Method for recovering valuable metals from waste printed circuit board

A technology for printed circuit boards and valuable metals, applied in the field of recovering valuable metals, can solve the problems of incomplete extraction and separation of metals, high metal loss rate, high acid and alkali consumption, etc., and achieves environmental friendliness, less reagent consumption, and operation. simple effect

Active Publication Date: 2010-07-28
HUNAN JIANG YE MECHANICAL & ELECTRICAL TECH CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

The above technologies are limited to recovering a kind of metal from waste circuit boards or only separating plastics from metals. Without thorough refining and separation of metals, the metal loss rate is high, and the consumption of acid and alkali is high, which is easy to cause secondary pollution, etc.

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0020] The pulverized and sorted PCB containing polymetallic powder was mixed with NaOH:NaNO 3 = The melting agent of 1:0 is mixed according to the mass ratio of 1:0.4, then put into the heating furnace, and smelted at a low temperature of 420°C for 2.5h; weight ratio), temperature 25°C, leaching for 2h under the condition of stirring at a speed of 1000r / min; the solution after leaching was filtered, and the filtrate was evaporated and concentrated to obtain Na 2 PbO 3 、Na 2 SnO 3 、Na 2 SbO 3 , NaAlO 2 Mix and crystallize, return to the corresponding smelters such as lead smelting or tin smelting to extract valuable metals; evaporate the mother liquor and return to the water immersion process; put 500g of filter residue in 1.5mol / LH 2 SO 4 Add 10g of persulfate oxidant to the solution, and leaching at a temperature of 55°C for 2 hours. After leaching and leaching, the solution is filtered, and the filter residue enters the subsequent process. The filtrate uses cyclone e...

Embodiment 2

[0024] The pulverized and sorted PCB containing polymetallic powder was mixed with NaOH:NaNO3 = The melting agent of 1:0.4 is mixed according to the mass ratio of 1:0.1, then put into the heating furnace, and smelted at 350°C for 1.5h at a low temperature; weight ratio), temperature 35°C, leaching for 0.5h under the condition of stirring at a speed of 100r / min; the solution after leaching was filtered, and the filtrate was evaporated and concentrated to obtain Na 2 PbO 3 , N a2 SnO 3 、Na 2 SbO 3 , NaAlO 2 Mix and crystallize, return to the corresponding smelters such as lead smelting or tin smelting to extract valuable metals; evaporate the mother liquor and return to the water immersion process; put 500g of filter residue in 3.5mol / LH 2 SO 4 The solution was fed with O at 20g / h 3 , At a temperature of 20°C, leaching for 8 hours, after leaching and filtering the leached solution, the filter residue enters the subsequent process, and the filtrate uses cyclone electrowinn...

Embodiment 3

[0028] The pulverized and sorted PCB containing polymetallic powder was mixed with NaOH:NaNO 3 = 1: 1.0 melting agent is mixed according to the mass ratio of 1: 0.8, then put into the heating furnace, and smelted at 550°C for 1 hour at a low temperature; Ratio), temperature 45°C, leaching for 3h under the condition of stirring at a speed of 400r / min; the solution after leaching was filtered, and the filtrate was evaporated and concentrated to obtain Na 2 PbO 3 、Na 2 SnO 3 、Na 2 SbO 3 , NaAlO 2 Mix and crystallize, return to the corresponding smelters such as lead smelting or tin smelting to extract valuable metals; evaporate the mother liquor and return to the water immersion process; put 500g of filter residue in 0.5mol / LH 2 SO 4 Add 40ml H to the solution 2 o 2 , At a temperature of 35°C, leaching for 4 hours, after leaching and filtering the leached solution, the filter residue enters the subsequent process, and the filtrate is selectively deposited on metal copper...

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PUM

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Abstract

The invention discloses a method for recovering valuable metals from a waste printed circuit board. The method comprises the following steps: sorting and crushing the printed circuit board, evenly mixing powder containing multiple metal parts with a fluxing agent, and smelting at low temperature for 1-3.5h; adding hot water into smelting products for leaching; evaporating and concentrating filtrate after filtration, and then returning evaporation mother liquor to the water leaching process step; using solution after leaching for swirl electrodeposition of metal silver, and adding 5-25% of HNO3 into filter residue for leaching; filtering the solution after electrodeposition, and adding 1-5 times of the weight of aqua regia into the filter residue for leaching; using the solution after leaching by the aqua regia for the swirl electrodeposition of gold, adding saturated NH4Cl into the solution after the electrodeposition for reaction, then filtering, using ammonium chloroplatinate for refining the filter residue, obtaining sponge platinum, adding methanoic acid into the solution after precipitation, and carrying out reaction for obtaining crude palladium powder. The method can extract copper, nickel, silver, gold, platinum, palladium and other main products and other by-products, realize the maximization of reutilization of value metal resources in the waste printed circuit board and solve the environmental pollution problem; and the adoption of the swirl electrolysis technology can realize low energy consumption, low reagent consumption, short process flow and simple operation.

Description

technical field [0001] The invention relates to a method for recovering valuable metals from waste printed circuit boards. Specifically, it is a method for recovering valuable metals from waste printed circuit boards by swirl electrolysis technology. Background technique [0002] According to reports, 30 to 40 million tons of waste electronic products are produced globally every year, and printed circuit boards (PCBs) contain many toxic and harmful substances such as Pb, Sn, Sb, Al, polyvinyl chloride, and halogenated flame retardants. , is a highly dangerous solid waste. At the same time, waste printed circuit boards are also rich in precious metals such as gold, silver, palladium, and platinum. According to reports, 1 ton of computer components contains 0.9kg of gold, 270kg of plastic, 128.7kg of copper, 58.8kg of lead, 39.6kg of tin, 36kg of nickel, 19.8kg of antimony, and precious metals such as platinum and palladium. According to statistics, 1 ton of randomly collec...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C25C1/12C25C1/08C25C1/20C22B7/00B22F9/24
CPCY02P10/20
Inventor 郭学益田庆华石文堂李栋李菲李晓静
Owner HUNAN JIANG YE MECHANICAL & ELECTRICAL TECH CO LTD
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