Recycling process of tin-removing waste liquid

A technology of tin stripping and waste liquid, which is applied in the field of recycling process of tin stripping waste liquid, can solve problems such as entrainment, affecting the quality and stability of the circuit board tin stripping process, and unavoidable chemical components, so as to achieve the process and process The effect of simple equipment, great social environmental health value, and low production cost

Inactive Publication Date: 2015-09-09
CHENGDU HONGHUA ENVIRONMENTAL SCI & TECH CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

These methods add chemical reagents such as electrolytes, flocculants, and extractants, which inevitably have some chemical components entrained into the circulating tin stripping water, which affects the quality and stability of the circuit board stripping process.

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0026] [Example 1] A recycling process for tin stripping waste liquid, comprising the following steps:

[0027] S1. Pass the tin stripping waste liquid into the distillation device, at 65°C, the pressure is 0.5×1.03×10 5 Under Pa, carry out underpressure distillation and reclaim nitric acid;

[0028] S2. The above-mentioned distilled residual liquid is passed into an electrolytic cell provided with an ion exchange membrane for electrolysis, and the copper in the residual liquid is electrolyzed and recovered by controlling the current density and the cathode potential, and tin dioxide is obtained at the anode of the electrolytic cell, and metallic copper is obtained at the negative electrode;

[0029] S3. After the metal copper is recovered, the current density is controlled to remain unchanged, and the cathode potential is changed to electrolytically recover tin, and during the electrolysis process, sulfuric acid solution needs to be continuously added to the cathode chamber u...

Embodiment 2

[0035] [Example 2] A recycling process for tin stripping waste liquid, comprising the following steps:

[0036] S1. Pass the tin stripping waste liquid into the distillation device, at 70°C, the pressure is 0.4×1.03×10 5 Under Pa, carry out underpressure distillation and reclaim nitric acid;

[0037] S2. The above-mentioned distilled residual liquid is passed into an electrolytic cell provided with an ion exchange membrane for electrolysis, and the copper in the residual liquid is electrolyzed and recovered by controlling the current density and the cathode potential, and tin dioxide is obtained at the anode of the electrolytic cell, and metallic copper is obtained at the negative electrode;

[0038] S3. After the metal copper is recovered, the current density is controlled to remain unchanged, and the cathode potential is changed to electrolytically recover tin, and during the electrolysis process, sulfuric acid solution needs to be continuously added to the cathode chamber u...

Embodiment 3

[0044] [Example 3] A recycling process for tin stripping waste liquid, comprising the following steps:

[0045] S1. Pass the tin stripping waste liquid into the distillation device, at 75°C, the pressure is 0.3×1.03×10 5 Under Pa, carry out underpressure distillation and reclaim nitric acid;

[0046] S2. The above-mentioned distilled residual liquid is passed into an electrolytic cell provided with an ion exchange membrane for electrolysis, and the copper in the residual liquid is electrolyzed and recovered by controlling the current density and the cathode potential, and tin dioxide is obtained at the anode of the electrolytic cell, and metallic copper is obtained at the negative electrode;

[0047] S3. After the metal copper is recovered, the current density is controlled to remain unchanged, and the cathode potential is changed to electrolytically recover tin, and during the electrolysis process, sulfuric acid solution needs to be continuously added to the cathode chamber u...

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PUM

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Abstract

The invention discloses a recycling process of tin-removing waste liquid. The method includes the steps of S1, feeding the tin-removing waste liquid into a distilling device, and performing pressure reduction distillation under the temperature of 65-80 DEG C and the pressure of (0.2-0.5)*1.03*10<5>Pa to recycle nitric acid; S2, feeding distillation residual liquid into an electrolytic tank with an ion exchange membrane for electrolysis, controlling current density and cathode potential to recycle copper in the residual liquid through electrolysis, acquiring tin dioxide at the anode of the electrolytic tank, and acquiring metal copper at the cathode of the electrolytic tank; S3, controlling current density to be unchanged after metal copper is recycled, and changing cathode potential to recycle tin through electrolysis, constantly adding sulfuric acid solution in a cathode chamber during the electrolysis process until the electrolysis is ended, acquiring the tin dioxide at the anode of the electrolytic tank, and acquiring metal tin at the cathode of the electrolytic tank, wherein the current density is 100-200A/m<2>. The recycling process has the advantages that no chemical reagent is added, and secondary pollution is avoided.

Description

technical field [0001] The invention relates to a recycling process for tin stripping waste liquid, which belongs to the technical field of environmental protection. Background technique [0002] PCB circuit board, also known as printed circuit board, is the provider of electrical connection for electronic components. Its development has a history of more than 100 years. Its design is mainly layout design. The main advantage of using circuit boards is that it greatly reduces wiring and assembly errors, and improves the automation level and production labor rate. With the development of the information industry and the increase in demand for electronic products, the printed circuit board industry is booming. There are more than 20 processes in the production process of PCB boards, and a large amount of liquid waste liquid will be generated in these processes, among which the tin stripping process produces the most waste liquid. The tin stripping liquid is the waste liquid p...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C25C1/12C25C1/14C01B21/38C23F1/46
CPCC01B21/38C23F1/46C25C1/12C25C1/14Y02P10/20
Inventor 韦建敏吴梅赵兴文张晓蓓冯坤
Owner CHENGDU HONGHUA ENVIRONMENTAL SCI & TECH CO LTD
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