A method for full resource utilization of tin-containing sludge in a steel industry cold rolling plant

Abstract

The application discloses a kind of full-amount resource utilization method of tin-containing sludge in steel industry cold rolling plant, belong to the field of hazardous waste treatment, including S1, acid leaching: tin-containing sludge is poured into reaction tank, then the mass concentration of 37% concentrated hydrochloric acid and water is added in reaction tank;S2, biological leaching: the temperature of reaction tank is reduced to 20-30 DEG C, then mixed culture type acidophilic microorganism inoculum is added;S3, leaching residue treatment: the leaching residue obtained in step S2 is washed with water, and the washed mixture obtained after cleaning is filtered to obtain washed liquid and inorganic residue, the inorganic residue is sintered, and the sintered block is obtained after sintering;S4, leaching liquid treatment: the leaching liquid obtained in step S2 is placed in displacement tank, zinc powder is added and stirred, and tin is replaced out, the present application uses efficient and active microorganism to leach tin mud, which not only solves the problem of wet acid leaching unable to break down complex, but also avoids the defects of high energy consumption, low recovery rate and difficult to treat flue gas to meet the standard in fire method.

Description

Technical Field

[0001] This invention relates to the field of hazardous waste treatment technology, specifically to a method for the full resource utilization of tin-containing sludge from cold rolling mills in the steel industry. Background Technology

[0002] The tin plating process in the cold rolling workshop of steel plants generally uses tinplate tin plating technology. This process generates a large amount of tin-containing sludge, commonly known as "tin mud".

[0003] In the plating bath, Sn²⁺ is oxidized to Sn⁴⁺ by oxygen in the air and Fe³⁺ dissolved from the steel plate. Sn⁴⁺ readily forms precipitates such as SnO₂ and Sn(OH)₄, or forms complexes with organic matter in the plating bath. These substances, along with other metallic impurities and precipitates in the plating bath, form tin sludge. The main components of tin sludge are Sn, Fe, S, C, and O, and it has significant resource recovery value.

[0004] Tin sludge has a complex composition, with a tin content generally greater than 50%. It also contains sulfonic acid groups, aromatic rings, tin oxides and hydroxides, etc. Due to the presence of complexes, the tin element cannot be effectively separated by direct wet separation.

[0005] Currently, the mainstream method for disposing of tin sludge is to recover tin or tin compounds using pyrometallurgical smelting or high-temperature incineration. High temperatures can effectively remove components that are difficult to handle using wet methods, such as complexes, ultimately forming crude tin metal or tin oxide powder, thus achieving the resource recovery of tin. However, due to the high water content, low calorific value, and diverse impurities of tin sludge, pyrometallurgical smelting or incineration methods suffer from drawbacks such as high energy consumption, low recovery rate, and difficulty in treating flue gas to meet standards. Summary of the Invention

[0006] To address the aforementioned technical problems, this invention provides a method for the full resource utilization of tin-containing sludge from cold rolling mills in the steel industry.

[0007] The technical solution of this invention is: a method for the full resource utilization of tin-containing sludge from cold rolling mills in the steel industry, comprising the following steps:

[0008] S1, Acid Immersion:

[0009] Pour the tin-containing sludge into the reaction tank, then add 37% concentrated hydrochloric acid and water to the reaction tank to adjust the pH to 3-5. The temperature of the reaction tank is 50-60℃, and the reaction tank is continuously stirred at a stirring speed of 20-30 r / min. The reaction time is 4-5 h. After the reaction is completed, let it stand for 8-10 h. Take 2 / 3 of the volume of the supernatant in the reaction tank for filtration. After filtration, filtrate A and filter residue A are obtained. Filter residue A is added into the reaction tank.

[0010] The main chemical reactions that occur during this process are:

[0011] Sn(OH)₄ + 4HCl → SnCl₄ + 4H₂O

[0012] SnO2 + 4HCl → SnCl4 + 4H2O;

[0013] S2, Bio-extraction:

[0014] Lower the temperature of the reaction tank to 20-30℃, then add a mixed-culture acidophilic microbial agent, and add 37% concentrated hydrochloric acid to adjust the pH value to 3-5. Continue to stir the reaction tank at a stirring speed of 20-30 r / min for 4-8 hours. After the reaction is completed, filter to obtain filtrate B and leaching residue. Mix filtrate A and filtrate B from step S1 to obtain leachate.

[0015] S3. Leaching residue treatment:

[0016] The leaching residue obtained in step S2 is washed with water, and the resulting water-washed mixture is filtered to obtain washing liquid and inorganic residue. The inorganic residue is sintered to obtain sintered blocks.

[0017] S4. Leachate treatment:

[0018] The leachate obtained in step S2 is placed in a displacement tank, zinc powder is added and stirred. The temperature of the displacement tank is 25-35℃ and the stirring speed is 20-30 r / min. After adding zinc powder until no precipitation occurs, stirring is stopped to obtain a displacement solution. The displacement solution is then filtered to obtain a filter filtrate and a filter residue. The filter residue is dried at a temperature of 80-100℃ until the moisture content is ≤1% to obtain tin powder. The tin powder is then placed in a vacuum melting furnace for melting. After melting, it is cast to obtain tin ingots. The tin ingots are recycled for secondary use.

[0019] The main chemical reactions that occur during this process are:

[0020] 2Zn + SnCl4 → 2ZnCl2 + Sn.

[0021] Furthermore, the amount of mixed-culture acidophilic microbial agent added in step S2 is 10-30 wt%.

[0022] Note: Inoculating too much will waste the mixed-culture acidophilic microbial agent, while inoculating too little will reduce the decomposition efficiency of organic matter.

[0023] Further, the mixed-culture acidophilic microbial agent in step S2 consists of the following components in parts by weight: 4-5 parts Helicobacter pylori, 1-3 parts acidifying methanogens, 2-5 parts acidophilic thermofluidic leaf bacteria, 1-2 parts acidophilic Bacillus, 7-9 parts sulfite-oxidizing Bacillus, 4-5 parts iron-oxidizing archaea, 2.3-4.5 parts sulfur-oxidizing archaea, 2-6 parts cycloaliphatic Bacillus, and the remainder is bacterial culture medium.

[0024] Note: The above-mentioned mixed-culture acidophilic microbial agent has high decomposition efficiency for complexes in tin-containing sludge, which can greatly improve the efficiency of acid leaching.

[0025] Furthermore, the bacterial culture medium is composed of the following components by mass percentage: 3-5% peptone, 7-9% sugar and sodium chloride, 10-15% tryptone, 1-2% magnesium chloride, 1-3% calcium chloride, 30-35% dilute hydrochloric acid with a mass concentration of 20%, and the balance being purified water.

[0026] Note: The above bacterial culture medium can provide an acidic environment for the above bacterial strains, as well as the trace elements required for the decomposition of organic matter, and the proteins and carbon sources required for bacterial reproduction.

[0027] Furthermore, the filter screen used for filtration in steps S1 and S2 is 200-300 mesh.

[0028] Note: The above-mentioned mesh size of the filter screen has a good filtration effect and can effectively separate the filter residue in tin-containing sludge.

[0029] Further, the water washing method for the leaching residue in step S3 is as follows: the leaching residue is placed in a water washing tank, and then tap water is added. The volume ratio of tap water to leaching residue is 2:1. The leaching residue in the water washing tank is stirred at a speed of 60-80 r / min for 20-30 min. After stirring, the mixture is left to stand for 1-2 hours. The upper liquid is discharged, and the mixture of the lower water and leaching residue is filtered. The filtered liquid and the upper liquid are mixed to obtain the washing liquid.

[0030] Note: The acidic liquid in the leaching residue is diluted by the above-mentioned water washing method and then reused, so as to make full use of resources and reduce the treatment cost of tin-containing sludge.

[0031] Furthermore, the washing liquid is used as a substitute for water in step S1 to adjust the pH value of the reaction tank.

[0032] Note: Reusing the residual hydrochloric acid in the washing solution helps reduce enterprise costs and is in line with the principles of environmental protection and energy conservation.

[0033] Furthermore, the sintering method of the inorganic slag in step S4 is as follows: the inorganic slag is placed in a sintering furnace, the sintering temperature is 800-1000℃, the sintering time is 30-45min, and after sintering, a sintered block is obtained. The sintered block is used for the preparation of high-temperature fireproof boards.

[0034] Note: The prepared molten blocks can be used as raw materials for fireproof materials or high-temperature resistant plates for secondary processing and utilization, thereby improving resource recycling efficiency and increasing the economic value of this process.

[0035] Furthermore, the pressure filtration is performed by first using a 100-200 mesh filter and then using a 200-300 mesh filter, with the pressure for both filtrations being 120-140 kPa.

[0036] Note: Double filtration can improve filtration efficiency and extend the service life of the filter screen.

[0037] Furthermore, the filtrate obtained in step S4 is used in the electroplating zinc process as an electrolytic solution in the electroplating zinc process.

[0038] Note: The filtrate contains a large amount of zinc chloride. Zinc chloride, as an electrolyte in zinc electroplating, can effectively improve electroplating efficiency and can be recycled and reused, thus effectively increasing its economic value.

[0039] Furthermore, the melting method of the tin powder in the vacuum melting furnace is as follows: first, the tin powder is placed in the vacuum melting furnace, then the vacuum melting furnace is evacuated to a vacuum degree of 2-5 Pa, then argon gas is introduced into the vacuum melting furnace to a gas pressure of 80-90 kPa, then the temperature of the vacuum melting furnace is raised to 250-400℃ at a heating rate of 4-8℃ / min, and after all the tin powder in the vacuum melting furnace has melted, the mold containing the melt is taken out for casting.

[0040] Explanation: Tin powder is melted through smelting and then cast into metal ingots, which facilitates secondary use, storage, and transportation.

[0041] The beneficial effects of this invention are:

[0042] (1) The present invention uses highly active microorganisms to extract tin mud, which not only solves the problem that wet acid leaching cannot break the influence of complexes, but also avoids the defects of high energy consumption, low recovery rate and difficulty in treating flue gas to meet standards in pyrometallurgical methods.

[0043] (2) This invention realizes the full resource recycling of solid waste, no longer generates secondary solid waste, the leaching residue is all inorganic components, which can be directly recycled to the sintering plant, and the sintered blocks formed by the inorganic residue can be used for the preparation of high temperature resistant plates, thus improving the economic value of this invention.

[0044] (3) This invention achieves efficient extraction of tin and converts it into tin ingots, which can be directly used in production. Ultimately, it realizes the recycling of the entire industrial chain and truly achieves the resource utilization, reduction and harmlessness of solid waste.

[0045] (4) The core extraction process of this invention uses biological decomposition of complexes, which has high extraction efficiency, simple process, low energy consumption and low cost. Detailed Implementation

[0046] Example 1:

[0047] A method for the full resource utilization of tin-containing sludge from cold rolling mills in the steel industry includes the following steps:

[0048] S1, Acid Immersion:

[0049] The tin-containing sludge was poured into the reaction tank, and then 37% concentrated hydrochloric acid and water were added to the reaction tank to adjust the pH value to 3. The temperature of the reaction tank was 50℃, and the reaction tank was continuously stirred at a stirring speed of 20r / min for 4 hours. After the reaction was completed, it was allowed to stand for 8 hours. Two-thirds of the volume of the supernatant in the reaction tank was extracted for filtration. After filtration, filtrate A and filter residue A were obtained. The filter screen used for filtration was 200 mesh. Filter residue A was added into the reaction tank.

[0050] The main chemical reactions that occur during this process are:

[0051] Sn(OH)₄ + 4HCl → SnCl₄ + 4H₂O

[0052] SnO2 + 4HCl → SnCl4 + 4H2O;

[0053] S2, Bio-extraction:

[0054] The temperature of the reaction tank was lowered to 20°C, and then 10 wt% of a mixed-culture acidophilic microbial agent was added. 37% concentrated hydrochloric acid was added to adjust the pH value to 3. The reaction tank was stirred at a speed of 20 r / min for 4 hours. After the reaction was completed, the mixture was filtered to obtain filtrate B and leaching residue. Filtrate A and filtrate B from step S1 were mixed to obtain leachate.

[0055] S3. Leaching residue treatment:

[0056] The leaching residue obtained in step S2 is washed with water. The water-washed mixture is then filtered to obtain the washing liquid and inorganic residue. The inorganic residue is sintered to obtain sintered blocks.

[0057] S4. Leachate treatment:

[0058] The leachate obtained in step S2 is placed in a displacement tank, zinc powder is added and stirred. The temperature of the displacement tank is 25°C and the stirring speed is 20 r / min. After adding zinc powder until no precipitation occurs, stirring is stopped to obtain a displacement solution. The displacement solution is then filtered to obtain a filter filtrate and a filter residue. The filter residue is dried at 80°C until the moisture content is 1% to obtain tin powder. The tin powder is then placed in a vacuum melting furnace for melting. After melting, the powder is cast to obtain tin ingots. The tin ingots are then recycled for secondary use.

[0059] The main chemical reactions that occur during this process are:

[0060] 2Zn + SnCl4 → 2ZnCl2 + Sn.

[0061] The mixed-culture acidophilic microbial agent in step S2 consists of the following components by weight: 4 parts Helicobacter pylori, 1 part acidifying methanogens, 2 parts acidophilic thermofluidic leaf bacteria, 1 part acidophilic Bacillus, 7 parts sulfite-oxidizing bacteria, 4 parts iron-oxidizing archaea, 2.3 parts sulfur-oxidizing archaea, 2 parts cycloaliphatic Bacillus, and the remainder is bacterial culture medium.

[0062] The bacterial culture medium consists of the following components by weight percentage: 3% peptone, 7% sugar and sodium chloride, 10% tryptone, 1% magnesium chloride, 1% calcium chloride, 30% dilute hydrochloric acid with a weight concentration of 20%, and the balance being purified water.

[0063] The water washing method for the leaching residue in step S3 is as follows: put the leaching residue into a water washing tank, then add tap water, with a volume ratio of tap water to leaching residue of 2:1. Stir the leaching residue in the water washing tank at a stirring speed of 60 r / min for 20 min. After stirring, let it stand for 1 h, drain the upper liquid, filter the mixture of the lower water and leaching residue, and mix the filtered liquid with the upper liquid to obtain the washing liquid.

[0064] The washing liquid is used as a substitute for water in step S1 to adjust the pH value of the reaction tank.

[0065] The sintering method of inorganic slag in step S4 is as follows: the inorganic slag is placed in a sintering furnace, the sintering temperature is 800℃, the sintering time is 30min, and after sintering, a sintered block is obtained. The sintered block is used for the preparation of high temperature resistant fireproof boards.

[0066] Filtration involves first using a 100-mesh filter and then a 200-mesh filter, with both filtration pressures at 120 kPa.

[0067] The melting method of tin powder in a vacuum melting furnace is as follows: First, put the tin powder into the vacuum melting furnace, then evacuate the vacuum melting furnace to a vacuum degree of 2 Pa, then fill the vacuum melting furnace with argon gas until the gas pressure in the vacuum furnace is 80 kPa, then raise the temperature of the vacuum melting furnace to 250℃ at a heating rate of 4℃ / min, and after all the tin powder in the vacuum melting furnace has melted, take out the mold containing the melt for casting.

[0068] Example 2:

[0069] A method for the full resource utilization of tin-containing sludge from cold rolling mills in the steel industry includes the following steps:

[0070] S1, Acid Immersion:

[0071] The tin-containing sludge was poured into the reaction tank, and then concentrated hydrochloric acid and water with a mass concentration of 37% were added to the reaction tank to adjust the pH value to 4. The temperature of the reaction tank was 55℃, and the reaction tank was continuously stirred at a stirring speed of 25r / min for a reaction time of 4.5h. After the reaction was completed, the mixture was allowed to stand for 9h. Two-thirds of the volume of the supernatant in the reaction tank was extracted for filtration, and filtrate A and filter residue A were obtained after filtration. The filter screen used for filtration was 250 mesh. Filter residue A was added into the reaction tank.

[0072] The main chemical reactions that occur during this process are:

[0073] Sn(OH)₄ + 4HCl → SnCl₄ + 4H₂O

[0074] SnO2 + 4HCl → SnCl4 + 4H2O;

[0075] S2, Bio-extraction:

[0076] The temperature of the reaction tank was lowered to 25°C, and then 20 wt% of a mixed-culture acidophilic microbial agent was added. 37% concentrated hydrochloric acid was added to adjust the pH value to 4. The reaction tank was stirred at a speed of 25 r / min for 5 h. After the reaction was completed, the mixture was filtered to obtain filtrate B and leaching residue. Filtrate A and filtrate B from step S1 were mixed to obtain leachate.

[0077] S3. Leaching residue treatment:

[0078] The leaching residue obtained in step S2 is washed with water. The water-washed mixture is then filtered to obtain the washing liquid and inorganic residue. The inorganic residue is sintered to obtain sintered blocks.

[0079] S4. Leachate treatment:

[0080] The leachate obtained in step S2 is placed in a displacement tank, zinc powder is added and stirred. The temperature of the displacement tank is 30°C and the stirring speed is 25 r / min. After adding zinc powder until no precipitation occurs, stirring is stopped to obtain a displacement solution. The displacement solution is then filtered to obtain a filter filtrate and a filter residue. The filter residue is dried at 90°C until the moisture content is 0.8% to obtain tin powder. The tin powder is then placed in a vacuum melting furnace for melting. After melting, the powder is cast to obtain tin ingots. The tin ingots are then recycled for secondary use.

[0081] The main chemical reactions that occur during this process are:

[0082] 2Zn + SnCl4 → 2ZnCl2 + Sn.

[0083] The mixed-culture acidophilic microbial agent in step S2 consists of the following components by weight: 4.5 parts Helicobacter pylori, 2 parts acidifying methanogens, 3 parts acidophilic thermofluidic leaf bacteria, 1.5 parts acidophilic Bacillus, 8 parts sulfite-oxidizing Bacillus, 4.5 parts iron-oxidizing archaea, 3 parts sulfur-oxidizing archaea, 4 parts cycloaliphatic Bacillus, and the remainder is bacterial culture medium.

[0084] The bacterial culture medium consists of the following components by weight percentage: 4% peptone, 8% sugar and sodium chloride, 13% tryptone, 1.5% magnesium chloride, 2% calcium chloride, 32% dilute hydrochloric acid with a weight concentration of 20%, and the balance being purified water.

[0085] The water washing method for the leaching residue in step S3 is as follows: put the leaching residue into a water washing tank, then add tap water, with a volume ratio of tap water to leaching residue of 2:1. Stir the leaching residue in the water washing tank at a stirring speed of 70 r / min for 25 min. After stirring, let it stand for 1.5 h, drain the upper liquid, filter the mixture of the lower water and leaching residue, and mix the filtered liquid with the upper liquid to obtain the washing liquid.

[0086] The washing liquid is used as a substitute for water in step S1 to adjust the pH value of the reaction tank.

[0087] The sintering method of inorganic slag in step S4 is as follows: the inorganic slag is placed in a sintering furnace, the sintering temperature is 900℃, the sintering time is 40min, and after sintering, a sintered block is obtained. The sintered block is used for the preparation of high temperature resistant fireproof boards.

[0088] Filtration involves first using a 150-mesh filter screen, then using a 200-300 mesh filter screen, with both filtration pressures at 130 kPa.

[0089] The melting method of tin powder in a vacuum melting furnace is as follows: First, put the tin powder into the vacuum melting furnace, then evacuate the vacuum melting furnace to a vacuum degree of 3 Pa, then fill the vacuum melting furnace with argon gas until the gas pressure in the vacuum furnace is 85 kPa, then raise the temperature of the vacuum melting furnace to 350℃ at a heating rate of 5℃ / min, and after all the tin powder in the vacuum melting furnace has melted, take out the mold containing the melt for casting.

[0090] Example 3:

[0091] A method for the full resource utilization of tin-containing sludge from cold rolling mills in the steel industry includes the following steps:

[0092] S1, Acid Immersion:

[0093] The tin-containing sludge was poured into the reaction tank, and then 37% concentrated hydrochloric acid and water were added to the reaction tank to adjust the pH value to 5. The temperature of the reaction tank was 50-60℃, and the reaction tank was continuously stirred at a stirring speed of 30r / min for 5 hours. After the reaction was completed, it was allowed to stand for 10 hours. Two-thirds of the volume of the supernatant in the reaction tank was extracted for filtration. After filtration, filtrate A and filter residue A were obtained. The filter screen used for filtration was 300 mesh. Filter residue A was added into the reaction tank.

[0094] The main chemical reactions that occur during this process are:

[0095] Sn(OH)₄ + 4HCl → SnCl₄ + 4H₂O

[0096] SnO2 + 4HCl → SnCl4 + 4H2O;

[0097] S2, Bio-extraction:

[0098] The temperature of the reaction tank was lowered to 30°C, and then 30 wt% of a mixed-culture acidophilic microbial agent was added. 37% concentrated hydrochloric acid was added to adjust the pH value to 5. The reaction tank was stirred at a speed of 30 r / min for 8 hours. After the reaction was completed, the mixture was filtered to obtain filtrate B and leaching residue. Filtrate A and filtrate B from step S1 were mixed to obtain leachate.

[0099] S3. Leaching residue treatment:

[0100] The leaching residue obtained in step S2 is washed with water. The water-washed mixture is then filtered to obtain the washing liquid and inorganic residue. The inorganic residue is sintered to obtain sintered blocks.

[0101] S4. Leachate treatment:

[0102] The leachate obtained in step S2 is placed in a displacement tank, zinc powder is added and stirred. The temperature of the displacement tank is 35℃ and the stirring speed is 30r / min. After adding zinc powder until no precipitation occurs, stirring is stopped to obtain a displacement solution. The displacement solution is then filtered to obtain a filter filtrate and a filter residue. The filter residue is dried at 100℃ until the moisture content is 0.5% to obtain tin powder. The tin powder is then placed in a vacuum melting furnace for melting. After melting, the powder is cast to obtain tin ingots. The tin ingots are then recycled for secondary use.

[0103] The main chemical reactions that occur during this process are:

[0104] 2Zn + SnCl4 → 2ZnCl2 + Sn.

[0105] The mixed-culture acidophilic microbial agent in step S2 consists of the following components by weight: 5 parts Helicobacter pylori, 3 parts acidifying methanogens, 5 parts acidophilic thermofluidic leaf bacteria, 2 parts acidophilic Bacillus, 9 parts sulfite-oxidizing Bacillus, 5 parts iron-oxidizing archaea, 4.5 parts sulfur-oxidizing archaea, 6 parts cycloaliphatic Bacillus, and the remainder is bacterial culture medium.

[0106] The bacterial culture medium consists of the following components by weight percentage: 5% peptone, 9% sugar and sodium chloride, 15% tryptone, 2% magnesium chloride, 3% calcium chloride, 35% dilute hydrochloric acid with a weight concentration of 20%, and the balance being purified water.

[0107] The water washing method for the leaching residue in step S3 is as follows: put the leaching residue into a water washing tank, then add tap water, with a volume ratio of tap water to leaching residue of 2:1. Stir the leaching residue in the water washing tank at a stirring speed of 80 r / min for 30 min. After stirring, let it stand for 2 hours, drain the upper liquid, filter the mixture of the lower water and leaching residue, and mix the filtered liquid with the upper liquid to obtain the washing liquid.

[0108] The washing liquid is used as a substitute for water in step S1 to adjust the pH value of the reaction tank.

[0109] The sintering method of inorganic slag in step S4 is as follows: the inorganic slag is placed in a sintering furnace, the sintering temperature is 1000℃, the sintering time is 45min, and after sintering, a sintered block is obtained. The sintered block is used for the preparation of high temperature resistant fireproof boards.

[0110] Filtration involves first using a 200-mesh filter and then a 300-mesh filter, with both filtration pressures at 140 kPa.

[0111] The melting method of tin powder in a vacuum melting furnace is as follows: First, put the tin powder into the vacuum melting furnace, then evacuate the vacuum melting furnace to a vacuum degree of 5 Pa, then fill the vacuum melting furnace with argon gas until the gas pressure in the vacuum furnace is 90 kPa, then raise the temperature of the vacuum melting furnace to 400℃ at a heating rate of 8℃ / min, and after all the tin powder in the vacuum melting furnace has melted, take out the mold containing the melt for casting.

[0112] Comparing Examples 1-3, Example 3 showed the best treatment effect and the highest tin leaching rate. Therefore, Example 3 is the best example.

[0113] Example 4:

[0114] Based on Example 3, this example provides a method for applying sintered blocks and filtrate, wherein the filtrate obtained in step S4 is applied in the metal electroplating zinc process as an electrolytic solution in electroplating zinc.

Claims

1. A method for the full resource utilization of tin-containing sludge from cold rolling mills in the steel industry, characterized in that, Includes the following steps: S1, Acid Immersion: Pour the tin-containing sludge into the reaction tank, then add 37% concentrated hydrochloric acid and water to the reaction tank, adjust the pH value to 3-5, maintain the temperature of the reaction tank at 50-60℃, and continuously stir the reaction tank at a stirring speed of 20-30 r / min for 4-5 hours. After the reaction is completed, let it stand for 8-10 hours, then extract 2 / 3 of the volume of the supernatant from the reaction tank for filtration. After filtration, filtrate A and filter residue A are obtained. Filter residue A is added into the reaction tank. S2, Bio-extraction: Lower the temperature of the reaction tank to 20-30℃, then add a mixed-culture acidophilic microbial agent, and add 37% concentrated hydrochloric acid to adjust the pH value to 3-5. Continue to stir the reaction tank at a stirring speed of 20-30 r / min for 4-8 hours. After the reaction is completed, filter to obtain filtrate B and leaching residue. Mix filtrate A and filtrate B from step S1 to obtain leachate. S3. Leaching residue treatment: The leaching residue obtained in step S2 is washed with water, and the resulting water-washed mixture is filtered to obtain washing liquid and inorganic residue. The inorganic residue is sintered to obtain sintered blocks. S4. Leachate treatment: The leachate obtained in step S2 is placed in a displacement tank, zinc powder is added and stirred. The temperature of the displacement tank is 25-35℃ and the stirring speed is 20-30 r / min. After adding zinc powder until no precipitation occurs, stirring is stopped to obtain a displacement solution. The displacement solution is then filtered to obtain a filter filtrate and a filter residue. The filter residue is dried at a temperature of 80-100℃ until the moisture content is ≤1% to obtain tin powder. The tin powder is then placed in a vacuum melting furnace for melting. After melting, it is cast to obtain tin ingots. The tin ingots are recycled for secondary use. The amount of mixed-culture acidophilic microbial agent added in step S2 is 10-30 wt%. The filter used in steps S1 and S2 is 200-300 mesh.

2. The method for full resource utilization of tin-containing sludge from cold rolling mills in the steel industry as described in claim 1, characterized in that, The water washing method for the leaching residue in step S3 is as follows: the leaching residue is placed in a water washing tank, and then tap water is added. The volume ratio of tap water to leaching residue is 2:

1. The leaching residue in the water washing tank is stirred at a speed of 60-80 r / min for 20-30 min. After stirring, the mixture is left to stand for 1-2 hours. The upper liquid is discharged, and the mixture of the lower water and leaching residue is filtered. The filtered liquid and the upper liquid are mixed to obtain the washing liquid.

3. The method for full resource utilization of tin-containing sludge from cold rolling mills in the steel industry as described in claim 1, characterized in that, The sintering method of the inorganic slag in step S4 is as follows: the inorganic slag is placed in a sintering furnace, the sintering temperature is 800-1000℃, the sintering time is 30-45min, and after sintering, a sintered block is obtained. The sintered block is used for the preparation of high temperature resistant fireproof boards.

4. The method for full resource utilization of tin-containing sludge from cold rolling mills in the steel industry as described in claim 1, characterized in that, The pressure filtration process involves first using a 100-200 mesh filter and then using a 200-300 mesh filter, with both pressure filtrations performed at 120-140 kPa.

5. A method for the full resource utilization of tin-containing sludge from cold rolling mills in the steel industry as described in claim 1, characterized in that, The filtrate obtained in step S4 is used in the electroplating zinc process as an electrolytic solution in the electroplating zinc.

6. The method for full resource utilization of tin-containing sludge from cold rolling mills in the steel industry as described in claim 1, characterized in that, The filtrate obtained in step S4 is used in the metal electroplating zinc process.