Лако-красочные материалы — производство

While cadmium will dissolve in sulfuric, hydrochloric and nitric acids, a mixture of sulfuric and nitric acids is preferred, to obtain a controllable reaction rate to avoid producing noxious fumes.

Sulfuric acid on its own does not dissolve cadmium metal well, as hydrogen bubbles produce a coating which prevents further attack.

Typically, cadmium moss or sponge is packed into a tower. The mixture of diluted acids (with sulfuric in excess) is recirculated through the tower. Cadmium ingots are avoided, as they provide insufficient surface area, and the solution reac­tion would be too slow. Purification and dilution to the required strength then pro­ceeds as previously discussed.

3.4.4