Report on Metal content mobilisation using mild leaching

This deliverable is related to Task 2.1 in which various metal mobilisation methods will be investigated. The use of mild leaching fluids (such as a combination of O2 and CO2) for the mobilisation of metals in sulphide deposits will be investigated, not just because this solution is expected to offer an efficient and yet environmentally acceptable method for metals mobilisation, but also because its deep synergy with the primary aim of this proposal (energy generation). The oxidation of sulphides is an intensely exothermic reaction, and heating is likely to increase mineral dissolution rates. At the investigated high temperature and pressure conditions, we expect that the oxidation of sulphides will substantially raise the temperatures of the host rock and the fluids. In terms of initial estimates the following experiences are relevant: i) coal mining/processing industry, where oxidation of pyrite can cause enough heating to initiate spontaneous combustion of the coal, and ii) sulphide mineral mining industry where oxidation of waste tips (or underground) can give rise to high temperatures and environmental (or safety) issues.