Process for comprehensively utilizing waste tin-stripping solution

Abstract

The invention relates to a process for comprehensively utilizing a waste tin-stripping solution. According to the process, the waste tin-stripping solution and electronic copper tin alloy solid wastes are used as process raw materials; a two-section leaching step, a parallel flow triple-effect evaporation, concentration and crystallization step, and a step for preparing acid by absorption of tail gas are combined; synchronous treatment is performed; all components in raw materials react with each other; copper and tin are efficiently leached out and separated; after being absorbed by water, the tail gas can be used for preparing acid; the absorption rate can be more than 95 percent; and primary SnO2, industrial cupric nitrate crystals and nitric acid products are obtained finally. The wastewater produced in the whole process and the discharge of the tail gas can meet the national requirement of environment friendliness, the environment is effectively protected from being polluted, and the treatment cost of the wastewater can be reduced greatly.

Description

technical field [0001] The invention relates to a process for comprehensive utilization of waste tin stripping water in the production process of printed circuit boards. Background technique [0002] Waste tin stripping water is the process of printed circuit board manufacturing, which needs to remove the plating layer of the protective pattern, and a large amount of waste tin lead or tin liquid is produced in this process. Waste stripping water not only contains a large amount of tin or lead-tin compounds, but also contains 0.5% copper, more than 3.0mol / L nitric acid and a large amount of iron and other inorganic salts. The composition is very complex and difficult to handle. There are two main ways to recycle and treat the waste tin stripping solution: one is to add alkali alone to neutralize the sediment, and press filter to obtain the filter mud. Processing costs are higher. The other is the Chinese Invention Patent Application Publication No. CN1530466A on September 2...

AI Technical Summary

Problems solved by technology

Waste tin stripping water not only contains a large amount of tin or lead-tin compounds, but also contains 0.5% copper and more than 3.0mol / L nitric acid and a large amount of iron and other inorganic salts. The composition is very complex and difficult to handle

There are two main ways to recycle and treat the waste tin stripping solution: one is to add alkali alone to neutralize the precipitation, and press filter to obtain the filter mud. This treatment method not only produces a large amount of waste residue, the water quality is difficult to meet the discharge standard, higher processing fees

The other is the Chinese Invention Patent Application Publication No. CN1530466A on September 22, 2004, which discloses a method for reclaiming tin from tin stripping or tin-lead waste liquid. The process is to add alkali to the waste liquid after distillation to neutralize the pH After the value is 6-10, filter, add alkali to the obtained filter cake and heat it to 100°C-300°C to dissolve completely, then heat soak, filter the filtrate, crystallize, cool again, and centrifuge to obtain the recovered product; this processing method High energy consumption, a large amount of treatment water is wasted, and a large amount of waste lye is produced, and the treatment cost is high

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