Microbial treatment method for cyanide-containing tailings slurry in gold mines

Abstract

This application provides a microbial treatment method for cyanide-containing tailings slurry from gold mines, belonging to the field of pollutant treatment technology. This application first enriches cyanide-reducing bacteria from the soil surrounding cyanide tailings or cyanide tailings ponds. A high-performance cyanide-reducing bacteria community is constructed through domestication and proliferation using low-concentration cyanide tailings slurry. Then, the number and activity of cyanide-reducing bacteria in the slurry system are rapidly increased by efficiently inoculating high-concentration cyanide tailings slurry with cyanide-reducing bacteria or by refluxing cyanide tailings slurry containing cyanide-reducing bacteria. By controlling parameters such as pH, stirring speed, aeration rate, and nutrients in the slurry system, the method achieves green microbial treatment of high-concentration cyanide-containing tailings slurry pollutants, reducing the environmental risks of tailings storage. This method is effective, low-cost, safe, and reliable, with broad application prospects.

Description

Technical Field

[0001] This invention relates to the field of pollutant technology, specifically to a microbial treatment method for cyanide-containing tailings slurry from gold mines. Background Technology

[0002] Cyanide-containing tailings slurry contains not only free, highly toxic cyanide and its derivatives (metal cyanide complexes, thiocyanates, etc.) in the liquid phase, but also cyanide and its derivatives adsorbed on the surface of tailings particles. Tailings must be rendered harmless to meet the requirements for subsequent disposal and comprehensive utilization. Improper treatment not only restricts the resource utilization of this large volume of solid waste, cyanide tailings, but also pollutes soil, groundwater, and surface water through leaching and leakage during subsequent treatment and disposal processes, threatening the ecological environment and human health. Therefore, it is necessary to achieve simultaneous treatment of both liquid and solid pollutants in the tailings slurry to meet standards.

[0003] Currently, the technology for microbial treatment of cyanide-containing wastewater is relatively mature, but the technology for microbial treatment of cyanide-containing tailings slurry is still in the exploratory stage. The core limitations of microbial treatment of cyanide tailings are: 1) a lack of highly efficient functional bacteria adapted to the complex conditions of the slurry. Single-function strains have poor adaptability to the high salt content and multiple pollutant components of the slurry system, resulting in insufficient stability in cyanide removal treatment and difficulty in handling complex pollution scenarios where cyanide and conversion derivatives coexist, leading to easily inhibited degradation efficiency; 2) low-concentration slurry treatment requires additional dilution processes, leading to increased treatment scale and higher engineering investment and operating costs. High-concentration tailings slurry (mass concentration > 20%), due to its high viscosity and uneven particle size distribution, significantly affects the growth, metabolism, migration, distribution, and degradation activity of microorganisms, making efficient treatment impossible with existing technologies. Summary of the Invention

[0004] In view of the technical problems existing in the background art, this application provides a microbial treatment method for cyanide-containing tailings slurry in gold mines, which aims to solve the problems of high cost, difficulty in simultaneously treating solid and liquid phase pollutants, and poor adaptability of microorganisms to high-concentration cyanide-containing tailings slurry in existing microbial treatment processes.

[0005] This application provides a microbial treatment method for cyanide-containing tailings slurry from gold mines, comprising the following steps:

[0006] S1. Enriching cyanide-degrading bacteria from cyanide tailings or soil surrounding cyanide tailings ponds;

[0007] S2. The cyanide-reducing bacteria are cultured in a cyanide tailings slurry with a concentration of 1-5% to obtain a slurry containing the cyanide-reducing bacteria.

[0008] S3. Inject the cyanide tailings slurry into the bioreactor, and then add nutrients to obtain the cyanide tailings slurry system.

[0009] S4. Control the pH value, stirring speed, and aeration rate of the cyanide tailings slurry system in the bioreactor to reach the predetermined values, and simultaneously inoculate with cyanide-reducing bacteria solution to continuously reduce cyanide by microorganisms until the cyanide content in the leachate of the cyanide tailings slurry filter residue reaches the treatment standard, thereby obtaining the treated slurry.

[0010] S5. The treated slurry is filtered to obtain filter residue and treated filtrate; the filter residue is piled into the tailings pond for storage, and the treated filtrate is returned to the process flow for reuse.

[0011] In the technical solution of this application embodiment, cyanide-reducing bacteria are first enriched from the soil surrounding cyanide tailings or cyanide tailings ponds. A high-performance cyanide-reducing bacteria community is constructed through domestication and proliferation using low-concentration cyanide tailings slurry. Then, the number and activity of cyanide-reducing bacteria in the slurry system are rapidly increased by efficiently inoculating high-concentration cyanide tailings slurry with cyanide-reducing bacteria and by refluxing cyanide tailings slurry containing cyanide-reducing bacteria. By controlling parameters such as pH, stirring speed, aeration rate, and nutrients in the slurry system, the green microbial treatment of high-concentration cyanide-containing tailings slurry pollutants is achieved, reducing the environmental risks of tailings storage. This method is effective, low-cost, safe, and reliable, with broad application prospects.

[0012] In some embodiments, step S1, the enrichment of cyanide-reducing bacteria, specifically includes the following steps: adding 5-20g of cyanide tailings or soil surrounding the tailings pond to an enrichment medium containing 10mg / L of total cyanide, culturing at 30℃ and 120rpm for 7-15 days, and then transferring 1-5mL of the bacterial solution to fresh enrichment medium; repeating the above experimental steps 5-10 times with an increment of 10-50mg / L of total cyanide; the enrichment medium includes 5-10g / L of glucose, 1-2g / L of ammonium sulfate, 0.4-1g / L of disodium hydrogen phosphate, 0.4-1g / L of potassium dihydrogen phosphate, 0.2-0.5g / L of magnesium sulfate, and 0.01-0.05g / L of calcium chloride.

[0013] In this embodiment, by enriching functional bacteria in the cyanide tailings and surrounding soil of the cyanide tailings pond in a typical environment, the bacteria are more adaptable to cyanide and its derivatives and inhibitors. By culturing the bacteria with a gradient increase in cyanide concentration, the tolerance and degradation capacity of the functional bacteria to cyanide can be improved.

[0014] In some embodiments, step S2, the expanded culture specifically includes the following steps: supplementing nutrients, adjusting the pH value to 8.0~10.0, stirring at a speed of 200~300 rpm, aeration at a rate of 0.1~1.0 L / (L·min), and culturing for 96~120 h.

[0015] In this embodiment, enrichment and domestication are carried out by using low-concentration slurry and specific culture conditions, which not only provides screening and domestication materials, but also increases the influence of solid minerals in tailings slurry on microbial screening, while providing growth space for microorganisms and screening out functional bacteria suitable for the tailings slurry system.

[0016] In some embodiments, the nutrients include 1.25-5 g / L glucose, 0.25-2 g / L ammonium sulfate, 0.4-1 g / L disodium hydrogen phosphate, 0.4-1 g / L potassium dihydrogen phosphate, 0.2-0.5 g / L magnesium sulfate, and 0.01-0.05 g / L calcium chloride.

[0017] In this embodiment, by controlling the amount of exogenous nutrients added, functional bacteria that use pollutants such as cyanide and thiocyanate as nutrients are selectively enriched and screened.

[0018] In some embodiments, in step S2, the number of effective viable bacteria in the slurry containing cyanide-reducing bacteria is 10. 8 More than 1 / mL.

[0019] In this embodiment, a sufficient number of effective live bacteria are obtained through expanded cultivation, which can be used for subsequent decyanation treatment of high-concentration cyanide tailings slurry.

[0020] In some embodiments, in step S3, the nutrients include 1.25-5 g / L glucose, 0.25-2 g / L ammonium sulfate, 0.4-1 g / L disodium hydrogen phosphate, 0.4-1 g / L potassium dihydrogen phosphate, 0.2-0.5 g / L magnesium sulfate, and 0.01-0.05 g / L calcium chloride.

[0021] In this embodiment, nutrients are added to the cyanide slurry to provide the energy required for the subsequent inoculation of cyanide-reducing bacteria during the cyanide reduction process.

[0022] In some embodiments, in step S4, the cyanide-reducing bacterium solution is derived from the cyanide-reducing slurry or the treated slurry.

[0023] In this embodiment, the number and activity of cyanide-reducing bacteria in the slurry system are rapidly increased by inoculating the slurry with cyanide-reducing bacteria or by refluxing the cyanide tailings slurry with cyanide-reducing bacteria.

[0024] In some embodiments, in step S4, the pH value is 7~10, the stirring speed is 100~500 rpm, and the aeration rate is 0.2~1.5 L / (L·min).

[0025] In this embodiment, by controlling parameters such as pH value, stirring speed, and aeration rate in the slurry system, suitable reaction conditions are provided for the cyanide reduction process of cyanide-reducing bacteria, thus realizing the green treatment of high-concentration cyanide-containing tailings slurry pollutants by microorganisms.

[0026] In some embodiments, in step S4, the treatment time for microbial cyanide reduction is 24-68 hours.

[0027] In this embodiment, by using a specific cyanide reduction treatment time, the cyanide in the cyanide-containing tailings slurry can be fully degraded.

[0028] The above description is only an overview of the technical solution of this application. In order to better understand the technical means of this application and to implement it in accordance with the contents of the specification, and to make the above and other objects, features and advantages of this application more obvious and understandable, specific embodiments of this application are given below. Detailed Implementation

[0029] The embodiments of the technical solution of this application will be described in detail below. The following embodiments are only used to illustrate the technical solution of this application more clearly, and are therefore only examples, and should not be used to limit the scope of protection of this application.

[0030] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0031] To address the problems of high cost, difficulty in simultaneously treating solid and liquid pollutants, and poor adaptability of microorganisms to high-concentration cyanide-containing tailings slurry in existing microbial treatment processes for cyanide-containing tailings slurry, this application provides a microbial treatment method for cyanide-containing tailings slurry in gold mines. This application first enriches cyanide-reducing bacteria from the soil surrounding the tailings pond or cyanide tailings. A high-performance cyanide-reducing bacteria community is constructed through domestication and proliferation using low-concentration cyanide tailings slurry. Then, the number and activity of cyanide-reducing bacteria in the slurry system are rapidly increased by efficiently inoculating high-concentration cyanide tailings slurry with cyanide-reducing bacteria or by refluxing cyanide tailings slurry containing cyanide-reducing bacteria. By controlling parameters such as pH, stirring speed, aeration rate, and nutrients in the slurry system, green microbial treatment of high-concentration cyanide-containing tailings slurry pollutants is achieved, reducing the environmental risks of tailings storage. This method involves enriching cyanide-reducing bacteria through a gradient-increasing pollution load approach. Functional microorganisms are then cultivated and trained using low-concentration tailings slurry, enhancing their adaptability to medium- and high-concentration cyanide tailings slurry. This results in highly adaptable, high-performance cyanide-reducing bacteria. The low-concentration slurry provides both solid minerals and liquid pollutants, offering both screening and training materials and increasing the influence of solid minerals on microbial screening. Simultaneously, it provides growth space for microorganisms, allowing for the selection of suitable functional bacteria for the tailings slurry system. The cyanide-reducing functional bacteria in this scheme consist of a composite functional bacteria group including Pseudomonas, Achromobacterium, Oligotrophozoites, Bacillus, and yeast. To improve the efficiency of microbial treatment in medium- and high-concentration cyanide tailings slurry, the method involves inoculating high-concentration cyanide tailings slurry with cyanide-reducing bacteria or refluxing cyanide tailings slurry containing cyanide-reducing bacteria to promote in-situ proliferation and enrichment of functional microorganisms, increasing their effective quantity and biological activity. This method is effective, cost-efficient, and produces cyanide-reducing microorganisms with strong adaptability to the slurry, showing broad application prospects.

[0032] This application provides a microbial treatment method for cyanide-containing tailings slurry from gold mines, comprising the following steps:

[0033] S1. Accumulate cyanide-reducing bacteria from cyanide tailings or soil surrounding tailings ponds;

[0034] S2. The cyanide-reducing bacteria are cultured in a cyanide tailings slurry with a concentration of 1-5% to obtain a slurry containing the cyanide-reducing bacteria.

[0035] S3. Inject the cyanide tailings slurry into the bioreactor, and then add nutrients to obtain the cyanide tailings slurry system.

[0036] S4. Control the pH value, stirring speed, and aeration rate of the cyanide tailings slurry system in the bioreactor to reach the predetermined values, and simultaneously inoculate with cyanide-reducing bacteria solution to continuously reduce cyanide by microorganisms until the cyanide content in the leachate of the cyanide tailings slurry filter residue reaches the treatment standard, thereby obtaining the treated slurry.

[0037] S5. The treated slurry is filtered to obtain filter residue and treated filtrate; the filter residue is piled into the tailings pond for storage, and the treated filtrate is returned to the process flow for reuse.

[0038] In the technical solution of this application embodiment, cyanide-reducing bacteria are first enriched from cyanide tailings or the soil surrounding cyanide tailings ponds. A high-performance cyanide-reducing bacteria community is constructed through domestication and proliferation using low-concentration cyanide tailings slurry. Then, the number and activity of cyanide-reducing bacteria in the slurry system are rapidly increased by efficiently inoculating high-concentration cyanide tailings slurry with cyanide-reducing bacteria or by refluxing cyanide tailings slurry containing cyanide-reducing bacteria. By controlling parameters such as pH, stirring speed, aeration rate, and nutrients in the slurry system, the green microbial treatment of high-concentration cyanide-containing tailings slurry pollutants is achieved, reducing the environmental risks of tailings storage. This method is effective, low-cost, safe, and reliable, with broad application prospects.

[0039] Further, in some embodiments, step S1, the enrichment of cyanide-reducing bacteria specifically includes the following steps: adding 5-20g of cyanide tailings or soil surrounding the tailings pond to an enrichment medium containing 10mg / L of total cyanide, culturing at 30℃ and 120rpm for 7-15 days, and then transferring 1-5mL of the bacterial solution to fresh enrichment medium; repeating the above experimental steps 5-10 times with an increment of 10-50mg / L of total cyanide; the enrichment medium includes 5-10g / L of glucose, 1-2g / L of ammonium sulfate, 0.4-1g / L of disodium hydrogen phosphate, 0.4-1g / L of potassium dihydrogen phosphate, 0.2-0.5g / L of magnesium sulfate, and 0.01-0.05g / L of calcium chloride.

[0040] In the technical solution of this application embodiment, functional bacteria are enriched in the cyanide tailings pond and surrounding soil in a typical environment. These bacteria are more adaptable to cyanide and its derivatives, inhibitors, etc. The concentration of cyanide is increased by gradient and culture is carried out to select high-performance cyanide-reducing bacteria that are adapted to specific environments.

[0041] Furthermore, in some embodiments, step S2, the expanded culture specifically includes the following steps: supplementing nutrients, adjusting the pH value to 9.0~9.5, stirring at a speed of 200~300 rpm, aeration at a rate of 0.1~1.0 L / (L·min), and culturing for 96~120 h.

[0042] In the technical solution of this application embodiment, by using low-concentration slurry and specific culture conditions for enrichment and domestication, it not only provides screening and domestication materials, but also increases the influence of tailings slurry solid minerals on microbial screening, while providing growth space for microorganisms, and screening out functional bacteria suitable for the tailings slurry system.

[0043] Furthermore, in some embodiments, the nutrients include 1.25-5 g / L glucose, 0.25-2 g / L ammonium sulfate, 0.4-1 g / L disodium hydrogen phosphate, 0.4-1 g / L potassium dihydrogen phosphate, 0.2-0.5 g / L magnesium sulfate, and 0.01-0.05 g / L calcium chloride.

[0044] In the technical solution of this application embodiment, by controlling the amount of exogenous nutrients added, functional bacteria that use pollutants such as cyanide and thiocyanate as nutrients are selectively enriched and screened.

[0045] Furthermore, in some embodiments, in step S2, the number of effective viable bacteria in the slurry containing cyanide-reducing bacteria is 10. 8 More than 1 / mL.

[0046] In the technical solution of this application embodiment, a sufficient number of effective live bacteria are obtained by expanding the culture, which can be used for subsequent cyanide reduction treatment of high-concentration cyanide tailings slurry.

[0047] Further, in some embodiments, in step S3, the nutrients include 1.25~5 g / L glucose, 0.25~2 g / L ammonium sulfate, 0.4~1 g / L disodium hydrogen phosphate, 0.4~1 g / L potassium dihydrogen phosphate, 0.2~0.5 g / L magnesium sulfate and 0.01~0.05 g / L calcium chloride.

[0048] In the technical solution of this application embodiment, nutrients are added to the cyanide slurry to provide the energy required for the cyanide reduction process of the subsequently inoculated cyanide-reducing bacteria.

[0049] Furthermore, in some embodiments, in step S4, the cyanide-reducing bacterium solution is derived from the cyanide-reducing slurry or the treated slurry containing the cyanide-reducing bacteria.

[0050] In the technical solution of this application embodiment, the number and activity of cyanide-reducing bacteria in the slurry system are rapidly increased by inoculating slurry containing cyanide-reducing bacteria or by refluxing cyanide tailings slurry containing cyanide-reducing bacteria.

[0051] Furthermore, in some embodiments, in step S4, the pH value is 7~10, the stirring speed is 100~500 rpm, and the aeration rate is 0.2~1.5 L / (L·min).

[0052] Furthermore, in some embodiments, sulfuric acid is used as a pH adjuster if it is necessary to lower the pH value; and lime slurry or carbide slag is used as a pH adjuster if it is necessary to raise the pH value.

[0053] In the technical solution of this application embodiment, by controlling parameters such as pH value, stirring speed, and aeration rate in the slurry system, suitable reaction conditions are provided for the cyanide reduction process of cyanide-reducing bacteria, thereby realizing the green treatment of high-concentration cyanide-containing tailings slurry pollutants by microorganisms.

[0054] Furthermore, in some embodiments, in step S4, the treatment time for microbial cyanide reduction is 24~68h.

[0055] In the technical solution of this application embodiment, cyanide in cyanide-containing tailings slurry can be fully degraded through a specific cyanide reduction treatment time.

[0056] The following are some specific embodiments. It should be noted that the embodiments described below are exemplary and are only used to explain this application, and should not be construed as limiting this application. Where specific techniques or conditions are not specified in the embodiments, they shall be performed in accordance with the techniques or conditions described in the literature in this field or according to the product instructions. Reagents or instruments whose manufacturers are not specified are all conventional products that can be obtained commercially.

[0057] Example 1

[0058] This embodiment provides a microbial treatment method for cyanide-containing tailings slurry from a gold mine, specifically including the following steps:

[0059] (1) Transfer 20g of cyanide tailings to a 500mL conical flask and add 10mg / L of total cyanide (CN). T After culturing the bacterial culture in an enrichment medium at 30℃ and 120rpm for 7 days, 2mL of the bacterial solution was transferred to fresh enrichment medium. The total cyanide concentration was increased in increments of 10mg / L, and the above experimental steps were repeated 10 times until the concentration reached 100mg / L, thus obtaining the cyanide-reducing bacterial solution. The enrichment medium contained: glucose 10g / L, ammonium sulfate 1g / L, disodium hydrogen phosphate 1g / L, potassium dihydrogen phosphate 1g / L, magnesium sulfate 0.2g / L, and calcium chloride 0.01g / L.

[0060] (2) Nutrients were added to cyanide tailings slurry with a slurry concentration of 1%. The nutrient additions were glucose concentration of 2 g / L, ammonium sulfate concentration of 0.25 g / L, disodium hydrogen phosphate of 0.4 g / L, potassium dihydrogen phosphate of 0.4 g / L, magnesium sulfate of 0.25 g / L, and calcium chloride of 0.02 g / L. The slurry was cultured for 96 h at a stirring speed of 300 rpm, an aeration rate of 0.5 L / (L·min), and a pH of 9.0 to obtain cyanide-reducing bacteria slurry.

[0061] (3) Take 2L of cyanide tailings slurry with a mass concentration of 40% and inject it into the bioreactor. Add nutrients to the bioreactor to obtain the cyanide tailings slurry system. The slurry system contains 1.5g / L glucose, 0.25g / L ammonium sulfate, 0.4g / L disodium hydrogen phosphate, 0.4g / L potassium dihydrogen phosphate, 0.2g / L magnesium sulfate, and 0.01g / L calcium chloride.

[0062] (4) Add sulfuric acid to the cyanide tailings slurry system to adjust the pH to 9. Under the stirring speed of 200 rpm and the aeration rate of 1.0 L / (L·min), inoculate 5% of the slurry containing cyanide-reducing bacteria and continue microbial cyanide reduction for 24 h. After the reaction is completed, filter and test the toxicity of the filter residue and the CN content in the leachate. T The concentration was 1.90 mg / L, meeting the warehousing requirements of the "Technical Specification for Pollution Control of Cyanide Slag in the Gold Industry" (CN). T ≤5mg / L).

[0063] (5) The filter residue is piled into the tailings pond for storage, and the treated filtrate is reused as slurry water.

[0064] The sources and performance parameters of the raw materials are as follows:

[0065] The cyanide tailings slurry from a gold mine has a mass concentration of 40% and a pH of 10.52. The main pollutants are: total cyanide concentration of 148.27 mg / L, Cu concentration of 35 mg / L, Zn concentration of 60.80 mg / L, and COD concentration of 300 mg / L. The total cyanide content of the toxic leachate from the filter residue is 5.57 mg / L, and it also contains trace amounts of other heavy metal ions.

[0066] Examples 2-3 and Comparative Examples 1-2

[0067] Examples 2-3 and Comparative Examples 1-2 respectively provide a microbial treatment method for cyanide tailings slurry in gold mines. Compared with Example 1, the difference is that the concentration of cyanide tailings slurry in step (2) is different, as shown in Table 1. Other steps are roughly the same as in Example 1, and will not be repeated here.

[0068] Table 1. Concentration of cyanide tailings slurry and CN content in filter residue leachate in Examples 1-3 and Comparative Examples 1-2 T concentration

[0069]

[0070] As shown in Table 1, when the concentration of cyanide tailings slurry enriched and acclimatized with cyanide-reducing bacteria is 1-5%, the cyanide content in the toxic leachate from the filter residue after 24 hours of subsequent microbial treatment can meet the warehousing requirements of the "Technical Specification for Pollution Control of Cyanide Slag in the Gold Industry" (CN). T(≤5mg / L); Comparative Example 1 used cyanide-containing tailings slurry supernatant (without solid minerals) without slurry acclimation, and failed to achieve the target. This is because the cyanide-reducing bacteria enriched and acclimated in the cyanide-containing tailings slurry supernatant grew, accumulated, and metabolized pollutants relatively slowly in the slurry system. Furthermore, the lack of tailings slurry solid minerals for microbial screening made it impossible to completely screen out the target bacteria. In addition, the bacteria had poor adaptability to the high-concentration slurry system, affecting the cyanide-reducing effect of the microorganisms. Comparative Example 2 used functional bacteria acclimated in high-concentration slurry, and the subsequent treatment effect also failed to achieve the target. This is because the increased solid content in the slurry system affected the growth and enrichment process of functional microorganisms, thus affecting the cyanide-reducing effect of the subsequent cyanide tailings slurry.

[0071] Enrichment and domestication using low-concentration slurry and specific culture conditions not only provides screening and domestication materials, but also increases the influence of solid minerals in tailings slurry on microbial screening, while providing growth space for microorganisms, thus enabling the screening of functional bacteria adapted to the tailings slurry system.

[0072] In summary, this application provides a microbial treatment method for cyanide-containing tailings slurry in gold mines. First, cyanide-reducing bacteria are enriched from the soil surrounding the cyanide tailings or cyanide tailings pond. A high-performance cyanide-reducing bacteria community is constructed through domestication and proliferation using low-concentration cyanide tailings slurry. Then, the number and activity of cyanide-reducing bacteria in the slurry system are rapidly increased by efficiently inoculating high-concentration cyanide tailings slurry with cyanide-reducing bacteria or by refluxing cyanide tailings slurry containing cyanide-reducing bacteria. By controlling parameters such as pH, stirring speed, aeration rate, and nutrients in the slurry system, the method achieves green microbial treatment of high-concentration cyanide-containing tailings slurry pollutants, reducing the environmental risks associated with tailings storage. This method involves enriching cyanide-reducing bacteria through a gradient-increasing pollution load approach. Functional microorganisms are then cultivated and trained using low-concentration tailings slurry, enhancing their adaptability to medium- and high-concentration cyanide tailings slurry. This results in highly adaptable, high-performance cyanide-reducing bacteria. The low-concentration slurry provides both solid minerals and liquid pollutants, offering both screening and training materials and increasing the influence of solid minerals on microbial screening. Simultaneously, it provides growth space for microorganisms, allowing for the selection of suitable functional bacteria for the tailings slurry system. The cyanide-reducing functional bacteria in this scheme consist of a composite functional bacteria group including Pseudomonas, Achromobacterium, Oligotrophozoites, Bacillus, and yeast. To improve the efficiency of microbial treatment in medium- and high-concentration cyanide tailings slurry, the method involves inoculating high-concentration cyanide tailings slurry with cyanide-reducing bacteria or refluxing cyanide tailings slurry containing cyanide-reducing bacteria to promote in-situ proliferation and enrichment of functional microorganisms, increasing their effective quantity and biological activity. This method is effective, cost-efficient, and produces cyanide-reducing microorganisms with strong adaptability to the slurry, showing broad application prospects.

[0073] It should be noted that this application is not limited to the above-described embodiments. The above embodiments are merely examples, and any embodiments with the same structure and effect as the technical concept within the scope of this application are included in the technical scope of this application. Furthermore, various modifications that can be conceived by those skilled in the art to the embodiments, and other ways of constructing by combining some of the constituent elements of the embodiments, without departing from the spirit of this application, are also included in the scope of this application.

Claims

1. A microbial treatment method for cyanide-containing tailings slurry from a gold mine, characterized in that, Includes the following steps: S1. Enriching cyanide-degrading bacteria from cyanide tailings or soil surrounding cyanide tailings ponds; The enrichment of cyanide-reducing bacteria specifically includes the following steps: 5-20g of cyanide tailings or soil surrounding the tailings pond is added to an enrichment medium containing 10mg / L of total cyanide. After culturing at 30℃ and 120rpm for 7-15 days, 1-5mL of the bacterial solution is transferred to fresh enrichment medium. The above steps are repeated 5-10 times with an increment of 10-50mg / L of total cyanide. The enrichment medium includes 5-10g / L of glucose, 1-2g / L of ammonium sulfate, 0.4-1g / L of disodium hydrogen phosphate, 0.4-1g / L of potassium dihydrogen phosphate, 0.2-0.5g / L of magnesium sulfate, and 0.01-0.05g / L of calcium chloride. S2. The cyanide-reducing bacteria are cultured in a cyanide tailings slurry with a concentration of 1-5% to obtain a slurry containing the cyanide-reducing bacteria. The culture specifically includes the following steps: supplementing nutrients, adjusting the pH to 8.0-10.0, stirring at 200-300 rpm, aerating at 0.1-1.0 L / (L·min), and culturing for 96-120 h. The nutrients include 1.25-5 g / L glucose, 0.25-2 g / L ammonium sulfate, 0.4-1 g / L disodium hydrogen phosphate, 0.4-1 g / L potassium dihydrogen phosphate, 0.2-0.5 g / L magnesium sulfate, and 0.01-0.05 g / L calcium chloride. S3. Inject the cyanide tailings slurry into the bioreactor, and then add nutrients to obtain the cyanide tailings slurry system. S4. Control the pH value, stirring speed, and aeration rate of the cyanide tailings slurry system in the bioreactor to reach predetermined values, and simultaneously inoculate the cyanide-reducing bacteria solution from the slurry containing cyanide-reducing bacteria, and continue to carry out microbial cyanide reduction until the cyanide content in the leachate of the cyanide tailings slurry filter residue reaches the treatment standard, thereby obtaining the treated slurry. S5. The treated slurry is filtered to obtain filter residue and treated filtrate; the filter residue is piled into the tailings dam for storage, and the treated filtrate is returned to the process flow for reuse.

2. The microbial treatment method for cyanide-containing tailings slurry in gold mines according to claim 1, characterized in that, In step S2, the number of effective viable bacteria in the slurry containing cyanide-reducing bacteria is 10. 8 More than 1 / mL.

3. The microbial treatment method for cyanide-containing tailings slurry in gold mines according to claim 1, characterized in that, In step S3, the nutrients include 1.25-5 g / L glucose, 0.25-2 g / L ammonium sulfate, 0.4-1 g / L disodium hydrogen phosphate, 0.4-1 g / L potassium dihydrogen phosphate, 0.2-0.5 g / L magnesium sulfate, and 0.01-0.05 g / L calcium chloride.

4. The microbial treatment method for cyanide-containing tailings slurry in gold mines according to claim 1, characterized in that, In step S4, the pH value is 7~10, the stirring speed is 100~500 rpm, and the aeration rate is 0.2~1.5 L / (L·min).

5. The microbial treatment method for cyanide-containing tailings slurry in gold mines according to claim 1, characterized in that, In step S4, the treatment time for microbial cyanide reduction is 24~68h.

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