example 1

The method of pretreatment of metal sulfur slag to strengthen hot-melt sulfur filtration separation includes the following steps:

The polymetallic sulfur slag (main components: S 80wt%, Zn 3.5wt%, Fe 4wt%, Pb 0.35wt%, others 12.15wt%) was crushed, ground, and sieved (200 mesh), and the mass ratio was 2:1. Deionized water was added to the polymetallic sulfur slag, and sulfuric acid was used to adjust pH=1.5. Under stirring (500rpm) conditions, use an air pump to aerate for 1 hour, and then add regulatory reagent A (including ferric sulfate, sodium chloride and ammonium chloride, the total concentration of Fe ³⁺ , chloride ions and NH ₄ ⁺ is 0.4M, In terms of mass fraction, the composition ratio is 70% iron sulfate, 10% sodium chloride, 20% ammonium chloride), and the reaction is carried out for 16 hours at normal temperature and pressure. The obtained slurry is filtered and washed multiple times until pH=7, and vacuum dried to a moisture content of 8%. The dehydrated metal sulfur slag is sent to the melting cyclone, and the temperature is maintained at 150°C in the crude sulfur melting cyclone. After 30 minutes of heat preservation, molten sulfur (molten polymetallic sulfur slag) was discharged from the bottom of the crude sulfur cyclone into the crude sulfur pool with stirring, and its viscosity was measured to be 1240 mPa.s. Then the molten sulfur slag (molten slag to be separated) is pumped into a hot filter (temperature 150°C) for filtration (pressure 0.6MPa, filter diameter 8μm) to obtain metal filter slag and high-purity sulfur liquid; The sulfur liquid is granulated and packaged to obtain sulfur products.

In this embodiment, the purity of sulfur in the sulfur product is 99.51%, the sulfur separation recovery rate in the polymetallic sulfur residue is 65.70%, and the heavy metals in the metal filter residue can be further recovered.

Comparative example 1

Compared with Example 1 in this comparative example, the polymetallic sulfur slag has not undergone pretreatment.

Specifically: vacuum-dry the polymetallic sulfur slag without any treatment to a moisture content of 8%, send it to the melting cyclone, maintain the temperature at 150°C in the crude sulfur melting cyclone, and after holding for 30 minutes, melt the sulfur ( The molten polymetallic sulfur slag) is discharged from the bottom of the crude sulfur cyclone into the crude sulfur pool with stirring, and its viscosity is measured to be 2660mPa.s. Then the molten sulfur slag (molten slag to be separated) is pumped into a hot filter (temperature 150°C) for filtration (pressure 0.6MPa, filter diameter 8μm) to obtain metal filter slag and high-purity sulfur liquid; The sulfur liquid is granulated and packaged to obtain sulfur products.

In this comparative example, the purity of sulfur in the sulfur product is 99.21%, and the sulfur separation recovery rate in the polymetallic sulfur slag is 53%.

Comparative example 2

Compared with Example 1, the steps of adding acid to adjust pH and aeration in the pretreatment process were omitted in this comparative example.

Specifically: the polymetallic sulfur slag (main components: S 80wt%, Zn 3.5wt%, Fe 4wt%, Pb 0.35wt%, others 12.15wt%) is pulverized, ground, and sieved (200 mesh) to a mass ratio of 2 :1 Add deionized water to the polymetallic sulfur slag, and add regulating reagents (including iron sulfate, sodium chloride and ammonium chloride) under stirring (500rpm) conditions. The total concentration of Fe ³⁺ , chloride ions and NH ₄ ⁺ is 0.4M, based on mass fraction, its composition ratio is 70% iron sulfate, 10% sodium chloride, 20% ammonium chloride), react for 16 hours at normal temperature and pressure. Filter and vacuum dry to a moisture content of 8%. Send the dehydrated metal sulfur slag to the melting cyclone. Keep the temperature at 150°C in the crude sulfur melting cyclone. After 30 minutes of heat preservation, the molten sulfur (polymer in molten state) Metal sulfur slag) is discharged from the bottom of the crude sulfur cyclone into the crude sulfur pool with stirring, and its viscosity is measured to be 1372mPa.s. Then the molten sulfur slag (molten slag to be separated) is pumped into a hot filter (temperature 150°C) for filtration (pressure 0.6MPa, filter diameter 8μm) to obtain metal filter slag and high-purity sulfur liquid; The sulfur liquid is granulated and packaged to obtain sulfur products.

In this comparative example, the purity of sulfur in the sulfur product is 99.22%, the sulfur separation recovery rate in the polymetallic sulfur residue is 58.4%, and the heavy metals in the metal filter residue can be further recovered.

Comparative example 3

Compared with Example 1 in this comparative example, no regulating reagent was added during the pretreatment process.

Specifically: the polymetallic sulfur slag (main components: S 80wt%, Zn 3.5wt%, Fe 4wt%, Pb 0.35wt%, others 12.15wt%) is pulverized, ground, and sieved (200 mesh) to a mass ratio of 2 :1 Add deionized water to the polymetallic sulfur slag, and adjust pH=1.5 with sulfuric acid. Under stirring (500 rpm) conditions, use an air pump to aerate for 1 hour. The obtained slurry is filtered and washed multiple times until pH=7, vacuum dried to a moisture content of 8%, and the dehydrated metal sulfur slag is sent to the melting cyclone. The temperature is maintained at 150°C in the crude sulfur melting cyclone. After 30 minutes of heat preservation, the molten sulfur (molten polymetallic sulfur slag) is discharged from the bottom of the crude sulfur cyclone into the crude sulfur pool with stirring. Measurement Its viscosity is 1410mPa.s. Then the molten sulfur slag (molten slag to be separated) is pumped into a hot filter (temperature 150°C) for filtration (pressure 0.6MPa, filter diameter 8μm) to obtain metal filter slag and high-purity sulfur liquid; The sulfur liquid is granulated and packaged to obtain sulfur products.

In this comparative example, the purity of sulfur in the sulfur product is 99.33%, the sulfur separation recovery rate in the polymetallic sulfur residue is 55.7%, and the heavy metals in the metal filter residue can be further recovered.

Comparative example 4

Compared with Example 1, this comparative example contains only one of the regulating reagents added during the pretreatment process.

Specifically: the polymetallic sulfur slag (main components: S 80wt%, Zn 3.5wt%, Fe 4wt%, Pb 0.35wt%, others 12.15wt%) is pulverized, ground, and sieved (200 mesh) to a mass ratio of 2 :1 Add deionized water to the polymetallic sulfur slag, and add the regulating reagent (iron sulfate, Fe ₃ ⁺ concentration is 0.4M, and its composition ratio is 100% iron sulfate in terms of mass fraction) under stirring (500 rpm) conditions. , react at room temperature and pressure for 16 hours. Filter and vacuum dry to a moisture content of 8%. Send the dehydrated metal sulfur slag to the melting cyclone. Keep the temperature at 150°C in the crude sulfur melting cyclone. After 30 minutes of heat preservation, the molten sulfur (polymer in molten state) Metal sulfur slag) is discharged from the bottom of the crude sulfur cyclone into the crude sulfur pool with stirring, and its viscosity is measured to be 1658mPa.s. Then the molten sulfur slag (molten slag to be separated) is pumped into a hot filter (temperature 150°C) for filtration (pressure 0.6MPa, filter diameter 8μm) to obtain metal filter slag and high-purity sulfur liquid; The sulfur liquid is granulated and packaged to obtain sulfur products.

In this comparative example, the purity of sulfur in the sulfur product is 99.18%, the sulfur separation recovery rate in the polymetallic sulfur slag is 58.89%, and the heavy metals in the metal filter residue can be further recovered.

Example 2

The method of pretreatment of metal sulfur slag to strengthen hot-melt sulfur filtration separation includes the following steps:

The polymetallic sulfur slag (main components: S 82wt%, Zn 4.1wt%, Fe 3.8wt%, Pb 0.52wt%, others 9.58wt%) was crushed, ground, and sieved (200 mesh) to a mass ratio of 2:1 Add deionized water to the polymetallic sulfur residue, and adjust pH=1.5 with sulfuric acid. Under stirring (500rpm) conditions, use an air pump to aerate for 1 hour, and then add regulatory reagent B (including ferric sulfate, sodium chloride and ammonium chloride, the total concentration of Fe ³⁺ , chloride ions and NH ₄ ⁺ is 0.3M, In terms of mass fraction, the composition ratio is 60% iron sulfate, 10% sodium chloride, 30% ammonium chloride), and the reaction is carried out for 16 hours at normal temperature and pressure. The obtained slurry is filtered and washed multiple times until pH=7, and vacuum dried until the moisture content is 10%. The dehydrated metal sulfur slag is sent to the melting cyclone, and the temperature is maintained at 150°C in the crude sulfur melting cyclone. After 30 minutes of heat preservation, molten sulfur (molten polymetallic sulfur slag) was discharged from the bottom of the crude sulfur cyclone into the crude sulfur pool with stirring, and its viscosity was measured to be 1160 mPa.s. Then the molten sulfur slag (molten slag to be separated) is pumped into a hot filter (temperature 150°C) for filtration (pressure 0.6Mpa, filter diameter 8μm) to obtain metal filter slag and high-purity sulfur liquid; The sulfur liquid is granulated and packaged to obtain sulfur products.

In this embodiment, the purity of sulfur in the sulfur product is 99.43%, the sulfur separation recovery rate in the polymetallic sulfur residue is 66.1%, and the heavy metals in the metal filter residue can be further recovered.

Example 3

The method of pretreatment of metal sulfur slag to strengthen hot-melt sulfur filtration separation includes the following steps:

The polymetallic sulfur slag (main components: S 77wt%, Zn 5.6wt%, Fe 6.4wt%, Pb 0.79wt%, others 10.21wt%) was crushed, ground, and sieved (200 mesh) to a mass ratio of 2:1 Add deionized water to the polymetallic sulfur residue, and adjust pH=2 with sulfuric acid. Under stirring (500rpm) conditions, use an air pump to aerate for 1 hour, and then add regulatory reagent C (including ferric sulfate, sodium chloride and ammonium chloride, the total concentration of Fe ³⁺ , chloride ions and NH ₄ ⁺ is 0.5M, In terms of mass fraction, the composition ratio is 40% iron sulfate, 15% sodium chloride, 45% ammonium chloride), and the reaction is carried out for 16 hours at normal temperature and pressure. The obtained slurry is filtered and washed multiple times until pH=7, and vacuum dried to a moisture content of 9%. The dehydrated metal sulfur slag is sent to the melting cyclone, and the temperature is maintained at 150°C in the crude sulfur melting cyclone. After 30 minutes of heat preservation, molten sulfur (molten polymetallic sulfur slag) was discharged from the bottom of the crude sulfur cyclone into the crude sulfur pool with stirring, and its viscosity was measured to be 1221mPa.s. Then the molten sulfur slag (molten slag to be separated) is pumped into a hot filter (temperature 150°C) for filtration (pressure 0.6Mpa, filter diameter 8μm) to obtain metal filter slag and high-purity sulfur liquid; The sulfur liquid is granulated and packaged to obtain sulfur products.

In this embodiment, the purity of sulfur in the sulfur product is 99.38%, the sulfur separation recovery rate in the polymetallic sulfur residue is 64%, and the heavy metals in the metal filter residue can be further recovered.

Among the above technical solutions of the present invention, the above are only preferred embodiments of the present invention and do not limit the patent scope of the present invention. Under the technical concept of the present invention, equivalent structural transformations can be made using the contents of the description and drawings of the present invention. , or direct/indirect application in other related technical fields are included in the scope of patent protection of the present invention.

Claims (9)

1. A method for pretreatment of metal sulfur slag to enhance hot-melt sulfur filtration separation, which is characterized by: including the following steps: 1) After crushing and grinding the metal sulfur slag, add water and acid to adjust the slurry to obtain a metal sulfur slag slurry; 2) After aeration treatment of the metal sulfur slag slurry, an impurity removal regulator is added to remove impurities to obtain a leaching solution; the impurity removal regulator includes ferric sulfate, sodium chloride and ammonium chloride; 3) The leaching solution is filtered to separate the solid product. After the solid product is washed and dehydrated, the sulfur liquid is separated by hot melt filtration. 2. A method for pretreatment of metal sulfur slag to enhance sulfur hot-melt filtration and separation according to claim 1, characterized in that: the metal sulfur slag is ground to a particle size of ≤106 μm. 3. A method for metal sulfur slag pretreatment to strengthen sulfur hot-melt filtration and separation according to claim 1, characterized in that: the solid-liquid mass ratio of the metal sulfur slag slurry is 1:2 to 1:5, pH=1～3. 4. A method for pretreatment of metal sulfur slag to strengthen sulfur hot-melt filtration and separation according to claim 1, characterized in that: the aeration adopts stirring-assisted blast aeration, the stirring rate is 300-700 rpm, and the aeration method is 300 to 700 rpm. The gas time is 0.5 to 2 hours. 5. A method for metal sulfur slag pretreatment to strengthen sulfur hot-melt filtration and separation according to claim 1, characterized in that: the impurity removal regulator contains the following mass percentage components: iron sulfate 20-80%, chlorine Sodium chloride 2-20%, ammonium chloride 10-60%. 6. A method for pretreatment of metal sulfur slag to strengthen sulfur hot melt filtration and separation according to claim 1 or 5, characterized in that: the amount of the impurity removal regulator is based on the iron ions and chloride ions in the metal sulfur slag slurry. The total concentration of ammonium ions is 0.1~0.6M. 7. A method for pretreatment of metal sulfur slag to enhance sulfur hot-melt filtration and separation according to claim 1 or 5, characterized in that: the impurity removal conditions are: reaction at normal temperature for 10 to 24 hours. 8. A method for pretreatment of metal sulfur slag to strengthen sulfur hot-melt filtration and separation according to claim 1, characterized in that: during the hot-melt filtration process, the melting temperature is 140-150°C and the duration is 60-180 min. , the filter pressure is 0.6~0.8MPa. 9. A method for pre-treating metal sulfur slag to strengthen sulfur hot melt filtration and separation according to claim 1, 2, 3, 4, 5 or 8, characterized in that: the sulfur element content in the metal sulfur slag is ≥55wt %, zinc element content ≤ 10wt%, iron element content ≤ 20wt%, lead element content ≤ 3wt%.