Method for leaching valuable metals in waste circuit board by acidophilic bacteria mixed culture

A technology for waste circuit boards and valuable metals, applied in the direction of improving process efficiency, etc., can solve problems such as the complexity of environmental samples, insufficient large-scale application, high toxicity, etc., achieve high recovery rate, simplify processing procedures, and low energy consumption Effect

Inactive Publication Date: 2011-02-02
SOUTH CHINA UNIV OF TECH
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, these are only limited to laboratory research and are not enough for large-scale application. The main reason is the complexity and high toxicity of environmental samples. High leaching efficiency is more difficult

Method used

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  • Method for leaching valuable metals in waste circuit board by acidophilic bacteria mixed culture
  • Method for leaching valuable metals in waste circuit board by acidophilic bacteria mixed culture
  • Method for leaching valuable metals in waste circuit board by acidophilic bacteria mixed culture

Examples

Experimental program
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Effect test

Embodiment 1

[0040] Collect acidic pit wastewater from sulfide ore (mainly pyrite) mines, and inoculate the pit water into 9K medium according to the inoculum amount of 5%, 10%, 20%, 30%, and 40%. The components of 9K medium are as follows (g / L): (NH 4 ) 2 SO 4 , 3.0; KCl, 0.1; K 2 HPO 4 , 0.5; MgSO 4 ·7H 2 O, 0.5; Ca(NO 3 ) 2 , 0.01; FeSO 4 ·7H 2 O, 44.3, the initial pH was adjusted to 2.5, shake culture at 30°C, 160 rpm, observe the color change of the solution, after a large amount of reddish-brown precipitates were produced, first filter the precipitates with filter paper, and then use a 0.22 μm microporous membrane Filter the filtrate, and take the bacterial mixed culture on the membrane as the strain source.

[0041] Through the experiments of different inoculum amounts of mine wastewater in this example, the time required for the solution color to change to reddish brown is respectively 40%<30%<20%<10%<5%. Short, 5% required culture time is too long; compare the amount of...

Embodiment 2

[0043] Acid pit wastewater was collected from sulfide ore (mainly pyrite) mines, and the pit water was inoculated to 9K medium at an inoculation amount of 20%. The components of 9K medium are as follows (g / L): (NH 4 ) 2 SO 4 , 3.0; KCl, 0.1; K 2 HPO 4 , 0.5; MgSO 4 ·7H 2 O, 0.5; Ca(NO 3 ) 2 , 0.01; FeSO 4 ·7H 2 O, 44.3, the initial pH was adjusted to 3.0, shake culture at 25°C, 30°C, 35°C, 40°C, 160 rpm, observe the color change of the solution, after a large amount of reddish-brown precipitate was produced, first filter the precipitate with filter paper , and then filter the filtrate with a 0.22 μm microporous membrane, and take the mixed culture of bacteria on the membrane as the strain source.

[0044] Through the experiment of cultivating at different temperatures in this example, the time required for the color of the solution to change to reddish brown is 35°C≈30°C<40°C<25°C, too high or too low temperature will affect the culture time of the mixed culture, and...

Embodiment 3

[0046] Acid pit wastewater was collected from sulfide ore (mainly pyrite) mines, and the pit water was inoculated to 9K medium at an inoculation amount of 20%. The components of 9K medium are as follows (g / L): (NH 4 ) 2 SO 4 , 3.0; KCl, 0.1; K 2 HPO 4 , 0.5; MgSO 4 ·7H 2 O, 0.5; Ca(NO 3 ) 2 , 0.01; FeSO 4 ·7H 2 O, 44.3, the initial pH was adjusted to 2.5, shake culture at 30°C, 100, 140, 160, 180, 250 rpm, observe the color change of the solution, after a large amount of reddish-brown precipitate was produced, first filter the precipitate with filter paper, Then filter the filtrate with a 0.22 μm microporous membrane, and take the mixed culture of bacteria on the membrane as the strain source.

[0047] Through the experiment of cultivating at different rotation speeds in this example, the time required for the color of the solution to change to reddish brown is 180rpm≈160rpm<140rpm<250rpm<120rpm, that is, too high or too low a rotation speed will affect the cultivati...

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Abstract

The invention discloses a method for leaching valuable metals in a waste circuit board by acidophilic bacteria mixed culture, comprising steps of: (1) preparing metal concentrate powders from the waste circuit board; (2) preparing the acidophilic bacteria mixed culture: collecting acid mine drainage from a sulfide ore mine, inoculating the pit water to 9K culture medium according to the inoculation amount of 5-40% by volume, culturing the culture medium in shaking conditions until a large number of reddish-brown precipitates are produced, filtering the solution and obtaining the acidophilic bacteria mixed culture; (3) leaching metals in the metal concentrate powders by the acidophilic bacteria mixed culture. The method of the invention has the advantages of high target metal recovery, low energy consumption, improves the leaching yield of copper by 98% or more during 2 days and the leaching yield of zinc and aluminum by 90% or more during 4 days, simplifies the treatment process and reduces the cost without separating and purifying microbial strains, can recycle the leach liquor repeatedly and substantially realizes zero-pollution emission.

Description

technical field [0001] The invention relates to a microbial leaching method for recovering valuable metals from waste circuit boards. Background technique [0002] Printed Circuit Boards (PCBs for short) is one of the largest industries in the electronic components industry. In recent years, with the development of electronic information technology, the production of printed circuit boards in the world has entered a stage of rapid development. Discarded printed circuit boards are mainly defective products, leftovers and PCBs substrates of components disassembled and assembled from discarded electronic products during the manufacturing process of PCBs. At present, the replacement speed of electronic products is getting faster and faster, and the average service life of electronic products is getting shorter and shorter. With the elimination of electronic products, PCBs are eliminated, and the amount of discarded PCBs shows a high-speed growth trend. Studies have shown that...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C22B3/18
CPCY02P10/20
Inventor 朱能武吴平霄项赟李平吴锦华
Owner SOUTH CHINA UNIV OF TECH
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