The process of steel mesh galvanizing will produce a lot of waste materials, which will pollute the environment. Let's talk about the disposal of waste residue.
The waste residue of zinc plating mainly comes from two aspects: one is carbonate produced in alkaline zinc plating solution; the other is metal hydroxide formed in sewage treatment process.
The first is the treatment of alkaline zinc carbonate: zinc cyanide and alkaline zincate are widely used in sodium hydroxide and sodium oxide, both of which can absorb carbon dioxide in the air to form sodium carbonate. When the content of sodium carbonate is low, it is good for bathing. However, when the content is large, the performance of the bath will be affected. Carbonate precipitates by freezing or adding lime water to form sludge.
The sludge formed in alkaline zincate zinc plating solution can be dissolved in water and discharged directly by adjusting pH value.
The sludge formed in the cyanide zinc plating solution produced in the production of galvanized steel mesh contains not only a large amount of carbonate, but also sodium cyanide, which brings trouble to the treatment. The treatment method is to dissolve the sludge and water, and then treat the wastewater containing cyanide.
In terms of sludge treatment, it can be seen from the previous discussion that the sludge produced in the treatment of zinc plating wastewater is mainly hydroxide and chromium hydroxide. Pure zinc hydroxide sludge can be dissolved in concentrated sodium hydroxide solution, and then returned to the plating solution (alkaline zinc solution) for use. In the acid zinc plating solution, the sludge should be dissolved in zinc chloride with hydrochloric acid first, and then added to the plating solution.
The above is about the relevant content of the steel mesh, I hope to help you.