Recuperation of cyanides from rinsing solutions of cyanidric processes for eletrodeposition of metals
OwnerMichael F. Peuser, Jose B. Bartoloinventors
Life of this patent
Estimating the term…
Abstract
Process for the recuperation of an insoluble salt of a metal from the rinsing solution of an electrodeposition of the metal.
Claims3
A process for recuperation of a cyanide from a rinsing solution of a cyanidric process for electrodeposition of copper, the solution containing a soluble complex cyanide of an alkali metal and copper, comprising adding to the solution a soluble simple salt of bivalent copper reacting with said complex cyanide and any free cyanide ions in said solution to form and precipitate an insoluble cyanide of copper, and separating said precipitant for reuse, said precipitation, being conducted without using hydrochloric acid by adding sodium bisulfite to the solution to reduce the pH of the solution to between 1.5 and 4.0 and the copper ion of the simple salt to a cuprous state for precipitating insoluble cuprous cyanide.
A process for recuperation of a cyanide from a rinsing solution of a cyanidric process for electrodeposition of cadmium, the solution containing a soluble complex cyanide of an alkali metal and cadmium, comprising conducting the process in two stages, in a first whereof the solution is diluted to a cadmium content below 17 g/l, a soluble salt of zinc and a strong acid is added to the diluted solution to precipitate insoluble zinc cyanide, and the precipitate is separated from the solution, and in the second stage adding to the solution from the first stage an alkali compound reacting with cadmium ions in the solution to form and precipitate an insoluble cadmium salt, and separating the precipitate.
Dependencies are inferred from the claim text.