The Mponeng Gold Mine, located 4km below the Earth’s surface, is the deepest gold mine in the world today.
Miners working in a mine in Gauteng province, South Africa, have to take a 90-minute elevator ride to get there, wearing protective gear and wearing emergency breathing apparatus, according to IFL Science. The well is so deep that the Earth’s geothermal gradient becomes a big problem because the temperature inside the Earth increases with depth. The temperature of soil and rock can reach 60 degrees Celsius in the ground , far beyond the heat that humans can withstand. This spurred many innovations with cooling mechanisms, which kept the world’s deepest mines at a workable temperature despite the planet’s molten core.
Mponeng gold mine has extremely high temperature because it is deep underground. (Photo: A_Dozmorov).
Ventilation systems combined with chillers bring cool air through the man-made cave system as well as a mixture of ice and cold water, helping to mitigate the worst effects of high temperatures. However, miners need to work in shifts to avoid exposure to dangerously hot conditions for too long.
Working at such great depths also comes with the possibility of barotrauma , which was first reported in French miners in the early 19th century. Barotrauma occurs when moving from high pressure areas. to a place of low pressure in a short time. For this reason, also known as decompression sickness, today most affects divers, pilots, astronauts and people working in compressed air.
Moving from a high pressure area like the deepest mine on Earth to a low pressure area like the ground can create nitrogen bubbles in the body . According to the Centers for Disease Control and Prevention, this becomes a big problem when the pressure changes happen too quickly, releasing gas into the body. The process can be very painful and sometimes fatal. Therefore, there are many measures to be followed to control the temperature and airflow, which helps to reduce the pressure on the miner’s body.
Mining at extreme depths requires creating and maintaining tunnels that can withstand the pressure of the surrounding rock without collapsing. Every day, 2,300kg of explosives are used to clear 6,400 tons of rock, according to Guinness World Records. In addition to providing gold, Mponeng also brought many unexpected discoveries. In 2006, researchers discovered the first organism to live independently of the Sun in a gold mine. They rely on radioactive activity for energy and may be examples of how life exists on other planets.