A method for extracting copper from waste circuit boards by using moderately thermophilic bacteria

A waste circuit board, moderate thermophilic technology, applied in the direction of improving process efficiency, can solve the problems of large investment in mechanical equipment, difficult metal separation, large energy consumption, etc., to achieve low processing cost, small investment and high efficiency Effect

Active Publication Date: 2017-02-22
CENT SOUTH UNIV
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

The mechanical equipment used by the physical method has large investment, large energy consumption, high maintenance costs, and it is difficult to separate the metals in the product

Method used

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  • A method for extracting copper from waste circuit boards by using moderately thermophilic bacteria

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Experimental program
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Effect test

Embodiment 1

[0030] The domestication process of the mixed strains of the present invention is specifically as follows: firstly cultivate various strains separately, centrifuge and collect the strains after reaching the late logarithmic period of growth, count them under a microscope, and when the concentration of each pure strain is 2×10 8 ~8×108 When cells / mL, mix the four kinds of pure bacteria in equal volumes, and then insert the mixed bacteria solution into the improved 9K medium according to the volume percentage of 10-15%, and add 16g / LFeSO 4 ·7H 2 O and 8g / L elemental sulfur are used as energy substances, the circuit board waste residue concentration is 1% (100g / L), the stirring speed is 45r / min, the ventilation rate is 8L / min, and the evaporation of water in the reactor is supplemented by adding distilled water. When the microbial concentration reaches 2×10 9 When the individual / mL is more than the second acclimatization, specifically, under the same culture conditions, insert 1...

Embodiment 2

[0032] 10kg of waste circuit boards with a Cu content of 11.46% were crushed to less than 1.0mm, and 1.98kg of metal with a copper content of 49.46% and 8.02kg of non-metal powder waste residue with a copper content of 0.82% were obtained by hydraulic separation; at 45°C, inoculation of 10% was carried out Example 1 The domesticated bacterial solution (adjust the pH to 2), the circuit board waste residue concentration is 8%, the stirring speed is 48r / min, and the ventilation rate is 8L / min. Under the condition of leaching for 18-22d, a copper-rich solution and a Cu content of 0.04 are obtained. % glass fiber resin composite material 7.96kg, copper leaching rate reached 93%. The copper-rich solution is filtered by an external pressure hollow fiber membrane system, and the obtained strains are put into the stirring and leaching device for reuse. The copper-containing filtrate uses LIX984: kerosene volume ratio = 10:90 as the extraction agent, and the phase ratio is 1. Two-stage ...

Embodiment 3

[0034] 10kg of discarded circuit boards with a Cu content of 12.00% were crushed to below 1.0mm, and 2.07kg of metal with a copper content of 50.03% and 7.93kg of non-metallic powder with a copper content of 1.32% were obtained through hydraulic separation; at 45°C, inoculated with 12% 1 The domesticated bacterial solution (adjust the pH to 2), stirred and leached for 18 to 22 days under the conditions of circuit board waste residue concentration of 12%, stirring speed of 45r / min, and air flow of 10L / min, to obtain copper-rich solution and Cu content The 0.06% glass fiber resin composite material is 7.84kg, and the copper leaching rate reaches 93%. The copper-rich solution is filtered by an external pressure hollow fiber membrane system, and the obtained strains are put into the stirring and leaching device for reuse. The copper-containing filtrate uses LIX984: kerosene volume ratio = 20:80 extractant, the phase ratio is 1, and carries out 4-stage countercurrent cascade extrac...

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Abstract

The invention relates to a method for extracting copper in waste printed circuit boards by virtue of moderately thermophilic bacteria. The method comprises the following steps of carrying out shaker hydraulic sorting on the artificially dismounted and pulverized waste printed circuit boards to obtain metal and waste residues; putting the waste residues into an improved 9K culture medium, adjusting the pH value to 2 and leaching with a mixed strain of leptospirillum ferriphilum, acidithiobacillus caldus, sulfobacillus thermosulfidooxidans and thermoacidiferriphile as a leaching strain to obtain a copper-enriched solution and leaching residues; filtering the copper-enriched solution with a hollow fiber membrane system to obtain the strain and a copper-containing filtrate and putting the strain again into the leaching system for repeatedly using; and extracting the copper-containing filtrate with hydroxy oxime and a hydroxy oxime complex Lix984 as extraction agents to obtain a copper-loaded organic phase and a raffinate, carrying out back extraction on the copper-loaded organic phase with a 10-30% sulfuric acid solution to obtain a back extract and a blank organic phase and carrying out electrodeposition on the back extract to obtain cathode copper and an electrodeposited barren liquid. By the method disclosed by the invention, the environment-friendly, economic and full-value recovery of the waste printed circuit boards is achieved and the method has the advantages of short flow, low investment, high efficiency and low treatment cost and is suitable for the recovery of all types of the waste printed circuit boards.

Description

[0001] Technical field: [0002] The invention belongs to the technical field of recovery and preparation of copper in waste printed circuit boards, and in particular relates to a method for extracting copper in waste circuit boards by using moderately thermophilic bacteria. [0003] Background technique: [0004] Waste printed circuit boards contain a large amount of metal substances, and the metal content in some circuit boards even exceeds 45%. The recycling of metal substances in them has been reported in relevant literature. Since copper is the main metal in printed circuit boards, the general content is about 15%, therefore, the potential for recovering copper from waste printed circuit boards is very large. Recycling copper from waste printed circuit boards can not only maintain the surrounding environment and ensure the welfare of residents, but also make up for the increasingly scarce copper resources. [0005] At present, the methods for extracting copper from waste ...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): C22B7/00C22B15/00C22B3/18
CPCY02P10/20
Inventor 曾伟民王亚萍邱冠周刘学端周洪波顾帼华姜涛
Owner CENT SOUTH UNIV
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