The Rhyolite Ridge deposit is amenable to low-cost open pit mining methods and simple acid leaching with low acid consumption.
Mining is likely to be low-cost as the host rock is competent but relatively soft (hardness of 3.5 on Mohs scale).
The strip ratio is likely to be quite low as the Mineral Resource outcrops over a 3 km strike length along the western margin of the South Basin.
RPM Global completed an initial mining study in conjunction with the October 2017 Mineral Resource estimate. The study evaluated conceptual pit designs and development, scheduling and mine site design and layout. The study was based on only the high-grade (lithium-boron) component of the South Basin Resource.
The mining study provides the basis for estimating the cost of feed to the processing plant and is an integral part of the PFS. Whilst no decision has been made at this stage, the Company is considering production rates in the range of 2 million to 4 million tonnes per annum. By way of illustration, one million tonnes of mineralisation contains approximately 8,700 tonnes of lithium carbonate and 77,200 tonnes of boric acid.
Further information is available in the announcement “Initial Rhyolite Ridge Mining Study Confirms Potential for Long Mine Life from Currently Defined South Basin Resource”.