There are four different basic methods of gold mining, each with their own unique processes of accessing, extracting and processing the gold that has been located in the surrounding earth. These four methods are placer mining, hard rock gold mining, byproduct mining, and finally, gold ore processing. Below you’ll find some information on each of them, so that you have some idea about how your gold has got out of the ground!
Hard Rock Mining
This method involves creating either open pit mines, or underground tunnels in order to access the gold in the surrounding rock. The majority of the gold supply in the world is extracted using this process as it gives miners the ability to access large areas of earth where gold has been detected.
Placer mining is popular amongst amateur and hobbyist gold hunters as it is a simple process requiring affordable equipment. Gold is usually detected with a metal detector, and the processes of panning, cradling and dredging are then carried out to separate the gold from the surrounding rock and other earth materials. The density of the gold makes this separation possible with even the most basic of equipment.
The same as hard rock mining in that underground or open pit mining methods are employed, however in by-product mining the gold itself is a by-product of the primary material that is being mined at the site. Usually sand, gravel, copper or other materials are being mined as the primary item, however when it has been deemed that there is enough gold present to warrant mining it as a by-product, it adds considerable revenue to the overall mining operation. One particular example of this type of mine is Grasberg in Papua, Indonesia. This is primarily a copper mine, however it still manages to extract more gold as a by-product than other mine throughout the world.
Gold Ore Processing
A method that is rarely in use anymore, mostly due to the significant negative environmental impact of the method, as well as operational costs. Additionally, the gold yield using this method is low and therefore not economically viable in most situations. Gold ore processing involves extracting only trace quantities of gold from crushed rock. A chemical process is required to undertake this, and the chemical used is often cyanide; one of the many reasons why this particular method of gold mining has largely ceased in many parts of the world.