Gold is mined in Australia using various methods, including an underground method. According to mining company Citigold, this process involves accessing the gold using two downward angled tunnels or declines five meters long and five meters high, allowing for the mining equipment to fit through it. Then contemporary drill and blast techniques are used. Equipment with single or double drill booms drill holes into the gold ore. Explosives are then placed in them, which blast through the rock. The rock is then carried toward the surface using loading machines.
The rock is next placed on trucks that carry it to the surface. Gold-bearing ore is then treated with various chemicals at a plant and transported via city-approved roads to another plant for extraction of the gold. Using this blast technique, an extensive and complicated network of tunnels is created by which the gold ore is removed from the earth.
Another technique called open pit mining is conducted at the Fimiston Pit or Super Pit, run by Kalgoorie Consolidated Gold Mines. With this method, waste rock is removed and taken to another location, revealing the gold ore underneath. The exposed gold is then mined.
Sub-level extraction is another technique used in Australia by the Newcrest company. In method, ore is mined from the top down using the drill and blast method. This allows for the rock to cave in as operations head deeper into the ground.
Following extraction, the gold is processed using a variety of steps. The material can be pulverized and then exposed to lime, cyanide and other chemicals for purification. It can also be processed using a technique called flotation, in which gold ore powder is separated from other minerals by being placed in a liquid. The materials separate from one another since some sink and others will float in the liquid. After further processing, gold doré, or bars, are made.
- Stockbyte/Stockbyte/Getty Images