A method for extracting manganese and silver from oxidized manganese silver ore and acidophilic thiobacillus

Abstract

The application provides a method for extracting manganese and silver from oxidized manganese silver ore and acidophilic Thiobacillus, and the method comprises the following steps: step 1, crushing and finely grinding the oxidized manganese silver ore and reducing minerals, and then making a slurry to obtain a mineral slurry; step 2, adding sulfuric acid into the mineral slurry and performing chemical leaching, and then performing solid-liquid separation on the obtained chemical leaching product to obtain a chemical leaching residue and a manganese-rich low-acid chemical leaching liquid; step 3, inoculating the chemical leaching residue with the acidophilic Thiobacillus and then performing biological leaching, and then performing solid-liquid separation on the obtained biological leaching product to obtain a low-manganese high-acid biological leaching liquid and a silver-containing biological leaching residue; and step 4, leaching silver from the silver-containing biological leaching residue. The method provided by the application is a full-wet extraction process, and is particularly suitable for treating low-grade oxidized manganese silver ore, can help to reduce the mining boundary grade of manganese silver resources, can improve the resource utilization efficiency, and can obtain greater economic benefits, social benefits and environmental benefits.

Description

Technical Field

[0001] This invention relates to the field of metallurgical technology, and in particular to a method for extracting manganese silver from oxidized manganese silver ore and to acidophilic sulfobacterium. Background Technology

[0002] In manganese-silver ore, silver often exists as extremely fine particles encased within manganese oxide minerals. Direct leaching of silver generally results in low leaching rates, leading to challenging smelting processes, low metal recovery, and poor economic efficiency. For low-grade manganese-silver ore, Chinese research has proposed a "two-ore one-step process." This process uses pyrite, a reducing sulfide mineral, to reduce manganese-silver ore, primarily composed of pyrolusite and manganese-bearing minerals. At a relatively high reaction temperature (80-100℃), excess sulfuric acid and pyrite are added to promote the reduction of manganese oxide, thereby increasing the manganese reduction leaching efficiency and breaking the manganese mineral encapsulation of silver, thus improving the silver leaching rate to some extent. However, in this "two-ore one-step process," insufficient addition of sulfuric acid and pyrite, or excessively low reaction temperatures, leads to insufficient chemical oxidation and dissolution rates of pyrite, resulting in low sulfur oxidation rates. This reduces the actual concentration of reactants, consequently decreasing the manganese reduction leaching rate and overall reduction leaching efficiency. Therefore, excess reactants and higher reaction temperatures are required. Although the above-mentioned "two-mine one-step process" guarantees the recovery rate to a certain extent, the process has problems with poor economic and ecological benefits: (1) The large amount of materials used leads to increased costs (the large amount of sulfuric acid and pyrite used, and the insufficient effective utilization rate of pyrite and sulfuric acid will further waste resources; at the same time, due to the excessive use of sulfuric acid, the acidity of the manganese-rich solution is high and the concentration of heavy metal ions is high, so a large amount of lime, sodium carbonate, sodium hydroxide and other neutralizing agents are required in the solution purification and impurity removal stage, which leads to excessive use of reagents and increased costs); (2) The solid waste disposal process is complicated (the amount of reaction leaching residue is large, and the large amount of pyrite remaining in the leaching residue is not fully utilized, and then the acid dissolves iron due to natural weathering during the stockpiling process, which causes potential harm to the environment; at the same time, due to the use of a large amount of lime, sodium carbonate, sodium hydroxide and other neutralizing agents in the solution purification and impurity removal stage, a large amount of neutralizing residue is generated, which generates a large amount of solid waste and even hazardous waste that needs further treatment); (3) The low grade of ore leads to low unit material output value, which in turn leads to poor economic efficiency. The above-mentioned technological problems have limited the mining of oxide-type manganese silver ores, especially low-grade, fine-grained manganese silver ores, which are difficult to utilize economically. There is an urgent need to develop new low-carbon and environmentally friendly processes.

[0003] Therefore, in the field of metallurgical technology, how to extract manganese and silver from low-grade manganese-silver ore in a green and environmentally friendly manner while reducing production costs (reducing the consumption of neutralizing reagents, pyrite, sulfuric acid, and other materials) without affecting the efficient recovery of manganese and silver has become an urgent technical problem to be solved. Summary of the Invention

[0004] To address the aforementioned problems, in a first aspect, the present invention provides a method for extracting manganese silver from oxidized manganese silver ore, the method comprising:

[0005] Step 1: Crush and finely grind the oxidized manganese silver ore and the reducing minerals, then mix them into a slurry to prepare a mineral slurry;

[0006] Step 2: Add sulfuric acid to the slurry and perform chemical leaching. Separate the chemical leaching product into solid and liquid phases to obtain chemical leaching residue and manganese-rich, low-acid chemical leaching solution. The manganese-rich, low-acid chemical leaching solution is used to produce manganese products.

[0007] Step 3: After inoculating the chemical leaching residue with Sulfobacillus sp. Biometek-YM-II, bioleaching is performed. The resulting bioleaching product is subjected to solid-liquid separation to obtain a low-manganese, high-acid bioleaching solution and a silver-containing bioleaching residue. The low-manganese, high-acid bioleaching solution is returned to Step 1 and thoroughly mixed with the oxidized manganese silver ore and the reducing mineral to form the slurry in Step 1.

[0008] Step 4: Leach silver from the silver-containing bioleaching residue.

[0009] Preferably, the fine grinding involves grinding the crushed oxidized manganese silver ore and the reduced minerals to a particle size of -0.074 mm or more, with the latter accounting for more than 50%.

[0010] Preferably, the reducing mineral is pyrite, pyrrhotite, or a mixture of the two in any proportion.

[0011] Preferably, the mass ratio of the oxidized manganese silver ore to the reducing mineral is 10:(1~5).

[0012] Preferably, in step 2, the concentration of the slurry after adding sulfuric acid is 10-40% and the pH value is ≤4.00.

[0013] Preferably, during the chemical leaching process, the leaching temperature is 20 ℃ to 100 ℃, the leaching time is 3 h to 24 h, and the stirring speed is 100 r / min to 800 r / min; the manganese-rich, low-acid chemical leaching solution has a manganese concentration ≥ 70 g / L and a pH value of 3.00 to 4.00.

[0014] Preferably, in step 3, before the bioleaching, the concentration of the chemical leaching residue after inoculation with *Sulphoacidophilus* is 10-25%, and the pH value is 0.80-1.50; the inoculation amount of *Sulphoacidophilus* accounts for 1%-99% of the slurry.

[0015] Preferably, during the bioleaching process, the bioleaching temperature is 40℃~50℃, the bioleaching time is 48 h~96 h, the stirring speed is 100 r / min~600 r / min, and the aeration volume is 0.05 m³. 3 / h~0.30 m 3 / h;

[0016] In step 3, the low-manganese, high-acid bioleaching solution accounts for 20% to 100% of the total liquid volume in the slurry of step 1, and the manganese concentration in the low-manganese, high-acid bioleaching solution is ≤15 g / L, and the pH value is 0.6 to 1.50.

[0017] Preferably, the manganese-rich, low-acid chemical leaching solution is used to produce manganese products, comprising:

[0018] The manganese-rich, low-acid chemical leachate, after impurity removal, purification, and enrichment pretreatment, can be used to produce manganese sulfate, electrolytic manganese, or electrolytic manganese dioxide.

[0019] Step 4 includes:

[0020] The silver-containing bioleaching residue is slurried with calcium oxide and then leached with gold and silver leaching agents; wherein the silver cyanide leaching time is 48 h and the stirring speed of the silver cyanide leaching is 400 r / min.

[0021] Secondly, the present invention provides an acidophilic sulfobacterium, wherein the acidophilic sulfobacterium with accession number CCTCC No:M2023188 ( Sulfobacillus (spe. Biometek-YM-II) is used in the method described in the first aspect above.

[0022] Compared with the prior art, the present invention has the following advantages:

[0023] This invention provides a method for extracting manganese silver from oxidized manganese silver ore and an acidophilic sulfobacterium. The method includes: Step 1: crushing and finely grinding oxidized manganese silver ore and reducing minerals, and then preparing a slurry; Step 2: adding sulfuric acid to the slurry and performing chemical leaching, and separating the resulting chemical leaching product into solid and liquid phases to obtain chemical leaching residue and a manganese-rich, low-acid chemical leaching solution; Step 3: inoculating the chemical leaching residue with acidophilic sulfobacterium and performing bioleaching, and separating the resulting bioleaching product into solid and liquid phases to obtain a low-manganese, high-acid bioleaching solution and a silver-containing bioleaching residue; Step 4: leaching silver from the silver-containing bioleaching residue. The method provided by this invention is a fully wet extraction process, particularly suitable for processing low-grade oxidized manganese silver ore, which helps to reduce the mining cutoff grade of manganese silver resources, improves resource utilization efficiency, and achieves greater economic, social, and environmental benefits.

[0024] The method provided by this invention, through chemical-biological synergistic leaching and the introduction of specific bacteria, not only achieves efficient recovery of manganese and silver, but also effectively promotes the oxidation and dissolution of pyrite to produce acid, improves the utilization rate of pyrite, reduces the amount of sulfuric acid and pyrite added, and simultaneously reduces the amount of impurity removal reagents and neutralization reagents used in subsequent solution purification processes, reduces the residual pyrite content in the leaching residue and the subsequent treatment cost of the leaching residue, and significantly reduces the generation of solid waste and even hazardous waste (leaching residue and neutralization residue). This method features low material consumption, low production cost, no waste gas generation, low leaching residue volume, high manganese and silver recovery rate, shortened process time, reduced process energy consumption, and shortened auxiliary process flow.

[0025] By employing both chemical and biological leaching, the oxidative decomposition of reducing minerals is promoted, thereby improving the utilization rate of reducing minerals and achieving efficient recovery of manganese and silver without the need for large amounts of reducing minerals and sulfuric acid. Chemical leaching achieves initial leaching of manganese, while biological leaching achieves further leaching. First, the introduction of specific bacteria promotes the biological oxidation and dissolution of reducing minerals to produce acid, improving the utilization rate of reducing minerals and making the decomposition and oxidation of reducing minerals more thorough. This achieves efficient recovery of manganese while better breaking the encapsulation of silver and silver minerals by manganese minerals, thus achieving efficient recovery of silver. The introduction of specific bacteria not only promotes the decomposition of reducing minerals but also promotes the oxidation of reduced sulfur in the chemical reaction residue to produce acid. The sulfuric acid solution produced by oxidation is returned to the chemical leaching process (i.e., the low-manganese, high-acid bioleaching solution is returned to step 1) as a reactant in the chemical leaching reaction. This promotes the generation of sulfuric acid while improving the utilization rate of reducing minerals, thereby reducing the amount of reducing minerals and sulfuric acid used and the final amount of residue. Attached Figure Description

[0026] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0027] Figure 1 This invention provides a flowchart of a method for extracting manganese silver from oxidized manganese silver ore;

[0028] Figure 2 This is a process flow diagram of an embodiment of the present invention. Detailed Implementation

[0029] The following embodiments are provided to better understand the present invention and are not limited to the preferred embodiments described. They do not constitute a limitation on the content and scope of protection of the present invention. Any product that is the same as or similar to the present invention, derived by any person under the guidance of the present invention or by combining the features of the present invention with other prior art, falls within the protection scope of the present invention.

[0030] Specific experimental steps or conditions are not specified in the embodiments; they can be performed according to the conventional experimental steps or conditions described in the prior art. Reagents and other instruments used, unless otherwise specified, are all commercially available conventional reagent products. Furthermore, the accompanying drawings are merely illustrative diagrams of the embodiments of this disclosure and are not necessarily drawn to scale. The same reference numerals in the drawings denote the same or similar parts, and therefore, repeated descriptions of them will be omitted. Some block diagrams shown in the drawings are functional entities and do not necessarily correspond to physically or logically independent entities.

[0031] Oxidized manganese-silver ore is a mixture of one or more of the following: silver-bearing pyrolusite, silver-bearing pyrolusite, and silver-bearing cryptopotassium manganese ore. It is a type of associated mineral primarily composed of pyrolusite and pyrolusite, with silver and silver minerals mainly distributed within the manganese minerals. In existing technologies, the processing difficulties of oxidized manganese-silver ore are mainly reflected in the following aspects: the grade of valuable elements in the ore is relatively low; manganese exists in the tetravalent state, requiring a reduction process for extraction; and silver and silver minerals are encapsulated by manganese minerals, necessitating the complete removal of the manganese encapsulation to achieve silver leaching.

[0032] When extracting manganese from low-grade manganese-silver ore, the reduction leaching rate and reduction leaching percentage of manganese will decrease if the amount of sulfuric acid and pyrite added is insufficient or the reaction temperature is too low. Furthermore, the low reduction leaching rate and percentage are mainly due to the insufficient chemical oxidation and dissolution rate of pyrite, resulting in a low concentration of reactants and thus low pyrite utilization. Therefore, in the existing "two-ore one-step process," to improve the manganese recovery rate and ensure full utilization of pyrite, an excessive amount of concentrated sulfuric acid and pyrite are added, and the redox reaction is carried out at a relatively high reaction temperature (80~100℃). However, in the "two-ore one-step process," the excessive sulfuric acid added to ensure reaction rate and efficiency leads to excessively high residual acid levels in the system at the reaction endpoint. This residual acid is difficult to recover and requires further neutralization in subsequent processing of the manganese-rich solution. Furthermore, due to the low utilization rate of pyrite oxidation, the large amount of pyrite added to ensure sufficient participation in the reaction can cause environmental damage due to natural weathering. In addition, the processing conditions are more stringent, especially for fine-grained manganese-silver ores, resulting in higher energy and material consumption. For ores with many types and high impurity content, the high residual acid at the leaching endpoint leads to the dissolution of large amounts of impurities, making the purification process more complex and increasing the cost of wastewater and waste residue disposal.

[0033] In view of this, the present invention promotes the bio-oxidation of pyrite through bioleaching and the introduction of specific bacteria, especially promoting the oxidation of reduced sulfur produced during the chemical reaction into sulfuric acid, thereby further reducing the amount of pyrite and sulfuric acid added. This solves the problems of high consumption of sulfuric acid and pyrite materials, insufficient effective utilization of pyrite, and large amount of leaching residue and neutralization residue that easily cause environmental pollution in conventional processes.

[0034] Firstly, referring to Figure 1 , Figure 1 This invention provides a flowchart of a method for extracting manganese silver from oxidized manganese silver ore, the method comprising:

[0035] S101, after crushing and finely grinding the oxidized manganese silver ore and the reducing minerals, they are thoroughly mixed with the low-manganese, high-acid bioleaching solution from step 4 to prepare a slurry;

[0036] In particular, step S101 involves crushing and finely grinding oxidized manganese silver ore and reducing minerals, and then thoroughly mixing them with the low-manganese, high-acid bioleaching solution from step S104 to prepare a slurry.

[0037] Among them, oxidized manganese silver ore mainly refers to ore in which manganese minerals exist in the form of tetravalent oxides.

[0038] In specific implementation, manganese-silver ore and reducing minerals, crushed and finely ground to a density of -0.074mm or higher (50% or more), are thoroughly mixed with the low-manganese, high-acid bioleaching solution obtained in step S103 (the bioleaching solution is used for slurry preparation) to obtain a slurry. The use of bioleaching solution return not only makes reasonable use of the manganese element in the bioleaching solution but also achieves manganese enrichment, increasing the manganese concentration of the manganese-rich solution obtained from chemical leaching, which is beneficial to subsequent processes. More importantly, the existing "two-ore one-step method" requires the addition of a large amount of sulfuric acid, while in this invention, the use of low-manganese, high-acid bioleaching solution for slurry preparation utilizes the sulfuric acid within it, thereby reducing the amount of added sulfuric acid and eliminating the need for impurity removal from the bioleaching solution (the bioleaching solution is directly returned to step S101 without the need for impurity removal).

[0039] S102, sulfuric acid is added to the slurry and chemical leaching is carried out. The resulting chemical leaching product is subjected to solid-liquid separation to obtain chemical leaching residue and manganese-rich, low-acid chemical leaching solution. The manganese-rich, low-acid chemical leaching solution is used to produce manganese products.

[0040] Among them, the acid in the manganese-rich, low-acid chemical leachate is the residual acid after the reaction. The residual acid is the acid remaining after the initial added sulfuric acid and the acid in the low-manganese, high-acid biological leachate have reacted and been consumed.

[0041] In practice, under certain pH conditions (with the addition of sulfuric acid), the MnO2 in reducing minerals and manganese silver ore undergoes a redox reaction with sulfuric acid. The reducing minerals then release the Mn from the MnO2. 4＋ Restored to Mn 2＋ Thus, the reduced Mn 2＋ Dissolution yields a manganese-rich, low-acid chemical leaching solution, completing the initial leaching of manganese. The mechanisms involved in step S102, the chemical leaching process, are as follows (taking pyrite as the reducing mineral as an example, all of the following reactions are involved in the system, but their reaction rates differ):

[0042] 15MnO2+2FeS2+14H2SO4→15MnSO4+Fe2(SO4)3+14H2O (1)

[0043] 3MnO2+2FeS2+6H2SO4→3MnSO4+Fe2(SO4)3+6H2O+4S (2)

[0044] 2Fe 3+ +FeS2→3Fe 2+ +2S (3)

[0045] 2S + 3O2 + 2H2O → 2H2SO4 (4)

[0046] In the S102 process, the main reactions between the reducing minerals and MnO2 in the manganese silver ore are reactions (1) and (2). In these two redox reactions, manganese oxide is reduced and the reducing minerals are oxidized. It should be noted that in the chemical leaching process, reaction (1) is secondary and reaction (2) is primary. Therefore, the amount of manganese oxide minerals reduced per unit mass of pyrite is relatively small, and sulfur is mostly oxidized to elemental sulfur. In the chemical leaching process, reactions (3) and (4) are carried out less frequently, resulting in a low-acidity chemical leaching solution (the low acidity is also due to the reduction in the amount of acid added and the lowering of the reaction temperature in the process). Furthermore, it should be noted that sulfuric acid is both a material that directly participates in the redox reaction and the addition of sulfuric acid controls the pH, an important reaction condition, to maintain a high reaction rate. The reactant, sulfuric acid, comes from both the amount of sulfuric acid added and the sulfuric acid contained in the bioleaching solution. Therefore, in the chemical leaching process, the amount of added sulfuric acid is effectively reduced. It should be noted that in the S102 process, both manganese oxide minerals and reducing minerals do not react completely. The reactants that do not react completely in S102 need to be further reacted in S103. The main reason for the incomplete reaction of reducing minerals is that reaction (1) is less carried out.

[0047] S103, inoculate the chemical leaching residue with *Sitobacterium acidophilus* (S103). Sulfobacillus After bioleaching (spe. Biometek-YM-II), the resulting bioleaching product is subjected to solid-liquid separation to obtain a low-manganese, high-acid bioleaching solution and a silver-containing bioleaching residue; wherein, the low-manganese, high-acid bioleaching solution is returned to S101 and thoroughly mixed with the oxidized manganese silver ore and the reduced mineral to form the slurry in S101.

[0048] The taxonomic names of the above-mentioned acidophilic sulfur bacteria are: Sulfobacillus sp. Biometek-YM-II, deposited at the China Center for Type Culture Collection, Wuhan University, Wuhan, China, on February 23, 2023, with accession number CCTCC No: M2023188.

[0049] In specific implementation, in step S103, the unreacted reducing minerals and the MnO2 in the unreacted manganese-silver ore undergo a redox reaction with sulfuric acid (from added unreacted sulfuric acid and unreacted sulfuric acid in the low-manganese, high-acid bioleaching solution). MnO2 is reduced, the reducing minerals are oxidized, and the reducing minerals remove Mn from the MnO2 in the manganese-silver ore. 4＋ Restored to Mn 2＋ Thus, the reduced Mn 2＋Dissolving the manganese in sulfuric acid yields a low-manganese, high-acid bioleaching solution, at which point manganese leaching is essentially complete. It should be noted that bioleaching is also a process of leaching manganese; silver is not leached during this stage, but rather in step S104. The mechanisms involved in the bioleaching process in step S103 are as follows (using pyrite as an example, all reactions are involved, but their rates of reaction differ):

[0050] 15MnO2+2FeS2+14H2SO4→15MnSO4+Fe2(SO4)3+14H2O (1)

[0051] 3MnO2+2FeS2+6H2SO4→3MnSO4+Fe2(SO4)3+6H2O+4S (2)

[0052] 2Fe 3+ +FeS2→3Fe 2+ +2S (3)

[0053] 2S + 3O2 + 2H2O → 2H2SO4 (4)

[0054] In the process of bioleaching manganese, namely reactions (1) and (2), sulfuric acid is a reactant, so sulfuric acid still needs to be added to carry out the redox reaction to leach manganese. In this invention, the amount of sulfuric acid added in step S103 is significantly reduced.

[0055] In practice, specialized bacteria are used for bioleaching, which promotes the bio-oxidation and dissolution of reducing minerals to produce acid. This not only accelerates the decomposition of reducing minerals but also reduces the consumption of added sulfuric acid, further achieving efficient recovery of manganese and silver. By increasing the utilization rate of reducing minerals and further reducing the amount of reducing minerals and sulfuric acid added, the amount of neutralizing reagent used in the solution purification and impurity removal stage is reduced, as are the subsequent leaching residue treatment costs and inputs.

[0056] When the specific bacteria are introduced into the reaction system, firstly, the introduction of the specific bacteria promotes the bio-oxidation of the reducing mineral (pyrite FeS2) (the leaching of manganese by bacteria is indirect, not by the specific bacteria directly using their own redox properties), which improves the utilization rate of the reducing mineral (pyrite FeS2), that is, promotes the reaction (1), promotes the bioleaching of manganese by the reducing mineral, realizes the efficient recovery of manganese, and then dissolves and produces acid through bio-oxidation (2S+3O2+2H2O→2H2SO4), reducing the amount of sulfuric acid added; compared with step S102, the oxidation of the reducing mineral is more thorough, thus opening more of the manganese mineral's encapsulation of silver and silver mineral, thereby improving the utilization rate of the reducing mineral. Secondly, the specific bacteria promote the decomposition of the reducing mineral, that is, promote the reaction (3), and then obtain elemental sulfur through oxidation decomposition, and further oxidize to generate sulfuric acid; the full decomposition of the reducing mineral improves the utilization rate of the reducing mineral and further promotes the generation of sulfuric acid, reducing the amount of added sulfuric acid. The specific bacteria also promoted the oxidation of elemental sulfur in the chemical reaction residue to obtain sulfuric acid, which reduced the amount of sulfuric acid added, thus promoting the reaction (4).

[0057] The sulfuric acid obtained above is returned to the chemical leaching process for further chemical and biological leaching (i.e., the low-manganese, high-acid biological leaching solution is returned to step S101). It should be noted that during the chemical leaching process, reaction (1) proceeds less frequently; during the biological leaching process, the presence of specific bacteria promotes the progress of reaction (1).

[0058] It should be noted that the utilization rate of pyrite mainly depends on the degree of oxidation of pyrite, that is, the extent to which reactions (1) and (2) proceed, and pyrite is oxidized most thoroughly in reaction (1). Therefore, whether reaction (1) is complete or its proportion largely determines the amount of pyrite and sulfuric acid used. The higher the proportion of reaction (1) compared to reaction (2), the more fully the pyrite is utilized. In this invention, by introducing specific bacteria, the proportion of reaction (1) is increased, making reaction (1) the main component, and promoting the occurrence of reactions (3) and (4), so that the reducing mineral (pyrite FeS2) is fully utilized, thereby increasing the acid production and reducing the amount of reducing mineral and sulfuric acid added.

[0059] S104, Leaching silver from the silver-containing bioleaching residue.

[0060] In practice, since silver and silver minerals are encapsulated by manganese minerals, the manganese encapsulation needs to be completely removed to achieve silver leaching. Therefore, in this invention, steps S101-S103 extract manganese, achieving efficient manganese leaching and removing the manganese minerals' encapsulation of silver and silver minerals, creating conditions for subsequent silver leaching of the leaching residue; then, after slurry preparation, silver cyanide leaching is performed using gold and silver leaching agents to leach silver from the bioleaching residue, achieving silver leaching, i.e., step S104.

[0061] In this embodiment of the invention, through chemical-biological synergistic leaching and the introduction of specific bacteria, not only is efficient recovery of manganese and silver achieved, but also large amounts of sulfuric acid and pyrite are eliminated due to insufficient reaction and inadequate utilization of pyrite. This eliminates the need for large amounts of neutralizing reagents, avoids the generation of large amounts of solid waste or even hazardous waste (leaching residue and neutralization residue), and eliminates the environmental hazards caused by the weathering of residual pyrite. Specifically, the chemical-biological synergistic effect is as follows: ① Chemical leaching and bioleaching jointly promote the oxidative decomposition of reducing minerals (pyrite FeS2), thereby improving the utilization rate of reducing minerals and achieving efficient recovery of manganese and silver: Chemical leaching is used to reduce MnO2 to obtain Mn... 2＋ That is, reactions (1) and (2), with reaction (2) being the main one in the chemical leaching; the initial enrichment of manganese is achieved by chemical leaching. Bioleaching is performed using a specific bacterium to reduce manganese to Mn. 2＋That is, reactions (1) and (2). Due to the introduction of specific bacteria, the bio-oxidation of FeS2 is promoted, the utilization rate of FeS2 is improved, thereby reducing its dosage and the final slag volume, which promotes the progress of reaction (1). Compared with chemical leaching, the oxidation of reducing minerals is more thorough. Bioleaching achieves further enrichment of manganese and realizes efficient recovery of manganese. Since the main reaction in bioleaching is reaction (1), more of the manganese minerals can be opened to encapsulate silver and silver minerals, thereby achieving efficient recovery of silver, and thus achieving efficient recovery of manganese and silver. ② Utilization of sulfuric acid generated in the two-stage leaching process: Before the start of chemical leaching, sulfuric acid (not in large quantities) is added to maintain the rate of redox reaction. Due to the introduction of the specific bacteria, firstly, the bio-oxidation of the reducing mineral (pyrite FeS2) was promoted, which promoted the reaction (1). The elemental sulfur was oxidized to sulfuric acid by the oxidation of reduced sulfur by the specific bacteria. The sulfuric acid was returned to the chemical leaching process for chemical leaching and bio-leaching (i.e., the low-manganese high-acid bio-leaching solution was returned to step 101), thereby reducing the amount of sulfuric acid added. Secondly, the decomposition of the reducing mineral was also promoted, that is, the reaction (3) was promoted. The elemental sulfur obtained from the decomposition was oxidized and dissolved to obtain sulfuric acid, which was returned to the chemical leaching process. This not only improved the utilization rate of the reducing mineral, thereby reducing the amount of reducing mineral and the final amount of slag, but also further promoted the generation of sulfuric acid, reducing the amount of sulfuric acid added. Finally, the introduction of the specific bacteria also promoted the oxidation of elemental sulfur in the chemical reaction slag, that is, promoted the reaction (4). The sulfuric acid obtained was returned to the chemical leaching process, thereby reducing the amount of sulfuric acid added.

[0062] The method provided by this invention is a fully wet extraction process, particularly suitable for processing low-grade oxidized manganese-silver ores. This method features low material consumption, low production costs, no waste gas generation, low leaching residue, and high manganese-silver recovery rates. Besides the low dosage of added materials and reagents, the cost advantage of this invention also lies in its potential to shorten processing time, reduce process energy consumption, and shorten auxiliary processing steps. Furthermore, the method helps to lower the mining cutoff grade of manganese-silver resources, thereby improving resource utilization efficiency and achieving greater economic, social, and environmental benefits.

[0063] The invention features several advantages, including lower material consumption, specifically reduced consumption of sulfuric acid and reducing minerals. Compared to traditional processing techniques for oxidized manganese silver ore, this invention not only uses less raw material but also reduces the consumption of auxiliary materials such as neutralizing agents, impurity removal agents, and rinsing water. Furthermore, it is expected to reduce the difficulty of subsequent silver leaching slag disposal. Production costs are also lower, as it eliminates the need for excessive amounts of concentrated sulfuric acid, reducing minerals, and neutralizing agents, thereby shortening processing time, reducing energy consumption, and streamlining auxiliary processes. Finally, it produces no waste gas, unlike pyrometallurgical reduction processes and hydrometallurgical sulfur dioxide reduction processes, which both generate waste gas. The leaching residue is low, specifically because it does not require a large amount of pyrite, thus avoiding the generation of a large amount of leaching residue. In the existing "two-ore one-step method," the chemical oxidation and dissolution of pyrite requires high energy consumption and has low decomposition efficiency, resulting in the need to add excessive amounts of pyrite (generally 5 to 10 times the amount). This invention promotes the oxidative decomposition of reducing minerals and improves the utilization rate of reducing minerals by introducing specific bacteria and improving the process (from chemical leaching to chemical-biological co-leaching), thereby reducing the amount of reducing minerals used and the final residue.

[0064] It should be noted that, compared with the traditional "two-mine one-step method", the advantages of this invention are: lower addition of sulfuric acid and reducing minerals; lower final acidity in the chemical stage reaction; lower impurity content in the chemical leachate, making it easier to purify; and lower reaction temperature and shorter time for the same materials.

[0065] Preferably, the fine grinding involves grinding the crushed oxidized manganese silver ore and the reduced minerals to a particle size of -0.074 mm or more, with the latter accounting for more than 50%.

[0066] In practice, since the process used in step S102 is stirred leaching (chemical stirred leaching), the mineral material needs to be ground into powder. If the mineral material is not finely ground to a concentration of more than 50% -0.074mm, the mineral particles will be too coarse, resulting in insufficient mass transfer. Furthermore, insufficient grinding will lead to incomplete stirred leaching in the subsequent process, both of which will further affect the process efficiency.

[0067] Preferably, the reducing mineral is pyrite, pyrrhotite, or a mixture of the two in any proportion.

[0068] In practical implementation, copper and nickel sulfide minerals introduce more impurity metals, and the recovery of these metals also makes the process more complex; therefore, they are not used in this invention. In this invention, pyrite has the advantages of being widely available and easy to store; pyrrhotite has the characteristics of lower lattice energy and faster oxidation and dissolution rates.

[0069] Preferably, the mass ratio of the oxidized manganese silver ore to the reducing mineral is 10:(1~5).

[0070] In practice, if the mass ratio of oxidized manganese silver ore to reducing minerals is greater than 10:(1~5), such as 10:8, it will lead to problems such as large leaching residue that is difficult to handle, difficulty in subsequent disposal, and increased material costs.

[0071] Preferably, in step 102, the concentration of the slurry after adding sulfuric acid is 10-40% and the pH value is ≤4.00.

[0072] In practice, the pH value should be maintained at or below 4 throughout the entire chemical reaction process. Therefore, sulfuric acid can be added once or in multiple intervals. Furthermore, the concentration of the slurry is preferably 40%.

[0073] In specific implementation, the aforementioned slurry concentration refers to the concentration range that the slurry needs to reach before chemical leaching. The amount of sulfuric acid added is determined by the final pH value. In this invention, sulfuric acid is a material that directly participates in the redox reaction, and the reaction also requires a certain pH value to maintain a high reaction rate. The mass ratio of manganese silver ore to sulfuric acid is positively correlated with the manganese content in the manganese silver ore. When the manganese content is about 20%, the mass ratio of manganese silver ore to sulfuric acid is about 5:1 to 1.5. When the amount of sulfuric acid exceeds this range, it is generally considered excessive. In the "two-ore one-step method," at this manganese content, the mass ratio of manganese silver ore to sulfuric acid can reach 5:2 or even higher.

[0074] Preferably, during the chemical leaching process, the leaching temperature is 20 ℃ to 100 ℃, the leaching time is 3 h to 24 h, and the stirring speed is 100 r / min to 800 r / min; the manganese-rich, low-acid chemical leaching solution has a manganese concentration ≥ 70 g / L and a pH value of 3.00 to 4.00.

[0075] In practice, the chemical leaching temperature is further specified as 20°C to 70°C. For some more difficult-to-process materials, such as manganese minerals with finer and more complex mineral inclusions, a higher reaction temperature, such as above 70°C, is required.

[0076] In practice, the pH value of the manganese-rich solution in the existing "two-mine one-step method" can reach below 1.5, or even below 1. In this invention, the final pH value of the manganese-rich chemical leaching solution is controlled at 4, which significantly reduces the amount of neutralizing reagent required for the neutralization operation.

[0077] In this invention, for a given oxidized manganese silver mineral material, the amount of pyrite, the iron and sulfur content of pyrite, the amount of sulfuric acid added, the particle size of pyrite, the reaction temperature, and the reaction time all affect the manganese leaching rate, and there is an interaction between these factors. The reason for this interaction is that the factor that directly affects the manganese leaching rate is the oxidation and dissolution of pyrite. Any change that promotes the oxidation and dissolution of pyrite will promote the leaching of manganese, while the opposite change will inhibit the leaching of manganese.

[0078] In existing technologies, the reduction leaching rate and reduction leaching efficiency of manganese decrease when the amount of sulfuric acid and pyrite added is insufficient or the reaction temperature is too low. Furthermore, the low reduction leaching rate and efficiency are mainly due to the insufficient chemical oxidation dissolution rate and oxidation rate of pyrite, resulting in a lower concentration of reactants and thus low pyrite utilization. Therefore, in existing "two-ore one-step method," to fully utilize pyrite and improve manganese recovery, excessive amounts of concentrated sulfuric acid and pyrite, along with a high reaction temperature (100 °C), are added for the redox reaction. In this application, due to the use of chemical-biological synergistic leaching and the introduction of specific bacteria, it is unnecessary to add large amounts of sulfuric acid and reducing minerals, nor is it necessary to set the chemical leaching temperature to 100 °C.

[0079] Preferably, in step 103, before the bioleaching, the concentration of the chemical leaching residue after inoculation with *Sulphoacidophilus* is 10-25%, and the pH value is 0.80-1.50; the inoculation amount of *Sulphoacidophilus* accounts for 1%-99% of the volume of the chemical leaching residue.

[0080] In practice, the concentration of the aforementioned slurry is the range that the slurry needs to reach before bioleaching.

[0081] Preferably, during the bioleaching process, the bioleaching temperature is 40℃~50℃, the bioleaching time is 48 h~96 h, the stirring speed is 100 r / min~600 r / min, and the aeration volume is 0.05 m³. 3 / h~0.30 m 3 / h;

[0082] In step 103, the low-manganese, high-acid bioleaching solution accounts for 20% to 100% of the total liquid volume in the slurry of step 101, and the manganese concentration in the low-manganese, high-acid bioleaching solution is ≤15 g / L, and the pH value is 0.6 to 1.50.

[0083] In specific implementation, the preferred temperature for bioleaching is 45 ℃, and the preferred aeration rate during stirring is 0.1 m³. 3 / h. Since it is a bioleaching process, the entire process must be carried out within a certain pH range, at a certain temperature, and at a certain minimum. To ensure the manganese leaching rate, the slurry concentration, temperature, stirring speed, reaction time, and pH value must all be within the listed ranges throughout the entire bioleaching process.

[0084] Preferably, the manganese-rich, low-acid chemical leaching solution is used to produce manganese products, comprising:

[0085] The manganese-rich, low-acid chemical leachate, after impurity removal, purification, and enrichment pretreatment, can be used to produce manganese sulfate, electrolytic manganese, or electrolytic manganese dioxide.

[0086] Step 104 includes:

[0087] The silver-containing bioleaching residue was slurried with calcium oxide and then subjected to silver cyanide leaching with a gold and silver leaching agent; wherein the silver cyanide leaching time was 48 h and the stirring speed of the silver cyanide leaching was 400 r / min.

[0088] In practice, gold and silver leaching agents such as cyanide or thiourea can be used.

[0089] Secondly, the present invention provides an acidophilic sulfobacterium, wherein the acidophilic sulfobacterium with accession number CCTCC No:M2023188 ( Sulfobacillus *S. biometek-YM-II* is used in the method described in the first aspect above. The acidophilic sulfur bacteria ( Sulfobacillus The culture conditions for sp. Biometek-YM-II are as follows: culture temperature is 40~50℃, culture pH is 0.80~2.50, and the energy substance is a mixture composed of ferrous sulfate heptahydrate, elemental sulfur, and metal sulfide minerals in any proportion.

[0090] In this embodiment of the invention, the introduction of a specific bacterium (sulfobacillus acidophilus) promotes the bio-oxidation of reducing minerals, especially the oxidation of elemental sulfur produced during the chemical reaction into sulfuric acid, thereby further reducing the amount of reducing minerals and sulfuric acid added, and lowering the temperature of chemical leaching.

[0091] To enable those skilled in the art to better understand the present invention, the preparation method provided by the present invention will be described below through several specific embodiments.

[0092] Example 1

[0093] Reference Figure 2 , Figure 2 This is a process flow diagram of an embodiment of the present invention.

[0094] Manganese silver ore (manganese content 25.22%, silver grade 869.90 g / t) and pyrite (iron content 48.74%, sulfur content 46.44%) were crushed and finely ground to a particle size of -0.074 mm or more (more than 50%), and then thoroughly mixed with a low-manganese, high-acid bioleaching solution to prepare a slurry; the mass ratio of manganese silver ore to pyrite was 4:1.

[0095] Sulfuric acid was added to the slurry after conditioning for chemical leaching. The slurry concentration was 40%. During the chemical leaching process, the pH value was maintained at ≤4.00, the chemical leaching temperature was 80 ℃, the stirring speed was 300 r / min, the sulfuric acid dosage was 269.85 kg / t (manganese-silver ore), and the reaction time was 4 h. Stirring was carried out continuously during the chemical leaching process. After the chemical leaching was completed, solid-liquid separation was performed to obtain a manganese-rich, low-acid chemical leaching solution and a chemical leaching residue. The manganese-rich, low-acid chemical leaching solution, after pretreatment such as impurity removal, purification, and enrichment, can be used to produce manganese sulfate, electrolytic manganese, or electrolytic manganese dioxide.

[0096] Inoculate chemical leaching residue with specific microbial strains Sulfobacillus Bioleaching was performed using *S. biometek-YM-II* sp. with an inoculum size of 20% of the chemical leaching residue volume and a pulp concentration of 20% (i.e., the concentration of the chemical leaching residue after inoculation with *S. acidophilus*). Stirring was maintained throughout the bioleaching process. The pH was maintained at 0.80–1.50, the reaction temperature was controlled at 45 °C, the stirring speed was 150 r / min, and the aeration rate was 0.1 m³ / min. 3 The bioleaching time was 96 h. After leaching, solid-liquid separation was performed to obtain a silver-containing bioleaching residue and a low-manganese, high-acid bioleaching solution. The total manganese leaching rate was 98.03%, and the pH of the manganese-rich, low-acid solution was 3.51. The silver-containing bioleaching residue was leached with calcium oxide slurry and gold and silver leaching agents. The silver leaching conditions were: slurry concentration 40%, slurry pH 11.5, stirring speed 400 r / min, and leaching time 48 h. The silver leaching rate was 97.05%.

[0097] Example 2

[0098] Manganese silver ore (manganese content 25.22%, silver grade 869.90 g / t) and pyrite (iron content 48.74%, sulfur content 46.44%) were crushed and finely ground to a particle size of -0.074 mm or more (more than 50%), and then thoroughly mixed with a low-manganese, high-acid bioleaching solution to prepare a slurry; the mass ratio of manganese silver ore to pyrite was 4:0.9.

[0099] Sulfuric acid was added to the slurry after conditioning for chemical leaching. The slurry concentration was 40%, the pH was maintained at ≤4.00, the chemical leaching temperature was 80 ℃, the stirring speed was 300 r / min, the sulfuric acid dosage was 275.81 kg / t (manganese-silver ore), and the chemical leaching reaction time was 4 h. Stirring was carried out continuously during the chemical leaching process. After chemical leaching, solid-liquid separation was performed to obtain a manganese-rich, low-acid chemical leaching solution and a chemical leaching residue. The manganese-rich, low-acid chemical leaching solution, after pretreatment such as impurity removal, purification, and enrichment, can be used to produce manganese sulfate, electrolytic manganese, or electrolytic manganese dioxide.

[0100] Inoculate chemical leaching residue with specific microbial strains Sulfobacillus Bioleaching was performed using *S. biometek-YM-II* sp., with the bacterial inoculum accounting for 20% of the volume of the chemical leaching residue. The pulp concentration was 20% (i.e., the concentration of the chemical leaching residue after inoculation with *S. acidophilus*). Stirring was maintained throughout the bioleaching process. The pH was maintained at 0.80–1.50, the reaction temperature was controlled at 45 °C, the stirring speed was 150 r / min, and the aeration rate was 0.1 m³ / min. 3 The bioleaching time was 96 hours. After leaching, solid-liquid separation was performed to obtain a silver-containing bioleaching residue and a low-manganese, high-acid bioleaching solution. The total manganese leaching rate was 98.85%, and the pH of the manganese-rich, low-acid solution was 3.27. The silver-containing leaching residue was leached with calcium oxide slurry and gold and silver leaching agents. The silver leaching conditions were: slurry concentration 40%, slurry pH 11.5, stirring speed 400 r / min, and leaching time 48 hours. The silver leaching rate was 98.26%.

[0101] Comparative Example 1 (Comparative Example of Example 1)

[0102] Manganese silver ore (manganese content 25.22%, silver grade 869.90 g / t) and pyrite (iron content 48.74%, sulfur content 46.44%) were crushed and finely ground to a particle size of -0.074 mm or more (more than 50%), and then thoroughly mixed with a low-manganese, high-acid bioleaching solution to prepare a slurry; the mass ratio of manganese silver ore to pyrite was 5:2.

[0103] Sulfuric acid was added to the slurry after conditioning for chemical leaching. The slurry concentration was 40%, the chemical leaching temperature was 50 °C, the stirring speed was 300 r / min, the sulfuric acid dosage was 465.13 kg / t (manganese-silver ore), and the chemical leaching reaction time was 120 h. Stirring was carried out continuously during the chemical leaching process. After chemical leaching, solid-liquid separation was performed to obtain a manganese-rich, low-acid chemical leaching solution and a chemical leaching residue. The manganese-rich, low-acid chemical leaching solution, after pretreatment such as impurity removal, purification, and enrichment, can be used to produce manganese sulfate, electrolytic manganese, or electrolytic manganese dioxide. The total manganese leaching rate was 88.10%, and the pH of the manganese-rich solution was 0.60. The silver-containing leaching residue was leached with calcium oxide slurry and an environmentally friendly gold and silver leaching agent. The silver leaching conditions were: slurry concentration 40%, slurry pH 11.5, stirring speed 400 r / min, and leaching time 48 h. The silver leaching rate was 93.41%.

[0104] Therefore, it can be seen that in the existing technology, the leaching rate is increased by adding excess sulfuric acid.

[0105] Comparative Example 2 (Comparative Example of Example 1)

[0106] Manganese silver ore (manganese content 25.22%, silver grade 869.90 g / t) and pyrite (iron content 48.74%, sulfur content 46.44%) were crushed and finely ground to a particle size of -0.074 mm or more (more than 50%), and then thoroughly mixed with a low-manganese, high-acid bioleaching solution to prepare a slurry; the mass ratio of manganese silver ore to pyrite was 5:2.

[0107] Sulfuric acid was added to the slurry after conditioning for chemical leaching. The slurry concentration was 40%, the chemical leaching temperature was 90 °C, the stirring speed was 300 r / min, the sulfuric acid dosage was 465.13 kg / t (manganese-silver ore), and the chemical leaching reaction time was 4 h. Stirring was carried out continuously during the chemical leaching process. After chemical leaching, solid-liquid separation was performed to obtain a manganese-rich, low-acid chemical leaching solution and a chemical leaching residue. The manganese-rich, low-acid chemical leaching solution, after pretreatment such as impurity removal, purification, and enrichment, can be used to produce manganese sulfate, electrolytic manganese, or electrolytic manganese dioxide. The total manganese leaching rate was 94.27%, and the pH of the manganese-rich solution was 1.02. The silver-containing leaching residue was leached with calcium oxide slurry and an environmentally friendly gold and silver leaching agent. The silver leaching conditions were: slurry concentration 40%, slurry pH 11.5, stirring speed 400 r / min, and leaching time 48 h. The silver leaching rate was 93.41%.

[0108] Therefore, in the existing technology, the leaching rate can be further increased by adding excess sulfuric acid and then raising the leaching temperature. It should be noted that to achieve the same high leaching rate as in Examples 1 and 2, the chemical leaching temperature needs to be further increased, such as to 100°C or higher.

[0109] Example 3

[0110] Manganese silver ore (manganese content 12.08%, silver grade 628.70 g / t) and pyrite (iron content 48.74%, sulfur content 46.44%) were crushed and finely ground to a particle size of -0.074 mm or more (more than 50%), and then thoroughly mixed with a low-manganese, high-acid bioleaching solution to prepare a slurry; the mass ratio of manganese silver ore to pyrite was 10:1.

[0111] Sulfuric acid was added to the slurry after conditioning for chemical leaching. The slurry concentration was 40%. During the chemical leaching process, the pH value was maintained at ≤4.00, the chemical leaching temperature was 80 ℃, the stirring speed was 300 r / min, the sulfuric acid dosage was 151.22 kg / t (manganese-silver ore), and the reaction time was 4 h. Stirring was carried out continuously during the chemical leaching process. After the chemical leaching was completed, solid-liquid separation was performed to obtain a manganese-rich, low-acid chemical leaching solution and a chemical leaching residue. The manganese-rich, low-acid chemical leaching solution, after pretreatment such as impurity removal, purification, and enrichment, can be used to produce manganese sulfate, electrolytic manganese, or electrolytic manganese dioxide.

[0112] Inoculate chemical leaching residue with specific microbial strains Sulfobacillus Bioleaching was performed using *S. biometek-YM-II* sp. with an inoculum size of 20% of the chemical leaching residue volume and a pulp concentration of 20% (i.e., the concentration of the chemical leaching residue after inoculation with *S. acidophilus*). Stirring was maintained throughout the bioleaching process. The pH was maintained at 0.80–1.50, the reaction temperature was controlled at 45 °C, the stirring speed was 150 r / min, and the aeration rate was 0.1 m³ / min. 3 The bioleaching time was 96 h. After leaching, solid-liquid separation was performed to obtain a silver-containing bioleaching residue and a low-manganese, high-acid bioleaching solution. The total manganese leaching rate was 95.27%, and the pH of the manganese-rich, low-acid solution was 3.13. The silver-containing bioleaching residue was leached with calcium oxide slurry and gold and silver leaching agents. The silver leaching conditions were: slurry concentration 40%, slurry pH 11.5, stirring speed 400 r / min, and leaching time 48 h. The silver leaching rate was 94.68%.

[0113] Example 4

[0114] Manganese silver ore (manganese content 25.22%, silver grade 869.90 g / t) and pyrite (iron content 48.74%, sulfur content 46.44%) were crushed and finely ground to a particle size of -0.074 mm or more (more than 50%), and then thoroughly mixed with a low-manganese, high-acid bioleaching solution to prepare a slurry; the mass ratio of manganese silver ore to pyrite was 10:5.

[0115] Sulfuric acid was added to the slurry after conditioning for chemical leaching. The slurry concentration was 40%. During the chemical leaching process, the pH value was maintained at ≤4.00, the chemical leaching temperature was 80 ℃, the stirring speed was 300 r / min, the sulfuric acid dosage was 221.57 kg / t (manganese-silver ore), and the reaction time was 4 h. Stirring was carried out continuously during the chemical leaching process. After the chemical leaching was completed, solid-liquid separation was performed to obtain a manganese-rich, low-acid chemical leaching solution and a chemical leaching residue. The manganese-rich, low-acid chemical leaching solution, after pretreatment such as impurity removal, purification, and enrichment, can be used to produce manganese sulfate, electrolytic manganese, or electrolytic manganese dioxide.

[0116] Inoculate chemical leaching residue with specific microbial strains Sulfobacillus Bioleaching was performed using *S. biometek-YM-II* sp. with an inoculum size of 20% of the chemical leaching residue volume and a pulp concentration of 20% (i.e., the concentration of the chemical leaching residue after inoculation with *S. acidophilus*). Stirring was maintained throughout the bioleaching process. The pH was maintained at 0.80–1.50, the reaction temperature was controlled at 45 °C, the stirring speed was 150 r / min, and the aeration rate was 0.1 m³ / min. 3 The bioleaching time was 96 h. After leaching, solid-liquid separation was performed to obtain a silver-containing bioleaching residue and a low-manganese, high-acid bioleaching solution. The total manganese leaching rate was 99.14%, and the pH of the manganese-rich, low-acid solution was 3.34. The silver-containing bioleaching residue was leached with calcium oxide slurry and gold and silver leaching agents. The silver leaching conditions were: slurry concentration 40%, slurry pH 11.5, stirring speed 400 r / min, and leaching time 48 h. The silver leaching rate was 98.77%.

[0117] Example 5

[0118] Manganese silver ore (manganese content 25.22%, silver grade 869.90 g / t) and pyrrhotite (iron content 62.81%, sulfur content 33.67%) were crushed and finely ground to a particle size of -0.074 mm or more (more than 50%), and then thoroughly mixed with a low-manganese, high-acid bioleaching solution to prepare a slurry; the mass ratio of manganese silver ore to pyrrhotite was 5:1.

[0119] Sulfuric acid was added to the slurry after conditioning for chemical leaching. The slurry concentration was 40%. During the chemical leaching process, the pH value was maintained at ≤4.00, the chemical leaching temperature was 80 ℃, the stirring speed was 300 r / min, the sulfuric acid dosage was 311.30 kg / t (manganese-silver ore), and the reaction time was 4 h. Stirring was carried out continuously during the chemical leaching process. After the chemical leaching was completed, solid-liquid separation was performed to obtain a manganese-rich, low-acid chemical leaching solution and a chemical leaching residue. The manganese-rich, low-acid chemical leaching solution, after pretreatment such as impurity removal, purification, and enrichment, can be used to produce manganese sulfate, electrolytic manganese, or electrolytic manganese dioxide.

[0120] Inoculate chemical leaching residue with specific microbial strains Sulfobacillus Bioleaching was performed using *S. biometek-YM-II* sp. with an inoculum size of 20% of the chemical leaching residue volume and a pulp concentration of 20% (i.e., the concentration of the chemical leaching residue after inoculation with *S. acidophilus*). Stirring was maintained throughout the bioleaching process. The pH was maintained at 0.80–1.50, the reaction temperature was controlled at 45 °C, the stirring speed was 150 r / min, and the aeration rate was 0.1 m³ / min. 3 The bioleaching time was 96 h. After leaching, solid-liquid separation was performed to obtain a silver-containing bioleaching residue and a low-manganese, high-acid bioleaching solution. The total manganese leaching rate was 97.19%, and the pH of the manganese-rich, low-acid solution was 3.66. The silver-containing bioleaching residue was leached with calcium oxide slurry and gold and silver leaching agents. The silver leaching conditions were: slurry concentration 40%, slurry pH 11.5, stirring speed 400 r / min, and leaching time 48 h. The silver leaching rate was 96.55%.

[0121] Example 6

[0122] A mixture of manganese silver ore (manganese content 25.22%, silver grade 869.90 g / t), pyrite (iron content 48.74%, sulfur content 46.44%), and pyrrhotite (iron content 62.81%, sulfur content 33.67%) (mixing mass ratio 1:1) was crushed and finely ground to a particle size of -0.074 mm or more (more than 50%), and then thoroughly mixed with a low-manganese, high-acid bioleaching solution to prepare a slurry; wherein the mass ratio of manganese silver ore to pyrrhotite was 5:1.

[0123] Sulfuric acid was added to the slurry after conditioning for chemical leaching. The slurry concentration was 40%. The pH value was maintained at ≤4.00 during the chemical leaching process, the leaching temperature was 80 ℃, the stirring speed was 300 r / min, the sulfuric acid dosage was 281.77 kg / t (manganese-silver ore), and the reaction time was 4 h. Stirring was carried out continuously during the chemical leaching process. After the chemical leaching was completed, solid-liquid separation was performed to obtain a manganese-rich, low-acid chemical leaching solution and a chemical leaching residue. The manganese-rich, low-acid chemical leaching solution, after pretreatment such as impurity removal, purification, and enrichment, can be used to produce manganese sulfate, electrolytic manganese, or electrolytic manganese dioxide.

[0124] Inoculate chemical leaching residue with specific microbial strains SulfobacillusBioleaching was performed using *S. biometek-YM-II* sp. with an inoculum size of 20% of the chemical leaching residue volume and a pulp concentration of 20% (i.e., the concentration of the chemical leaching residue after inoculation with *S. acidophilus*). Stirring was maintained throughout the bioleaching process. The pH was maintained at 0.80–1.50, the reaction temperature was controlled at 45 °C, the stirring speed was 150 r / min, and the aeration rate was 0.1 m³ / min. 3 The bioleaching time was 96 h. After leaching, solid-liquid separation was performed to obtain a silver-containing bioleaching residue and a low-manganese, high-acid bioleaching solution. The total manganese leaching rate was 98.16%, and the pH of the manganese-rich, low-acid solution was 3.40. The silver-containing bioleaching residue was leached with calcium oxide slurry and gold and silver leaching agents. The silver leaching conditions were: slurry concentration 40%, slurry pH 11.5, stirring speed 400 r / min, and leaching time 48 h. The silver leaching rate was 95.98%.

[0125] Therefore, when using different pyrites, different pyrrhotites, or mixtures of the two to process different manganese-silver ores, the introduction of specific bacteria and this application helps to improve the utilization rate of reducing minerals, reduce process energy consumption and the consumption of added materials such as sulfuric acid, while improving the recovery rate of valuable metals and reducing environmental harm to varying degrees.

[0126] For the sake of simplicity, the method embodiments are described as a series of actions. However, those skilled in the art should understand that the present invention is not limited to the described order of actions, as some steps can be performed in other orders or simultaneously according to the present invention. Furthermore, those skilled in the art should also understand that the embodiments described in the specification are preferred embodiments, and the actions and components involved are not necessarily essential to the present invention.

[0127] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of this disclosure. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. In addition, those skilled in the art can combine and integrate the different embodiments or examples described in this specification.

[0128] The above provides a detailed description of a method for extracting manganese silver from oxidized manganese silver ore and the acidophilic sulfur bacteria provided by the present invention. Specific examples have been used to illustrate the principle and implementation of the present invention. The description of the above embodiments is only for the purpose of helping to understand the method and core idea of ​​the present invention. At the same time, for those skilled in the art, there will be changes in the specific implementation and application scope based on the idea of ​​the present invention. Therefore, the content of this specification should not be construed as a limitation of the present invention.

Claims

1. A method for extracting manganese silver from oxidized manganese silver ore, characterized in that, The method includes: Step 1: Crush and finely grind the oxidized manganese silver ore and the reducing minerals, then mix them into a slurry to prepare a mineral slurry; Step 2: Add sulfuric acid to the slurry and perform chemical leaching. The resulting chemical leaching product is subjected to solid-liquid separation to obtain chemical leaching residue and manganese-rich, low-acid chemical leaching solution. The manganese-rich, low-acid chemical leaching solution is used to produce manganese products. Step 3: Inoculate the chemical leaching residue with *Sitobacterium acidophilus* (S. acidophilus). Sulfobacillus Following Biometek-YM-II, bioleaching is performed, and the resulting bioleaching product undergoes solid-liquid separation to obtain a low-manganese, high-acid bioleaching solution and a silver-containing bioleaching residue. The bioleaching temperature is 40 ℃~50 ℃. The low-manganese, high-acid bioleaching solution is returned to step 1 and thoroughly mixed with the oxidized manganese silver ore and the reducing mineral to form the slurry in step 1. Before the bioleaching process, the concentration of the chemical leaching residue after inoculation with Biometek-YM-II acidophilus is 10%~25% and the pH value is 0.80~1.

50. The biometek-YM-II acidophilus is accessed under the CCTCC No.: M2023188. Step 4: Leach silver from the silver-containing bioleaching residue.

2. The method according to claim 1, characterized in that, The fine grinding involves grinding the crushed oxidized manganese silver ore and the reduced minerals to a concentration of -0.074 mm or higher, which accounts for more than 50%.

3. The method according to claim 1, characterized in that, The reducing mineral is pyrite, pyrrhotite, or a mixture of the two in any proportion.

4. The method according to claim 1, characterized in that, The mass ratio of the oxidized manganese silver ore to the reduced mineral is 10:(1~5).

5. The method according to claim 1, characterized in that, In step 2, the concentration of the slurry after adding sulfuric acid is 10%~40% and the pH value is ≤4.

00.

6. The method according to claim 1, characterized in that, During the chemical leaching process, the leaching temperature is 20 ℃~100 ℃, the leaching time is 3 h~24 h, and the stirring speed is 100 r / min~800 r / min; the manganese-rich low-acid chemical leaching solution has a manganese concentration ≥70 g / L and a pH value of 3.00~4.

00.

7. The method according to claim 1, characterized in that, In step 3, the amount of the acidophilic sulfur bacillus Biometek-YM-II inoculated is 1% to 99% of the volume of the slurry.

8. The method according to claim 1, characterized in that, During the bioleaching process, the bioleaching time is 48 h to 96 h, the stirring speed is 100 r / min to 600 r / min, and the aeration rate is 0.05 m³. 3 / h~0.30 m 3 / h; In step 3, the low-manganese, high-acid bioleaching solution accounts for 20% to 100% of the total liquid volume in the slurry of step 1, and the manganese concentration in the low-manganese, high-acid bioleaching solution is ≤15 g / L, and the pH value is 0.6 to 1.

50.

9. The method according to claim 1, characterized in that, The manganese-rich, low-acid chemical leaching solution is used to produce manganese products, including: The manganese-rich, low-acid chemical leachate is used to produce manganese sulfate, electrolytic manganese, or electrolytic manganese dioxide after impurity removal, purification, and enrichment pretreatment. Step 4 includes: The silver-containing bioleaching residue was slurried with calcium oxide and then subjected to silver cyanide leaching with a gold and silver leaching agent; wherein the silver cyanide leaching time was 48 h and the stirring speed of the silver cyanide leaching was 400 r / min.

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