Treatment method for recycling tin, copper and waste gas from PCB (Printed Circuit Board) tin waste liquid in cyclic regeneration manner
A waste liquid recycling and treatment method technology, applied in chemical instruments and methods, separation methods, dispersed particle separation, etc., can solve problems such as high transfer costs, major environmental protection and safety hazards, and nitrogen oxides cannot be recycled and reused. The effect of recovered value, large economic benefits and social benefits
A waste liquid recycling and treatment method technology, applied in chemical instruments and methods, separation methods, dispersed particle separation, etc., can solve problems such as high transfer costs, major environmental protection and safety hazards, and nitrogen oxides cannot be recycled and reused. The effect of recovered value, large economic benefits and social benefits
CN114277249APending Publication Date: 2022-04-05江西瑞亿电子科技有限公司
Examples
Experimental program
Comparison scheme
Effect test
Embodiment
[0030] 1. The specific process:
[0031] Step 1, a precipitation and solid-liquid separation process: first, add concentrated sulfuric acid to the PCB tin waste liquid to precipitate tin ions into tin sulfate, the color of the precipitate is white, and then add an appropriate amount of diatomaceous earth and polyacrylamide to further increase Large sediment particles, through the solid-liquid separation device to effectively separate the required tin metal precipitate from the supernatant; the white precipitate becomes tin sludge after pressure filtration (the dry basis content of tin in the tin sludge is 40-65%) Directly sold to smelters for smelting to obtain elemental tin;
[0032] Step 2, directly add the supernatant of solid-liquid separation for the first time in the new PCB tin waste liquid that has added concentrated sulfuric acid and an appropriate amount of diatomaceous earth in the second tank (this supernatant is used as a circulating separation agent), and then A...
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The invention provides a treatment method for recycling tin, copper and waste gas from PCB (Printed Circuit Board) tin waste liquid in a cyclic regeneration manner, which comprises the following steps of: adding sulfuric acid and a filter aid into the PCB tin waste liquid to precipitate tin ions, and separating tin sulfate precipitate from supernate; adding the supernatant as a circulating separating agent into a new PCB tin waste liquid for precipitation separation of tin sulfate, and entering the next step until the copper content of the supernatant meets the requirement; oxalic acid and a filter aid are added into the supernate with the copper content reaching the standard, and copper ions are precipitated; then, the filtrate is subjected to regeneration liquid blending, and tin-stripping regeneration sub-liquid is obtained and returned to a production line for use; and finally, spraying the generated tail gas with hydrogen peroxide, and discharging the tail gas after the tail gas is detected to meet the standard. According to the method, metal ions tin and copper in the waste liquid can be selectively precipitated and separated, the tin content in the tin sludge and the copper content in the copper sludge are increased, the tin stripping liquid medicine can be regenerated and recycled, in the whole production process, no waste water or dangerous waste gas is generated, the method is green and environmentally friendly, and the production cost is greatly reduced.
Description
【Technical field】 [0001] The invention relates to a treatment method for recycling tin, copper and waste gas of PCB tin waste liquid. 【Background technique】 [0002] The etching of the outer circuit of PCB enterprises uses electroplating pure tin (pattern electroplating process) as the protective layer of the circuit. After etching by the copper-ammonia-ammonium chloride alkaline buffer system, the tin protective layer on the surface of the circuit must be stripped (removing tin) process) and enter the next process. At present, all PCB companies basically use nitric acid-ferric chloride type tin stripping liquid. The tin stripping waste liquid contains 60-80g / L tin, 10-20g / L iron, 5-6.5mol / L nitrate and a small amount of organic additives such as benzotriazole for copper protection. [0003] The traditional nitric acid + ferric nitrate type tin stripping water uses the strong oxidizing property of nitric acid, supplemented by the oxidizing property of Fe3+. The potion first...
Claims
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Patent Timeline
05 Apr 2022
Publication
CN114277249A
- IPC
- C22B7/00; C22B15/00; C22B25/06; C23F1/46; C23F1/30; B01D53/78; B01D53/56
- Inventors
- 莫忠达