THE BOURSE WHISPERER: Global Geoscience (ASX: GSC) has completed the first phase of a Pre-Feasibility Study (PFS) for the company’s 100 per cent-owned Rhyolite Ridge lithium-boron project in Nevada, USA.
Global Geoscience said the critical trade-off studies it conducted for the PFS had demonstrated a clear path forward for the project while highlighting the potential for Rhyolite Ridge to be a major, low-cost producer of lithium and boron in an environmentally sustainable manner that uses self-generated, zero-carbon power and minimises both water usage and surface disturbance.
Trade-off studies completed as Phase 1 of the PFS included Vat Leaching resulting in this being the preferred leaching method.
The study found it provides a more controlled leach environment with higher concentrations of lithium and boron into the pregnant leach solution (PLS).
Less evaporation of the PLS is required because of the higher initial concentrations, resulting in fewer mechanical evaporators and lower power consumption.
The upshot is materially lower capital and operating costs compared to alternative leaching techniques.
Global Geoscience claims Rhyolite Ridge as a global front-runner to become the first mine to recover lithium using the proven and well understood vat leaching method.
An on-site acid plant has been selected as the source of sulphuric acid providing substantially lower sulphuric acid cost estimated at $20 to 30 per tonne including credit for steam and power generation used in the operation.
“Sulphuric acid is an important economic driver for the project, and the combination of vat leaching together with an on-site acid plant will substantially lower the cost of acid, thus reducing the overall operating costs,” Global Geoscience managing director Bernard Rowe said in the company’s announcement to the Australian Securities Exchange.
“An acid plant will produce large amounts of steam that can be used for heating in the processing plant and for generation of electricity via steam-driven turbines with excess power available for selling into the grid.
“Steam produced from the acid plant negates the high input costs normally associated with mechanical evaporation.
“Vat leaching, coupled with mechanical evaporation, produces the most concentrated pregnant leach solution with consistent composition, thus simplifying downstream processing.
“With the critical trade-off analysis completed, the PFS is on track to be completed in mid-2018 with the outcomes scheduled to be released in Q3 2018.”