Strategic placement of compressors for future mine developments HG Brand August 2012

Introduction Rustenburg Platinum Mine (RPM) consists of eight shafts supplied with air from six compressor houses Mandate of the simulation: 1. Determine the best position of the compressors replacing the West 10 compressors 2. Reduce the system’s reliance on the VK-125 compressor 3. Determine whether Khusuleka 1 (Townlands) and Khusuleka 2 (Boschfontein) can be isolated

Surface layout

Simulation 1: Description Aim: Verify accuracy at high flow rates The average flow profile for the air network is determined The simulation is run to replicate the pressures at the shafts These pressures are compared to the actual pressures at the shafts

Simulation 1: Results

Simulation 2: Description Aim: To alleviate the system’s reliance on the VK-125 West 10 compressor house is decommissioned The high risk pipe section from Siphumelele 3 (Bleskop), via West 10 to Khomanani 1 (Frank 1) is removed Two BB Sulzer compressors are simulated at Khomanani 1 (Frank 1) A GHH compressor is moved from West 10 to Siphumelele 1 (Turffontein) to replace the VK-125

Simulation 2: Results

Simulation 2: Summary Average required flow at Siphumelele 1 (Turffontein) is 107 Х 10 ³ m³/h Peak flow can be 30 Х 10 ³ m³/h above average profile and the required flow can be as high as 137 Х 10 ³ m³/h Available flow from two GHHs is 66 Х 10 ³ m³/h The available flow is too low and the VK-125 cannot be stopped

Simulation 3: Description Both GHHs and the VK-125 are started at Siphumelele 1 (Turffontein) Aim: Determine maximum pressure at Siphumelele 1 (Turffontein)

Simulation 3: Results

Simulation 3: Summary The pressure at Siphumelele 1 (Turffontein) increases to 622 kPa at the compressor house while the pressure at the shaft is 605 kPa The pressure rating of the pipes are 800 kPa

Simulation 4-6: Description With the VK-125 running - Determined how many additional BB Sulzers are required and where to position them A BB Sulzer was placed at Thembalani 1 (Paardekraal), Khomanani 1 (Frank 1) and Khomanani 2 (Frank 2) One GHH and the VK-125 was running at Siphumelele 1 (Turffontein)

Simulation 4-6: Results

Simulation 4-6: Summary Best position to place the BB Sulzer is at Khomanani 2 (Frank 2), followed by Khomanani 1 (Frank 1) and then Thembelani 1 (Paardekraal) Flow spikes occur at Khusuleka 1 (Townlands) and Khomanani 2 (Frank 2) To accommodate flow spikes it is suggested that the second BB Sulzer compressor be positioned at Khomanani 1 (Frank 1)

Simulation 7-8: Description Aim - Determine whether to place the two BB Sulzers in one or two compressor houses Three simulations are run In all the simulations one GHH and the VK-125 is running at Siphumelele 1 (Turffontein)

Simulation 7-8: Description Solution 1 - One compressor is placed at Khomanani 1 (Frank 1) and one at Khomanani 2 (Frank 2) Solution 2 - Both compressors are placed at Khomanani 1 (Frank) Solution 3 – Both GHH compressors at Siphumelele are running together with the VK- 125 Compare to the existing system pressures

Simulation 7-8: Results

Simulation 7-8: Summary Solution 3 is not viable Solution 1 offers the best option, followed by solution 2. Solution 2 will be the preferred option In both solution 1 and 2 the flow to Khusuleka 1 (Townlands) is in excess of m³/h This confirms that these shafts cannot be isolated

Conclusion The simulations indicated that the system relies too heavily on the VK-125 compressor The best compressor placement was at Khomanani 1 (Frank 1) Khusuleka 1 (Townlands) and Khusuleka 2 (Boschfontein) cannot be isolated from the rest of the air network.