WO2015090203A1 - Biological method for extracting metal from metallurgical and mineral solid waste - Google Patents

Abstract

A biological method for extracting metal from metallurgical and mineral solid waste comprises: crushing the solid waste, biological soaking, recycling the metal from leachate, and separating the soaked solid waste slag by a gravity concentration method. The method is characterized in that: crushing and sieving the metallurgical and mineral solid waste and then storing same in a biological soaking pool, adding water and stirring to form a slurry, then adding mixed bacteria composed of thiobacillus ferrooxidans, bacillus polymyxa and aspergillus niger into the biological soaking pool to make the number of viable bacteria in the slurry reache 500-1000 million/mL, performing oxygen aeration, soaking, turning over the solid waste once everyday and performing solid-liquid separation to obtain soaked solid waste and leachate, soaking the solid waste remained in the tank repeatedly, recycling the metal in the leachate and performing solid-liquid separation once again, introducing solution from the solid-liquid separation into the biological soaking pool for recycling, and separating the obtained soaked solid waste slag by gravity concentration method after 7-14 days. The treated tailings eventually obtained by the biological method meet the emission requirements according to "Test method standards for extraction toxicity of nonferrous metal solid waste" (GB5085.3-2007).

Description

Method for biologically extracting metals from metallurgical and mining wastes Technical field

This invention relates to mineral beneficiation processing methods, and more particularly to methods for recovering metals from waste minerals.

Background technique

With the development of the economy, human demand for natural resources has risen, mineral resources have become exhausted, and it has to be considered to develop and utilize low-grade mineral resources and recycle tailings. Therefore, higher requirements are placed on mineral processing and metallurgical technology. Microbial engineering technology combined with mineral processing technology has produced microbial metallurgical technology, and its role in mineral resource processing and metallurgy has become increasingly prominent. Microbial metallurgy technology has the characteristics of fully recycling and utilizing mineral resources, low environmental pollution hazard, low investment and low consumption of chemicals, and has broad application prospects. At present, the most widely used leaching microorganisms in China are Thiobacillus ferrooxidans, Thiobacillus thiooxidans, Leptospirillum oxidans, Aspergillus niger and the like.

There are some related literature reports on the use of biotechnology to separate metals from minerals or their wastes, such as:

The minerals treated by these technologies are mainly extracted from a certain target metal in the tailings. The method of leaching metal treatment is only one immersion, the leaching rate is not high, and the final emissions are not considered from an environmental point of view. The waste solids treated by the process are immersed in multiple cycles to ensure that most of the metal inside is leached; there is no waste water discharged during the treatment, and the treated waste solids meet the discharge standards of 5085.3-2007.

Summary of the invention

The object of the present invention is to provide a method for bio-extracting metal in a metallurgical industrial waste solid which is simple, easy to operate, low in cost, low in energy consumption, and capable of reaching the standard discharge, in view of the above-mentioned prior art problems.

The present invention is implemented as follows:

A method for extracting metal by using biotechnology from waste metallurgy in a metallurgical industry, including waste solids crushing, biological soaking, metal recovery in leachate, re-separation of waste solid residue after multiple cycles of soaking, and the like First, the metallurgical and mining waste solids are pulverized into more than 80 mesh and stored in a biological soaking tank. The mixture is stirred into a slurry at a weight ratio of 1:4 to 10, and then added to the biological soaking pool by Thiobacillus ferrooxidans. A mixed cell composed of Bacillus licheniformis and Aspergillus niger causes the viable cell count of the slurry to reach 5 to 1 billion/mL, soaked under normal temperature conditions, once per day, and solid-liquid separation to obtain the waste solid after soaking and The leachate, the waste solids remain in the soaking tank and repeatedly soaked, and then the metal in the leachate is recovered and then separated by solid and liquid again. The discharged water is re-introduced into the biological soaking tank for recycling, and after 7 to 14 days, the waste solid residue after soaking is obtained. Separation by re-selection.

The above-mentioned mixed bacteria consisting of Thiobacillus ferrooxidans (Tf), Bacillus polymyxa and Aspergillus niger has a ratio of active bacteria of 1 to 10:1 to 5: 1 to 5.

The solid-liquid separation described above uses the principle of gravity sedimentation to realize the solid-liquid separation after the soaked slurry flows through the deep-flow tank, the plate-frame filter, and the advection sedimentation tank.

The above-mentioned soaking waste slag re-election method is the final separation of the waste slag after soaking into fine concentrate, medium mine and treated tailings.

The total metal content of the concentrate obtained by the above-mentioned soaking waste slag re-election method can reach 60% (weight ratio, later) or more, and can be directly smelted.

The total metal weight content of the middle ore separated by the soaking waste slag re-selection method described above is between 10% and 20%, and can be used for secondary enrichment and re-election.

The treated tailings separated by the soaking waste slag re-election method described above meets the discharge standard of the Standard Test Method for Leaching Toxicity of Non-Ferrous Metal Solid Wastes (GB5085.3-2007).

DRAWINGS

Figure 1 is a process flow diagram of the present invention.

detailed description

Example 1

A method for biologically extracting metals from metallurgical and mining waste solids, including waste solids crushing, biological soaking, metal recovery in soaking liquid, and separation of waste solid residue after soaking by re-election method, first metallurgy and mining The waste solids are pulverized into powders of 80 mesh or less and put into a biological soaking tank, and the mixture is stirred into a slurry at a weight ratio of 1:4, and at the same time, according to the number of active bacteria 1:1:1, using Thiobacillus ferrooxidans, Bacillus polymyxa and Aspergillus niger is configured with mixed cells, and then the mixed cells are placed in the biological soaking pool to make the viable count of the slurry reach 500 million/mL, soaked under normal temperature conditions, once per day and separated by solid and liquid. After soaking waste solids and leachate, the waste solids remain in the soaking tank and repeatedly soaked, then the metal in the leachate is recovered and then solid-liquid separated again. The discharged water is re-introduced into the biological soaking tank for recycling, and after 7 days, it is soaked. The waste solid residue is separated by re-election method; finally, the waste solid residue after soaking is separated by re-election method to obtain a total metal content of 60% (weight ratio, later) or more, and the total metal content is 10%. 20% of the total ore processed and reaches "non-ferrous metals leaching toxicity of solid wastes Standard Test Method" (GB5085.3-2007) emissions standards tailings.

The solid-liquid separation described above uses the principle of gravity sedimentation to realize the solid-liquid separation after the soaked slurry flows through the deep-flow tank, the plate-frame filter, and the advection sedimentation tank.

Example 2

A method for biologically extracting metals from metallurgical and mining waste solids, including waste solids crushing, biological soaking, metal recovery in soaking liquid, and separation of waste solid residue after soaking by re-election method, first metallurgy and mining The waste solids are pulverized into powders of 80 mesh or less and put into a biological soaking tank, and the mixture is stirred into a slurry at a weight ratio of 1:6, and the ferrobacillus ferrooxidans and Bacillus polymyxa are used in advance according to the number of active bacteria 4:5:5. The Aspergillus niger is configured with mixed cells, and then the mixed cells are placed in the biological soaking pool to make the viable count of the slurry reach 700 million/mL, soaked under normal temperature conditions, once per day and separated by solid and liquid. After soaking waste solids and leachate, the waste solids remain in the soaking tank and repeatedly soaked, then the metal in the leachate is recovered and then solid-liquid separated again. The discharged water is re-introduced into the biological soaking tank for recycling, and after 9 days, it is soaked. The waste solid residue is separated by re-election method; finally, the waste solid residue after soaking is separated by re-election method to obtain a total metal content of 60% (by weight) or more, and the total metal content is 10% to 20%. Between the ore and the process reaches the total "non-ferrous metals leaching toxicity of solid wastes Standard Test Method" (GB5085.3-2007) emissions standards tailings.

The solid-liquid separation described above uses the principle of gravity sedimentation to realize the solid-liquid separation after the soaked slurry flows through the deep-flow tank, the plate-frame filter, and the advection sedimentation tank.

Example 3

A method for biologically extracting metals from metallurgical and mining waste solids, including waste solids crushing, biological soaking, metal recovery in soaking liquid, and separation of waste solid residue after soaking by re-election method, first metallurgy and mining The waste solids are pulverized into powders of 80 mesh or less and put into a biological soaking tank, and stirred in a weight ratio of 1:8 to form a slurry, and at the same time, according to the number of active bacteria 8:3:3, using Thiobacillus ferrooxidans, Bacillus polymyxa and Aspergillus niger is configured with mixed cells, and then the mixed cells are placed in the biological soaking pool to make the viable count of the slurry reach 800 million/mL, soaked under normal temperature conditions, once per day and separated by solid and liquid. After soaking the waste solids and leachate, the waste solids remain in the soaking tank and repeatedly soaked, then the metal in the leachate is recovered and then solid-liquid separated again. The discharged water is re-introduced into the biological soaking tank for recycling, and after 11 days, it is soaked. The waste solid residue is separated by re-election method; finally, the soaked waste solid residue is separated by re-election method to obtain a total metal content of up to 60% (weight The ratio of the above concentrates and the total metal content between 10% and 20% of the medium ore and the discharge standard of the "Standard for the Test Method of Leaching Toxicity of Nonferrous Metallic Solid Wastes" (GB5085.3-2007) .

The solid-liquid separation described above uses the principle of gravity sedimentation to realize the solid-liquid separation after the soaked slurry flows through the deep-flow tank, the plate-frame filter, and the advection sedimentation tank.

Example 4

A method for biologically extracting metals from metallurgical and mining waste solids, including waste solids crushing, biological soaking, metal recovery in soaking liquid, and separation of waste solid residue after soaking by re-election method, first metallurgy and mining The waste solids are pulverized into powders of 80 mesh or less and put into a biological soaking tank, and stirred at a weight ratio of 1:10 to form a slurry, and at the same time, according to the number of active bacteria 10:2:2, using Thiobacillus ferrooxidans, Bacillus polymyxa and Aspergillus niger is configured with mixed cells, and then the mixed cells are placed in the biological soaking pool to make the viable count of the slurry reach 1 billion/mL, soaked under normal temperature conditions, once per day and separated by solid and liquid. After soaking the waste solids and leachate, the waste solids remain in the soaking tank and repeatedly soaked, then the metal in the leachate is recovered and then solid-liquid separated again. The discharged water is re-introduced into the biological soaking tank for recycling, and after 14 days, it is soaked. The waste solid residue is separated by re-election method; finally, the waste solid residue after soaking is separated by re-election method to obtain a total metal content of 60% (by weight) or more, and the total metal content is 10%-20 Between the ore and the process reaches the total "non-ferrous metals leaching toxicity of solid wastes Standard Test Method" (GB5085.3-2007) emissions standards tailings.

The solid-liquid separation described above uses the principle of gravity sedimentation to realize the solid-liquid separation after the soaked slurry flows through the deep-flow tank, the plate-frame filter, and the advection sedimentation tank.

Effect of the invention:

After treating the mine waste solids with the method of the present invention in Guangxi Rongshui, it has a significant effect:

1. The leaching effect of various metals after treatment is obvious, as shown in Table 1.

Table 1. Various metal contents using the present invention before and after treatment (% by weight)

Component Sn Zn Cu SiO ₂ Al ₂ O ₃ Mn SO ₃ As Fe ₂ O ₃ Pb Before treatment 0.6 0.6 0.3 38 13 0.2 6.8 0.2 25 0.2 After processing 0.1 0.03 0.02 77 6.0 0.1 0.7 0.01 4.4 0.02

2. After treatment, the tailings fully meet the emission standards of the Standard Test Method for Leaching Toxicity of Non-Ferrous Metal Solid Wastes (GB5085.3-2007). See table 2 for comparison.

Table 2: Comparison of the concentration of each component of tailings after treatment with GB5085.3-2007 requirements

Serial number Harmful ingredient Concentration of each component of tailings after treatment (mg/L) GB5085.3-2007 (mg/L) 1 copper 0.0500 100 2 Zinc 0.0670 100 3 cadmium 0.0012 1

4 lead 0.0180 5 5 Total chromium <0.003 15 6 Chromium (hexavalent) - 5 7 Alkyl mercury - Not checked out 8 HG 0.002 0.1 9 beryllium <0.0002 0.02 10 barium 0.112 100 11 nickel <0.005 5 12 Total silver <0.01 5 13 arsenic 0.8 5 14 selenium 0.02 1 15 Inorganic fluoride 20 100 16 Cyanide 0.2 5 17 pH 5.6 12.5 ≥ or ≤ 2.0

3. The metal recovery rate is high, up to 80%, and the economic benefit is better than that of the original ore. The processing cost is low, the cost of processing tailings is 250 yuan per ton, and the value of tin, zinc, silver and other metals is 600 yuan.

Claims (7)

A method for biologically extracting metals from metallurgical and mining waste solids, including waste solids crushing, biological soaking, metal recovery in leachate, and waste solid residue after soaking, characterized by: metallurgy and mining waste The powder pulverized into 80 mesh or more is put into the biological immersion tank, and the mixture is stirred into a slurry at a weight ratio of 1:4 to 10, and then a solution consisting of Thiobacillus ferrooxidans, Bacillus licheniformis and Aspergillus niger is added to the biological immersion tank. Mixing the bacteria to make the viable count of the slurry reach 5-10 billion/mL, oxygenating and detonating, soaking under normal temperature conditions, turning once a day and separating the solid and liquid to obtain the solid waste and leachate after soaking, waste The solid remains in the soaking tank and is repeatedly soaked. Then the metal in the leachate is recovered and then separated by solid-liquid separation. The discharged water is re-introduced into the biological soaking tank for recycling. After 7 to 14 days, the waste residue after soaking is re-selected. Separation. The method for biologically extracting metal from metallurgical and mine waste solids according to claim 1, characterized in that: the active bacteria of the mixed cells consisting of Thiobacillus ferrooxidans, Bacillus polymyxa and Aspergillus niger The number ratio is 1 to 10:1 to 5:1 to 5. The method for biologically extracting metal from metallurgical and mine waste solids according to claim 1, wherein the solid-liquid separation is performed by gravity sedimentation principle, and the immersed slurry is flowed through the deep sinking tank and the plate frame. Solid-liquid separation is achieved after the filter and the advection sedimentation tank. The method for biologically extracting metal from metallurgical and mine waste solids according to claim 1, wherein the immersed waste slag re-election method is a re-election method for immersing waste slag. Separation into concentrate, medium mine and treated tailings. The method for biologically extracting metal from metallurgical and mine waste solids according to claim 1, wherein the concentrate obtained by the soaking waste slag re-election method has a total metal weight ratio of the concentrate. More than 60% can be directly smelted. The method for biologically extracting metal from metallurgical and mine waste solids according to claim 3, characterized in that the total metal weight of the medium ore separated by the soaking waste slag re-election method is 10%. Between ~20%, it can be used for secondary enrichment and re-election. The method for biologically extracting metal from metallurgical and mine waste solids according to claim 1, wherein the treated tailings separated by the immersed waste slag re-election method reaches the non-ferrous metal solid waste. Emission standards for the Standards for Leaching Toxicity Test Methods.

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