Mining occurs around the world to forage for some of the earth’s most valuable resources. Six of the ten deepest mines in the world are all located in the same area of South Africa, with many of their main objectives being to mine gold. Topping the list of the world’s deepest mines is Mponeng Gold Mine, located south-west of Johannesburg. At Prime Engineering we think the machinery and processes to attain these valuable minerals is incredible, and the AngloGold Ashanti’s Mponeng Gold Mine is the pinnacle of impressive engineering.
The Mponeng Gold Mine stretches a whopping 2.5 miles under the earth, making it the world’s deepest man-made hole. It’s chambers, tunnels and passages stretch 236 miles which is only slightly shorter than the entire London underground system. To propel themselves into the mine, miners use shaft elevators or ‘cages’ that can hold up to 120 people and are suspended on steel ropes that can stretch over 10,000 feet.
Going this deep into the Earth is a pretty risky gig so the mines have developed a variety of tools to keep miners safe during their work. Mining 2 miles below the earth’s surface can cause disturbance to surrounding areas, so these sites use seismic monitoring stations to transmit signs of movement to mine managers. This monitoring machinery is usually constructed using small, 7-inch cylinders with sensors and placed in deep, 30-inch boreholes. Drilling these tunnels can also cause the rock walls lining them to bulge and swell. To avoid them collapsing in or bursting, crews spray them with a reinforcement of ‘shotcrete’, which is a flexible mix of concrete and steel fibres.
The working conditions in these mines can be very uncomfortable and without the help of certain technologies, totally unworkable. Refrigeration is an essential process that is conducted at Mponeng that occurs through pumping ice slurry underground, reducing the temperature to below 30 degrees Celcius. These temperatures are then maintained by a thermal barrier constructed with concrete, rock and water. Ventilation is also an important consideration when creating these mines. Being over 2 miles underground, airflow is not properly available. Gigantic, adjustable fans, over 4 metres wide, are installed to produce an artificial airflow.
At Prime Engineering, we find the processes and machinery at Mponeng Gold Mine phenomenal and fascinating. It really puts into perspective just how much goes into those pieces of jewellery that you see in your local department store! If engineering is your passion and you are requiring work for your existing or new machinery, Prime Engineering is ready to help. Contact us today!