Method for extracting gold from waste printed circuit board

A printed circuit board and metal separation technology, which is applied in the field of gold extraction, can solve problems such as low metal recovery rate, toxic chemicals, and environmental pollution, and achieve the effects of efficient deposition, pollution elimination, and high gold leaching rate

Inactive Publication Date: 2009-03-25
DONGHUA UNIV
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0006] The purpose of the present invention is to provide a method for extracting gold from waste printed circuit boards, which can overcome the shortcomings of low metal recover...

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0039] Crush the waste printed circuit board to 0.5mm, separate metal and plastic, and in the reactor, separate the waste printed circuit board metal particles and HNO with a mass concentration of 15% 3Mix evenly and pour into the reaction kettle, the mass ratio of the two is 1:1, stir and react at a constant temperature of 10°C for 1h. Filter the reacted mixture, and extract copper from the filtrate by ionic membrane electrolysis; wash and dry the reaction residue and mix it with the mixed solution of the first iodine solution and the pro-oxidant hydrogen peroxide at a mass ratio of 1:1. The mass fraction of iodine in the first iodine solution is 0.2%, the mass fraction of iodine and potassium iodide is 1:1, the mass fraction of pro-oxidant hydrogen peroxide is 0.1%, and the pH value of the solution is adjusted to 3 with hydrochloric acid and sodium hydroxide. Next, shake the reaction for 2h. Among them, the copper extraction rate is 32.3%, and the gold leaching rate is 5.5%...

Embodiment 2

[0041] Crush the waste printed circuit board to 1mm, separate metal and plastic, and in the reactor, separate the waste printed circuit board metal particles and HNO with a mass concentration of 25% 3 Mix evenly and pour into the reaction kettle, the mass ratio of the two is 1:45, stir and react at a constant temperature of 80°C for 6h. The reacted mixture is filtered, and the filtrate is used to extract copper by ion membrane electrolysis; the reaction residue is washed and dried, and mixed evenly with the mixed solution of the first iodine solution and the pro-oxidant hydrogen peroxide. Wherein the mass ratio of residue and leaching mixed solution is 1:25, the massfraction of iodine in the first iodine solution is 2.0%, the mass ratio of iodine and sodium iodide is 1:13, the mixing of the first iodine solution and pro-oxidant hydrogen peroxide The mass fraction of pro-oxidant hydrogen peroxide in the liquid is 10%, and the pH value is adjusted to 9 with 1% (mass concentratio...

Embodiment 3

[0043] Crush the waste printed circuit board to 0.75mm, separate metal and plastic, and in the reactor, separate the waste printed circuit board metal particles and HNO with a mass concentration of 20% 3 Mix evenly and pour into the reaction kettle, the mass ratio of the two is 1:27, stir and react at a constant temperature of 20°C for 4h. The reacted mixture is filtered, and the filtrate is used to extract copper by ion membrane electrolysis; the reaction residue is washed and dried, and mixed evenly with the first iodine solution and the hydrogen peroxide mixed solution of the pro-oxidant. Wherein the mass ratio of residue and leaching mixed solution is 1:10, the mass fraction of iodine in the first iodine solution is 1.2%, the mass ratio of iodine and ammonium iodide is 1:6, the first iodine solution and pro-oxidant hydrogen peroxide mixed solution The mass fraction of the pro-oxidant hydrogen peroxide is 1.0%, the pH value is adjusted to 5 with 1% (mass concentration) HCl ...

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PUM

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Abstract

The invention provides a method for leaching gold from a deserted printed circuit board. The method comprises the specified steps: Step 1: the deserted printed circuit board is crushed and smashed to separate metals and plastics; Step 2: the metals obtained from the Step 1 are mixed with nitric acid solution, stirring and reaction are carried out for 1h to 6h at the constant temperature of 10 DEG C to 80 DEG C, products are filtered, copper is leached from the filtrate, and the filter residue is washed and dried; Step 3: the filter residue obtained from the Step 2 is added into the blended solution of first iodine solution and a pro-oxidant, a reaction pH value is controlled at 3 to 9 by an inorganic acid and alkaline solution, reaction is carried out for 2h to 5h in a constant temperature oscillator at the temperature of 10 DEG C to 60 DEG C; and Step 4: products obtained from the Step 3 are filtered, with the filtrate fed into the cathode region of an electrobath, second iodine solution composed of iodine, water-soluble iodide and water is used as the electrolyte and fed into the anode region of the electrobath, electrolysis is carried out, the solution at the cathode region is filtered, then the filter residue obtained is gold mud, and the second iodine solution at the anode region is recovered. The method has high gold leaching ratio, low cost and less environmental pollution.

Description

technical field [0001] The invention relates to a method for extracting gold from waste printed circuit boards, in particular to a novel environmentally friendly, efficient and economical method for extracting gold from waste printed circuit boards. Background technique [0002] With the continuous upgrading of the technical level of the electronic industry and the continuous updating of the society's demand for electronic consumer products, electronic products are being eliminated and discarded faster and faster, and the number is increasing. As an important part of electronic products, the waste of printed circuit boards (Printed Circuit Board) is also increasing day by day. Waste printed circuit boards are hazardous wastes, and the increase in their quantity has brought great pressure to the environment. Therefore, their reasonable treatment and disposal has become an urgent problem in economic development. [0003] The composition of printed circuit boards not only cont...

Claims

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Application Information

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IPC IPC(8): C22B11/00C25C1/12C22B7/00
CPCY02P10/20
Inventor 陈东辉徐渠陈亮黄满红陈超鹏姜萍华张丽萍王小玲张莹
Owner DONGHUA UNIV
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