THE SONORA LITHIUM PROJECT- MOLDING SUCCESS FROM CLAY

摘要

Ausenco completed the feasibility study for the Bacanora Minerals, Sonora Lithium Project in early 2018 having spent the best part of three years performing studies to refine the process and mitigate project risks. This presentation will describe the project background, technical challenges and innovative engineering solutions that have made the Sonora Lithium project a world-class investment opportunity. The Sonora Lithium project is located in the state of Sonora in north-west Mexico. The lithium is mineralised as polylithionite (clay). The measured and indicated resource is 291 Mt at 3.250 ppm lithium. The project consists of an open-pit mine with a mine plan for 19 years and a mineral conversion plant (MCP) to produce lithium carbonate. The design output for the project will commence at 17,500 t/y of battery-grade lithium carbonate (Stage 1) for the first four years of the project, followed by a proposed expansion, by duplicating the plant, to produce a target minimum design output of 35,000 t/y (Stage 2). The Sonora Lithium Project is designed to produce up to 28,800 t/y of potassium sulfate per stage as a by product, for sale to the fertiliser industry. Significant testwork was undertaken to define the flowsheet. Beneficiation was found to enable economic processing of the orebody. Roast chemistry was studied in detail to optimise lithium recovery and reduce reagent consumption and overcome limitations of conventional roasting equipment. The final flowsheet employs novel uses of established technology to achieve lithium recovery and impurity removal. Variability test work was done to verify robustness of the flowsheet for both the beneficiation and extraction sections of the process. Locked cycle testwork was also completed to test flow sheet stability. The study has resulted in an economic project worthy of investment. The economic analysis indicates a pretax net present value, discounted at 8%, of approximately $1,253M and an Internal Rate of Return of approximately 26%.