A method for leaching nickel and copper from a high-magnesium low-grade copper nickel sulfide ore by low-acid-consuming microorganisms

Abstract

The application provides a method for leaching nickel and copper in a high-magnesium low-grade copper-nickel sulfide ore by low-acid-consuming microorganisms, which comprises the following steps: first, setting a magnesium ion concentration gradient microbial domestication system under the condition of chalcopyrite as an energy substrate in a basic salt medium, obtaining a microorganism with high-efficiency iron-sulfur-oxidation function in a high-concentration Mg 2+ stress conditions; then, setting a pH gradient adaptation domestication system to further improve the alkali resistance of the acidophilic leaching bacteria. The domesticated leaching bacteria can oxidize chalcopyrite, nickel pyrite, pyrite and other sulfide minerals in the high-magnesium copper-nickel sulfide ore under a higher pH condition to produce Fe 3+ and H2SO4, which can promote the dissolution of gangue minerals such as chlorite, serpentine and phlogopite and the high-efficiency release of valuable metals such as nickel and copper while reducing the pH of the leaching system. The method has the advantages of simple process, high efficiency, low equipment requirement and no need for additional acid, and can effectively avoid the high cost and environmental pollution problems caused by traditional chemical and physical methods.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of biological hydrometallurgy, in particular to a method for efficiently leaching nickel and copper from high-magnesium low-grade copper-nickel sulfide ore by low-acid consumption microorganisms. BACKGROUND

[0002] Nickel (Ni) is an important strategic metal resource in China, playing an important role in the production of stainless steel, synthetic steel, corrosion-resistant materials, catalysts, and ternary batteries, and is an indispensable basic material for the development of emerging industries. In recent years, the rapid development of new energy industries has led to a sharp increase in demand for nickel. China's nickel resources are relatively scarce, with a total amount of only about 3% of the world's total reserves, and mainly in the form of sulfide ore. With the rapid improvement of smelting processes and mining intensity, high-quality nickel ore resources are gradually depleted, and efficient extraction of nickel from low-grade copper-nickel sulfide ore is an urgent need to ensure the supply of nickel resources needed for the development of China's military industry.

[0003] According to statistics, among the total resources of about 100 million tons of 339 types of nickel ore deposits that have been proven in China, Ni-Cu sulfide ore accounts for 86%. The Jinchuan nickel mine in Gansu has a world-renowned large-scale copper-nickel sulfide ore deposit with a characteristic of polymetallic symbiosis, with reserves ranking second in the world's sulfide nickel mines, only second to Russia's Nornickel mine. Data shows that the nickel and platinum group metal reserves in the Jinchuan nickel mine rank first in the country, accounting for 70% and 80% of the total proven reserves in China, respectively, and the copper and cobalt metal reserves also rank second in the country. However, compared with foreign sulfide nickel mines such as Glencore in Canada, the grade of the Jinchuan nickel mine is relatively low, only about 1%. Therefore, it is of great significance for the sustainable development of China's industry to vigorously develop extraction processes suitable for low-grade copper-nickel ore resources.

[0004] Due to the characteristics of low-grade copper-nickel ore, such as multiple types of mineral inclusions with fine particle size, complex symbiotic relationship, high alkaline gangue content, and low sulfur content, the processing difficulty of traditional beneficiation enrichment and pyrometallurgical process is greatly increased. In contrast, bioleaching technology driven by acidophilic microorganisms iron-sulfur oxidation has the advantages of low energy consumption, high recovery rate, and low equipment and control requirements, and has good feasibility and economic value in treating the Jinchuan low-grade copper-nickel sulfide ore. Nickel in copper-nickel sulfide ore usually exists in the form of nickel pyrite ((NiFe)9S8), accompanied by pyrite (FeS2), chalcopyrite (CuFeS2), marcasite (Fe 1-x S,x=0~0.223) and other sulfide ores can be used as energy sources for acidophilic leaching bacteria. However, the poor adaptability of bacteria and the prominent product passivation effect caused by the dissolution process of high-concentration Mg 2+ , gangue minerals (such as serpentine, olivine, chlorite, etc.) and other factors are the key factors that reduce the leaching rate of valuable metals in high-magnesium low-grade copper-nickel sulfide ore. SUMMARY

[0005] In view of this, the purpose of the present application is to provide a method for leaching nickel and copper in high-magnesium low-grade sulfide copper-nickel ore by low acid consumption and high efficiency, based on targeted domestication of functional leaching bacteria, systematically studying the influence of important factors such as pH and ore pulp concentration on the leaching process, exploring the key regulation links that limit the leaching rate, and effectively improving the leaching rate of valuable metals nickel and copper. The biological leaching method has the characteristics of simple process, low cost, high efficiency, mild reaction and environmental protection, and has important practical and popularization value for the pretreatment of low-grade sulfide copper-nickel ore.

[0006] A method for leaching nickel and copper in high-magnesium low-grade sulfide copper-nickel ore by low acid consumption, characterized by using Mg 2+ The acidophilic leaching bacteria after tolerance and pH increase domestication leach nickel and copper elements in the mineral.

[0007] The sulfide minerals in the high-magnesium low-grade sulfide copper-nickel ore mainly include nickel pyrite, arsenopyrite, chalcopyrite and pyrite; the metal oxides contained mainly include magnetite; the doped gangue minerals mainly include olivine, serpentine, chlorite, mica and the like. The nickel content in the ore is 0.6% to 1.5%, the MgO content is 15% to 35%, the copper content is 0.3% to 0.7%, the sulfur content is 2% to 5%, and the iron content is 9% to 12%.

[0008] Further, in the culture medium, the acidophilic leaching bacteria are subjected to Mg 2+ Tolerance domestication with the sulfide ore as an energy substrate, to obtain a bacterial strain that still maintains iron-sulfur oxidation activity under the concentration condition of magnesium ions released in the high-magnesium low-grade sulfide copper-nickel ore leaching system.

[0009] Still further, the ore pulp concentration of the sulfide ore is 8 to 10 g / L; the Mg 2+ The concentration range is set to 0.5 to 2.0 g / L, and 3 to 5 concentration gradients are set, and the Mg 2+ The concentration condition is domesticated for 7 to 12 days; and preferably, the magnesium sulfate compound is dissolved.

[0010] Further, the obtained Mg 2+ Tolerant bacteria are inoculated into a culture system containing a certain Mg 2+ Concentration and sulfide ore pulp concentration, and the pH value of the leaching solution is gradually increased to obtain a bacterial strain that still maintains iron-sulfur oxidation activity under the condition of pH increase.

[0011] Still further, the pH value of the leaching solution is gradually increased within the time period from the logarithmic growth phase to the stable phase of the bacteria.

[0012] Still further, the Mg 2+The concentration is 1.5-2.0 g / L, the concentration of sulfide ore slurry is 8-10 g / L, the time period of logarithmic growth period to stable period of leaching bacteria is 4-8 days, the pH adjustment gradient is set to 2.0-6.0, 4-6 gradients are set, and each pH gradient is domesticated for 7-12 days.

[0013] The sulfide ore used in the application includes at least one of pyrite, chalcopyrite, bornite and arsenopyrite.

[0014] The acidophilic leaching bacteria in the application includes at least one of Acidithiobacillus ferrooxidans, Sulfobacillus thermosulfidooxidans, Acidithiobacillus caldus, Acidithiobacillus thiooxidans and Acidianus manzaensis.

[0015] The sulfide ore and high-magnesium low-grade sulfide copper-nickel ore are ground and passed through a 200-400 mesh screen, and finally the mineral particles with a particle size in the range of 40-70 microns are screened.

[0016] Further, the slurry concentration of the high-magnesium low-grade sulfide copper-nickel ore in the bioleaching system of the application is 6-12 g / L; the initial pH of the culture medium is set to 1.6-2.2; the initial inoculation concentration of the domesticated leaching bacteria is 0.6-2 x 10 8 cells / mL.

[0017] Further, the rotation speed of the shaker during the culture process of the high-magnesium low-grade sulfide copper-nickel ore bioleaching system of the application is controlled to be 140-190 rpm, the culture temperature is 25-50 DEG C, and the leaching period is 20-40 days.

[0018] The selected acidophilic leaching bacteria are activated and enriched in the leaching environment with sulfide ore as energy substrate, and then subjected to Mg 2+ tolerance domestication to adapt to the high Mg 2+ concentration solution environment formed in the process of bioleaching of high-magnesium sulfide copper-nickel ore;

[0019] The Mg 2+ tolerant domesticated bacteria are collected and inoculated into a higher pH adaptive domestication system, and also use sulfide ore as energy substrate, and gradually increase the solution pH during the mineral oxidation process, to obtain a strain that still has iron and sulfur oxidation activity under the condition that the pH reaches about 6.0;

[0020] The present application obtains mineral powder in the target particle size range by screening after crushing and grinding of the high-magnesium low-grade copper-nickel sulfide ore, and analyzes the micro-morphological characteristics, phase and element composition of the mineral after drying.

[0021] The present application adds the treated low-grade copper-nickel sulfide ore to the culture medium at a proper ore slurry concentration, and inoculates bacteria collected by domestication at a certain concentration, so that the leaching bacteria adapt to the growth environment with high-magnesium sulfide ore as energy substrate.

[0022] The established bioleaching system is placed in a constant temperature shaker, and is shaken at a certain speed. Meanwhile, the effects of different culture media, ore slurry concentrations, initial pH and types of leaching bacteria on mineral dissolution and copper-nickel leaching rate are studied. The solution chemical change characteristics and solid residue composition during leaching are analyzed.

[0023] The high-magnesium low-grade copper-nickel sulfide ore used in the present application is collected from the Jinchuan copper-nickel sulfide ore deposit, and is mainly composed of chlorite, serpentine, mica, magnetite, nickel pyrite and a small amount of chalcopyrite, pyrite and pyrrhotite according to phase identification. The dissolution of gangue minerals such as chlorite and serpentine will release a large amount of Mg 2+ Therefore, domestication of acidophilic leaching bacteria is necessary. First, activate and expand the required strains in the pyrite system.

[0024] The domestication process of the leaching bacteria in the present application is to add 6-12 g / L sulfide ore as the energy substance for the growth of bacteria in the 0K culture medium. The composition of the 0K culture medium is (NH4)2SO4, 3.0 g / L; MgSO4, 0.5 g / L; K2HPO4, 0.5 g / L; KCl, 0.1 g / L; Ca(NO3)2, 0.01 g / L. The sulfide ore is preferably at least one of pyrite and chalcopyrite.

[0025] Further, the Mg 2+ tolerance of the leaching bacteria is domesticated in a constant sulfide ore slurry concentration (preferably 10 g / L) culture system, and the initial pH of the culture medium is set to 1.9; the Mg 2+ concentration is set from low to high (0.5, 1.0, 1.5 and 2.0 g / L, respectively) for gradual tolerance domestication. Each Mg 2+ concentration is domesticated for 12 days.

[0026] Further, the domesticated leaching bacteria can still oxidize iron and sulfur in the mineral in the solution pH range of 2.0-6.0, and can adapt to the temperature range of 25-50℃; 1 mol / L H2SO4 and NaOH are used to adjust the pH during the domestication process. Each pH value (pH=2.0, 3.0, 4.0, 5.0 and 6.0) is domesticated for 12 days.

[0027] The optimum growth pH range of the acidophilic leaching bacteria used in the application is 1.8-2.0. Iron-sulfur bio-oxidation is a key reaction of sulfide ore leaching, and the dissolution process of high-magnesium low-grade copper-nickel sulfide ore releases alkali into the solution, which causes the pH to rise and inhibits the growth of acidophilic leaching bacteria and the efficiency of iron-sulfur oxidation. By alkali-tolerant domestication, the bacteria can still oxidize sulfide minerals including chalcopyrite and nickel pyrite in high-magnesium copper-nickel sulfide ore under higher pH conditions, which effectively reverses the pH of the leaching system and promotes the continuous dissolution of the minerals.

[0028] The culture medium used in the application for the bioleaching of high-magnesium low-grade copper-nickel sulfide ore includes 0K medium, 9K medium, Mackintosh (MAC), mineral salt medium (MSM), and a simplified medium with some compounds removed or simply dilute sulfuric acid. Under the requirements of ensuring cost, bacterial growth activity, and low accumulation of secondary products, 0K medium, a simplified medium, or simply dilute sulfuric acid is preferred.

[0029] The pulp concentration of copper-nickel sulfide ore is preferably 10 g / L; the initial pH of the leaching system is preferably 1.9; the temperature is preferably 30°C; the shaking speed is preferably 170 rpm; and the initial inoculation amount of acidophilic leaching bacteria is preferably 1×10 8 cells / mL.

[0030] The leaching bacteria are preferably Acidithiobacillus thiooxidans.

[0031] Using the above method, copper and nickel in high-magnesium low-grade copper-nickel sulfide ore are effectively leached with efficient bio-oxidation of sulfide ore.

[0032] The source of the iron-sulfur oxidation functional bacteria used in the application is not particularly limited and can be any source of sulfur-oxidizing bacteria known in the art.

[0033] The application has the following beneficial effects:

[0034] (1) Acidophilic leaching bacteria suitable for efficient leaching of high-magnesium copper-nickel sulfide ore are obtained, and the key limiting factors and optimization strategies of the bioleaching process are systematically explored, resulting in a higher copper-nickel leaching rate.

[0035] (2) The bioleaching method of the application has the characteristics of simple process flow, low cost, high efficiency, mild reaction, and environmental protection, and has important practical and promotional value for efficient leaching of valuable metals from high-magnesium low-grade copper-nickel sulfide ore. BRIEF DESCRIPTION OF DRAWINGS

[0036] Figure 1 The figure is a schematic diagram of the method described in the application;

[0037] Figure 2Figure (a) is a real object diagram of high-magnesium low-grade copper-nickel sulfide ore used in the present application, and figure (b) is a SEM diagram of the original mineral after treatment;

[0038] Figure 3 Figure (a) is a real object diagram of high-magnesium low-grade copper-nickel sulfide ore used in the present application, and figure (b) is a SEM diagram of the original mineral after treatment;

[0039] Figure 4 Figure (a) is a real object diagram of high-magnesium low-grade copper-nickel sulfide ore used in the present application, and figure (b) is a SEM diagram of the original mineral after treatment; + Figure (a) is a real object diagram of high-magnesium low-grade copper-nickel sulfide ore used in the present application, and figure (b) is a SEM diagram of the original mineral after treatment; + Figure (a) is a real object diagram of high-magnesium low-grade copper-nickel sulfide ore used in the present application, and figure (b) is a SEM diagram of the original mineral after treatment;

[0040] Figure 5 Figure (a) is a real object diagram of high-magnesium low-grade copper-nickel sulfide ore used in the present application, and figure (b) is a SEM diagram of the original mineral after treatment; + Figure (a) is a real object diagram of high-magnesium low-grade copper-nickel sulfide ore used in the present application, and figure (b) is a SEM diagram of the original mineral after treatment; + DETAILED DESCRIPTION

[0041] The method for leaching nickel and copper from high-magnesium low-grade copper-nickel sulfide ore with low acid consumption and high microbial efficiency provided by the present application and the application thereof will be described in detail below in combination with examples, but they should not be understood as limiting the protection scope of the present application.

[0042] Unless otherwise specified, all the various raw materials, reagents, instruments and equipment used in the present application can be purchased from the market or prepared by the existing methods.

[0043] In the leaching bacteria domestication process in the example of the present application, 10 g / L sulfide ore is added to the 0K culture medium as the energy substance for the growth of the bacteria. The components of the 0K culture medium are (NH4)2SO4, 3.0 g / L; MgSO4, 0.5 g / L; K2HPO4, 0.5 g / L; KCl, 0.1 g / L; Ca(NO3)2, 0.01 g / L. The sulfide ore is pyrite.

[0044] The Mg 2+ tolerance domestication is carried out in a constant sulfide ore slurry concentration of 10 g / L culture system, and the initial pH of the culture medium is set to 1.9; the Mg 2+ concentration is set to 0.5, 1.0, 1.5 and 2.0 g / L from low to high for gradual tolerance domestication. The domestication is carried out for 12 days under each Mg 2+ concentration condition.

[0045] Then, when the leaching bacteria after domestication continue to carry out pH increase domestication, the Mg 2+ ​The concentration of the bacteria was 2.0 g / L, the concentration of the sulfide ore slurry was 10 g / L, and the time period from the logarithmic growth phase to the stable phase of the leaching bacteria was 6 days. During this time period, 1 mol / L H2SO4 and NaOH were used to adjust the pH. Each pH value (pH = 2.0, 3.0, 4.0, 5.0, and 6.0) was acclimated for 12 days. After acclimation, the leaching bacteria could oxidize iron and sulfur in the ore at a solution pH of 2.0-6.0 and could adapt to a temperature range of 25-50°C.

[0046] Example 1

[0047] (1) A basic salt (0K) medium was prepared, and the formulation of the 0K medium was as follows: (NH4)2SO4, 3.0 g / L; MgSO4, 0.5 g / L; K2HPO4, 0.5 g / L; KCl, 0.1 g / L; Ca(NO3)2, 0.01 g / L; and a 1 mol / L sulfuric acid solution was also prepared for adjusting the pH of the medium.

[0048] (2) The sterilized 0K medium was poured into the reaction system, and the liquid volume was controlled to be 1 / 3 of the total volume of the reaction container. The initial pH of the medium was adjusted to 1.6 using 1 mol / L dilute sulfuric acid. Then, a high-magnesium low-grade copper-nickel sulfide ore was added at a slurry concentration of 10 g / L. The bacteria in the Mg 2+ The Acidithiobacillus ferrooxidans acclimated at a concentration of 2.0 g / L and a pH of 6.0 was inoculated into the copper-nickel sulfide ore bioleaching system at a concentration of 1 x 10 8 cells / mL.

[0049] (3) The established bioleaching system was placed in a constant-temperature shaker, and the temperature was controlled at 30°C and the shaking speed was controlled at 170 rpm. The changes in the concentrations of related elements in the solution, the pH, and the oxidation-reduction potential were monitored regularly during the leaching process. After 25 days of bioleaching, the bioleaching system was taken out of the shaker, and after sufficient standing, solid-liquid separation was performed to obtain a valuable metal-enriched solution. The final leaching rates of Cu and Ni were 59.3% and 61.2%, respectively.

[0050] Example 2

[0051] (1) The 0K medium was prepared, and the components of the 0K medium were the same as in Example 1. A sulfuric acid solution with the same concentration as in Example 1 was also prepared for adjusting the pH of the medium.

[0052] (2) The sterilized 0K medium was poured into the reaction system, and the liquid volume was controlled to be 1 / 3 of the total volume of the reaction container. The initial pH of the medium was adjusted to 1.8 using 1 mol / L dilute sulfuric acid. Then, a high-magnesium low-grade copper-nickel sulfide ore was added at a slurry concentration of 10 g / L. The bacteria in the Mg 2+Acidithiobacillus ferrooxidans acclimated at a concentration of 2.0 g / L and pH = 6.0 was inoculated into the copper-nickel sulfide ore bioleaching system at a concentration of 1 x 10 8 cells / mL.

[0053] (3) The established bioleaching system was placed in a constant temperature shaker, the temperature was controlled at 30°C, the shaking speed was 170 rpm, and the solution related element concentration, pH, redox potential and other parameters were monitored periodically during the leaching process. After 25 days of bioleaching, the bioleaching system was taken out of the shaker, and after sufficient standing, solid-liquid separation was performed to obtain a valuable metal enriched solution. The final leaching rates of Cu and Ni were 61.8% and 59.6%, respectively.

[0054] Example 3

[0055] (1) 0K medium was prepared, the components of the 0K medium were the same as in Example 1; and a sulfuric acid solution with the same concentration as in Example 1 was also prepared for adjusting the pH of the medium.

[0056] (2) The sterilized 0K medium was poured into the reaction system, the liquid volume was controlled to be 1 / 3 of the total volume of the reaction container, and the initial pH of the medium was adjusted to 1.9 with 1 mol / L dilute sulfuric acid. Then, high-magnesium low-grade copper-nickel sulfide ore was added at a concentration of 10 g / L. The inoculation of Acidithiobacillus ferrooxidans was performed at a concentration of 1 x 10 2+ cells / mL. 8 cells / mL.

[0057] (3) The established bioleaching system was placed in a constant temperature shaker, the temperature was controlled at 30°C, the shaking speed was 170 rpm, and the solution related element concentration, pH, redox potential and other parameters were monitored periodically during the leaching process. After 25 days of bioleaching, the bioleaching system was taken out of the shaker, and after sufficient standing, solid-liquid separation was performed to obtain a valuable metal enriched solution. The final leaching rates of Cu and Ni were 61.8% and 59.6%, respectively.

[0058] Example 4

[0059] (1) 0K medium was prepared, the components of the 0K medium were the same as in Example 1; and a sulfuric acid solution with the same concentration as in Example 1 was also prepared for adjusting the pH of the medium.

[0060] (2) Pour the sterilized 0K medium into the reaction system, control the liquid volume to be 1 / 3 of the total volume of the reaction vessel, and adjust the initial pH of the medium to 2.2 with 1 mol / L dilute sulfuric acid. Then add the high-magnesium low-grade copper-nickel sulfide ore with a pulp concentration of 10 g / L. The Mg 2+ concentration of 2.0 g / L and pH = 6.0, inoculate Acidithiobacillus ferrooxidans with a cell concentration of 1 x 10 8 cells / mL into the copper-nickel sulfide ore bioleaching system.

[0061] (3) Place the established bioleaching system in a constant temperature shaker, control the temperature to be 30°C, and the shaking speed to be 170 rpm. Monitor the changes of the related element concentrations, pH, and redox potential of the solution during the leaching process. After 25 days of bioleaching, take the bioleaching system out of the shaker, perform solid-liquid separation after sufficient standing, and obtain the valuable metal enrichment solution. The final leaching rates of Cu and Ni are 63.7% and 60.1%, respectively.

[0062] Example 5

[0063] (1) Prepare 0K medium, the components of which are the same as in Example 1; and prepare sulfuric acid solution with the same concentration as in Example 1 for adjusting the pH of the medium.

[0064] (2) Pour the sterilized 0K medium into the reaction system, control the liquid volume to be 1 / 3 of the total volume of the reaction vessel, and adjust the initial pH of the medium to 1.9 with 1 mol / L dilute sulfuric acid. Then add the high-magnesium low-grade copper-nickel sulfide ore with a pulp concentration of 8 g / L. The Mg 2+ concentration of 2.0 g / L and pH = 6.0, inoculate Acidithiobacillus thiooxidans with a cell concentration of 1 x 10 8 cells / mL into the copper-nickel sulfide ore bioleaching system.

[0065] (3) Place the established bioleaching system in a constant temperature shaker, control the temperature to be 30°C, and the shaking speed to be 170 rpm. Monitor the changes of the related element concentrations, pH, and redox potential of the solution during the leaching process. After 25 days of bioleaching, take the bioleaching system out of the shaker, perform solid-liquid separation after sufficient standing, and obtain the valuable metal enrichment solution. The final leaching rates of Cu and Ni are 89.7% and 93.2%, respectively.

[0066] Example 6

[0067] (1) Preparation of 0K medium, the components of which are the same as in Example 1; at the same time, a sulfuric acid solution with the same concentration as in Example 1 is prepared for adjusting the pH of the medium.

[0068] (2) Pour the sterilized 0K medium into the reaction system, control the liquid volume to be 1 / 3 of the total volume of the reaction vessel, and adjust the initial pH of the medium to 1.9 with 1 mol / L dilute sulfuric acid. Then, add the high-magnesium low-grade copper-nickel sulfide ore at a pulp concentration of 10 g / L. Inoculate the Acidithiobacillus thiooxidans acclimated at a Mg 2+ concentration of 2.0 g / L and pH = 6.0 into the copper-nickel sulfide ore bioleaching system at a bacterial concentration of 1 x 10 8 cells / mL.

[0069] (3) Place the established bioleaching system in a constant-temperature shaker, control the temperature to be 30°C and the shaking speed to be 170 rpm, and monitor the changes in the concentration of relevant elements in the solution, pH, redox potential and other parameters during the leaching process. After 25 days of bioleaching, take the bioleaching system out of the shaker, separate the solid and liquid after sufficient standing, and obtain the valuable metal-enriched solution. The final leaching rates of Cu and Ni are 90.4% and 92.9%, respectively.

[0070] Example 7

[0071] (1) Preparation of 0K medium, the components of which are the same as in Example 1; at the same time, a sulfuric acid solution with the same concentration as in Example 1 is prepared for adjusting the pH of the medium.

[0072] (2) Pour the sterilized 0K medium into the reaction system, control the liquid volume to be 1 / 3 of the total volume of the reaction vessel, and adjust the initial pH of the medium to 1.9 with 1 mol / L dilute sulfuric acid. Then, add the high-magnesium low-grade copper-nickel sulfide ore at a pulp concentration of 10 g / L. Inoculate the Acidithiobacillus thiooxidans acclimated at a Mg 2+ concentration of 2.0 g / L and pH = 6.0 into the copper-nickel sulfide ore bioleaching system at a bacterial concentration of 1 x 10 8 cells / mL.

[0073] (3) Place the established bioleaching system in a constant-temperature shaker, control the temperature to be 30°C and the shaking speed to be 170 rpm, and monitor the changes in the concentration of relevant elements in the solution, pH, redox potential and other parameters during the leaching process.

[0074] (4) After the leaching reaction in step (3) is carried out to the 8th day, 1 mol / L H2SO4 is supplemented to the bioleaching system in 3 times (each time interval is 1 day, and the pH of the leaching system solution is adjusted to 2.0 at one time).

[0075] (5) After the bioleaching is carried out for 25 days, the bioleaching system is taken out from the oscillator, and after being fully static, solid-liquid separation is carried out to obtain a valuable metal enrichment solution. The final leaching rates of Cu and Ni are 90.8% and 91.5%, respectively.

[0076] Example 8

[0077] (1) The 0K medium is prepared, and the components of the 0K medium are the same as those in Example 1; and a sulfuric acid solution with the same concentration as in Example 1 is configured to adjust the pH of the medium.

[0078] (2) The sterilized 0K medium is poured into the reaction system, and the liquid volume is controlled to be 1 / 3 of the total volume of the reaction container. The initial pH of the medium is adjusted to 1.9 by using 1 mol / L dilute sulfuric acid. Then, the high-magnesium low-grade copper-nickel sulfide ore is added at a slurry concentration of 12 g / L. The Acidithiobacillus thiooxidans acclimated under the conditions of Mg 2+ concentration of 2.0 g / L and pH=6.0 is inoculated into the copper-nickel sulfide ore bioleaching system at a cell concentration of 1×10 8 cells / mL.

[0079] (3) The established bioleaching system is placed in a constant-temperature oscillator, and the temperature is controlled to be 30°C, and the oscillation speed is controlled to be 170 rpm. The leaching process is regularly monitored for changes in the concentration of related elements in the solution, pH, redox potential and other parameters. After 25 days of bioleaching, the bioleaching system is taken out from the oscillator, and after being fully static, solid-liquid separation is carried out to obtain a valuable metal enrichment solution. The final leaching rates of Cu and Ni are 81.9% and 86.4%, respectively.

[0080] Example 9

[0081] (1) The 0K medium is prepared, and the components of the 0K medium are the same as those in Example 1; and a sulfuric acid solution with the same concentration as in Example 1 is configured to adjust the pH of the medium.

[0082] (2) The sterilized 0K medium is poured into the reaction system, and the liquid volume is controlled to be 1 / 3 of the total volume of the reaction container. The initial pH of the medium is adjusted to 1.9 by using 1 mol / L dilute sulfuric acid. Then, the high-magnesium low-grade copper-nickel sulfide ore is added at a slurry concentration of 10 g / L. The Acidithiobacillus thiooxidans acclimated under the conditions of Mg 2+Sulfobacillus thermosulfidooxidans acclimated at a concentration of 2.0 g / L and pH = 6.0 was inoculated into the copper-nickel sulfide ore bioleaching system at a concentration of 1 x 10 8 cells / mL.

[0083] (3) The established bioleaching system was placed in a constant temperature shaker, the temperature was controlled at 30°C, the shaking speed was 170 rpm, and the changes in the concentration of relevant elements in the solution, pH, and redox potential were monitored periodically during the leaching process. After 25 days of bioleaching, the bioleaching system was taken out of the shaker, and after sufficient standing, solid-liquid separation was performed to obtain a valuable metal-enriched solution. The final leaching rates of Cu and Ni were 89.6% and 91.3%, respectively.

[0084] Example 10

[0085] (1) 0K medium was prepared, and the components of the 0K medium were the same as in Example 1; and a sulfuric acid solution with the same concentration as in Example 1 was also prepared for adjusting the pH of the medium.

[0086] (2) The sterilized 0K medium was poured into the reaction system, and the liquid volume was controlled to be 1 / 3 of the total volume of the reaction container. The initial pH of the medium was adjusted to 1.9 with 1 mol / L dilute sulfuric acid. Then, high-magnesium low-grade copper-nickel sulfide ore was added at a concentration of 10 g / L. The Mg 2+ Acidithiobacillus caldus acclimated at a concentration of 2.0 g / L and pH = 6.0 was inoculated into the copper-nickel sulfide ore bioleaching system at a concentration of 1 x 10 8 cells / mL.

[0087] (3) The established bioleaching system was placed in a constant temperature shaker, the temperature was controlled at 45°C, the shaking speed was 170 rpm, and the changes in the concentration of relevant elements in the solution, pH, and redox potential were monitored periodically during the leaching process. After 25 days of bioleaching, the bioleaching system was taken out of the shaker, and after sufficient standing, solid-liquid separation was performed to obtain a valuable metal-enriched solution. The final leaching rates of Cu and Ni were 88.1% and 85.9%, respectively.

[0088] Example 11

[0089] (1) 0K medium was prepared, and the components of the 0K medium were the same as in Example 1; and a sulfuric acid solution with the same concentration as in Example 1 was also prepared for adjusting the pH of the medium.

[0090] (2) The sterilized 0K medium was poured into the reaction system, and the liquid volume was controlled to be 1 / 3 of the total volume of the reaction vessel. The initial pH of the medium was adjusted to 1.9 with 1 mol / L dilute sulfuric acid. Then, the high-magnesium low-grade copper-nickel sulfide ore was added at a slurry concentration of 10 g / L. The Mg 2+ concentrated to 2.0 g / L and pH = 6.0 was inoculated into the copper-nickel sulfide ore bioleaching system at a bacterial concentration of 1 x 10 8 cells / mL.

[0091] (3) The established bioleaching system was placed in a constant temperature shaker, and the temperature was controlled at 30°C and the shaking speed was 170 rpm. The changes in the concentrations of related elements, pH, and redox potential were monitored during the leaching process. After 25 days of bioleaching, the bioleaching system was taken out of the shaker, and after sufficient standing, solid-liquid separation was performed to obtain a valuable metal-enriched solution. The final leaching rates of Cu and Ni were 91.8% and 93.6%, respectively.

[0092] Example 12

[0093] (1) 9K medium was prepared, and the formula of the 9K medium was as follows: (NH4)2SO4, 3.0 g / L; MgSO4, 0.5 g / L; K2HPO4, 0.5 g / L; KCl, 0.1 g / L; Ca(NO3)2, 0.01 g / L; FeSO4 7H2O, 44.8 g / L; and a sulfuric acid solution with the same concentration as in Example 1 was also prepared for adjusting the pH of the medium.

[0094] (2) The sterilized 9K medium was poured into the reaction system, and the liquid volume was controlled to be 1 / 3 of the total volume of the reaction vessel. The initial pH of the medium was adjusted to 1.9 with 1 mol / L dilute sulfuric acid. Then, the high-magnesium low-grade copper-nickel sulfide ore was added at a slurry concentration of 10 g / L. The Mg 2+ concentrated to 2.0 g / L and pH = 6.0 was inoculated into the copper-nickel sulfide ore bioleaching system at a bacterial concentration of 1 x 10 8 cells / mL.

[0095] (3) The established bioleaching system was placed in a constant temperature shaker, the temperature was controlled at 30°C, and the shaking speed was 170 rpm. The changes of the concentration of relevant elements, pH, and redox potential were monitored regularly during the bioleaching process. After 25 days of bioleaching, the bioleaching system was taken out of the shaker, and the solid-liquid separation was performed after sufficient standing to obtain the valuable metal-rich solution. The final leaching rates of Cu and Ni were 85.9% and 89.1%, respectively.

[0096] Example 13

[0097] (1) The simple culture medium was configured by removing (NH4)2SO4 (3.0 g / L), K2HPO4 (0.5 g / L), and KCl (0.1 g / L) in the 0K culture medium component; and the sulfuric acid solution with the same concentration as in Example 1 was configured to adjust the pH of the culture medium.

[0098] (2) The sterilized simple culture medium was poured into the reaction system, and the liquid volume was controlled to be 1 / 3 of the total volume of the reaction container. The initial pH of the culture medium was adjusted to 1.9 by using 1 mol / L dilute sulfuric acid. Then, the high-magnesium low-grade copper-nickel sulfide ore was added at a slurry concentration of 10 g / L. The Acidithiobacillus thiooxidans acclimated at a Mg2+ concentration of 2.0 g / L and pH = 6.0 was inoculated into the copper-nickel sulfide ore bioleaching system at a cell concentration of 1 x 10 2+ 8 cells / mL.

[0099] (3) The established bioleaching system was placed in a constant temperature shaker, the temperature was controlled at 30°C, and the shaking speed was 170 rpm. The changes of the concentration of relevant elements, pH, and redox potential were monitored regularly during the bioleaching process. After 25 days of bioleaching, the bioleaching system was taken out of the shaker, and the solid-liquid separation was performed after sufficient standing to obtain the valuable metal-rich solution. The final leaching rates of Cu and Ni were 85.9% and 89.1%, respectively.

[0100] Example 14

[0101] (1) The simple culture medium was configured by removing (NH4)2SO4 (3.0 g / L), K2HPO4 (0.5 g / L), and KCl (0.1 g / L) in the 0K culture medium component; and the sulfuric acid solution with the same concentration as in Example 1 was configured to adjust the pH of the culture medium.

[0102] (2) The sterilized simple culture medium was poured into the reaction system, and the liquid volume was controlled to be 1 / 3 of the total volume of the reaction container. The initial pH of the culture medium was adjusted to 1.9 by using 1 mol / L dilute sulfuric acid. Then, the high-magnesium low-grade copper-nickel sulfide ore was added at a slurry concentration of 10 g / L. The Acidithiobacillus thiooxidans acclimated at a Mg2+ concentration of 2.0 g / L and pH = 6.0 was inoculated into the copper-nickel sulfide ore bioleaching system at a cell concentration of 1 x 10 2+ 8 cells / mL.​cells / mL inoculated into the copper nickel sulfide ore bioleaching system.

[0103] (3) The established bioleaching system was placed in a constant temperature shaker, the temperature was controlled at 30°C, and the shaking speed was 170 rpm. The changes in the concentration of relevant elements in the solution, pH, and redox potential were monitored periodically during the leaching process. After 25 days of bioleaching, the bioleaching system was removed from the shaker, and after sufficient standing, solid-liquid separation was performed to obtain a valuable metal-enriched solution. The final leaching rates of Cu and Ni were 88.9% and 90.7%, respectively.

[0104] Comparative Example 1

[0105] (1) 0K medium was prepared, and the components of the 0K medium were the same as in Example 1. A sulfuric acid solution with the same concentration as in Example 1 was also prepared to adjust the pH of the medium.

[0106] (2) The sterilized 0K medium was poured into the reaction system, and the liquid volume was controlled to be 1 / 3 of the total volume of the reaction container. The initial pH of the medium was adjusted to 1.9 with 1 mol / L dilute sulfuric acid. Then, high-magnesium low-grade copper nickel sulfide ore was added at a slurry concentration of 10 g / L. Unacclimated Acidithiobacillus ferrooxidans was inoculated into the bioleaching system at a concentration of 1 x 10 8 cells / mL inoculated into the copper nickel sulfide ore bioleaching system.

[0107] (3) The established bioleaching system was placed in a constant temperature shaker, the temperature was controlled at 30°C, and the shaking speed was 170 rpm. The changes in the concentration of relevant elements in the solution, pH, and redox potential were monitored periodically during the leaching process. After 25 days of bioleaching, the bioleaching system was removed from the shaker, and after sufficient standing, solid-liquid separation was performed to obtain a valuable metal-enriched solution. The final leaching rates of Cu and Ni were 88.9% and 90.7%, respectively.

[0108] Comparative Example 2

[0109] (1) 0K medium was prepared, and the components of the 0K medium were the same as in Example 1. A sulfuric acid solution with the same concentration as in Example 1 was also prepared to adjust the pH of the medium.

[0110] (2) The sterilized 0K medium was poured into the reaction system, and the liquid volume was controlled to be 1 / 3 of the total volume of the reaction container. The initial pH of the medium was adjusted to 1.9 with 1 mol / L dilute sulfuric acid. Then, high-magnesium low-grade copper nickel sulfide ore was added at a slurry concentration of 10 g / L. Unacclimated Acidithiobacillus ferrooxidans was inoculated into the bioleaching system at a concentration of 1 x 10 8cells / mL were inoculated into the copper nickel sulfide ore bioleaching system.

[0111] (3) The established bioleaching system was placed in a constant temperature shaker, the temperature was controlled at 30°C, the shaking speed was 170 rpm, and the leaching process was monitored regularly for changes in solution related element concentration, pH, redox potential and other parameters. After 25 days of bioleaching, the bioleaching system was taken out of the shaker, and after sufficient standing, solid-liquid separation was performed to obtain a valuable metal enriched solution. The final leaching rates of Cu and Ni were 35.8% and 40.3%, respectively.

[0112] Comparative Example 3

[0113] (1) Prepare 0K medium, the components of the 0K medium are the same as in Example 1; at the same time, prepare a sulfuric acid solution with the same concentration as in Example 1 for adjusting the pH of the medium.

[0114] (2) Pour the sterilized 0K medium into the reaction system, control the liquid volume to be 1 / 3 of the total volume of the reaction container, and adjust the initial pH of the medium to 1.6 with 1 mol / L dilute sulfuric acid. Then add high-magnesium low-grade copper nickel sulfide ore with a slurry concentration of 10 g / L. No acidophilic leaching bacteria are added.

[0115] (3) The established copper nickel sulfide ore leaching system was placed in a constant temperature shaker, the temperature was controlled at 30°C, the shaking speed was 170 rpm, and the leaching process was monitored regularly for changes in solution related element concentration, pH, redox potential and other parameters. After 25 days of reaction, the leaching system was taken out of the shaker, and after sufficient standing, solid-liquid separation was performed to obtain a valuable metal enriched solution. The final leaching rates of Cu and Ni were 12.2% and 16.1%, respectively.

[0116] Comparative Example 4

[0117] (1) Prepare 0K medium, the components of the 0K medium are the same as in Example 1; at the same time, prepare a sulfuric acid solution with the same concentration as in Example 1 for adjusting the pH of the medium.

[0118] (2) Pour the sterilized 0K medium into the reaction system, control the liquid volume to be 1 / 3 of the total volume of the reaction container, and adjust the initial pH of the medium to 1.8 with 1 mol / L dilute sulfuric acid. Then add high-magnesium low-grade copper nickel sulfide ore with a slurry concentration of 10 g / L. No acidophilic leaching bacteria are added.

[0119] (3) The established copper nickel sulfide ore leaching system was placed in a constant temperature shaker, the temperature was controlled at 30°C, the shaking speed was 170 rpm, and the solution related element concentration, pH, redox potential and other parameters were monitored periodically during the leaching process. After 25 days of reaction, the leaching system was taken out of the shaker, and after sufficient standing, solid-liquid separation was carried out to obtain a valuable metal enriched solution. The final leaching rates of Cu and Ni were 17.8% and 19.2%, respectively.

[0120] Comparative Example 5

[0121] (1) Prepare 0K medium, the components of the 0K medium are the same as in Example 1; at the same time, prepare a sulfuric acid solution with the same concentration as in Example 1 for adjusting the pH of the medium.

[0122] (2) Pour the sterilized 0K medium into the reaction system, control the liquid volume to be 1 / 3 of the total volume of the reaction container, and adjust the initial pH of the medium to 1.9 with 1 mol / L dilute sulfuric acid. Then add high-magnesium low-grade copper nickel sulfide ore with a slurry concentration of 10 g / L. No acidophilic leaching bacteria are inoculated.

[0123] (3) The established copper nickel sulfide ore leaching system was placed in a constant temperature shaker, the temperature was controlled at 30°C, the shaking speed was 170 rpm, and the solution related element concentration, pH, redox potential and other parameters were monitored periodically during the leaching process. After 25 days of reaction, the leaching system was taken out of the shaker, and after sufficient standing, solid-liquid separation was carried out to obtain a valuable metal enriched solution. The final leaching rates of Cu and Ni were 17.8% and 19.2%, respectively.

[0124] Comparative Example 6

[0125] (1) Prepare 0K medium, the components of the 0K medium are the same as in Example 1; at the same time, prepare a sulfuric acid solution with the same concentration as in Example 1 for adjusting the pH of the medium.

[0126] (2) Pour the sterilized 0K medium into the reaction system, control the liquid volume to be 1 / 3 of the total volume of the reaction container, and adjust the initial pH of the medium to 1.9 with 1 mol / L dilute sulfuric acid. Then add high-magnesium low-grade copper nickel sulfide ore with a slurry concentration of 10 g / L. No acidophilic leaching bacteria are inoculated.

[0127] (3) The established copper nickel sulfide ore leaching system was placed in a constant temperature shaker, the temperature was controlled at 30°C, the shaking speed was 170 rpm, and the solution related element concentration, pH, redox potential and other parameters were monitored periodically during the leaching process.

[0128] (4) After the leaching reaction in step (3) is carried out for 8 days, 1 mol / L H2SO4 is supplemented to the leaching system in 3 times (each time interval is 1 day, and the pH of the leaching system solution is adjusted to 2.0 at one time).

[0129] (5) After the reaction is carried out for 25 days, the leaching system is taken out from the oscillator, and after being fully static, solid-liquid separation is carried out to obtain a valuable metal enrichment solution. The final leaching rates of Cu and Ni are 15.3% and 18.9%, respectively.

[0130] Comparative Example 7

[0131] (1) 0K medium is prepared, and the components of the 0K medium are the same as those in Example 1; and a sulfuric acid solution with the same concentration as that in Example 1 is configured to adjust the pH of the medium.

[0132] (2) The sterilized 0K medium is poured into the reaction system, and the liquid volume is controlled to be 1 / 3 of the total volume of the reaction container. The initial pH of the medium is adjusted to 2.2 by using 1 mol / L dilute sulfuric acid. Then, the high-magnesium low-grade copper-nickel sulfide ore is added at a slurry concentration of 10 g / L. No acidophilic leaching bacteria is inoculated.

[0133] (3) The established copper-nickel sulfide ore leaching system is placed in a constant temperature oscillator, and the temperature is controlled to be 30°C and the oscillation speed is controlled to be 170 rpm. The changes of the concentration of related elements in the solution, the pH and the redox potential are monitored regularly during the leaching process. After the reaction is carried out for 25 days, the leaching system is taken out from the oscillator, and after being fully static, solid-liquid separation is carried out to obtain a valuable metal enrichment solution. The final leaching rates of Cu and Ni are 7.3% and 10.7%, respectively.

[0134] Comparative Example 8

[0135] (1) 0K medium is prepared, and the components of the 0K medium are the same as those in Example 1; and a sulfuric acid solution with the same concentration as that in Example 1 is configured to adjust the pH of the medium.

[0136] (2) The sterilized 0K medium is poured into the reaction system, and the liquid volume is controlled to be 1 / 3 of the total volume of the reaction container. The initial pH of the medium is adjusted to 1.9 by using 1 mol / L dilute sulfuric acid. Then, the high-magnesium low-grade copper-nickel sulfide ore is added at a slurry concentration of 8 g / L. No acidophilic leaching bacteria is inoculated.

[0137] (3) The established copper-nickel sulfide ore leaching system is placed in a constant temperature oscillator, and the temperature is controlled to be 30°C and the oscillation speed is controlled to be 170 rpm. The changes of the concentration of related elements in the solution, the pH and the redox potential are monitored regularly during the leaching process. After the reaction is carried out for 25 days, the leaching system is taken out from the oscillator, and after being fully static, solid-liquid separation is carried out to obtain a valuable metal enrichment solution. The final leaching rates of Cu and Ni are 16.5% and 19.1%, respectively.

[0138] Comparative Example 9

[0139] (1) Prepare 0K medium, the components of which are the same as in Example 1; at the same time, prepare a sulfuric acid solution with the same concentration as in Example 1 for adjusting the pH of the medium.

[0140] (2) Pour the sterilized 0K medium into the reaction system, control the liquid volume to be 1 / 3 of the total volume of the reaction container, and adjust the initial pH of the medium to 1.9 with 1 mol / L dilute sulfuric acid. Then add the high-magnesium low-grade copper-nickel sulfide ore with a pulp concentration of 12 g / L. No acidophilic leaching bacteria are inoculated.

[0141] (3) Place the established copper-nickel sulfide ore leaching system in a constant temperature shaker, control the temperature to be 30°C, and the shaking speed to be 170 rpm. Monitor the changes in the concentration of relevant elements, pH, and redox potential of the solution during the leaching process. After 25 days of reaction, take the leaching system out of the shaker, perform solid-liquid separation after sufficient standing, and obtain a valuable metal-rich solution. The final leaching rates of Cu and Ni are 13.5% and 11.7%, respectively.

[0142] Comparative Example 10

[0143] (1) Prepare 0K medium, the components of which are the same as in Example 1; at the same time, prepare a sulfuric acid solution with the same concentration as in Example 1 for adjusting the pH of the medium.

[0144] (2) Pour the sterilized 0K medium into the reaction system, control the liquid volume to be 1 / 3 of the total volume of the reaction container, and adjust the initial pH of the medium to 1.9 with 1 mol / L dilute sulfuric acid. Then add the high-magnesium low-grade copper-nickel sulfide ore with a pulp concentration of 12 g / L. No acidophilic leaching bacteria are inoculated.

[0145] (3) Place the established copper-nickel sulfide ore leaching system in a constant temperature shaker, control the temperature to be 30°C, and the shaking speed to be 170 rpm. Monitor the changes in the concentration of relevant elements, pH, and redox potential of the solution during the leaching process. After 25 days of reaction, take the leaching system out of the shaker, perform solid-liquid separation after sufficient standing, and obtain a valuable metal-rich solution. The final leaching rates of Cu and Ni are 13.5% and 11.7%, respectively.

[0146] Comparative Example 11

[0147] (1) Prepare 0K medium, the components of which are the same as in Example 1; at the same time, prepare a sulfuric acid solution with the same concentration as in Example 1 for adjusting the pH of the medium.

[0148] (2) Pour the sterilized 0K medium into the reaction system, control the liquid volume to be 1 / 3 of the total volume of the reaction vessel, and adjust the initial pH of the medium to 1.9 with 1 mol / L dilute sulfuric acid. Then add the high-magnesium low-grade copper-nickel sulfide ore with a slurry concentration of 10 g / L. No acidophilic leaching bacteria are inoculated.

[0149] (3) Place the established copper-nickel sulfide ore leaching system in a constant temperature oscillator, control the temperature to be 25°C, and the oscillation speed to be 170 rpm. Monitor the changes of the solution related element concentration, pH, and redox potential during the leaching process. After 25 days of reaction, take the leaching system out of the oscillator, perform solid-liquid separation after sufficient standing, and obtain the valuable metal enriched solution. The final leaching rates of Cu and Ni are 6.6% and 9.2%, respectively.

[0150] Comparative Example 12

[0151] (1) Prepare 9K medium, the components of which are the same as those in Example 12; at the same time, prepare a sulfuric acid solution with the same concentration as in Example 1 for adjusting the pH of the medium.

[0152] (2) Pour the sterilized 9K medium into the reaction system, control the liquid volume to be 1 / 3 of the total volume of the reaction vessel, and adjust the initial pH of the medium to 1.9 with 1 mol / L dilute sulfuric acid. Then add the high-magnesium low-grade copper-nickel sulfide ore with a slurry concentration of 10 g / L. No acidophilic leaching bacteria are inoculated.

[0153] (3) Place the established copper-nickel sulfide ore leaching system in a constant temperature oscillator, control the temperature to be 40°C, and the oscillation speed to be 170 rpm. Monitor the changes of the solution related element concentration, pH, and redox potential during the leaching process. After 25 days of reaction, take the leaching system out of the oscillator, perform solid-liquid separation after sufficient standing, and obtain the valuable metal enriched solution. The final leaching rates of Cu and Ni are 11.3% and 8.9%, respectively.

[0154] Comparative Example 13

[0155] (1) Prepare 9K medium, the components of which are the same as those in Example 12; at the same time, prepare a sulfuric acid solution with the same concentration as in Example 1 for adjusting the pH of the medium.

[0156] (2) Pour the sterilized 9K medium into the reaction system, control the liquid volume to be 1 / 3 of the total volume of the reaction vessel, and adjust the initial pH of the medium to 1.9 with 1 mol / L dilute sulfuric acid. Then add the high-magnesium low-grade copper-nickel sulfide ore with a slurry concentration of 10 g / L. No acidophilic leaching bacteria are inoculated.

[0157] (3) The established leaching system of copper nickel sulfide ore was placed in a constant temperature shaker, the temperature was controlled at 40°C, the oscillation speed was 170 rpm, and the leaching process was monitored regularly for changes in the concentration of relevant elements in the solution, pH, redox potential and other parameters. After 25 days of reaction, the leaching system was taken out of the shaker, and after sufficient static state, solid-liquid separation was carried out to obtain a valuable metal-rich solution. The final leaching rates of Cu and Ni were 13.2% and 10.7%, respectively.

[0158] Comparative Example 14

[0159] (1) A simplified culture medium was configured, i.e. (NH4)2SO4 (3.0 g / L), K2HPO4 (0.5 g / L) and KCl (0.1 g / L) were removed from the 0K culture medium components; at the same time, a sulfuric acid solution with the same concentration as in Example 1 was configured to adjust the pH of the culture medium.

[0160] (2) The sterilized simplified culture medium was poured into the reaction system, the liquid volume was controlled to be 1 / 3 of the total volume of the reaction container, and the initial pH of the culture medium was adjusted to 1.9 with 1 mol / L dilute sulfuric acid. Then, high-magnesium low-grade copper nickel sulfide ore was added at a slurry concentration of 10 g / L. No acidophilic leaching bacteria were inoculated.

[0161] (3) The established leaching system of copper nickel sulfide ore was placed in a constant temperature shaker, the temperature was controlled at 25°C, the oscillation speed was 170 rpm, and the leaching process was monitored regularly for changes in the concentration of relevant elements in the solution, pH, redox potential and other parameters. After 25 days of reaction, the leaching system was taken out of the shaker, and after sufficient static state, solid-liquid separation was carried out to obtain a valuable metal-rich solution. The final leaching rates of Cu and Ni were 11.4% and 14.5%, respectively.

[0162] Comparative Example 15

[0163] (1) Directly replace the culture medium with dilute sulfuric acid alone.

[0164] (2) The sterilized dilute sulfuric acid was poured into the reaction system, the liquid volume was controlled to be 1 / 3 of the total volume of the reaction container, and the pH of the dilute sulfuric acid was diluted to 1.9 with deionized water. Then, high-magnesium low-grade copper nickel sulfide ore was added at a slurry concentration of 10 g / L. No acidophilic leaching bacteria were inoculated.

[0165] (3) The established leaching system of copper nickel sulfide ore was placed in a constant temperature shaker, the temperature was controlled at 30°C, the oscillation speed was 170 rpm, and the leaching process was monitored regularly for changes in the concentration of relevant elements in the solution, pH, redox potential and other parameters. After 25 days of reaction, the leaching system was taken out of the shaker, and after sufficient static state, solid-liquid separation was carried out to obtain a valuable metal-rich solution. The final leaching rates of Cu and Ni were 14.9% and 17.6%, respectively.

[0166] Comparative Example 16

[0167] (1) The base salt (0K) medium was prepared according to the formulation of Example 1, and a 1 mol / L sulfuric acid solution was prepared for adjusting the pH of the medium.

[0168] (2) The sterilized 0K medium was poured into the reaction system, and the liquid volume was controlled to be 1 / 3 of the total volume of the reaction vessel. The initial pH of the medium was adjusted to 1.9 with 1 mol / L dilute sulfuric acid. Then, the high-magnesium low-grade copper-nickel sulfide ore was added at a slurry concentration of 10 g / L. The unacclimated Acidithiobacillus ferrooxidans was inoculated into the copper-nickel sulfide ore bioleaching system at a cell concentration of 1 x 10 2+ 8 cells / mL.

[0169] (3) The established bioleaching system was placed in a constant-temperature shaker, and the temperature was controlled at 30°C and the shaking speed was controlled at 170 rpm. The changes in the concentrations of relevant elements in the solution, pH, and redox potential were monitored periodically during the leaching process. After 25 days of bioleaching, the bioleaching system was taken out of the shaker, and after sufficient standing, solid-liquid separation was performed to obtain a valuable metal-enriched solution. The final leaching rates of Cu and Ni were 54.2% and 51.9%, respectively.

[0170] Comparative Example 17

[0171] (1) The 0K medium was prepared according to the formulation of Example 1, and a sulfuric acid solution with the same concentration as in Example 1 was prepared for adjusting the pH of the medium.

[0172] (2) The sterilized 0K medium was poured into the reaction system, and the liquid volume was controlled to be 1 / 3 of the total volume of the reaction vessel. The initial pH of the medium was adjusted to 1.9 with 1 mol / L dilute sulfuric acid. Then, the high-magnesium low-grade copper-nickel sulfide ore was added at a slurry concentration of 10 g / L. The unacclimated Acidithiobacillus thiooxidans was inoculated into the copper-nickel sulfide ore bioleaching system at a cell concentration of 1 x 10 8

[0173] (3) The established bioleaching system was placed in a constant-temperature shaker, and the temperature was controlled at 30°C and the shaking speed was controlled at 170 rpm. The changes in the concentrations of relevant elements in the solution, pH, and redox potential were monitored periodically during the leaching process.

[0174] ​​(4) After the leaching reaction in step (3) is carried out to the 8th day, 1 mol / L H2SO4 is supplemented to the bioleaching system in 3 times (each time interval is 1 day, and the pH of the leaching system solution is adjusted to 2.0 in each time).

[0175] (5) After the bioleaching is carried out for 25 days, the bioleaching system is taken out from the oscillator, and after being fully stationary, solid-liquid separation is carried out to obtain a valuable metal enrichment solution. The final leaching rates of Cu and Ni are 58.6% and 61.3%, respectively.

[0176] The above only describes the preferred embodiments of the present application, and it should be noted that for those skilled in the art, some improvements and refinements can be made without departing from the principles of the present application, and these improvements and refinements should also be considered as the protection scope of the present application.

Claims

1. A process for leaching nickel and copper from a high magnesium low grade sulphide copper nickel ore by low acid consuming microorganisms, characterized by: Using Mg 2+ Nickel and copper leaching from minerals by acidophilic leaching bacteria after tolerance and pH increase acclimation; The acclimation process comprises: Mg 2+ resistant to domestication, which can maintain iron-sulfur oxidizing activity under the condition of the concentration of magnesium ions released in the leaching system of high-magnesium low-grade copper-nickel sulfide ore The pulp concentration of sulfide ore is 8-10 g / L; Mg 2+ The concentration range is set to 0.5-2.0 g / L, and 3-5 concentration gradients are set, and each Mg 2+ Acclimated for 7-12 days under the Mg 2+ Dissolved in the form of magnesium sulfate compound; The obtained Mg 2+ The bacteria species resistant to the inoculation of a certain Mg 2+ The culture system with a certain concentration of Mg and concentration of sulfide ore slurry, and gradually increasing the pH value of the leaching solution, to obtain the bacteria species that still maintain the iron and sulfur oxidation activity under the condition of pH increase. gradually increasing the pH of the leach liquor over a period of time as the bacteria move from the log phase to the stationary phase; The Mg 2+ The concentration of the leaching bacteria is 1.5-2.0 g / L, the concentration of the sulfide ore slurry is 8-10 g / L, the time period from the logarithmic growth phase to the stable phase of the leaching bacteria is 4-8 days, the pH adjustment gradient is set to 2.0-6.0, 4-6 gradients are set, and the acclimation time for each pH gradient is 7-12 days.

2. The method of claim 1, wherein, The sulfide ore includes at least one of pyrite, chalcopyrite, bornite, arsenopyrite; the acidophilic leaching bacteria includes at least one of Acidithiobacillus ferroxidans (ATCC 23270) Acidithiobacillus ferrooxidans , moderately thermophilic sulfur-oxidizing Acidithiobacillus thiooxidans (ATCC 19377) Sulfobacillus thermosulfidooxidans , Acidithiobacillus caldus (ATCC 10155) Acidithiobacillus caldus , Acidithiobacillus thiooxidans (ATCC 19377) Acidithiobacillus thiooxidans , and Acidimicrobium ferrophilum (ATCC 49884) Acidianus manzaensis .

3. The method of claim 1, wherein, The sulfide ore and high-magnesium low-grade sulfide copper-nickel ore are ground and passed through a 200-400 mesh screen, and finally screened mineral particles with a particle size in the range of 40-70 microns.

4. The method of claim 1, wherein, The pulp concentration of high magnesium type low grade copper nickel sulfide ore in the bioleaching system is 6-12 g / L; the initial pH of the culture medium is set to 1.6-2.2; the initial inoculation concentration of the acclimated ore leaching bacteria is 0.6-2×10 8 cells / mL.

5. The method according to claim 1 or 4, characterized in that, The rotation speed of the shaker is controlled at 140-190 rpm during the culture process of the high-magnesium low-grade sulfide copper-nickel ore bioleaching system, the culture temperature is 25-50 ℃, and the leaching period is 20-40 days.

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