Steel mesh after galvanizing treatment will produce a large amount of waste, which will pollute the environment. Next, we will talk about the method of waste slag treatment.
Zinc-plating slag mainly comes from two aspects: one is carbonate produced in alkaline zinc-plating bath; the other is metal hydroxide formed in sewage treatment.
The first is to treat alkaline zinc with carbonate: both cyanide zinc and alkaline zinc are treated with sodium hydroxide and sodium oxide, which can absorb carbon dioxide from the air and produce sodium carbonate. When the content of sodium carbonate is low, it is good for bathing. However, too much content can affect the performance of the bath. Carbonate is then precipitated by freezing or adding limewater.
Sludge formed in alkaline zinc zincate solution can be dissolved in water and discharged directly by adjusting PH value.
The sludge formed in cyanide zinc plating solution during the production of galvanized steel mesh contains not only a large amount of carbonate, but also sodium cyanide coating, which brings troubles to the treatment. The treatment method is to dissolve sludge and water and treat cyanide-containing wastewater according to the treatment method.
As for sludge treatment, we know from the previous discussion that the sludge from zinc plating wastewater treatment is mainly calcium hydroxide and chromium hydroxide. Simple zinc hydroxide sludge can be dissolved in concentrated sodium hydroxide solution and then returned to the plating solution (alkaline zinc plating solution). The sludge should be dissolved into zinc chloride with hydrochloric acid before adding bath solution.
Above is the relevant content of steel mesh, I hope to help you.