Efficient sorting method for refractory polymetallic ore poor in indium, tin and antimony

Abstract

The invention relates to the technical field of mineral processing, in particular to an efficient sorting method for refractory lean indium tin antimony polymetallic ore, which comprises the following steps: ore pretreatment: crushing the polymetallic ore to 10-20mm; cryogenic pretreatment is conducted, and the crushed ore is moved into a cryogenic reaction tank; unfreezing and drying: transferring the ore subjected to cryogenic freezing into a drying furnace for unfreezing and drying; superfine ore grinding is conducted, specifically, the dried ore is moved into superfine ore grinding equipment to be ground till D90 is smaller than 20 micrometers; bioleaching: blending the ore particles and water according to a solid-to-liquid ratio of 10-20% to obtain ore pulp, and adding microorganisms to obtain a leaching solution; and treatment and recovery of the leachate: filtering the leachate to separate out residue impurities, and then carrying out electrolytic deposition on the leachate to recover indium, tin and antimony metals. According to the method, the ore is subjected to high-selectivity pretreatment and leaching on indium tin antimony, multiple times of flotation are avoided, the reaction efficiency and environmental friendliness are improved, the production cost is reduced, and the production benefit is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of mineral processing, and in particular to an efficient separation method for difficult-to-separate indium-tin-antimony-poor polymetallic ores. Background Art

[0002] my country is rich in difficult-to-select polymetallic resources, among which indium and tin reserves rank among the highest in the world. However, metals such as indium, tin, and antimony are often embedded in sulfides, oxides, and silicates in the form of fine or ultrafine particles, with small particle sizes, usually between a few microns and tens of microns, and are closely embedded in minerals such as copper, zinc, and sulfur, making separation difficult. In order to achieve the goal of separating and sorting polymetallic resources in indium, tin, and antimony polymetallic ores, the existing technology requires the use of a production process of repeated flotation screening.

[0003] In the prior art, for the separation of difficult-to-separate indium-tin-antimony polymetallic ores, two methods are commonly used: hydrometallurgy of chemical beneficiation and pyrometallurgy of roasting separation. Among them, hydrometallurgy is the process of extracting metals by liquid chemical reaction. It has a good effect on the leaching of fine-grained minerals, can achieve the recovery of low-grade ores, and has little impact on the environment, but the process is relatively complex and the reaction speed is slow. Pyrometallurgy is the process of extracting metals directly from ores through high-temperature smelting and chemical reactions. It is suitable for high-grade ores, has a fast reaction speed and high production efficiency, but has a greater impact on the environment, consumes a lot of production energy, and produces harmful gases and waste slag.

[0004] Therefore, there is a need for an efficient and environmentally friendly separation method for difficult-to-separate indium-tin-antimony polymetallic ores. Summary of the invention

[0005] The main purpose of the present invention is to provide an efficient separation method for difficult-to-separate indium-tin-antimony polymetallic ores, aiming to solve the problems of low efficiency and environmental pollution in the existing separation process of difficult-to-separate indium-tin-antimony polymetallic ores.

[0006] To achieve the above object, the present invention proposes an efficient separation method for difficult-to-separate indium-tin-antimony polymetallic ore, which comprises the following steps:

[0007] Ore pretreatment, crushing polymetallic ore to 10-20mm;

[0008] Cryogenic pretreatment: the crushed ore is moved into a cryogenic reaction tank, the temperature is reduced to below -100°C, and maintained for 2 to 3 hours;

[0009] Thawing and drying: Move the deep-frozen ore into a drying furnace to thaw and dry it. The temperature in the drying furnace is raised to 90℃~110℃ and maintained for 1~2 hours.

[0010] Ultrafine grinding: the dried ore is moved into the ultrafine grinding equipment and the ore is ground to a D90 less than 20 μm to obtain ore particles;

[0011] Bioleaching, mixing ore particles with water, preparing a slurry with a solid-liquid ratio of 10-20% and maintaining the slurry temperature at 28-35°C and pH between 1.5 and 2.3, then adding Thiobacillus ferrooxidans and Thiobacillus thiooxidans, aerating and stirring for 7-14 days to obtain a leaching solution;

[0012] Leachate treatment and recovery: filter the leachate to separate the residual impurities, then electrolyze the leachate to recover indium, tin and antimony metals.

[0013] Furthermore, the ore pretreatment step of crushing the polymetallic ore to 10-20 mm comprises:

[0014] The polymetallic ore is subjected to primary crushing, and the polymetallic ore is crushed into 50 mm to 100 mm by a primary crusher;

[0015] The polymetallic ore after primary crushing is subjected to secondary crushing, and the polymetallic ore is crushed into 10-20 mm by a secondary crusher;

[0016] The polymetallic ore after secondary crushing is screened, and the polymetallic ore larger than 20 mm is directed back to the secondary crusher through a vibrating screen for further crushing, and the polymetallic ore smaller than 10 mm is stored in a storage container for future use.

[0017] Furthermore, the cryogenic pretreatment, in which the crushed ore is moved into a cryogenic reaction tank and the temperature is lowered to below -100°C and maintained for 2 to 3 hours, comprises the following steps:

[0018] Move the 10-20 mm polymetallic ore into the drying equipment, set the temperature at 80-100°C, and dry for 2-4 hours;

[0019] The dried polymetallic ore is transferred into a cryogenic reaction tank until the filling rate of the polymetallic ore reaches 75%;

[0020] Perform a leak test on the cryogenic reaction tank. After the leak test is completed, slowly inject liquid nitrogen into the cryogenic reaction tank until the temperature inside the cryogenic reaction tank reaches -100°C to -160°C, and maintain it for 2 to 3 hours;

[0021] The liquid nitrogen supply is turned off, and the temperature in the cryogenic reaction tank is slowly raised to room temperature through hot air circulation. During the heating process, the nitrogen is discharged through the exhaust valve.

[0022] Furthermore, the thawing and drying step includes moving the deep-frozen ore into a drying furnace for thawing and drying, and raising the temperature in the drying furnace to 90° C. to 110° C. for 1 to 2 hours. The step includes:

[0023] Mechanically tapping the polymetallic ore heated to room temperature to keep the polymetallic ore loose;

[0024] The dispersed polymetallic ore is moved into a drying furnace, and the temperature of the drying furnace is raised to 90-110°C and maintained for 1-2 hours;

[0025] The dried polymetallic ore is subjected to secondary mechanical tapping to ensure that the polymetallic ore remains loose.

[0026] Furthermore, the biological leaching comprises the steps of mixing ore particles with water, modulating the ore pulp with a solid-liquid ratio of 10 to 20%, maintaining the ore pulp temperature at 28 to 35° C., and pH between 1.5 and 2.3, adding Thiobacillus ferrooxidans and Thiobacillus thiooxidans, and aerating and stirring for 7 to 14 days to obtain the leaching solution:

[0027] Acidophilic heavy metal-resistant microorganisms are selected for cultivation, and at least one microorganism selected from Thiobacillus ferrooxidans and Thiobacillus thiooxidans is selected, and the microorganism is placed in a culture medium, and cultured at a temperature of 28 to 32° C. and a pH value of 1.5 to 2.2 to obtain a microbial culture liquid;

[0028] Prepare ore pulp, by mixing ore particles with water at a solid-liquid ratio of 10-20% by weight, and adjust the pH value of the ore pulp to between 1.5 and 2.3;

[0029] Inoculate microorganisms, add microbial liquid into the ore pulp, and the microbial liquid accounts for 5-10% of the total mass of the ore pulp;

[0030] The slurry temperature is maintained at 28-35°C, oxygen is provided at a ventilation rate of 0.5-1.3 L / min*L, stirring is performed at a speed of 200-300 rpm, and the reaction is performed for 7-14 days to obtain a leaching solution.

[0031] Furthermore, the leachate treatment and recovery, filtering the leachate to separate the residual impurities, and then electrolytically depositing the leachate to recover the indium, tin, and antimony metals, comprises:

[0032] The leaching solution is transferred to an electrolytic cell, and calcium hydroxide is added to adjust the pH value to 3.5-4.0, so that the impurity metal forms a hydroxide precipitate, and then the impurity metal is removed by filtering;

[0033] Using at least one of 2-ethylhexyl mono-2-ethylhexyl phosphate, di(2,4,4-trimethylpentyl) dithiophosphonate, tributyl phosphate, and trioctylamine as an extractant, adding the extractant into an electrolytic cell, and stirring for 1 to 1.5 hours;

[0034] Use 5 mol / L hydrochloric acid as the stripping agent, put the stripping agent into the electrolytic cell and let it stand for 0.5 to 2 hours;

[0035] Adding an acidic pH regulator into the electrolytic cell to adjust the pH of the leaching solution to 0.5-2;

[0036] Select one of stainless steel plate, lead plate, copper plate as cathode, graphite as anode, and pass 200-500A / m 2 The current is used for electrolysis;

[0037] After the electrolysis is completed, the metal deposits are stripped from the cathode plate to recover the indium, tin and antimony metals.

[0038] Furthermore, the efficient separation method for difficult-to-separate indium-tin-antimony polymetallic ores also includes:

[0039] Residue treatment: harmless treatment of the residue and recovery of residual valuable metals in the residue;

[0040] Wastewater treatment: The wastewater generated in the process is subjected to flocculation and neutralization treatment, and the flocculated water is returned to production.

[0041] The present invention improves the separation efficiency by combining cryogenic pretreatment and bioleaching. Cryogenic pretreatment causes microcracks in the minerals by taking advantage of the difference in thermal contraction coefficients of the minerals, thereby improving the grinding and separation efficiency, and is particularly suitable for processing ores with fine particle sizes and complex embeddings; bioleaching utilizes specific microorganisms to leach the ores, accelerates the leaching process, and is highly targeted, avoiding the need for multiple flotation separations to separate different metals, thereby improving production efficiency and environmental friendliness, reducing production costs, and improving production benefits. DETAILED DESCRIPTION

[0042] The technical solutions in the embodiments of the present invention are described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0043] It should be noted that all directional indications in the embodiments of the present invention (such as up, down, left, right, front, back, etc.) are only used to explain the relative position relationship, movement status, etc. between the components in a certain specific posture. If the specific posture changes, the directional indication will also change accordingly.

[0044] In addition, the descriptions of "first", "second", etc. in the present invention are only used for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In addition, the technical solutions between the various embodiments can be combined with each other, but they must be based on the ability of ordinary technicians in the field to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0045] The cryogenic pretreatment involved in the present invention refers to treating the ore material in a low-temperature environment, and reducing the ore temperature to a certain threshold by using liquid nitrogen or other low-temperature media. During this process, the physical properties of the ore change, and some components in the ore undergo phase changes or structural changes, which changes the brittleness and density of the ore, making the ore material easier to break, which is convenient for subsequent crushing and sorting.

[0046] The bioleaching method involved in the present invention, also known as biomineralization, is a method of recovering metals by dissolving metal elements in ores into liquid under suitable conditions using specific microorganisms (such as bacteria, fungi, etc.). This method has significant advantages in terms of environmental friendliness, economic benefits and resource recovery.

[0047] The primary crusher and secondary crusher involved in the present invention can be selected as one of a jaw crusher and a cone crusher. In detail, the operator breaks the large pieces of ore after mining into 50mm-100mm. The ore after primary screening is then transported to the secondary crusher by the operator, and the ore is broken down to 10-20mm again and the ore particles after secondary crushing are screened through a vibrating screen. Screening is used to remove oversized or overfine particles to ensure uniform ore particle size for subsequent processing. The ore particles obtained after screening are used to meet the subsequent deep cold pretreatment requirements. Among them, D90 means that in a certain particle group, 90% of the particles have a diameter less than or equal to this value.

[0048] Based on this, the present invention discloses an efficient separation method for difficult-to-separate indium-tin-antimony polymetallic ores. The present invention has application examples 1-3 and comparative examples 1 and 2 using the prior art, wherein comparative example 1 uses the pyrometallurgical technology in the prior art as the preparation method, and comparative example 2 uses the hydrometallurgical technology in the prior art as the preparation method to separate difficult-to-separate indium-tin-antimony polymetallic ores, as follows:

[0049] (I) Specific steps of the separation method for difficult to select indium-poor tin-antimony polymetallic ores

[0050] Embodiment 1:

[0051] S10, ore pretreatment, primary crushing of the polymetallic ore, crushing the polymetallic ore to 50 mm by a primary crusher; secondary crushing of the polymetallic ore after primary crushing, crushing the polymetallic ore to 10-20 mm by a secondary crusher; screening the polymetallic ore after secondary crushing, re-guiding the polymetallic ore larger than 20 mm to the secondary crusher through a vibrating screen for further crushing, and storing the polymetallic ore smaller than 10 mm in a storage container for standby use;

[0052] S20, moving the polymetallic ore of 10 to 20 mm into a drying device, setting the temperature at 80°C, and drying for 2 hours to remove excess moisture in the ore for subsequent cryogenic treatment; moving the dried polymetallic ore into a cryogenic reaction tank until the filling rate of the polymetallic ore reaches 75%; testing the cryogenic reaction tank for leaks, and after the leak testing is completed, slowly injecting liquid nitrogen into the cryogenic reaction tank until the temperature in the cryogenic reaction tank reaches -120°C, and maintaining it for 2 hours; after 2 hours of cryogenic treatment, turning off the liquid nitrogen supply, slowly heating the temperature in the cryogenic reaction tank to room temperature through hot air circulation, and discharging nitrogen through an exhaust valve during the heating process;

[0053] S30, thawing and drying, moving the deep-frozen ore into a drying furnace for thawing and drying, raising the temperature of the drying furnace to 90°C and maintaining it for 1 hour, and mechanically tapping the polymetallic ore that has been heated to room temperature to keep the polymetallic ore loose; moving the dispersed polymetallic ore into a drying furnace again, raising the temperature in the furnace to 110°C and maintaining it for 2 hours, moving the dried ore into an ultrafine grinding device, grinding the ore until D90 is less than 20μm, and obtaining ore particles;

[0054] S40, selecting acidophilic heavy metal-resistant microorganisms for cultivation, selecting two microorganisms, Thiobacillus ferrooxidans and Thiobacillus thiooxidans, and placing the microorganisms in a culture medium, culturing at a temperature of 28 to 32° C. and a pH value of 1.5 to 2.2 to obtain a microbial culture solution; then mixing the ore particles with water at a solid-liquid ratio of 10 to 20% by weight to prepare a slurry, and adjusting the pH value of the slurry to between 1.5 and 2.3; adding the microbial culture solution to the slurry until the microbial culture solution accounts for 5% of the total mass of the slurry; maintaining the slurry temperature at 28° C., providing oxygen at a ventilation rate of 0.5 L / min*L, stirring at a speed of 200 rpm, reacting for 7 days, and obtaining a leachate;

[0055] S50, the leachate is transferred to an electrolytic cell, and calcium hydroxide is added to adjust the pH value to 3.5, so that the impurity metal forms a hydroxide precipitate, and then the impurity metal is removed by filtering; 2-ethylhexyl mono-2-ethylhexyl phosphate and di(2,4,4-trimethylpentyl) dithiophosphonate are used as extractants, the extractants are put into the electrolytic cell, and stirred for 1 hour; 5 mol / L hydrochloric acid is used as a stripping agent, the stripping agent is put into the electrolytic cell, and it is allowed to stand for 0.5 hour; an acidic pH regulator is added to the electrolytic cell to adjust the pH of the leachate to 0.5; one of a stainless steel plate, a lead plate, and a copper plate is selected as a cathode, graphite is selected as an anode, and 200-500A / m is passed through 2 After the electrolysis is completed, the metal deposits are stripped from the cathode plate to recover indium, tin and antimony metals. The current density for recovering indium is 200A / m 2 The current density when recovering tin is 300A / m 2 The current density for antimony recovery is 400A / m 2 ;

[0056] S60: Use lime milk to neutralize the solid residue and waste liquid, adjust the pH to neutral, use cement to solidify the solid residue, and perform flocculation and neutralization treatment on the waste water generated in the process. The flocculated water is then reused in production.

[0057] Embodiment 2:

[0058] S10, ore pretreatment, primary crushing of the polymetallic ore, crushing the polymetallic ore to 50 mm by a primary crusher; secondary crushing of the polymetallic ore after primary crushing, crushing the polymetallic ore to 10-20 mm by a secondary crusher; screening the polymetallic ore after secondary crushing, re-guiding the polymetallic ore larger than 20 mm to the secondary crusher through a vibrating screen for further crushing, and storing the polymetallic ore smaller than 10 mm in a storage container for standby use;

[0059] S20, moving the polymetallic ore of 10 to 20 mm into a drying device, setting the temperature at 90°C, and drying for 1 hour to remove excess moisture in the ore for subsequent cryogenic treatment; moving the dried polymetallic ore into a cryogenic reaction tank until the filling rate of the polymetallic ore reaches 75%; testing the cryogenic reaction tank for leaks, and after the leak testing is completed, slowly injecting liquid nitrogen into the cryogenic reaction tank until the temperature in the cryogenic reaction tank reaches -100°C, and maintaining it for 2 hours; after 2 hours of cryogenic treatment, turning off the liquid nitrogen supply, slowly heating the temperature in the cryogenic reaction tank to room temperature through hot air circulation, and discharging nitrogen through the exhaust valve during the heating process;

[0060] S30, thawing and drying, moving the deep-frozen ore into a drying furnace for thawing and drying, heating the drying furnace to 100°C and maintaining for 2 hours, and mechanically tapping the polymetallic ore heated to room temperature to keep the polymetallic ore loose; moving the dispersed polymetallic ore into a drying furnace again, heating the furnace to 110°C and maintaining for 1 hour, moving the dried ore into an ultrafine grinding device, grinding the ore to a D90 of less than 15 μm, and obtaining ore particles;

[0061] S40, selecting acidophilic heavy metal-resistant microorganisms for cultivation, selecting Thiobacillus ferrooxidans and placing them in a culture medium, culturing them at a temperature of 28 to 32° C. and a pH value of 1.5 to 2.2 to obtain a microbial culture solution; then mixing the ore particles with water at a solid-liquid ratio of 18% by weight to prepare a slurry, and adjusting the pH value of the slurry to between 1.5 and 2.3; adding the microbial culture solution to the slurry until the microbial culture solution accounts for 7% of the total mass of the slurry; maintaining the slurry temperature at 30° C., providing oxygen at a ventilation rate of 0.8 L / min*L, stirring at a speed of 250 rpm, reacting for 7 days, and obtaining a leachate;

[0062] S50, the leachate is transferred to an electrolytic cell, and calcium hydroxide is added to adjust the pH value to 3.5, so that the impurity metal forms a hydroxide precipitate, and then the impurity metal is removed by filtering; tributyl phosphate and trioctylamine are used as extractants, the extractants are put into the electrolytic cell, and stirred for 1.5 hours; 5 mol / L hydrochloric acid is used as a stripping agent, the stripping agent is put into the electrolytic cell, and it is allowed to stand for 1 hour; an acidic pH regulator is added to the electrolytic cell to adjust the pH of the leachate to 1; one of a stainless steel plate, a lead plate, and a copper plate is selected as a cathode, graphite is selected as an anode, and 200-500A / m is passed through 2 After the electrolysis is completed, the metal deposits are stripped from the cathode plate to recover indium, tin and antimony metals. The current density for recovering indium is 200A / m 2 The current density when recovering tin is 300A / m 2 The current density for antimony recovery is 400A / m 2 ;

[0063] S60: Use lime milk to neutralize the solid residue and waste liquid, adjust the pH to neutral, use cement to solidify the solid residue, and perform flocculation and neutralization treatment on the waste water generated in the process. The flocculated water is then reused in production.

[0064] Embodiment 3:

[0065] S10, ore pretreatment, primary crushing of the polymetallic ore, crushing the polymetallic ore to 50 mm by a primary crusher; secondary crushing of the polymetallic ore after primary crushing, crushing the polymetallic ore to 10-20 mm by a secondary crusher; screening the polymetallic ore after secondary crushing, re-guiding the polymetallic ore larger than 20 mm to the secondary crusher through a vibrating screen for further crushing, and storing the polymetallic ore smaller than 10 mm in a storage container for standby use;

[0066] S20, moving the polymetallic ore of 10 to 20 mm into a drying device, setting the temperature at 90°C, and drying for 1 hour to remove excess moisture in the ore for subsequent cryogenic treatment; moving the dried polymetallic ore into a cryogenic reaction tank until the filling rate of the polymetallic ore reaches 75%; testing the cryogenic reaction tank for leaks, and after the leak testing is completed, slowly injecting liquid nitrogen into the cryogenic reaction tank until the temperature in the cryogenic reaction tank reaches -100°C, and maintaining it for 2 hours; after 2 hours of cryogenic treatment, turning off the liquid nitrogen supply, slowly heating the temperature in the cryogenic reaction tank to room temperature through hot air circulation, and discharging nitrogen through the exhaust valve during the heating process;

[0067] S30, thawing and drying, moving the deep-frozen ore into a drying furnace for thawing and drying, heating the drying furnace to 100°C and maintaining for 2 hours, and mechanically tapping the polymetallic ore heated to room temperature to keep the polymetallic ore loose; moving the dispersed polymetallic ore into a drying furnace again, heating the furnace to 110°C and maintaining for 1 hour, moving the dried ore into an ultrafine grinding device, grinding the ore to a D90 of less than 15 μm, and obtaining ore particles;

[0068] S40, selecting acidophilic heavy metal-resistant microorganisms for cultivation, selecting Thiobacillus ferrooxidans and placing them in a culture medium, culturing them at a temperature of 28 to 32° C. and a pH value of 1.5 to 2.2 to obtain a microbial culture solution; then mixing the ore particles with water at a solid-liquid ratio of 18% by weight to prepare a slurry, and adjusting the pH value of the slurry to between 1.5 and 2.3; adding the microbial culture solution to the slurry until the microbial culture solution accounts for 7% of the total mass of the slurry; maintaining the slurry temperature at 30° C., providing oxygen at a ventilation rate of 0.8 L / min*L, stirring at a speed of 250 rpm, reacting for 7 days, and obtaining a leachate;

[0069] S50, the leachate is transferred to an electrolytic cell, and calcium hydroxide is added to adjust the pH value to 3.5, so that the impurity metal forms a hydroxide precipitate, and then the impurity metal is removed by filtering; di(2,4,4-trimethylpentyl)phosphinic acid and trioctylamine are used as extractants, the extractants are put into the electrolytic cell, and stirred for 1.5 hours; 5 mol / L hydrochloric acid is used as a stripping agent, the stripping agent is put into the electrolytic cell, and it is allowed to stand for 1 hour; an acidic pH regulator is added to the electrolytic cell to adjust the pH of the leachate to 1; one of a stainless steel plate, a lead plate, and a copper plate is selected as a cathode, graphite is selected as an anode, and 200-500A / m is passed through 2 After the electrolysis is completed, the metal deposits are stripped from the cathode plate to recover indium, tin and antimony metals. The current density for recovering indium is 200A / m 2 The current density when recovering tin is 300A / m 2 The current density for antimony recovery is 400A / m 2 ;

[0070] S60: Use lime milk to neutralize the solid residue and waste liquid, adjust the pH to neutral, use cement to solidify the solid residue, and perform flocculation and neutralization treatment on the waste water generated in the process. The flocculated water is then reused in production.

[0071] Comparative Example 1:

[0072] S1. Fuming enrichment: Mix the difficult-to-select indium, tin and antimony polymetallic ore with anthracite at a coal ratio of 45% and granulate them, and put them into the fuming furnace for fuming volatilization at a temperature of 1300°C and a volatilization time of 80 minutes. The smelting slag is sent to the solid waste treatment center to recover the coal powder and other valuable metals therein, and the volatilized smoke is collected to obtain oxygen powder, which is sent to the wet zinc smelting process;

[0073] S2, hydrometallurgy: neutrally leaching the oxygen powder enriched by fuming, adding electrolytic zinc waste liquid with initial acid of 180g / L as base liquid, adding oxygen powder at a liquid-solid ratio of 3:1, controlling the temperature at 75°C, reacting for 60min, and then adjusting the endpoint pH value to 4.5 with oxygen powder, continuing to stir for 30min and filtering, returning the supernatant after neutral leaching to neutral leaching as base liquid, and repeating this cycle once;

[0074] S3, the neutral leaching residue is put into a reaction barrel mixed with electrolytic waste liquid and 98% concentrated sulfuric acid for acid leaching, the initial acid is controlled to 250g / L, the liquid-solid ratio is 2:1, the reaction temperature is controlled at 90°C, concentrated leaching is 100min, and then water is added to the liquid-solid ratio of 4:1, and leaching is carried out for 50min. After the reaction is completed, the solution is subjected to conventional purification, indium extraction, impurity removal, replacement, and casting to obtain a crude indium product containing 98.5% indium. The leached residue (lead mud) is sent to chloride salt treatment to further recover valuable metals such as tin, antimony, lead, and silver;

[0075] S4. Chloride treatment: put the lead mud into a reaction barrel with chloride solution (sodium chloride) at a solid-liquid ratio of 3:1 for chloride leaching, control the temperature at 60°C, react for 90 minutes, filter after the reaction, and the filter residue is the antimony slag product; add 50g / L sodium sulfate to the filtrate after chloride leaching to precipitate tin, react for 45 minutes, filter, and the filter residue is tin slag, which is washed to obtain the tin slag product.

[0076] Comparative Example 2:

[0077] S1. Ore pretreatment: crush the raw ore to less than 100 mm, then further grind it to less than 20 mm by a ball mill or a rod mill, and then prepare the ore particles into a slurry with a solid-liquid ratio of 10-20%;

[0078] S2, acid leaching: using 10% by weight of concentrated sulfuric acid at a liquid-solid ratio of 5:1 (volume / weight) into the slurry, and heating to 90°C for leaching, the leaching time is 5 hours, and the slurry is stirred at a stirring rate of 300 rpm during leaching;

[0079] S3, alkali leaching: using 10% by weight of concentrated sulfuric acid at a liquid-solid ratio of 5:1 (volume / weight) into the slurry, and heating to 90°C for leaching, the leaching time is 5 hours, and the slurry is stirred at a stirring rate of 300 rpm during leaching;

[0080] S4, solid-liquid separation: the leachate is separated from the solid residue by a filter press to obtain a metal-containing leachate and solid waste residue;

[0081] S5. Metal recovery: Through electrolysis, the metal-containing leaching solution is used as the electrolyte, the stainless steel plate is used as the cathode, and the graphite is used as the anode. After the cathode and the anode are inserted into the electrolytic cell, the electrolytic cell is energized, wherein the current density is 250A / m 2 , the electrolysis temperature is 45°C, the electrolysis time is 24 hours, and indium, tin and antimony metals are electrolytically deposited;

[0082] S6. Tailings treatment: Use lime milk to neutralize solid residue and waste liquid, adjust the pH to neutral, use cement to solidify solid residue, and ensure that the treated waste liquid and solid residue meet environmental protection standards before discharge.

[0083] (II) Metal recovery rate and purity test

[0084] Among them, taking indium metal as an example, the steps are:

[0085] S1. Weigh 1g of indium metal;

[0086] S2. Dissolve indium metal in 10 ml of 1 mol / L dilute hydrochloric acid and stir until the indium metal is completely dissolved;

[0087] S3, dilute the dissolved sample solution to 100 ml;

[0088] S4. Using an inductively coupled plasma mass spectrometer (ICP-MS) to determine the concentration of indium (mg / L) and the concentration of other impurity metals (mg / L) in the solution;

[0089] S5. Calculate the indium purity according to the purity formula: indium metal purity = (indium concentration / total metal concentration)*100%.

[0090] Table 1 Metal recovery rate and purity test data

[0091]

[0092] Experimental conclusion:

[0093] Through the experimental data of the above three groups of embodiments and two groups of control embodiments, it can be seen that the process adopted by the present invention through the use of deep cold pretreatment combined with biological leaching has a higher metal recovery rate and metal purity, and can effectively avoid the waste of metal resources in the development of difficult-to-select poor indium, tin and antimony multi-metal resources.

[0094] In combination with all the above embodiments, the present invention improves the sorting efficiency by combining cryogenic pretreatment and bioleaching. Among them, cryogenic pretreatment causes microcracks in the minerals through the difference in thermal contraction coefficients of the minerals, thereby improving the grinding and sorting efficiency, and is particularly suitable for processing ores with fine particle sizes and complex embeddings. In combination with the bioleaching method, the ore is leached using specific microorganisms, which accelerates the leaching process and is highly targeted, avoiding the need for multiple flotation to separate different metals. Compared with pyrometallurgy and hydrometallurgy in the prior art, it can significantly improve production efficiency and environmental friendliness, reduce production costs, and improve production benefits.

[0095] The above description is only a preferred embodiment of the present invention, and does not limit the patent scope of the present invention. All equivalent structural changes made by using the contents of the present invention specification under the inventive concept of the present invention, or directly / indirectly applied in other related technical fields are included in the patent protection scope of the present invention.

Claims

1. An efficient separation method for difficult-to-separate indium-tin-antimony polymetallic ores, characterized in that: The following steps are involved: Ore pretreatment, crushing polymetallic ore to 10-20mm; Cryogenic pretreatment: the crushed ore is moved into a cryogenic reaction tank, the temperature is reduced to below -100°C, and maintained for 2 to 3 hours; Thawing and drying: Move the deep-frozen ore into a drying furnace to thaw and dry it. The temperature in the drying furnace is raised to 90℃~110℃ and maintained for 1~2 hours. Ultrafine grinding: the dried ore is moved into the ultrafine grinding equipment and the ore is ground to a D90 less than 20 μm to obtain ore particles; Bioleaching, mixing ore particles with water, preparing a slurry with a solid-liquid ratio of 10-20% and maintaining the slurry temperature at 28-35°C and pH between 1.5 and 2.3, then adding Thiobacillus ferrooxidans and Thiobacillus thiooxidans, aerating and stirring for 7-14 days to obtain a leaching solution; Leachate treatment and recovery: filter the leachate to separate the residual impurities, then electrolyze the leachate to recover indium, tin and antimony metals.

2. The efficient separation method for difficult-to-separate indium-tin-antimony polymetallic ores according to claim 1, characterized in that: The ore pretreatment step of crushing the polymetallic ore to 10-20 mm includes: The polymetallic ore is subjected to primary crushing, and the polymetallic ore is crushed into 50 mm to 100 mm by a primary crusher; The polymetallic ore after primary crushing is subjected to secondary crushing, and the polymetallic ore is crushed into 10-20 mm by a secondary crusher; The polymetallic ore after secondary crushing is screened, and the polymetallic ore larger than 20 mm is directed back to the secondary crusher through a vibrating screen for further crushing, and the polymetallic ore smaller than 10 mm is stored in a storage container for future use.

3. The efficient separation method for difficult-to-separate indium-tin-antimony polymetallic ores according to claim 1, characterized in that: The cryogenic pretreatment, in which the crushed ore is moved into a cryogenic reaction tank and the temperature is reduced to below -100°C and maintained for 2 to 3 hours, comprises the following steps: Move the 10-20 mm polymetallic ore into the drying equipment, set the temperature at 80-100°C, and dry for 2-4 hours; The dried polymetallic ore is transferred into a cryogenic reaction tank until the filling rate of the polymetallic ore reaches 75%; Perform a leak test on the cryogenic reaction tank. After the leak test is completed, slowly inject liquid nitrogen into the cryogenic reaction tank until the temperature inside the cryogenic reaction tank reaches -100°C to -160°C, and maintain it for 2 to 3 hours; The liquid nitrogen supply is turned off, and the temperature in the cryogenic reaction tank is slowly raised to room temperature through hot air circulation. During the heating process, the nitrogen is discharged through the exhaust valve.

4. The efficient separation method for difficult-to-separate indium-tin-antimony polymetallic ores according to claim 1, characterized in that: The thawing and drying step includes moving the deep-frozen ore into a drying furnace to thaw and dry it, and heating the drying furnace to 90° C. to 110° C. for 1 to 2 hours. The step includes: Mechanically tapping the polymetallic ore heated to room temperature to keep the polymetallic ore loose; The dispersed polymetallic ore is moved into a drying furnace, and the temperature of the drying furnace is raised to 90-110°C and maintained for 1-2 hours; The dried polymetallic ore is subjected to secondary mechanical tapping to ensure that the polymetallic ore remains loose.

5. The efficient separation method for difficult-to-separate indium-tin-antimony polymetallic ores as claimed in claim 1, characterized in that: The biological leaching comprises the steps of mixing ore particles with water, modulating the ore pulp with a solid-liquid ratio of 10-20%, maintaining the ore pulp temperature at 28-35° C., and pH between 1.5 and 2.3, adding Thiobacillus ferrooxidans and Thiobacillus thiooxidans, and aerating and stirring for 7-14 days to obtain the leaching solution: Acidophilic heavy metal-resistant microorganisms are selected for cultivation, and at least one microorganism selected from Thiobacillus ferrooxidans and Thiobacillus thiooxidans is selected, and the microorganism is placed in a culture medium, and cultured at a temperature of 28 to 32° C. and a pH value of 1.5 to 2.2 to obtain a microbial culture liquid; Prepare ore pulp, by mixing ore particles with water at a solid-liquid ratio of 10-20% by weight, and adjust the pH value of the ore pulp to between 1.5 and 2.3; Inoculate microorganisms, add microbial liquid into the ore pulp, and the microbial liquid accounts for 5-10% of the total mass of the ore pulp; The slurry temperature is maintained at 28-35°C, oxygen is provided at a ventilation rate of 0.5-1.3 L / min*L, stirring is performed at a speed of 200-300 rpm, and the reaction is performed for 7-14 days to obtain a leaching solution.

6. The efficient separation method for difficult-to-separate indium-tin-antimony polymetallic ores according to claim 1, characterized in that: The leachate treatment and recovery, filtering the leachate to separate the residual impurities, and then electrolytically depositing the leachate to recover the indium, tin, and antimony metals, comprises the following steps: The leaching solution is transferred to an electrolytic cell, and calcium hydroxide is added to adjust the pH value to 3.5-4.0, so that the impurity metal forms a hydroxide precipitate, and then the impurity metal is removed by filtering; Using at least one of 2-ethylhexyl mono-2-ethylhexyl phosphate, di(2,4,4-trimethylpentyl) dithiophosphonate, tributyl phosphate, and trioctylamine as an extractant, adding the extractant into an electrolytic cell, and stirring for 1 to 1.5 hours; Use 5 mol / L hydrochloric acid as the stripping agent, put the stripping agent into the electrolytic cell and let it stand for 0.5 to 2 hours; Adding an acidic pH regulator into the electrolytic cell to adjust the pH of the leaching solution to 0.5-2; Select one of stainless steel plate, lead plate, copper plate as cathode, graphite as anode, and pass 200-500A / m 2 The current is used for electrolysis; After the electrolysis is completed, the metal deposits are stripped from the cathode plate to recover the indium, tin and antimony metals.

7. The efficient separation method for difficult-to-separate indium-tin-antimony polymetallic ores according to claim 1, characterized in that: The efficient separation method for difficult-to-separate indium-poor-tin-antimony polymetallic ores also includes: Residue treatment: harmless treatment of the residue and recovery of residual valuable metals in the residue; Wastewater treatment: The wastewater generated in the process is subjected to flocculation and neutralization treatment, and the flocculated water is returned to production.

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