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Method of leaching copper in waste printed circuit boards by virtue of mixed bacteria

A printed circuit board and mixed bacteria technology, which is applied in the field of copper recovery from waste printed circuit boards, can solve problems such as the decline of copper leaching ability, achieve the effects of increasing copper leaching rate, improving copper resistance, and saving energy

Active Publication Date: 2015-06-10
YANGZHOU NINGDA NOBLE METAL CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

In addition, the ability of bacteria to leach copper is closely related to their own growth and metabolism. The addition of PCBs will inhibit the growth of bacteria and lead to a decrease in copper leaching ability. Therefore, how to optimize the way of adding PCBs is another key to achieve efficient leaching of copper in PCBs by mixed bacteria. one of the factors

Method used

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  • Method of leaching copper in waste printed circuit boards by virtue of mixed bacteria
  • Method of leaching copper in waste printed circuit boards by virtue of mixed bacteria

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Experimental program
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Effect test

Embodiment 1）

[0029] The method for leaching copper in waste printed circuit boards with mixed bacteria of the present embodiment comprises the following steps:

[0030] ① Pretreatment of waste printed circuit boards. The waste printed circuit board PCBs from which electronic components have been removed are crushed and ground into powder, and the ground waste PCBs powder passes through a sieve of 100 μm to 200 μm (in this example, the waste printed circuit board powder obtained through grinding passes through a 100 μm sieve) , to collect the waste PCBs powder passing through the sieve for processing.

[0031] After the discarded PCBs processed in this embodiment were ground and sieved, their main metal content was analyzed.

[0032] The main metal content is shown in Table 1 below:

[0033] Table 1 Main metal content in waste printed circuit board powder

[0034]

[0035] ② domestication of strains.

[0036] (1) Acidophilus Thiobacillus ferrooxidans ( A. ferrooxidans ) of domesti...

Embodiment 2 to Embodiment 6）

[0065] The mixed bacteria of embodiment 2 to the method of embodiment 6 leaching copper in the waste printed circuit board all the other are the same as embodiment 1, difference is: the content of each component in the mixed bacteria culture solution used when step 3. mixed bacteria culture As well as the addition time and amount of waste printed circuit board powder in step ④, see Table 2 and Table 3 below for details.

[0066] Table 2 The content of each component in the mixed bacteria culture solution used in step ③ mixed bacteria culture

[0067]

[0068] Table 3 Addition time and amount of waste printed circuit board powder in step ④

[0069]

[0070] Note: The addition time mentioned in the above table refers to the time for powder addition after the start of the mixed bacteria culture in step ③; the added amount refers to the weight of waste printed circuit board powder added per 1L of mixed bacteria culture system , the unit is grams.

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Abstract

The invention discloses a method of leaching copper in waste printed circuit boards by virtue of mixed bacteria. The method comprises the following steps: pretreating the waste printed circuit boards (PCBs) for later use, carrying out copper tolerance acclimatization culture on Acidithiobacillus ferrooxidans and Acidithiobacillus thiooxidans respectively, and carrying out mixed culture in a mixed bacterium culture medium; starting to add PCBs powder when the culture time achieves 40-55h, then adding the PCBs powder with adding the amount increased point by point at other time points, and carrying out bioleaching. According to the method disclosed by the invention, when the mixed bacteria are cultured, two kinds of the bacteria can both grow in a balancing mode without needing to regulate a pH value of the culture medium, meanwhile, when the two kinds of the bacteria grow, a great amount of sulfuric acid and Fe<3+> are produced to be used for leaching the copper in the waste PCBs powder in later period, and thus in the whole process, the efficiency is high, and the energy is saved; with the adoption of the multi-point gradually-increased addition mode, on the basis of increasing the additive amount of the waste PCBs powder, the leaching rate of the copper is remarkably increased, and the growth inhibition degree of the bacteria is relatively small.

Description

[0001] This application is a divisional application of an invention patent application with the application number 201310457250.3 and the application date of September 30, 2013, and the invention name is "Method for Leaching Copper from Waste Printed Circuit Boards by Mixed Bacteria". technical field [0002] The invention relates to a method for recovering copper in waste printed circuit boards, in particular to a method for leaching copper in waste printed circuit boards with mixed bacteria. Background technique [0003] With the rapid development of information technology, the output of Waste Electric and Electronic equipment (WEEE) continues to increase. As an important component of WEEE, waste printed circuit boards (PCBs) usually contain about 40% of metals, of which metals Copper is the main component, with a content as high as 20% to 30%. It is estimated that my country needs to process more than 500,000 tons of PCBs every year and it is growing at a rate of 22%. If...

Claims

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Application Information

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IPC IPC(8): C22B7/00C22B15/00C12N1/20C12R1/01
CPCY02P10/20
Inventor 梁国斌马飞蒋莉刘维平周全法
Owner YANGZHOU NINGDA NOBLE METAL CO LTD