The New Student's Reference Work/Cyanide-Process, The

Cyanide-Process, The. The cyanide-process is one of two ways in which gold is extracted from low-grade ores, which contain only from 2 to 10 dollars per ton of gold. The ore is first crushed in stamp-mills, until it is quite fine; it is then treated with a solution of potassic cyanide, which dissolves the gold. This liquid is then treated with zinc, by which the gold is released and precipitated. This method is chiefly employed in the Transvaal goldmines and, to a less extent, in the low-grade mines of Dakota, Wyoming and other western states.