This illustration shows a Blake Ore Breaker (stone crusher), used in a gold stamp mill. This crusher breaks the large, mined rocks containing the gold (ore) into small pieces, to then be reduced to the finest powder by stamps.

Blake Ore Breaker

This illustration shows a Blake Ore Breaker (stone crusher), used in a gold stamp mill. This crusher…

Gold miners paning for gold in California.

California Gold Mining

Gold miners paning for gold in California.

The chlorination process in gold extraction employs large vats or revolving barrels, the material inside of which is moistened with water and treated with chlorine gas to form a solution of Gold Chloride. This is then run off, and the gold precipitated , usually by means of Ferrous Sulphate or charcoal.

Chlorination Barrel

The chlorination process in gold extraction employs large vats or revolving barrels, the material inside…

The chlorination process in gold extraction employs large vats or revolving barrels, the material inside of which is moistened with water and treated with chlorine gas to form a solution of Gold Chloride. This is then run off, and the gold precipitated , usually by means of Ferrous Sulphate or charcoal.

Chlorination Barrel (End Section)

The chlorination process in gold extraction employs large vats or revolving barrels, the material inside…

In the gold extraction process, finely crushed ores are leached in vats with a very diluted solution of Potassuim Cyanide (KCN), containing 0.05 to 0.3 percent KCN (or its equivalent, Sodium Cyanide, NaCN) which is allowed to remain for twelve to twenty-four hours to dissolve the gold.

Cyanide Leaching Tank (Gold Extraction)

In the gold extraction process, finely crushed ores are leached in vats with a very diluted solution…

A Frue Vanner is a shaking, rubber belt used to concentrate gold ore 'pulp'.

Frue Vanner (End View)

A Frue Vanner is a shaking, rubber belt used to concentrate gold ore 'pulp'.

A Frue Vanner is a shaking, rubber belt used to concentrate gold ore 'pulp'.

Frue Vanner (Side View)

A Frue Vanner is a shaking, rubber belt used to concentrate gold ore 'pulp'.

The Klondike Gold Rush during the late 19th century. Many immigrants moved to Dawson City in the Yukon Territory, Canada, in hopes of finding gold.

Klondike Miners

The Klondike Gold Rush during the late 19th century. Many immigrants moved to Dawson City in the Yukon…

An illustration of a man sitting in a coal mine shaft with a shovel in hand.

Miner

An illustration of a man sitting in a coal mine shaft with a shovel in hand.

French sappers and miners.

Miners

French sappers and miners.

This furnace is used to purify a gold concentrate. The gold concentrates, if non-pyritic, are treated in grinding pans in the bottom of which mercury is placed. The amalgam (mercury alloy), after squeezing out the excess mercury, is heated in the retort, to distil (separate) off the rest and leave the gold, which is then melted and cast into bars of gold bullion of varying fineness.

Retort Furnace for Gold Bullion

This furnace is used to purify a gold concentrate. The gold concentrates, if non-pyritic, are treated…