For those of you who are interested, I am a miner. The technical term for my position is, "Industrial Millwright Technician". In layman's terms I am a "Dirt Bag Mechanic". I'm often asked if I pan for gold, or if I work deep in a cavernous mine shaft. The truth is I do neither. I work in the process division where we take the ore and refine it using a leaching process that removes the microscopic gold particles from the dirt.
Let me break it down for you. In a large pit the ore is extracted from the earth using large shovels and haul pack trucks. The ore is then brought to a crusher that smashes the large rocks and dirt to a size that we call 4" minus. This means the rocks start out at 50" in diameter and are crushed to 4" or smaller.
The next step involves milling the ore. For those of you who have a rock polishing mill you'll know what I'm talking about. These mills are 20' tall, and 40' in length. They are basically a large cylinder full of steel balls that spins and crushes the 4" minus rock to sand.
Now the next part may be a bit disturbing for those of you who are environmentally conscious. From the mill the ore is pumped to acidulation vessels. These large tanks mix sulfuric acid with the ore to aid in the oxidation process. The oxidation process is necessary due to the nature of the ore. Most of the dirt below the surface of Nevada is what geologists call sulfide ore, and emits large amounts of So2 as a result. Because of this natural occurrence the slurry must be oxidized using a process call...tada...pressure oxidation.
Now this next step uses the acid to help burn off excess carbides, but it is the autoclave vessels that do the oxidizing. When the mixture of acid and mud enter these vessels they reach a temp. of 400 degrees F. and exceed pressures of 400 psi. while pure oxygen is pumped in simultaneously. In the end the gold mixed in with the ore can be leached off of the silica using cyanide. If it were not for the oxidation process the hi levels of carbon and sulfur would make it impossible for the cyanide to cling to the gold.
That's what I do; I play with dangerous chemicals and heavy equipment all day long! Hope your desk job isn't boring you to death. Peace
