These are the deepest known underground mines in the world. Some are no longer active, however they have achieved great depths and extracted many tones of gold and mineralized ore.
Working at depth has it's challenges, and that starts with the time it takes to get workers to the mining areas, and the time it takes to get the ore back to surface. Additionally the workers extreme heat with the earths core radiating temperature that would be unbearable to most.
The time and cost related to mining at depth has it challenges for mining companies, and the ore needs to be rich and abundant to maintain a deep mine.
In recent times the mining companies along side the equipment manufacturers have dev...