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Method for selectively recovering precious metal gold in solid waste through polar aprotic solvent reaction system

A polar aprotic, reaction system technology, applied in the field of selective recovery of precious metal gold from solid waste by polar aprotic solvent reaction system, can solve the problems of harsh roasting conditions, large environmental pollution, environmental pollution, etc., and achieves increased difficulty , low cost and high solubility

Pending Publication Date: 2022-07-29
SHANGHAI SECOND POLYTECHNIC UNIVERSITY
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0003] At present, the more mature technologies for gold recovery in industrial production are: oxidation roasting process, which mainly puts solid waste into a special roaster, oxidizes and roasts at a constant temperature of 1000 ° C for 30 minutes, takes it out and puts it into water, and pastes the gold layer and the solid waste. The waste is detached, then dissolved with dilute sulfuric acid, and the dissolved slag is separated to extract gold. The advantage of this process is that there is no polluting waste gas during the roasting process. The disadvantage is that the roasting conditions are harsh, and the sulfuric acid dissolved waste liquid has great environmental pollution.
The drum oxycyanation process is to put the pretreated gold-containing waste into the metal cyanide solution, so that the gold on the surface dissolves and enters the solution. During the operation, air needs to be blown in, the temperature is kept at 30°C, and an appropriate amount of Alkali protection, the gold-containing solution after filtration is recovered by reduction reaction, but the disadvantage of this cyanidation process is that there is a certain degree of toxicity. These technical processes can indeed recover gold in the current industry, but there is a great impact on the environment. Pollution, the need for a very high cost recovery device or the low recovery rate of gold and other disadvantages

Method used

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  • Method for selectively recovering precious metal gold in solid waste through polar aprotic solvent reaction system
  • Method for selectively recovering precious metal gold in solid waste through polar aprotic solvent reaction system
  • Method for selectively recovering precious metal gold in solid waste through polar aprotic solvent reaction system

Examples

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Effect test

Embodiment 1

[0025] Example 1 Discarded gold-containing circuit boards

[0026] After digestion and measurement, the gold content of the gold-containing circuit board is 0.005%, the copper content is 0.003%, and the nickel content is 0.001%. The extraction process is as follows figure 1 , take 0.41g of gold-containing circuit boards into 30ml of acetonitrile solvent containing 0.1mol / L of anhydrous copper chloride (liquid-solid ratio is 600ml / g), and place it on a constant temperature magnetic stirrer under the reflux device , heated and refluxed in an oil bath, the temperature of the oil bath was 100 °C, the speed of the stirrer was 450 rpm, and the leaching time was 30 min; after the leaching, the leaching solution contained Cu 2+ , Cu + , Au + , Ni 2+ , the leaching solution was distilled under reduced pressure, and the solid product (containing Au + , Cu 2+ etc.), add 20ml of deionized water and place it on a magnetic stirrer to stir and reduce, and deionized water selectively red...

Embodiment 2

[0028] Example 2 Discarded circuit boards

[0029] After digestion, it was found that the gold content of the waste circuit boards used was 0.05%, the copper content was 0.06%, the aluminum content was 0.02%, and the iron content was 0.08%. The extraction process is as follows: figure 1 , take 8.4g of waste circuit boards and put them into 50ml of acetonitrile solvent containing 0.2mol / L anhydrous copper chloride (the liquid-solid ratio is 400ml / g), and then leaching through the reflux oil bath, the oil bath temperature is 100 ℃, and the stirring speed is 500rpm, leaching for 60min, vacuum distillation after leaching, the leaching solution contains Cu 2+ , Cu + , Au + , Al 3+ , Fe 2+ Add 30ml of deionized water to the solid product and place it on a magnetic stirrer to stir and reduce, the leaching time is 20min, the stirring speed is 100rpm, and the Au in the solid product is reduced by deionized water. + , the leaching rate of gold was measured to reach more than 99.4% ...

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Abstract

The invention discloses a method for selectively recovering precious metal gold in solid waste through a polar aprotic solvent reaction system. According to the method, gold-containing solid waste is used as a raw material, and an acetonitrile-anhydrous chlorate system is added for a leaching reaction. And after leaching, carrying out reduced pressure distillation to recover acetonitrile, adding a certain amount of water into a solid product, continuously stirring and reducing, and filtering after the reduction reaction is finished to obtain precipitated gold and filtrate. According to the method, an acetonitrile-anhydrous chlorate system is adopted, the process is simple, operation is convenient and fast, a low-toxicity acetonitrile system is adopted to replace a traditional strong acid / strong alkali and aqua regia system, the green concept is advocated, meanwhile, precious metal gold in the gold-containing solid waste is selectively extracted, and green and low-cost recovery of gold is achieved.

Description

technical field [0001] The invention belongs to the technical field of metal recovery and solid waste recycling, and more particularly relates to a method for selectively recovering precious metal gold in solid waste by a polar aprotic solvent reaction system. Background technique [0002] As a precious metal with strong stability and good electrical and thermal conductivity, gold is used more and more widely in industry. In the development of aerospace technology, such as coatings for advanced vacuum tubes, electrical connectors for special purposes, and drawing wires in precision instruments As well as gold-plated conductors and alloys for high-temperature soldering. At present, the annual demand of gold in the world's electronics industry is about 123t, accounting for 7.7% of the total demand. In the chemical field, such as materials for nuclear chemical plants and alloy spinnerets, etc. Unlike gold extraction from gold mines, green recovery of precious metal gold from g...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C22B7/00C22B11/00
CPCC22B7/006C22B11/042
Inventor 王瑞雪范国梁张承龙白建峰张磊
Owner SHANGHAI SECOND POLYTECHNIC UNIVERSITY