Method for recovering valuable metals from electroplating sludge

A technology of valuable metals and electroplating sludge, which is applied in the direction of improving process efficiency, can solve problems such as poor practicability, large amount of leached slag, and reduced recovery rate, achieving significant economic and social benefits, and easy process conditions The effect of control and easy large-scale production

Inactive Publication Date: 2006-09-06
ZHEJIANG UNIV OF TECH +1
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0002] The existing electroplating sludge treatment process mainly focuses on harmless treatment, although some of them also comprehensively consider resource utilization and harmless treatment. For example, ammonia recovery uses ammonia water to leach Cu, Ni, and Zn in the sludge. However, iron and chromium, which are difficult to handle, remain in the solid, and the ammonia treatment process is lengthy. The ammonia leaching only separates copper, zinc, and nickel. To obtain a single metal, other separation methods are required, especially ammonia immersion liquid-solid comparison. Large, up to 12:1, resulting in large equipment volume, increased equipment investment, and a large amount of leached slag, some accounting for more than 50% of the initial sludge, and the iron and chromium in the slag must be treated in a harmless or resourceful manner.
Acid recovery usually removes iron and chromium in the leaching solution by co-precipitation, which is likely to cause co-precipitation of valuable heavy metal ions such as nickel and zinc for electroplating sludge with high content of iron and chromium, thereby reducing its recovery rate. A large amount of iron-chromium slag needs further harmless treatment or recycling
Therefore, the practicability is not good enough, so it is difficult to popularize and apply

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0032] (1) 500g of electroplating sludge raw material (Ni6.39%; Cu3.88%; Cr15.7%; Zn2.12%; Fe1.24%; Al5.17%) is first mixed with water and added to 1050ml in dilute sulfuric acid solution, stirred at room temperature for 60 minutes, filtered, and the filtrate was put into the next step for copper precipitation. The filter residue is washed, the washing solution is returned to prepare the leachate, and the washing residue is solidified.

[0033] (2) Add 25 g of sodium sulfide to the 1400 ml filtrate obtained above to react for 1 hour, control the temperature at 90° C., and pH around 1.5, and filter to obtain 30.10 g of copper sulfide and the precipitated mother liquor.

[0034] (3) 15% sodium hydroxide solution is slowly added to the above-mentioned precipitation mother liquor at normal temperature, and the pH value of the control solution is about 5.5, and the precipitation is completed and the mother liquor of 243g of chrome-aluminum slag and iron, zinc and nickel are separat...

Embodiment 2

[0040] (1) Mix 500g of electroplating sludge raw material (Ni4.63%; Cu12.43%; Zn4.23%; Fe17.50%) with water, add it to 1050ml of dilute sulfuric acid solution, and stir at room temperature After 60 minutes, filter, and put the filtrate into the next step for copper precipitation. The filter residue is washed, the washing solution is returned to prepare the leachate, and the washing residue is solidified.

[0041] (2) Add 80 g of sodium sulfide to the 1400 ml filtrate obtained above to react for 1 hour, control the temperature at 90° C., and pH at about 1.5, and filter to obtain 97 g of copper sulfide and precipitated mother liquor.

[0042] (3) Add 63ml of industrial hydrogen peroxide to the above-mentioned mother liquor containing iron, zinc and nickel, use 15% sodium hydroxide solution, adjust the pH at 90°C to about 5.4, keep the temperature for 2 hours, and isolate 143g yellow sodium iron through filtration Alum slag and mother liquor containing zinc and nickel.

[0043]...

Embodiment 3

[0047] (1) 500g of electroplating sludge raw material (Cr8.65%; Zn24.86%; Fe9.92%) is mixed with water first, added in the dilute sulfuric acid solution of 1050ml, stirred at room temperature for 60 minutes, filtered, The filtrate is put into the next step for chromium precipitation. The filter residue is washed, the washing solution is returned to prepare the leachate, and the washing residue is solidified.

[0048] (2) 15% sodium hydroxide solution is slowly added to the above-mentioned precipitation mother liquor at normal temperature, and the pH value of the solution is controlled at about 5.5, and after precipitation is completed, 132g of chrome-aluminum slag and mother liquor containing iron and zinc are separated by filtration.

[0049] (3) Add 44ml of industrial hydrogen peroxide to the above-mentioned mother liquor containing iron and zinc, use 15% sodium hydroxide solution, adjust the pH at 90°C and keep the temperature reaction at about 5.4 for 2 hours, and isolate ...

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PUM

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Abstract

The invention relates the recovering metal method from electroplating sludge, comprising the following step: 1 using diluted acid to extract metal from electroplating sludge, filtering and separating, getting pickle liquor; 2 setting the copper from pickle liquor with sulphide at 85-100Deg.C, filtering and separating, getting cupric sulfide and deposition mother liquid; 3 adding 5-20% queous alkali into deposition mother liquid, and controlling the PH between 5.0 and 6.0, setting chromium and aluminium, filtering and getting the chromium-aluminium slag and the mother liquid containing iron, zinc and nickel. The method has the advantages of good technology versatility, easy controlling, simple equipment and low cost.

Description

(1) Technical field [0001] The invention relates to a method for recovering valuable metals from electroplating sludge. (2) Background technology [0002] The existing electroplating sludge treatment process mainly focuses on harmless treatment, although some of them also comprehensively consider resource utilization and harmless treatment. For example, ammonia recovery uses ammonia water to leach Cu, Ni, and Zn in the sludge. However, iron and chromium, which are difficult to handle, remain in the solid, and the ammonia treatment process is lengthy. The ammonia leaching only separates copper, zinc, and nickel. To obtain a single metal, other separation methods are required, especially ammonia immersion liquid-solid comparison. Large, up to 12:1, resulting in large equipment volume, increased equipment investment, and a large amount of leached slag, some accounting for more than 50% of the initial sludge, and the iron and chromium in the slag must be treated in a harmless or...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C22B3/00C22B3/04C22B3/22C22B7/00
CPCY02P10/20
Inventor 郑国渠吴永光王定海陈小文
Owner ZHEJIANG UNIV OF TECH
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