Curious how is platinum mined? Platinum mining takes different forms depending on where it occurs and the level of technology used by the mining company. As one of the rarest of precious metal commodities, it's easier to understand why this metal is so valuable once you know about the mining process.
Meet the platinum group metals.
"Platinum group metals" is the phrase that describes platinum, palladium, iridium, osmium, rhodium and ruthenium. These metals are rare, and the mining process for these metals often produces far greater quantities of nickel and copper than platinum group metals. These pgm metals are all extracted during the refining process, so they undergo further processing to separate the respective metals. The typical platinum mining process takes 5 to 7 months, and it may require as much as 10 tons of ore to yield 1 ounce of platinum.
Ore leaves the mine to be refined.
The first step in the mining process is getting the platinum ore out of the ground and into a refinery or processing plant. Two methods exist to extract platinum ore: the old "narrow reef method" and newer mechanical mining methods. The original "narrow reef method" consists of drilling holes, loading them with explosives and removing the ore once it's blasted free.
Newer methods utilize specialized drilling equipment to remove the ore and load-haul-dump machines to transport the ore from the mine. Platinum may be mined using traditional open-pit strip-mining methods or underground mining methods, depending on where the vein is located.
Extracting pgm from the rest.
Once it's mined, the extraction process begins. The platinum ore is first crushed to produce tiny particles suitable for further treatment. The next step is the flotation separation method, which relies on air particles bubbling through an aeration tank to adhere to pgm particles and float them to the top of the tank. They form a froth at the top of the tank, which is then skimmed off for refining.
The concentration process requires smelting the dried pgm froth at high temperatures to separate the pgm further from unwanted materials. Other minerals oxidize and are removed. The pgm is then treated with air to blow out particles of iron and sulfur in order to further concentrate the platinum group metals.
After mining, extraction and concentration, platinum group metals must be refined. This is another step that removes nickel, copper and cobalt from the other pgm. Electrolytic techniques remove the copper, cobalt and nickel from platinum group metals. Finally, a series of ion-exchange techniques, distillation and solvent extraction occur. Soluble metals, such as gold, are dissolved in hydrochloric acid and chlorine gas, and finally only platinum remains.