or MacArthur-Forrest process
Method of extracting silver and gold from their cyanide or potassium cyanide.
The process
invented in 1887 by the Scottish chemists John S. MacArthur, Robert W. Forrest, and William Forrest
includes contacting the finely ground ore with the cyanide solution, separating unwanted solids from the clear solution, and recovering the precious metals from the solution by precipitation with zinc dust.