Method for recovering tin and indium from lead ore refining waste residues

Abstract

The invention discloses a method for recovering tin and indium from lead ore refining waste residues, which comprises the following steps: adding limestone and crushed coal into the lead ore refining waste residues, uniformly mixing, feeding into a side blowing furnace, smelting under an oxygen-enriched air condition, cooling collected furnace slag, adding a sulfuric acid solution and lauryl sodium sulfate, and grinding to obtain slag powder; adding acid liquor into the slag powder for acid leaching, filtering and separating to obtain filtrate A and filter residue B, drying and crushing the filter residue B, and smelting and recovering to obtain crude tin; adding sodium sulfite into the filtrate A, stirring, adding calcium carbonate to adjust the pH value to 4.5-5.5, stirring, and filtering to obtain filtrate C and filter residues D; and taking the filter residue D, adding an acid solution for secondary acid leaching to obtain a leaching solution, adding zinc powder into the leaching solution for replacement and recovery to obtain crude indium, collecting a replaced solution, and mixing the replaced solution with the filtrate C to prepare zinc sulfate. According to the method, the recovery efficiency of tin and indium elements in the refining waste residues can be improved, and recycling of the lead ore refining waste residues is facilitated.

Description

Technical Field

[0001] The invention belongs to the technical field of lead ore refining waste slag recycling, and in particular relates to a method for recovering tin and indium from lead ore refining waste slag. Background Art

[0002] Lead ore refining is a complex chemical and physical process, the purpose of which is to extract pure lead metal from lead ore. Fire refining is one of the common methods of lead ore refining. It is to blow air, oxygen or add oxidants into the molten crude lead to oxidize the impurity metal and form oxide slag. Due to the difference in density and chemical reaction, the oxide slag and other impurities will form a slag layer, which will either float on the surface of the lead liquid (forming scum) or sink to the bottom of the lead liquid (forming bottom slag). Then, the scum and bottom slag are separated from the lead liquid by mechanical skimming or lead liquid discharge, so as to obtain high-purity lead liquid. At the same time, the separated scum and bottom slag form refining waste slag. The obtained refining waste slag also includes oxides of metals such as iron, copper, tin, antimony, arsenic, silver, silicates, sulfides of lead and other metals, and precious metals. China is the world's largest producer of lead concentrate, accounting for about 43.7% of the world's total output. Therefore, recycling these refining waste slags not only helps save resources and protect the environment, but also creates economic benefits. However, the currently commonly used methods such as pyrometallurgical recovery, wet recovery and thermal treatment-magnetic separation recovery are not efficient in recovering tin and indium elements in refining waste slag, which is not conducive to the large-scale treatment of lead ore refining waste slag. Summary of the invention

[0003] In view of the above shortcomings, the present invention discloses a method for recovering tin and indium from lead ore refining waste slag, which improves the recovery efficiency of tin and indium elements in the refining waste slag and is beneficial to the recycling of lead ore refining waste slag.

[0004] The present invention is achieved by adopting the following technical solutions: A method for recovering tin and indium from lead ore refining waste residue comprises the following steps: (1) Take the lead ore refining waste slag, add limestone and crushed coal to mix evenly, and then send it into the side-blowing furnace, then introduce oxygen-enriched air with an oxygen content of 50% and heat it to 600-700℃ for smelting for 1-2h to obtain crude lead liquid and slag, cast the crude lead liquid into ingots and send it to the electrolysis process for refining, and collect the slag for rapid cooling; the side-blowing furnace adopts oxygen-enriched side blowing for smelting, which can reduce the amount of flue gas during the smelting process; (2) taking the slag after rapid cooling in step (1), adding sulfuric acid solution and sodium dodecyl sulfate, uniformly mixing, and then feeding into a grinder for grinding to obtain slag powder, wherein the weight ratio of the slag, sulfuric acid solution and sodium dodecyl sulfate is 100:(2-3):(1-2); (3) taking the slag powder obtained in step (2), adding acid solution to the mixture to obtain a slurry for acid leaching, wherein the liquid-to-solid ratio of the acid solution to the slag powder is (10-15) L:1 kg, the acid solution is a sulfuric acid solution with a concentration of 50-100 g / L, the pressure of the acid leaching is 0.5-1.0 MPa, the acid leaching temperature is 60-80° C., the pH value of the slurry is controlled at 1.5-2.0 during the acid leaching, and the acid leaching time is 1-3 h; after the acid leaching is completed, filtering and separating to obtain a filtrate A and a filter residue B, drying and crushing the filter residue B, and then smelting and recovering the crude tin; (4) adding sodium sulfite to the filtrate A in step (3) and stirring for 10 to 20 minutes, then adding calcium carbonate to adjust the pH of the filtrate A to 4.5 to 5.5 and stirring for 45 to 60 minutes, filtering to obtain a filtrate C and a residue D; adding the acid solution in step (3) to the residue D until the pH value of the solution is 1.5 to 2.0, stirring for 10 to 30 minutes, filtering to obtain a filtrate E; adding zinc powder to the filtrate E for displacement recovery to obtain crude indium, and collecting the liquid phase after displacement to obtain a post-displacement liquid; (5) The filtrate C obtained in step (4) and the replacement solution are mixed evenly and used to prepare zinc sulfate.

[0005] As a further technical solution, in the above step (1), the weight ratio of the lead ore refining waste slag, limestone and crushed coal is 100: (5-10): (20-30). By adjusting the ratio of lead ore refining waste slag, limestone and crushed coal, the smelting effect is improved, the metal is ensured to be fully melted, which is conducive to the separation of lead from other metals, and the fluidity of the slag can be improved, thereby improving the slag making effect.

[0006] As a further technical solution, in the above step (1), the slag is rapidly cooled at a rate of 10-20°C / min. Rapid cooling destroys the internal structure of the slag, which helps to grind and crush the slag and leaching of metals such as tin and indium in the subsequent acid leaching process.

[0007] As a further technical solution, in the above step (2), the concentration of the sulfuric acid solution is 10-20%.

[0008] As a further technical solution, in the above step (2), the particle size of the slag powder is 80-100 mesh. Grinding the slag to 80-100 mesh can help the leaching of metals such as tin and indium in the subsequent acid leaching process and improve the leaching efficiency.

[0009] As a further technical solution, in the above step (3), potassium permanganate is added to the slurry during acid leaching, and the amount of potassium permanganate added is 1-3% of the weight of the slurry. Adding potassium permanganate can oxidize the existing elemental tin and form a precipitate that enters the slag, thereby improving the recovery rate of tin.

[0010] As a further technical solution, in the above step (3), the slurry is stirred at a speed of 200 to 300 r / min during acid leaching. By controlling the stirring speed, the slag powder can be fully contacted with the acid solution, thereby improving the metal leaching efficiency.

[0011] As a further technical solution, in the above step (4), sodium sulfite is added to the filtrate A in step (3) and stirred at a speed of 50 to 80 r / min for 10 to 20 minutes. The addition of sodium sulfite can reduce the residual trivalent iron in the filtrate A to divalent iron, and after adding calcium carbonate to neutralize and adjust the pH value, indium can precipitate before divalent iron, thereby avoiding the influence of iron on the precipitation of indium and improving the recovery efficiency of indium.

[0012] As a further technical solution, in the above step (5), the filtrate C obtained in step (4) and the replaced liquid are mixed evenly to obtain a mixed liquid, potassium permanganate is added to the mixed liquid and the pH value of the mixed liquid is controlled to be 5.0-5.5, after stirring for 20-30 minutes, zinc powder is added to react for 10-15 minutes, during which the pH value is controlled to be 5.0-5.5, after the reaction is completed, the reaction is filtered, and the filtered liquid phase is concentrated, crystallized, dried and crushed to prepare zinc sulfate.

[0013] Compared with the prior art, this technical solution has the following beneficial effects: 1. The present invention adopts a combination of pyrometallurgy and hydrometallurgy to treat lead ore refining waste slag, so as to fully recover tin and indium in the waste slag. First, the lead with a high content in the waste slag can be separated by pyrometallurgy, and tin and indium can be enriched in the slag. Then, the slag is crushed and acid leached. The leaching of metal indium is promoted by controlling the temperature, pressure, pH value and other conditions of the acid leaching. At the same time, tin can also be enriched in the acid leaching slag, so as to achieve the effect of recovering tin. Then, calcium carbonate is added to the leachate containing indium to adjust the pH value so that indium forms a precipitate, and the precipitate containing indium is subjected to secondary acid leaching and then zinc powder is added for replacement, so that indium is effectively recovered and the purity of indium can be improved.

[0014] 2. The method of the present invention has simple process and convenient operation, and can effectively recover metals such as lead, zinc, tin and indium in the waste residue of lead ore refining, thereby realizing resource conservation and harmless treatment of waste residue, being beneficial to protecting the environment and reducing pollution. DETAILED DESCRIPTION

[0015] The present invention is further described by the following examples, but is not intended to be limiting of the present invention. Specific experimental conditions and methods not specified in the following examples are conventional methods commonly known to those skilled in the art.

[0016] Embodiment 1:

[0017] A method for recovering tin and indium from lead ore refining waste residue comprises the following steps: (1) taking lead ore refining waste slag, adding limestone and crushed coal to mix evenly, and then feeding into a side-blown furnace, then introducing oxygen-enriched air with an oxygen content of 50% and heating to 640°C for smelting for 1.5 hours to obtain crude lead liquid and slag, casting the crude lead liquid into ingots and feeding it into an electrolysis process for refining, and collecting the slag and rapidly cooling it at a rate of 18°C / min; the weight ratio of lead ore refining waste slag, limestone and crushed coal is 100:6:25; (2) taking the slag after rapid cooling in step (1), adding a 15% sulfuric acid solution and sodium dodecyl sulfate, uniformly mixing, and then feeding into a grinder for grinding to obtain slag powder with a particle size of 85 mesh, wherein the weight ratio of the slag, the sulfuric acid solution and the sodium dodecyl sulfate is 100:2.2:1.5; (3) taking the slag powder obtained in step (2), adding acid solution to the mixture to obtain a slurry for acid leaching, wherein the liquid-to-solid ratio of the acid solution to the slag powder is 12L:1kg, the acid solution is a sulfuric acid solution with a concentration of 50-100g / L, the acid leaching pressure is 0.8MPa, the acid leaching temperature is 65°C, the pH value of the slurry is controlled at 1.8 during the acid leaching, and the acid leaching time is 2h; after the acid leaching is completed, filtering and separating to obtain a filtrate A and a filter residue B, drying and crushing the filter residue B, and then smelting and recovering the crude tin; adding potassium permanganate to the slurry during the acid leaching, and the amount of potassium permanganate added is 2% of the weight of the slurry; and stirring the slurry at a speed of 250r / min during the acid leaching; (4) adding sodium sulfite to the filtrate A in step (3) and stirring at a speed of 60 r / min for 15 min, then adding calcium carbonate to adjust the pH of the filtrate A to 5.0 and stirring for 50 min, filtering to obtain a filtrate C and a residue D; adding the acid solution in step (3) to the residue D until the pH value of the solution reaches 1.8, stirring for 15 min, filtering to obtain a filtrate E; adding zinc powder to the filtrate E for replacement recovery to obtain crude indium, and collecting the liquid phase after replacement to obtain a replacement liquid; (5) The filtrate C obtained in step (4) and the replaced liquid are mixed evenly to obtain a mixed liquid, potassium permanganate is added to the mixed liquid and the pH value of the mixed liquid is controlled to be 5.2. After stirring for 25 minutes, zinc powder is added to react for 12 minutes. The pH value is controlled at 5.2 during the reaction process. After the reaction process is completed, the mixture is filtered, and the filtered liquid phase is concentrated, crystallized, dried and crushed to prepare zinc sulfate.

[0018] Embodiment 2:

[0019] A method for recovering tin and indium from lead ore refining waste residue comprises the following steps: (1) taking lead ore refining waste slag, adding limestone and crushed coal to mix evenly, and then feeding into a side-blown furnace, then introducing oxygen-enriched air with an oxygen content of 50% and heating to 600°C for smelting for 2 hours to obtain crude lead liquid and slag, casting the crude lead liquid into ingots and feeding it into an electrolysis process for refining, and collecting the slag and rapidly cooling it at a rate of 10°C / min; the weight ratio of lead ore refining waste slag, limestone and crushed coal is 100:5:20; (2) taking the slag after rapid cooling in step (1), adding a 10% sulfuric acid solution and sodium dodecyl sulfate, uniformly mixing, and then feeding into a grinder for grinding to obtain slag powder with a particle size of 80 mesh, wherein the weight ratio of the slag, the sulfuric acid solution and the sodium dodecyl sulfate is 100:2:1; (3) taking the slag powder obtained in step (2), adding acid solution to the mixture to obtain a slurry for acid leaching, wherein the liquid-to-solid ratio of the acid solution to the slag powder is 10L:1kg, the acid solution is a sulfuric acid solution with a concentration of 50g / L, the acid leaching pressure is 0.5MPa, the acid leaching temperature is 60°C, the pH value of the slurry is controlled at 1.5 during the acid leaching, and the acid leaching time is 3h; after the acid leaching is completed, filtering and separating to obtain a filtrate A and a filter residue B, drying and crushing the filter residue B, and then smelting and recovering the crude tin; adding potassium permanganate to the slurry during the acid leaching, and the amount of potassium permanganate added is 1% of the weight of the slurry; and stirring the slurry at a speed of 200r / min during the acid leaching; (4) adding sodium sulfite to the filtrate A in step (3) and stirring at a speed of 50 r / min for 10 min, then adding calcium carbonate to adjust the pH of the filtrate A to 4.5 and stirring for 45 min, filtering to obtain a filtrate C and a residue D; adding the acid solution in step (3) to the residue D until the pH value of the solution reaches 1.5, stirring for 10 min, filtering to obtain a filtrate E; adding zinc powder to the filtrate E for replacement recovery to obtain crude indium, and collecting the liquid phase after replacement to obtain a replacement liquid; (5) The filtrate C obtained in step (4) and the replaced liquid are mixed evenly to obtain a mixed liquid, potassium permanganate is added to the mixed liquid and the pH value of the mixed liquid is controlled to be 5.0, and after stirring for 20 minutes, zinc powder is added to react for 10 minutes. During the reaction process, the pH value is controlled to be 5.0. After the reaction is completed, the mixture is filtered, and the filtered liquid phase is concentrated, crystallized, dried and crushed to prepare zinc sulfate.

[0020] Embodiment 3:

[0021] A method for recovering tin and indium from lead ore refining waste residue comprises the following steps: (1) taking lead ore refining waste slag, adding limestone and crushed coal to mix evenly, and then feeding into a side-blown furnace, then introducing oxygen-enriched air with an oxygen content of 50% and heating to 680°C for smelting for 1.5 hours to obtain crude lead liquid and slag, casting the crude lead liquid into ingots and feeding it into an electrolysis process for refining, and collecting the slag and rapidly cooling it at a rate of 12°C / min; the weight ratio of lead ore refining waste slag, limestone and crushed coal is 100:8:28; (2) taking the slag after rapid cooling in step (1), adding 18% sulfuric acid solution and sodium dodecyl sulfate, uniformly mixing, and then feeding into a grinder for grinding to obtain slag powder with a particle size of 90 mesh, wherein the weight ratio of slag, sulfuric acid solution and sodium dodecyl sulfate is 100:2.6:1.8; (3) taking the slag powder obtained in step (2), adding acid solution to obtain a slurry for acid leaching, wherein the liquid-to-solid ratio of the acid solution to the slag powder is 18L:1kg, the acid solution is a sulfuric acid solution with a concentration of 80g / L, the acid leaching pressure is 0.8MPa, the acid leaching temperature is 75°C, the pH value of the slurry is controlled at 1.8 during acid leaching, and the acid leaching time is 2.5h; after the acid leaching is completed, filtering and separating to obtain a filtrate A and a filter residue B, drying and crushing the filter residue B, and then smelting and recovering the crude tin; adding potassium permanganate to the slurry during acid leaching, and the amount of potassium permanganate added is 2.5% of the weight of the slurry; stirring the slurry at a speed of 250r / min during acid leaching; (4) adding sodium sulfite to the filtrate A in step (3) and stirring at a speed of 70 r / min for 15 min, then adding calcium carbonate to adjust the pH of the filtrate A to 4.8 and stirring for 55 min, filtering to obtain a filtrate C and a residue D; adding the acid solution in step (3) to the residue D until the pH value of the solution reaches 1.8, stirring for 20 min, filtering to obtain a filtrate E; adding zinc powder to the filtrate E for replacement recovery to obtain crude indium, and collecting the liquid phase after replacement to obtain a replacement liquid; (5) The filtrate C obtained in step (4) and the replaced liquid are mixed evenly to obtain a mixed liquid, potassium permanganate is added to the mixed liquid and the pH value of the mixed liquid is controlled to be 5.3, and after stirring for 250 minutes, zinc powder is added to react for 15 minutes. During the reaction process, the pH value is controlled at 5.3. After the reaction is completed, the mixture is filtered, and the filtered liquid phase is concentrated, crystallized, dried and crushed to prepare zinc sulfate.

[0022] Embodiment 4:

[0023] A method for recovering tin and indium from lead ore refining waste residue comprises the following steps: (1) taking lead ore refining waste slag, adding limestone and crushed coal to mix evenly, and then feeding into a side-blown furnace, then introducing oxygen-enriched air with an oxygen content of 50% and heating to 700°C for smelting for 1 hour to obtain crude lead liquid and slag, casting the crude lead liquid into ingots and feeding it into an electrolysis process for refining, and collecting the slag and rapidly cooling it at a rate of 20°C / min; the weight ratio of lead ore refining waste slag, limestone and crushed coal is 100:10:30; (2) taking the slag after rapid cooling in step (1), adding a 20% sulfuric acid solution and sodium dodecyl sulfate, uniformly mixing, and then feeding into a grinder for grinding to obtain slag powder with a particle size of 100 mesh, wherein the weight ratio of the slag, the sulfuric acid solution and the sodium dodecyl sulfate is 100:3:2; (3) taking the slag powder obtained in step (2), adding acid solution to obtain a slurry for acid leaching, wherein the liquid-to-solid ratio of the acid solution to the slag powder is 15L:1kg, the acid solution is a sulfuric acid solution with a concentration of 100g / L, the acid leaching pressure is 1.0MPa, the acid leaching temperature is 80°C, the pH value of the slurry is controlled at 2.0 during acid leaching, and the acid leaching time is 1h; after the acid leaching is completed, filtering and separating to obtain a filtrate A and a filter residue B, drying and crushing the filter residue B, and then smelting and recovering the crude tin; adding potassium permanganate to the slurry during acid leaching, and the amount of potassium permanganate added is 3% of the weight of the slurry; stirring the slurry at a speed of 300r / min during acid leaching; (4) adding sodium sulfite to the filtrate A in step (3) and stirring at a speed of 80 r / min for 10 to 20 min, then adding calcium carbonate to adjust the pH of the filtrate A to 5.5 and stirring for 60 min, filtering to obtain a filtrate C and a residue D; adding the acid solution in step (3) to the residue D until the pH value of the solution reaches 2.0, stirring for 30 min, and filtering to obtain a filtrate E; adding zinc powder to the filtrate E for displacement recovery to obtain crude indium, and collecting the liquid phase after displacement to obtain a post-displacement liquid; (5) The filtrate C obtained in step (4) and the replaced liquid are mixed evenly to obtain a mixed liquid, potassium permanganate is added to the mixed liquid and the pH value of the mixed liquid is controlled to be 5.5, after stirring for 30 minutes, zinc powder is added to react for 10 to 15 minutes, during which the pH value is controlled to be 5.5, after the reaction is completed, the reaction is filtered, and the filtered liquid phase is concentrated, crystallized, dried and crushed to prepare zinc sulfate.

[0024] Comparative Example 1: The method for recovering tin and indium from lead ore refining waste slag in this comparative example is different from the method in Example 1 only in that, in step (1), the slag obtained after smelting is naturally cooled at room temperature.

[0025] Comparative Example 2: The method for recovering tin and indium from lead ore refining waste slag in this comparative example is different from the method in Example 1 only in that in step (2), sodium dodecyl sulfate is not added when the slag is ground.

[0026] Comparative Example 3: The method for recovering tin and indium from lead ore refining waste residue in this comparative example is different from the method in Example 1 only in that, in step (3), potassium permanganate is not added during the acid leaching process.

[0027] Comparative Example 4: The method for recovering tin and indium from lead ore refining waste residue in this comparative example is different from the method in Example 1 only in that in step (4), sodium sulfite is not added to the filtrate A for treatment.

[0028] Experimental Example: The experiment was carried out with the same batch of lead ore refining slag. The main components of the lead ore refining slag are shown in Table 1; the lead ore refining slag was evenly divided into 24 portions, each 3 portions forming a group, and a total of 8 groups of samples to be processed were divided, and then a group of samples to be processed was randomly selected according to the methods in Examples 1 to 4 and Comparative Examples 1 to 4 for processing, and the recovery rates of tin and indium were detected. The specific results are shown in Table 2.

[0029] Table 1 Main components of lead ore refining slag

[0030] Table 2 Recovery rates of tin and indium obtained by different treatment methods (%)

[0031] As can be seen from the data in Table 2, the present invention adopts a combination of pyrometallurgy and hydrometallurgy to effectively recover tin and indium from lead ore refining waste slag by rapidly cooling the slag and adding sodium dodecyl sulfate, potassium permanganate, sodium sulfite and other preparations.

[0032] In addition, it should be understood that although the present specification is described according to implementation modes, not every implementation mode contains only one independent technical solution. This description of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment may also be appropriately combined to form other implementation modes that can be understood by those skilled in the art.

Claims

1. A method for recovering tin and indium from lead ore refining waste residue, characterized in that: The following steps are involved: (1) Take the lead ore refining waste slag, add limestone and crushed coal to mix evenly, and then send it into a side-blown furnace, then introduce oxygen-enriched air with an oxygen content of 50% and heat it to 600-700°C for smelting for 1-2 hours to obtain crude lead liquid and slag, cast the crude lead liquid into ingots and send it to the electrolysis process for refining, and collect the slag for rapid cooling; (2) taking the slag after rapid cooling in step (1), adding sulfuric acid solution and sodium dodecyl sulfate, uniformly mixing, and then feeding into a grinder for grinding to obtain slag powder, wherein the weight ratio of the slag, sulfuric acid solution and sodium dodecyl sulfate is 100:(2-3):(1-2); (3) taking the slag powder obtained in step (2), adding acid solution to the mixture to obtain a slurry for acid leaching, wherein the liquid-to-solid ratio of the acid solution to the slag powder is (10-15) L:1 kg, the acid solution is a sulfuric acid solution with a concentration of 50-100 g / L, the pressure of the acid leaching is 0.5-1.0 MPa, the acid leaching temperature is 60-80° C., the pH value of the slurry is controlled at 1.5-2.0 during the acid leaching, and the acid leaching time is 1-3 h; after the acid leaching is completed, filtering and separating to obtain a filtrate A and a filter residue B, drying and crushing the filter residue B, and then smelting and recovering the crude tin; (4) adding sodium sulfite to the filtrate A in step (3) and stirring for 10 to 20 minutes, then adding calcium carbonate to adjust the pH of the filtrate A to 4.5 to 5.5 and stirring for 45 to 60 minutes, filtering to obtain a filtrate C and a residue D; adding the acid solution in step (3) to the residue D until the pH value of the solution is 1.5 to 2.0, stirring for 10 to 30 minutes, filtering to obtain a filtrate E; adding zinc powder to the filtrate E for displacement recovery to obtain crude indium, and collecting the liquid phase after displacement to obtain a post-displacement liquid; (5) The filtrate C obtained in step (4) and the replacement solution are mixed evenly and used to prepare zinc sulfate.

2. The method for recovering tin and indium from lead ore refining waste according to claim 1, characterized in that: In step (1), the weight ratio of the lead ore refining waste slag, limestone and crushed coal is 100: (5-10): (20-30).

3. The method for recovering tin and indium from lead ore refining waste according to claim 1, characterized in that: In step (1), the slag is rapidly cooled at a rate of 10 to 20°C / min.

4. The method for recovering tin and indium from lead ore refining waste according to claim 1, characterized in that: In step (2), the concentration of the sulfuric acid solution is 10-20%.

5. The method for recovering tin and indium from lead ore refining waste according to claim 1, characterized in that: In step (2), the particle size of the slag powder is 80-100 mesh.

6. The method for recovering tin and indium from lead ore refining waste according to claim 1, characterized in that: In step (3), potassium permanganate is added to the slurry during acid leaching, and the amount of potassium permanganate added is 1 to 3% of the weight of the slurry.

7. The method for recovering tin and indium from lead ore refining waste according to claim 1, characterized in that: In step (3), the slurry is stirred at a speed of 200 to 300 r / min during acid leaching.

8. The method for recovering tin and indium from lead ore refining waste according to claim 1, characterized in that: In step (4), sodium sulfite is added to the filtrate A in step (3) and stirred at a speed of 50 to 80 r / min for 10 to 20 minutes.

9. The method for recovering tin and indium from lead ore refining waste according to claim 1, characterized in that: In step (5), the filtrate C obtained in step (4) and the replaced liquid are mixed uniformly to obtain a mixed liquid, potassium permanganate is added to the mixed liquid and the pH value of the mixed liquid is controlled to be 5.0-5.5, after stirring for 20-30 minutes, zinc powder is added to react for 10-15 minutes, during which the pH value is controlled to be 5.0-5.5, after the reaction is completed, the reaction is filtered, and the filtered liquid phase is concentrated, crystallized, dried and crushed to prepare zinc sulfate.

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