The Importance of Accurate Rock Property and Virgin Rock Temperature Data in Ventilation and Cooling Planning Requirements
Alexander Russell, BBE Consulting; Frank von Glehn, BBE Consulting; Andrew Branch, BBE Projects; Morne Beukes, BBE
In deep hot hard rock mines the annual operational power cost for refrigeration and cooling can be as much as 35 % of the total operational power cost. This can typically be in the region of $10 000 000 per annum for a large mine in the 2nd and 3rd critical ventilation and refrigeration mining horizons. This cost excludes issues such as, loss in production, reduction in productivity and negative impacts on employee health and safety. With mines becoming deeper, this cost will only increase. To make these mines profitable and extend their life-of-mine every cost saving effort that can be made needs to be made. As thermal rock properties and virgin rock temperatures (VRT) are factors that influence design ventilation and refrigeration requirements, one such cost saving can be to establish when the accuracy of thermal rock properties and VRTs matters for ventilation and refrigeration design. This paper investigates when is it critical for a mine to accurately determine thermal rock properties and virgin rock temperatures of the ore body being mined, and not rely on generic information. This will be done by looking at a generic case study of a deep hot mine moving deep into the 3rd mining horizon by quantifying the impact that thermal rock properties and VRT variations have on the projected mine heat load. Guidance will be given on the effect of these parameters on life of mine planning.