Method for preparing high-purity lead sulfate through lead zinc ore conversion driven by sulfur biological oxidation

Abstract

The invention discloses a method for preparing high-purity lead sulfate through lead-zinc ore conversion driven by biological oxidation of sulfur, and belongs to the technical field of biological metallurgy. According to the method, sulfate ions are generated in situ and mineral dissolution and lead and zinc metal ion release are promoted through the biological oxidation effect of acidophilic sulfur oxidizing bacteria on sulfur components in lead-zinc ore; and the bioleaching process of minerals is enhanced by optimizing reaction conditions (culture medium composition, pH, temperature, ore pulp concentration and the like). After leaching, Zn < 2 + > exists in a leaching solution, Pb < 2 + > reacts with SO4 < 2-> generated by sulfur biological oxidation in time to form a high-purity lead sulfate precipitate, finally, separation is performed, the precipitate is simply washed and then dried, a lead sulfate product with the purity larger than or equal to 99% is obtained, and the conversion rate gt of Pb to PbSO4 in the lead zinc ore is larger than or equal to 99%; the yield is 99.6%. Compared with a traditional acid leaching method, the method has the advantages of being low in energy consumption, small in pollution, high in metal recovery rate and excellent in product purity, and is suitable for efficient and clean utilization of lead zinc ore resources.

Description

Technical Field

[0001] The present invention belongs to the technical field of bioleaching, and specifically relates to a method for preparing high-purity lead sulfate by sulfur biooxidation-driven transformation of lead-zinc ore. Background Art

[0002] Lead-zinc ore is an important non-ferrous metal mineral resource, rich in metals such as lead (Pb), zinc (Zn), sulfur (S), and small amounts of iron (Fe), copper (Cu), silver (Ag), etc. Lead and zinc have a wide range of uses, including fields such as batteries, coatings, galvanizing, and alloys. With the development of industry, the demand for the mining and processing of lead-zinc ore is increasing day by day.

[0003] At present, the treatment technologies for lead-zinc ore mainly include pyrometallurgy, hydrometallurgy, and bioleaching technologies. Pyrometallurgical smelting reduces metal oxides in lead-zinc ore to metals through high temperatures. This method mainly includes sintering-blast furnace smelting, flash smelting, etc. The advantages of pyrometallurgical smelting are large processing capacity, but the disadvantages are high energy consumption and serious environmental pollution, especially the generation of a large amount of harmful gases such as SO2, which causes serious pollution to the environment. Hydrometallurgy extracts metals through chemical reactions in solutions. This method mainly includes leaching-electrolysis, cyanidation, etc. In hydrometallurgical smelting, lead-zinc ore is usually crushed and ground, and then leached with leaching agents such as sulfuric acid or hydrochloric acid to make the metals enter the solution. Then, the metals are separated and purified through steps such as solvent extraction, ion exchange, and electrolysis. Although hydrometallurgy is relatively environmentally friendly, the acid-base reagents used in the leaching process will corrode the equipment, and the waste liquid treatment cost is relatively high. Bioleaching is a method of using the metabolic activities of microorganisms to extract metals. This method is mainly applied to the pretreatment of low-grade ores and the extraction of metals. Compared with traditional pyrometallurgical and hydrometallurgical processes, bioleaching has the advantages of mild operating conditions, low energy consumption, and less environmental pollution.

[0004] In summary, applying bioleaching technology to the treatment of lead-zinc ore can overcome the problems of environmental pollution, high energy consumption, and low metal recovery rate existing in other treatment technologies, and is of great significance for realizing the efficient utilization of lead-zinc ore resources and environmental protection. Therefore, the present invention proposes a method for preparing high-purity lead sulfate by sulfur biooxidation-driven transformation of lead-zinc ore, providing a more environmentally friendly, efficient, and economical method for treating lead-zinc ore. Summary of the Invention

[0005] The object of the present invention is to provide a method for preparing high-purity lead sulfate by sulfur biooxidation-driven transformation of lead-zinc ore. This method utilizes the biooxidation of sulfur components (including galena PbS and sphalerite ZnS) in lead-zinc ore by acidophilic sulfur-oxidizing functional bacteria (including Acidithiobacillus thiooxidans, Acidithiobacillus caldus, etc.) to in-situ generate sulfate ions and release Pb2+ , Zn 2+ Metal ions. By regulating parameters such as the composition of the culture medium (such as nitrogen source, phosphorus source, trace elements, etc.), pH (usually controlled in the strong acidic range of 1.5 - 2.5), temperature (25 - 35 °C), and pulp concentration (10 - 20% solid content), the activity of the functional bacteria and the sulfur oxidation efficiency are optimized to accelerate the dissolution and transformation of lead-zinc ore. During the leaching process, Pb 2+ rapidly combines with SO4 2- produced by biological oxidation to form lead sulfate (PbSO4) precipitate with extremely low solubility, while Zn 2+ remains in the leaching solution due to the high solubility of its sulfate (ZnSO4). By real-time monitoring of the Pb 2+ concentration in the solution and combining with reaction kinetics control (such as stirring rate, residence time), it is ensured that Pb 2+ and SO4 2- fully contact and completely precipitate to achieve efficient separation of lead and zinc. After the leaching is completed, the PbSO4 precipitate is separated from the leaching solution containing Zn 2+ through solid-liquid separation (such as filtration, centrifugation). After the precipitate is washed with deionized water or dilute acid to remove surface adsorbed impurities, it is dried at low temperature to finally obtain a high-purity lead sulfate product. Zn 2+ in the leaching solution can be recovered by subsequent electrodeposition, solvent extraction or chemical precipitation methods to achieve efficient utilization of zinc resources.

[0006] The object of the present invention can be achieved by the following technical solutions:

[0007] A method for preparing high-purity lead sulfate by sulfur bi-oxidation-driven transformation of lead-zinc ore, which uses acidophilic sulfur-oxidizing bacteria to bi-oxidize the sulfur component in lead-zinc ore to in-situ generate sulfate ions (SO4 2- ), and promotes the dissolution of lead-zinc ore and the release of lead (Pb 2+ ) and zinc (Zn 2+ ) metal ions. Zn 2+ exists in the leaching solution, while Pb 2+ reacts with SO4 2- produced by sulfur bi-oxidation to form high-purity lead sulfate (PbSO4) precipitate.

[0008] Specifically, it includes the following steps:

[0009] (1) Pretreatment of lead-zinc ore: The lead-zinc ore is crushed, ground and sieved to obtain ore powder with a particle size ≤ 200 mesh;

[0010] (2) Bacterial activation and scale-up culture: Using sulfide ore or elemental sulfur (S 0The powder is used as an electron donor and dispersed in the basal salt (0K) medium at a certain concentration; subsequently, the selected acidophilic sulfur-oxidizing bacteria are inoculated into the culture system, and the system is placed in a constant-temperature shaker and cultured for 5-7 days under constant temperature and rotation speed conditions, and the bacteria are collected;

[0011] (3) Biological oxidation: The lead-zinc ore treated in step (1) is added to the culture solution at a certain concentration, the initial pH of the culture solution is adjusted to acidic, and then the acidophilic sulfur-oxidizing bacteria activated in step (2) are inoculated. Control the reaction temperature and oscillation speed to release the Pb in the lead-zinc ore 2+ and convert it into lead sulfate precipitate;

[0012] (4) Solid-liquid separation: After the biological oxidation reaction is completed, solid-liquid separation is carried out to obtain the leaching solution and the precipitate;

[0013] (5) Washing and filtration: The precipitated lead sulfate is washed to remove impurity ions, and then filtered to obtain a lead sulfate filter cake;

[0014] (6) Drying: The lead sulfate filter cake is dried to obtain a high-purity (purity ≥ 99%) lead sulfate product.

[0015] Furthermore, the acidophilic sulfur-oxidizing bacteria described in step (2) are selected from one or more of the following combinations: Acidithiobacillus thiooxidans, Acidithiobacillus ferrooxidans, Acidithiobacillus caldus, Sulfobacillus thermosulfidooxidans.

[0016] Furthermore, the sulfide ores with the properties of electron donors in step (2) include various metal sulfide ores such as pyrite (FeS2), chalcopyrite (CuFeS2), mackinawite (FeS), arsenopyrite (FeAsS), etc.

[0017] Furthermore, the formula of the basal salt (0K) medium in step (2) is: (NH4)2SO4, 3.0 g / L; MgSO4, 0.5 g / L; K2HPO4, 0.5 g / L; KCl, 0.1 g / L; Ca(NO3)2, 0.01 g / L.

[0018] Furthermore, the addition concentration of the electron donor during the bacteria activation process in step (2) is 8-12 g / L.

[0019] Furthermore, the initial inoculation concentration of the acidophilic sulfur-oxidizing bacteria in step (2) is 0.2×10 8 cells / mL.

[0020] Further, in step (3), the concentration of the added lead-zinc ore is 6-10 g / L; the culture medium includes 0K medium, 9K medium, Mackintosh (MAC), mineral salt medium (MSM), and acidic solution medium, and the initial pH of the culture is adjusted to 1.8-3.0.

[0021] Further, the acidic solution medium includes, but is not limited to, dilute hydrochloric acid and dilute nitric acid.

[0022] Further, in step (3), the initial inoculation concentration of the activated acidophilic sulfur-oxidizing bacteria is (0.4-1.0)×10 8 cells / mL.

[0023] Further, after inoculation in step (3), the system temperature is controlled at 30-45°C, the oscillation speed is 140-190 rpm, and the reaction time is 10-15 days.

[0024] Further, in step (5), the lead sulfate precipitate is washed with dilute sulfuric acid.

[0025] After testing, the conversion rate of Pb in the lead-zinc ore to PbSO4 can reach 99.8%.

[0026] Advantages of the present invention:

[0027] (1) High conversion efficiency: The best conversion recovery rate of lead in the lead-zinc ore reaches 99.8%, and the purity of lead sulfate reaches 99.5%, which can be directly used in high-value fields such as lead-acid batteries.

[0028] (2) Low-carbon and environmentally friendly: It replaces traditional high-temperature roasting and strong acid leaching, reduces SO2 emissions and the generation of acidic wastewater, and meets the standards of green metallurgy.

[0029] (3) By coupling sulfur bi-oxidation with the mineral dissolution-precipitation process, the present invention innovatively constructs an integrated technical system of "microbial-driven sulfur oxidation - in-situ acid and sulfate generation - lead directional precipitation - zinc liquid-phase enrichment", solves the problems of heavy pollution, high energy consumption, and low product purity in the traditional acid leaching method, and realizes the efficient, clean, and high-value utilization of lead-zinc ore resources, having important practical and promotional values. Description of the Drawings

[0030] The present invention will be further described below with reference to the accompanying drawings.

[0031] Figure 1 SEM (a diagram) and XRD (b diagram) analyses of the surface morphology and phase composition of the lead-zinc ore used in the embodiment of the present invention;

[0032] Figure 2XRD analysis of the phase composition of the precipitate after 12 days of biooxidation of lead-zinc ore by Acidithiobacillus thiooxidans in dilute sulfuric acid medium in Example 3 of the present invention;

[0033] Figure 3 SEM-EDS analysis of the surface morphology and elemental composition of the precipitate after 12 days of biooxidation of lead-zinc ore by Acidithiobacillus thiooxidans in dilute sulfuric acid medium in Example 3 of the present invention;

[0034] Figure 4 Schematic flow chart of the present invention. Detailed implementation manners

[0035] The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without any creative work shall fall within the protection scope of the present invention.

[0036] As Figure 4 shown is the schematic flow chart of the present invention, and the following embodiments are all carried out according to the Figure 4 shown process; as Figure 1 shown are the SEM and XRD diagrams of the lead-zinc ore used in the following embodiments.

[0037] Example 1

[0038] (1) Prepare the basal salt (0K) medium, and the formula of the 0K medium is as follows: (NH4)2SO4, 3.0 g / L; MgSO4, 0.5 g / L; K2HPO4, 0.5 g / L; KCl, 0.1 g / L; Ca(NO3)2, 0.01 g / L; at the same time, prepare 2 mol / L sulfuric acid solution to adjust the pH of the medium.

[0039] (2) Add the sterilized 0K medium to the reactor, control the liquid volume to account for 1 / 3 of the total volume of the reactor, and adjust the initial pH of the medium to 2.0 ± 0.1 with 2 mol / L sulfuric acid. Add the pretreated lead-zinc ore powder at a pulp concentration of 10 g / L, and inoculate the activated Acidithiobacillus thiooxidans at an inoculation concentration of 1×10 8 cells / mL.

[0040] (3) Control the constructed biooxidation system to react at a constant temperature of 30 °C and a rotation speed of 170 rpm, sample every 1 - 2 days, and analyze the Pb in the solution 2+, SO4 2- , Zn 2+ , as well as the pH and redox potential values, and record the data. After 12 days of the biological oxidation reaction, stop stirring and perform solid-liquid separation by centrifugation or membrane filtration. Wash the precipitate 1-2 times with 0.1 mol / L dilute sulfuric acid and then dry it. Finally, combine XRD and ICP-OES (determine Pb after dissolving with aqua regia 2+ , SO4 2- , etc.) to analyze the phase and elemental composition of the precipitate. The experimental results show that under this condition, the conversion rate of Pb in the lead-zinc ore to PbSO4 is 96.8%, and the purity of the formed PbSO4 is 95.6%.

[0041] Example 2

[0042] (1) Use dilute sulfuric acid as the solution medium for the biological oxidation reaction.

[0043] (2) Add sterilized deionized water to the reactor, control the liquid volume to account for 1 / 3 of the total volume of the reactor, and adjust the initial pH of the deionized water to 2.0 ± 0.1 with concentrated sulfuric acid. Add the pretreated lead-zinc ore powder at a pulp concentration of 10 g / L, and inoculate the activated Acidithiobacillus thiooxidans at an inoculation concentration of 1×10 8 cells / mL.

[0044] (3) Control the constructed biological oxidation system to react at a constant temperature of 30 °C and a rotation speed of 170 rpm. Take samples every 1-2 days to analyze Pb 2+ , SO4 2- , Zn 2+ , as well as the pH and redox potential values, and record the data. After 12 days of the biological oxidation reaction, stop stirring and perform solid-liquid separation by centrifugation or membrane filtration. Wash the precipitate 1-2 times with 0.1 mol / L dilute sulfuric acid and then dry it. Finally, combine XRD and ICP-OES (determine Pb after dissolving with aqua regia 2+ , SO4 2- , etc.) to analyze the phase and elemental composition of the precipitate. The experimental results show that under this condition, the conversion rate of Pb in the lead-zinc ore to PbSO4 is 99.6%, and the purity of the formed PbSO4 is 99.4%.

[0045] Example 3

[0046] (1) Use dilute sulfuric acid as the solution medium for the biological oxidation reaction.

[0047] (2) Add the sterilized deionized water into the reactor, control the liquid volume to account for 1 / 3 of the total volume of the reactor, and adjust the initial pH of the deionized water to 1.8 ± 0.1 with concentrated sulfuric acid. Add the pretreated lead-zinc ore powder at a pulp concentration of 10 g / L, and inoculate the activated Acidithiobacillus thiooxidans at an inoculation concentration of 1×10 8 cells / mL.

[0048] (3) Control the constructed bio-oxidation system to react under the conditions of a constant temperature of 30 °C and a rotation speed of 170 rpm. Take samples every 1 - 2 days to analyze Pb 2+ , SO4 2- , Zn 2+ in the solution, as well as the pH and redox potential values, and record the data. After 12 days of bio-oxidation reaction, stop stirring and perform solid-liquid separation by centrifugation or membrane filtration. Wash the precipitate 1 - 2 times with 0.1 mol / L dilute sulfuric acid and then dry it. As shown in Figure 2 and Figure 3 , combine XRD and ICP-OES (determine Pb 2+ , SO4 2- etc. after dissolving with aqua regia) to analyze the phase and elemental composition of the precipitate. The experimental results show that the conversion rate of Pb in the lead-zinc ore to PbSO4 under this condition is 99.8%, and the purity of the formed PbSO4 is 99.5%.

[0049] Example 4

[0050] (1) Use dilute sulfuric acid as the solution medium for the bio-oxidation reaction.

[0051] (2) Add the sterilized deionized water into the reactor, control the liquid volume to account for 1 / 3 of the total volume of the reactor, and adjust the initial pH of the deionized water to 1.8 ± 0.1 with concentrated sulfuric acid. Add the pretreated lead-zinc ore powder at a pulp concentration of 10 g / L, and inoculate the activated Acidithiobacillus thiooxidans at an inoculation concentration of 1×10 8 cells / mL.

[0052] (3) Control the constructed bio-oxidation system to react under the conditions of a constant temperature of 40 °C and a rotation speed of 170 rpm. Take samples every 1 - 2 days to analyze Pb 2+ , SO4 2- , Zn 2+, as well as the pH and redox potential values, and record the data. After 12 days of the biological oxidation reaction, stop stirring and perform solid-liquid separation by centrifugation or membrane filtration. Wash the precipitate 1-2 times with 0.1 mol / L dilute sulfuric acid and then dry it. Finally, combine XRD and ICP-OES (measure Pb after dissolving with aqua regia) 2+ , SO4 2- etc.) to analyze the phase and elemental composition of the precipitate. The experimental results show that under this condition, the conversion rate of Pb in the lead-zinc ore to PbSO4 is 89.7%, and the purity of the formed PbSO4 is 99.3%.

[0053] Example 5

[0054] (1) Use dilute sulfuric acid as the solution medium for the biological oxidation reaction.

[0055] (2) Add sterilized deionized water to the reactor, control the liquid volume to account for 1 / 3 of the total volume of the reactor, and adjust the initial pH of the deionized water to 2.5 ± 0.1 with concentrated sulfuric acid. Add the pretreated lead-zinc ore powder at a pulp concentration of 10 g / L, and inoculate the activated Acidithiobacillus thiooxidans at an inoculation concentration of 1×10 8 cells / mL.

[0056] (3) Control the constructed biological oxidation system to react under the conditions of a constant temperature of 40 °C and a rotation speed of 170 rpm. Take samples every 1-2 days to analyze Pb in the solution 2+ , SO4 2- , Zn 2+ , as well as the pH and redox potential values, and record the data. After 12 days of the biological oxidation reaction, stop stirring and perform solid-liquid separation by centrifugation or membrane filtration. Wash the precipitate 1-2 times with 0.1 mol / L dilute sulfuric acid and then dry it. Finally, combine XRD and ICP-OES (measure Pb after dissolving with aqua regia) 2+ , SO4 2- etc.) to analyze the phase and elemental composition of the precipitate. The experimental results show that under this condition, the conversion rate of Pb in the lead-zinc ore to PbSO4 is 84.3%, and the purity of the formed PbSO4 is 99.1%.

[0057] Example 6

[0058] (1) Use dilute sulfuric acid as the solution medium for the biological oxidation reaction.

[0059] (2) Add sterilized deionized water to the reactor, control the liquid volume to account for 1 / 3 of the total volume of the reactor, and adjust the initial pH of the deionized water to 1.8 ± 0.1 with concentrated sulfuric acid. Add the pretreated lead-zinc ore powder at a pulp concentration of 10 g / L, and at a concentration of 1×108 Inoculate Acidithiobacillus ferrooxidans that has been activated at an inoculation concentration of cells / mL.

[0060] (3) Control the constructed biological oxidation system to react under the conditions of a constant temperature of 30 °C and a rotation speed of 170 rpm. Take samples every 1 - 2 days to analyze Pb in the solution 2+ , SO4 2- , Zn 2+ , as well as the pH and redox potential values, and record the data. After 12 days of biological oxidation reaction, stop stirring and perform solid-liquid separation by centrifugation or membrane filtration. Wash the precipitate 1 - 2 times with 0.1 mol / L dilute sulfuric acid and then dry it. Finally, combine XRD and ICP-OES (determine Pb after dissolving with aqua regia 2+ , SO4 2- etc.) to analyze the phase and elemental composition of the precipitate. The experimental results show that under these conditions, the conversion rate of Pb in galena to PbSO4 is 99.1%, and the purity of the formed PbSO4 is 99.3%.

[0061] Example 7

[0062] (1) Use dilute sulfuric acid as the solution medium for the biological oxidation reaction.

[0063] (2) Add sterilized deionized water to the reactor, control the liquid volume to account for 1 / 3 of the total volume of the reactor, and adjust the initial pH of the deionized water to 1.8 ± 0.1 with concentrated sulfuric acid. Add pretreated galena powder at a pulp concentration of 10 g / L, and inoculate Acidithiobacillus caldus that has been activated at an inoculation concentration of 1×10 8 cells / mL.

[0064] (3) Control the constructed biological oxidation system to react under the conditions of a constant temperature of 45 °C and a rotation speed of 170 rpm. Take samples every 1 - 2 days to analyze Pb in the solution 2+ , SO4 2- , Zn 2+ , as well as the pH and redox potential values, and record the data. After 12 days of biological oxidation reaction, stop stirring and perform solid-liquid separation by centrifugation or membrane filtration. Wash the precipitate 1 - 2 times with 0.1 mol / L dilute sulfuric acid and then dry it. Finally, combine XRD and ICP-OES (determine Pb after dissolving with aqua regia 2+ , SO4 2- etc.) to analyze the phase and elemental composition of the precipitate. The experimental results show that under these conditions, the conversion rate of Pb in galena to PbSO4 is 88.6%, and the purity of the formed PbSO4 is 99.5%.

[0065] Example 8

[0066] (1) Prepare the basic salt (0K) medium, and the formulation of the 0K medium is as shown in Example 1; meanwhile, prepare 2 mol / L sulfuric acid solution for adjusting the pH of the medium.

[0067] (2) Add the sterilized 0K medium into the reactor, control the liquid volume to account for 1 / 3 of the total volume of the reactor, and adjust the initial pH of the medium to 2.0 ± 0.1 with 2 mol / L sulfuric acid. Add the pretreated lead-zinc ore powder at a pulp concentration of 10 g / L, and inoculate the activated Sulfobacillus thermosulfidooxidans at an inoculation concentration of 1×10 8 cells / mL.

[0068] (3) Control the constructed biological oxidation system to react under the conditions of a constant temperature of 45 °C and a rotation speed of 170 rpm, sample every 1 - 2 days, and analyze Pb 2+ , SO4 2- , Zn 2+ in the solution, as well as the pH and redox potential values, and record the data. After 12 days of biological oxidation reaction, stop stirring, and perform solid-liquid separation by centrifugation or membrane filtration. Wash the precipitate 1 - 2 times with 0.1 mol / L dilute sulfuric acid and then dry it. Finally, analyze the phase and elemental composition of the precipitate by combining XRD and ICP-OES (determine Pb 2+ , SO4 2- etc. after dissolving with aqua regia). The experimental results show that the conversion rate of Pb in the lead-zinc ore to PbSO4 under this condition is 97.9%, and the purity of the formed PbSO4 is 95.1%.

[0069] Example 9

[0070] (1) Prepare the 9K medium, and the formulation of the 9K medium is as follows: (NH4)2SO4, 3.0 g / L; MgSO4, 0.5 g / L; K2HPO4, 0.5 g / L; KCl, 0.1 g / L; Ca(NO3)2, 0.01 g / L; FeSO4·7H2O, 44.7 g / L; meanwhile, prepare 2 mol / L sulfuric acid solution for adjusting the pH of the medium.

[0071] (2) Add the sterilized 0K medium into the reactor, control the liquid volume to account for 1 / 3 of the total volume of the reactor, and adjust the initial pH of the medium to 2.0 ± 0.1 with 2 mol / L sulfuric acid. Add the pretreated lead-zinc ore powder at a pulp concentration of 10 g / L, and inoculate at an inoculation concentration of 1×10 8Inoculate Acidithiobacillus thiooxidans which has been activated at an inoculation concentration of

[0072] (3) Control the constructed biological oxidation system to react under the conditions of a constant temperature of 30 °C and a rotation speed of 170 rpm. Sample every 1 - 2 days to analyze Pb 2+ , SO4 2- , Zn 2+ in the solution, as well as the pH and redox potential values, and record the data. After 12 days of biological oxidation reaction, stop stirring and perform solid-liquid separation by centrifugation or membrane filtration. Wash the precipitate 1 - 2 times with 0.1 mol / L dilute sulfuric acid and then dry it. Finally, combine XRD and ICP-OES (determine Pb 2+ , SO4 2- etc. after dissolving with aqua regia) to analyze the phase and elemental composition of the precipitate. The experimental results show that under these conditions, the conversion rate of Pb in galena to PbSO4 is 98.6%, and the purity of the formed PbSO4 is 88.9%.

[0073] Example 10

[0074] (1) Use dilute sulfuric acid as the solution medium for the biological oxidation reaction.

[0075] (2) Add sterilized deionized water to the reactor, control the liquid volume to account for 1 / 3 of the total volume of the reactor, and adjust the initial pH of the deionized water to 1.8 ± 0.1 with concentrated sulfuric acid. Add the pretreated galena powder at a pulp concentration of 10 g / L, and inoculate Acidithiobacillus caldus and Sulfobacillus thermosulfidooxidans which have been activated at an inoculation concentration of 1×10 8 cells / mL.

[0076] (3) Control the constructed biological oxidation system to react under the conditions of a constant temperature of 45 °C and a rotation speed of 170 rpm. Sample every 1 - 2 days to analyze Pb 2+ , SO4 2- , Zn 2+ in the solution, as well as the pH and redox potential values, and record the data. After 12 days of biological oxidation reaction, stop stirring and perform solid-liquid separation by centrifugation or membrane filtration. Wash the precipitate 1 - 2 times with 0.1 mol / L dilute sulfuric acid and then dry it. Combine XRD and ICP-OES (determine Pb 2+ , SO4 2-Analyze the phase and elemental composition of the precipitate (etc.). The experimental results show that under this condition, the conversion rate of Pb in the lead-zinc ore to PbSO4 is 99.2%, and the purity of the formed PbSO4 is 99.4%.

[0077] Example 11

[0078] (1) Use dilute hydrochloric acid as the solution medium for the biooxidation reaction.

[0079] (2) Add sterilized deionized water to the reactor, control the liquid volume to account for 1 / 3 of the total volume of the reactor, and adjust the initial pH of the deionized water to 1.8 ± 0.1 with concentrated hydrochloric acid. Add the pretreated lead-zinc ore powder at a pulp concentration of 10 g / L, and inoculate the activated Acidithiobacillus thiooxidans at an inoculation concentration of 1×10 8 cells / mL.

[0080] (3) Control the constructed biooxidation system to react under the conditions of a constant temperature of 30 °C and a rotation speed of 170 rpm. Take samples every 1 - 2 days to analyze Pb 2+ , Cl - , Zn 2+ in the solution, as well as the pH and redox potential values, and record the data. After 12 days of biooxidation reaction, stop stirring and perform solid-liquid separation by centrifugation or membrane filtration. Wash the precipitate 1 - 2 times with 0.1 mol / L dilute sulfuric acid and then dry it. Combine XRD and ICP-OES (measure Pb 2+ , SO4 2- etc. after dissolving with aqua regia) to analyze the phase and elemental composition of the precipitate. The experimental results show that under this condition, the conversion rate of Pb in the lead-zinc ore to PbSO4 is 52.1%, and the purity of the formed PbSO4 is 79.3%.

[0081] Comparative Example 1

[0082] (1) Prepare a basal salt (0K) medium, and the formula of the 0K medium is as shown in Example 1; at the same time, prepare a 2 mol / L sulfuric acid solution for adjusting the pH of the medium.

[0083] (2) Add the sterilized 0K medium to the reactor, control the liquid volume to account for 1 / 3 of the total volume of the reactor, and adjust the initial pH of the medium to 2.0 ± 0.1 with 2 mol / L sulfuric acid. Add the pretreated lead-zinc ore powder at a pulp concentration of 10 g / L, and no microorganisms are inoculated.

[0084] (3) Control the constructed reaction system to react under the conditions of a constant temperature of 30 °C and a rotation speed of 170 rpm. Take samples every 1 - 2 days to analyze Pb 2+ , SO42- 、Zn 2+ , as well as the pH and redox potential values, and record the data. After reacting for 12 days, stop stirring and perform solid-liquid separation by centrifugation or membrane filtration. Wash the precipitate 1-2 times with 0.1 mol / L dilute sulfuric acid and then dry it. Finally, combine XRD and ICP-OES (determine Pb after dissolving with aqua regia 2+ 、SO4 2- etc.) to analyze the phase and elemental composition of the precipitate. The experimental results show that under this condition, the conversion rate of Pb in the lead-zinc ore to PbSO4 is 4.3%, and the purity of the formed PbSO4 is 88.6%.

[0085] Comparative Example 2

[0086] (1) Prepare the basal salt (0K) medium, and the formula of the 0K medium is as shown in Example 1; at the same time, prepare a 2 mol / L sulfuric acid solution for adjusting the pH of the medium.

[0087] (2) Add the sterilized 0K medium to the reactor, control the liquid volume to account for 1 / 3 of the total volume of the reactor, and adjust the initial pH of the medium to 2.0 ± 0.1 with 2 mol / L sulfuric acid. Add the pretreated lead-zinc ore powder at a pulp concentration of 10 g / L, and no microorganisms are inoculated.

[0088] (3) Control the constructed reaction system to react under the conditions of a constant temperature of 45°C and a rotation speed of 170 rpm. Take samples every 1-2 days to analyze Pb 2+ 、SO4 2- 、Zn 2+ in the solution, as well as the pH and redox potential values, and record the data. After reacting for 12 days, stop stirring and perform solid-liquid separation by centrifugation or membrane filtration. Wash the precipitate 1-2 times with 0.1 mol / L dilute sulfuric acid and then dry it. Finally, combine XRD and ICP-OES (determine Pb 2+ 、SO4 2- etc.) to analyze the phase and elemental composition of the precipitate. The experimental results show that under this condition, the conversion rate of Pb in the lead-zinc ore to PbSO4 is 5.1%, and the purity of the formed PbSO4 is 89.3%.

[0089] Comparative Example 3

[0090] (1) Use dilute sulfuric acid as the solution medium for the biological oxidation reaction.

[0091] (2) Add the sterilized deionized water to the reactor, control the liquid volume to account for 1 / 3 of the total volume of the reactor, and adjust the initial pH of the deionized water to 1.8 ± 0.1 with concentrated sulfuric acid. Add the pretreated lead-zinc ore powder at a pulp concentration of 10 g / L, and no microorganisms are inoculated.

[0092] (3) Control the constructed reaction system to react under the conditions of a constant temperature of 30 °C and a rotation speed of 170 rpm. Sampling is carried out every 1 - 2 days to analyze Pb in the solution 2+ , SO4 2- , Zn 2+ , as well as the pH and redox potential values, and record the data. After 12 days of reaction, stop stirring and perform solid - liquid separation by centrifugation or membrane filtration. Wash the precipitate 1 - 2 times with 0.1 mol / L dilute sulfuric acid and then dry it. Finally, combine XRD and ICP - OES (determine Pb after dissolving with aqua regia 2+ , SO4 2- etc.) to analyze the phase and elemental composition of the precipitate. The experimental results show that under these conditions, the conversion rate of Pb in the lead - zinc ore to PbSO4 is 3.8%, and the purity of the formed PbSO4 is 87.4%.

[0093] Comparative Example 4

[0094] (1) Use dilute sulfuric acid as the solution medium for the biological oxidation reaction.

[0095] (2) Add sterilized deionized water to the reactor, control the liquid volume to account for 1 / 3 of the total volume of the reactor, and adjust the initial pH of the deionized water to 2.0 ± 0.1 with concentrated sulfuric acid. Add the pretreated lead - zinc ore powder at a pulp concentration of 10 g / L, and no microorganisms are inoculated.

[0096] (3) Control the constructed reaction system to react under the conditions of a constant temperature of 30 °C and a rotation speed of 170 rpm. Sampling is carried out every 1 - 2 days to analyze Pb in the solution 2+ , SO4 2- , Zn 2+ , as well as the pH and redox potential values, and record the data. After 12 days of reaction, stop stirring and perform solid - liquid separation by centrifugation or membrane filtration. Wash the precipitate 1 - 2 times with 0.1 mol / L dilute sulfuric acid and then dry it. Finally, combine XRD and ICP - OES (determine Pb after dissolving with aqua regia 2+ , SO4 2- etc.) to analyze the phase and elemental composition of the precipitate. The experimental results show that under these conditions, the conversion rate of Pb in the lead - zinc ore to PbSO4 is 3.2%, and the purity of the formed PbSO4 is 88.5%.

[0097] Comparative Example 5

[0098] (1) Prepare 9K medium, and the formula of the 9K medium is as shown in Example 9; at the same time, prepare 2 mol / L sulfuric acid solution for adjusting the pH of the medium.

[0099] (2) Add the sterilized 9K medium to the reactor, control the liquid volume to account for 1 / 3 of the total reactor volume, and adjust the initial pH of the medium to 1.8 ± 0.1 with 2 mol / L sulfuric acid. Add the pretreated lead-zinc ore powder at a pulp concentration of 10 g / L, and no microorganisms are inoculated.

[0100] (3) Control the constructed reaction system to react under the conditions of a constant temperature of 30 °C and a rotation speed of 170 rpm. Sampling is carried out every 1 - 2 days to analyze Pb 2+ , SO4 2- , Zn 2+ in the solution, as well as the pH and redox potential values, and record the data. After 12 days of reaction, stop stirring and perform solid-liquid separation by centrifugation or membrane filtration. Wash the precipitate 1 - 2 times with 0.1 mol / L dilute sulfuric acid and then dry it. Finally, combine XRD and ICP-OES (measure Pb 2+ , SO4 2- etc. after dissolving with aqua regia) to analyze the phase and elemental composition of the precipitate. The experimental results show that the conversion rate of Pb in the lead-zinc ore to PbSO4 under this condition is 6.2%, and the purity of the formed PbSO4 is 80.8%.

[0101] Comparative Example 6

[0102] (1) Use dilute sulfuric acid as the solution medium for the biological oxidation reaction.

[0103] (2) Add the sterilized deionized water to the reactor, control the liquid volume to account for 1 / 3 of the total reactor volume, and adjust the initial pH of the deionized water to 2.5 ± 0.1 with concentrated sulfuric acid. Add the pretreated lead-zinc ore powder at a pulp concentration of 10 g / L, and no microorganisms are inoculated.

[0104] (3) Control the constructed reaction system to react under the conditions of a constant temperature of 30 °C and a rotation speed of 170 rpm. Sampling is carried out every 1 - 2 days to analyze Pb 2+ , SO4 2- , Zn 2+ in the solution, as well as the pH and redox potential values, and record the data. After 12 days of reaction, stop stirring and perform solid-liquid separation by centrifugation or membrane filtration. Wash the precipitate 1 - 2 times with 0.1 mol / L dilute sulfuric acid and then dry it. Finally, combine XRD and ICP-OES (measure Pb 2+ , SO4 2- etc. after dissolving with aqua regia) to analyze the phase and elemental composition of the precipitate. The experimental results show that the conversion rate of Pb in the lead-zinc ore to PbSO4 under this condition is 2.7%, and the purity of the formed PbSO4 is 91.9%.

[0105] Comparative Example 7

[0106] (1) Use dilute hydrochloric acid as the solution medium for the biooxidation reaction.

[0107] (2) Add sterilized deionized water to the reactor, control the liquid volume to account for 1 / 3 of the total volume of the reactor, and adjust the initial pH of the deionized water to 1.8 ± 0.1 with concentrated hydrochloric acid. Add the pretreated lead-zinc ore powder at a pulp concentration of 10 g / L, and no microorganisms are introduced.

[0108] (3) Control the constructed reaction system to react under the conditions of a constant temperature of 30 °C and a rotation speed of 170 rpm. Sampling is carried out every 1 - 2 days to analyze Pb 2+ , Cl - , Zn 2+ in the solution, as well as the pH and redox potential values, and record the data. After 12 days of reaction, stop stirring, and perform solid-liquid separation by centrifugation or membrane filtration. Wash the precipitate 1 - 2 times with 0.1 mol / L dilute sulfuric acid and then dry it. As Figure 2 and Figure 3 shown, combine XRD and ICP-OES (determine Pb 2+ , SO4 2- etc. after dissolving with aqua regia) to analyze the phase and elemental composition of the precipitate. The experimental results show that the conversion rate of Pb in the lead-zinc ore to PbSO4 under this condition is 0.3%, and the purity of the formed PbSO4 is 27.6%.

[0109] Comparative Example 8

[0110] (1) Use dilute sulfuric acid as the solution medium for the biooxidation reaction.

[0111] (2) Add sterilized deionized water to the reactor, control the liquid volume to account for 1 / 3 of the total volume of the reactor, and adjust the initial pH of the deionized water to 1.8 ± 0.1 with concentrated sulfuric acid. Add the pretreated lead-zinc ore powder at a pulp concentration of 10 g / L, and no microorganisms are introduced.

[0112] (3) Control the constructed reaction system to react under the conditions of a constant temperature of 45 °C and a rotation speed of 170 rpm. Sampling is carried out every 1 - 2 days to analyze Pb 2+ , SO4 2- , Zn 2+ in the solution, as well as the pH and redox potential values, and record the data. After 12 days of reaction, stop stirring, and perform solid-liquid separation by centrifugation or membrane filtration. Wash the precipitate 1 - 2 times with 0.1 mol / L dilute sulfuric acid and then dry it. Finally, combine XRD and ICP-OES (determine Pb 2+ , SO4 2-Analyze the phase and elemental composition of the precipitate (etc.). The experimental results show that under this condition, the conversion rate of Pb in the lead-zinc ore to PbSO4 is 3.6%, and the purity of the formed PbSO4 is 92.5%.

[0113] The above specific implementation part has specifically introduced the analysis method involved in the present invention. It should be noted that the above introduction is only to help those skilled in the art better understand the method and idea of the present invention, rather than a limitation on the relevant content. Without departing from the principle of the present invention, those skilled in the art can also make appropriate adjustments or modifications to the present invention, and the above adjustments and modifications should also fall within the protection scope of the present invention.

Claims

1. A method for preparing high-purity lead sulfate by converting lead-zinc ore driven by sulfur bi-oxidation, characterized in that, Using acidophilic sulfur-oxidizing bacteria to biologically oxidize the sulfur component in lead-zinc ore, in-situ generating sulfate ions, and promoting the dissolution of lead-zinc ore and the release of lead and zinc metal ions, Zn 2+ ions are present in the leaching solution, while Pb 2+ ions react with the SO4 2- ions produced by sulfur biological oxidation to form high-purity lead sulfate precipitate.

2. The method for preparing high-purity lead sulfate by converting lead-zinc ore driven by sulfur biocatalysis according to claim 1, wherein, Specifically, it includes the following steps: (1) Pretreatment of lead-zinc ore: The lead-zinc ore is crushed, ground and sieved to obtain ore powder with a particle size ≤ 200 mesh; (2) Bacterial activation and scale-up culture: Using sulfide ore or elemental sulfur powder as an electron donor, dispersed in a basal salt medium at a certain concentration; Subsequently, the selected acidophilic sulfur-oxidizing bacteria are inoculated into the culture system, and the system is placed in a constant temperature shaker and cultured for 5-7 days under constant temperature and rotation speed conditions to collect the bacteria; (3) Biological oxidation: Add the lead-zinc ore treated in step (1) to the culture medium at a certain concentration, adjust the initial pH of the culture medium to acidic, and then inoculate the acidophilic sulfur-oxidizing bacteria activated in step (2). Control the reaction temperature and oscillation speed to release Pb in the lead-zinc ore 2+ and convert it into lead sulfate precipitate; (4) Solid-liquid separation: After the biooxidation reaction is completed, solid-liquid separation is carried out to obtain a leachate and a precipitate; (5) Washing and filtration: The precipitated lead sulfate is washed to remove impurity ions, and then filtered to obtain a lead sulfate filter cake; (6) Drying: The lead sulfate filter cake is dried to obtain a high-purity lead sulfate product.

3. A method for preparing high-purity lead sulfate by converting lead-zinc ore driven by sulfur biocatalysis according to claim 1 or 2, characterized in that, The acidophilic sulfur-oxidizing bacteria are selected from one or more of the following combinations: Thiobacillus thiooxidans, Acidithiobacillus ferrooxidans, Thermoacidophilic sulfur-oxidizing bacteria, Sulfobacillus thermosulfidooxidans.

4. A method for preparing high-purity lead sulfate by converting lead-zinc ore driven by sulfur bi-oxidation according to claim 2, characterized in that, The sulfide ore with the property of electron donor in step (2) includes one or more of pyrite, chalcopyrite, mackinawite, arsenopyrite.

5. A method for preparing high-purity lead sulfate by converting lead-zinc ore driven by sulfur bi-oxidation according to claim 2, characterized in that, The formula of the basal salt medium in step (2) is: (NH4)2SO4, 3.0 g / L; MgSO4, 0.5 g / L; K2HPO4, 0.5 g / L; KCl, 0.1 g / L; Ca(NO3)2, 0.01 g / L.

6. The method for preparing high-purity lead sulfate by converting lead-zinc ore driven by sulfur bi-oxidation according to claim 2, wherein, In step (2), the addition concentration of the electron donor in the bacterial activation process is 8-12 g / L; the initial inoculation concentration of acidophilic sulfur-oxidizing bacteria is 0.2×10 8 cells / mL.

7. A method for preparing high-purity lead sulfate by converting lead-zinc ore driven by sulfur biocatalysis according to claim 2, characterized in that, The concentration of lead-zinc ore added in step (3) is 6-10 g / L; the culture medium includes 0K medium, 9K medium, Mackintosh, mineral salt medium, acidic solution medium, and the initial pH of the culture is adjusted to 1.8-3.

0.

8. A method for preparing high-purity lead sulfate by converting lead-zinc ore driven by sulfur bi-oxidation according to claim 7, characterized in that, The acidic solution medium includes but is not limited to dilute hydrochloric acid, dilute nitric acid.

9. A method for preparing high-purity lead sulfate by converting lead-zinc ore driven by sulfur biocatalysis according to claim 2, characterized in that, In step (3), the initial inoculation concentration of the activated Acidithiobacillus thiooxidans is (0.4 - 1.0)×10 8 cells / mL; after inoculation, the system temperature is controlled at 30 - 45°C, the oscillation speed is 140 - 190 rpm, and the reaction time is 10 - 15 days.

10. A method for preparing high-purity lead sulfate by converting lead-zinc ore driven by sulfur biocatalysis according to claim 2, characterized in that, In step (5), the lead sulfate precipitate is washed with dilute sulfuric acid.

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