Twenty stamp Mill - Apache Junction, AZ
Posted by: dkestrel
N 33° 26.836 W 111° 30.079
12S E 453406 N 3700985
The twenty-stamp mill was originally located on the grounds of the Goldfield Ghost Town i Apache Junction, Arizona. Today the Superstition Mountain Museum is home to the twenty-stamp mill.
Waymark Code: WMK38Y
Location: Arizona, United States
Date Posted: 02/06/2014
Views: 26
Stamp mills originated in Europe and came to the United States as early as the 1800's. This Twenty Stamp Mill is about 100 years old having been built around 1914-1915 at a mine in Bland, NM.
Ore when mined can be as large as a man could carry or lift. It was transported to a mill by ore car, mule, or wagon to be crushed so the gold or silver could be extracted, The stamp mill process starts with a separation process called a "grizzly" that lets small ore pieces fall through and directs larger pieces to an "ore crusher". Ore no larger than 2" or the size of a man's fist is fed into an "ore feeder" behind the stamp mill where it is automatically fed into the stamp mill along with water. The 900 pound stamps are lifted and dropped by the rotating action of cams which are turned by a "bull wheel" connected by a drive belt to a power source. The power source for this mill was originally steam. Later it was adapted to use electricity.
When the ore is crushed fine enough to pass through the mortar box screen, it is washed into a "roughing table" where visible gold can be removed. It is then washed further into a large tank and mixed with a cyanide solution that dissolves the gold. Rakes at the bottom of the cyanide tank stir the solution and when the ore is adequately dissolved, it is washed through filters that collect the gold for further refining in a smelter.
The Superstition Mountain Museum is in the process of restoring the end bank of five stamps to operating condition. They also intend to replicate the cyanide extraction process by reassembling that equipment. All of this work is being done by volunteers and supported by financial donations and grants.
Year built?: 1860
Is the mill or gin still in operation?: No
What is or was processed here?: Gold ore
Are tours available?: None offered, view from the outside only.
How is or was it powered?: Steam
Related link to this waymark.: [Web Link]
What is it used as today?: no
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Visit Instructions:
A picture of the mill or gin along with any information you can provide about the waymark and what you might have experienced while visiting.