We toured an underground diamond mine situated 40 kilometres (25 mi) east of Pretoria. Established in 1902, the mine rose to prominence in 1905, when the Cullinan Diamond — the largest rough diamond of gem quality ever found — was discovered there. The mine has produced over 750 stones that are greater than 100 carats (20 g) and more than a quarter of all the world's diamonds that are greater than 400 carats (80 g). It is also the only significant source of blue diamonds in the world.
We changed into full body cotton suits, storing our clothes and valuables in lockers, donned large rubber boots and thick leather belts, then proceeded to the safety room where we were each given a helmet, headlamp, a shoulder bag with water and dust mask, and an emergency breathing apparatus in a box which hung off the belt. Then we traipsed into a briefing room where we watched a video on how to drop to our knees, open the metal box with the breathing gear, put it on then proceed to a safe room. Next came the release forms. We really wanted to get down the mine apparently.
While standing in a tunnel waiting for the lift, our guide, Toy, a mine retiree who had been responsible for ventilation, explained the breeze we were feeling came from the air exchange system that pulled it in via the elevator shaft and expelled it via exhaust vents. If that system fails, we might need our emergency gear.
We descended at a modest rate to one of the lower levels on a lift used for both miners and all the machinery used in the mine, some of which goes down in pieces and is reassembled or, later, repaired in underground machine shops.
This mine started as an open pit over the oldest volcano on earth, after diamonds were discovered on the surface. As the pit grew, it became apparent that the helter skelter of multiple claims was inefficient and dangerous. Once the edges of the diamond rich vein were reached, they elected to tunnel down vs just expanding the diameter of the open pit. So now they use a series of tunnels at different levels to dig out the mine from the bottom up, allowing the honey combed structure to eventually collapse downward as they pull out the rock and sand horizontally, then up to the surface. The result is a much narrower and steeper mine which occasionally suffers some rock falls, but moves much less extraneous rock than would an open pit.
We walked quite a way through the tunnels and watched the mine operate with a train of cars dumping ore into a chute, a front loader doing the same, trucks driving down the tunnels to deliver supplies and equipment, a break room, a refuge room (in case of emergency) and all the while men with hoses keeping the floor wet and the dust down.
At one point, it became so dusty, I had to stop using my camera and switch to the smart phone to avoid dust in the lens mechanism. Thank goodness they had provided a zippered bag, so I could protect the camera, and a dust mask.
As we took the lift up and out, it became apparent that we were leaving at the change of shift, so that lift was crowded!
After exiting the mine, we walked the grounds to see how they move rock around and keep the mine running, even when one part of the operation is at rest. They have been piling up waste all around the mine for years and have recently discovered they can reprocess the waste to retrieve more diamonds, so the entire processing structure above ground is being replaced to do that and to continue the mining process.
The open pit is large and visible at the edge of the processing plant.
#CSCZA19 #IBMCSA
We changed into full body cotton suits, storing our clothes and valuables in lockers, donned large rubber boots and thick leather belts, then proceeded to the safety room where we were each given a helmet, headlamp, a shoulder bag with water and dust mask, and an emergency breathing apparatus in a box which hung off the belt. Then we traipsed into a briefing room where we watched a video on how to drop to our knees, open the metal box with the breathing gear, put it on then proceed to a safe room. Next came the release forms. We really wanted to get down the mine apparently.
While standing in a tunnel waiting for the lift, our guide, Toy, a mine retiree who had been responsible for ventilation, explained the breeze we were feeling came from the air exchange system that pulled it in via the elevator shaft and expelled it via exhaust vents. If that system fails, we might need our emergency gear.
We descended at a modest rate to one of the lower levels on a lift used for both miners and all the machinery used in the mine, some of which goes down in pieces and is reassembled or, later, repaired in underground machine shops.
This mine started as an open pit over the oldest volcano on earth, after diamonds were discovered on the surface. As the pit grew, it became apparent that the helter skelter of multiple claims was inefficient and dangerous. Once the edges of the diamond rich vein were reached, they elected to tunnel down vs just expanding the diameter of the open pit. So now they use a series of tunnels at different levels to dig out the mine from the bottom up, allowing the honey combed structure to eventually collapse downward as they pull out the rock and sand horizontally, then up to the surface. The result is a much narrower and steeper mine which occasionally suffers some rock falls, but moves much less extraneous rock than would an open pit.
We walked quite a way through the tunnels and watched the mine operate with a train of cars dumping ore into a chute, a front loader doing the same, trucks driving down the tunnels to deliver supplies and equipment, a break room, a refuge room (in case of emergency) and all the while men with hoses keeping the floor wet and the dust down.
As we took the lift up and out, it became apparent that we were leaving at the change of shift, so that lift was crowded!
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