Here’s the release from American Lithium:
American Lithium Corp. (“American Lithium” or the “Company”) (TSX-V:LI | OTCQB: LIACF | Frankfurt:5LA1) is pleased to provide details of a recent breakthrough on process development at its Tonopah Lithium Claims Project (“TLC”) located close to Tonopah, Nevada.
- Ongoing process work at Hazen Research Inc. has shown that roasting TLC lithium bearing claystones with sulfate and chloride salts, followed by water leaching, results in 82% of lithium being extracted with a significantly lower impurity load as compared to acid leaching.
- This alternative processing method will be investigated further at both Hazen Research Inc. in Golden, Colorado (“Hazen”) and at TECMMINE in Lima, Peru (“TECMMINE”).
- Test work at Hazen has so far utilized non-upgraded TLC claystones. Additional work will also commence on mechanically upgraded TLC claystones with even better results anticipated.
- Full roasting / water leaching results will be compared to results for sulfuric acid leaching to ascertain which method is best from an economic and environmental perspective.
- TLC claystone mineralization continues to demonstrate exceptional ability to be concentrated and amenable to multiple process options with lithium carbonate having already been produced.
- This latest round of process work is focused on optimizing flow-sheet design to deliver strong environmental and economic benefits to enable a robust Preliminary Economic Assessment.
Dr. Laurence Stefan, COO of American Lithium, states, “The early success of roasting demonstrates once again the robust nature of the TLC lithium resource and its processing versatility. This new metallurgical approach opens the door widely to produce either lithium carbonate or lithium hydroxide or both from the TLC project. The extremely low level of impurities in the leachate provides many advantages over the successful sulfuric acid leaching technique that has been the focus to date. We are excited to investigate the roasting route further and will be comparing the overall environmental and economic profiles of each route to make the best decision for the project moving forward.”
American Lithium Provides TLC Process Update:
The TLC project has previously shown that its Li-rich claystones are amenable to rapid sulfuric acid leaching, with lithium extraction in sulfate solution reaching 92% in 10 minutes, for some of the samples. While the flowsheet for sulfuric acid leaching has been successful and is being further optimized, an alternative roasting / water leaching technique has demonstrated early success and will be investigated with additional laboratory test work.
Experiments performed at Hazen Research Inc. in Golden, Colorado, demonstrate that roasting the lithium bearing claystones at 900°C with sulfate and chloride salts (sodium chloride, sodium sulfate, and/or gypsum – calcium sulfate dihydrate) and then leaching in 60°C water for 2 hours, results in 82% of the lithium being extracted into aqueous solution. This roasting process followed by water leaching not only increased the final pH of the solution to 8.5, making the eventual final lithium carbonate or hydroxide precipitation much easier, but also produced an astonishingly low level of impurities, when compared to sulfuric acid leaching.
Heavy elements such as iron, aluminum, and manganese in the leachate are below detection limit (<10 ppm), with magnesium extraction below 1% (54 ppm) and calcium extraction below 3% (500 ppm). As expected, sodium and potassium are leached in greater quantities, but still at manageable levels (Na 78%; K 52% extraction in aqueous solution). Test work at TECMMINE shows a good rubidium extraction of 63%. The high extraction of potassium and rubidium presents the opportunity to produce saleable by-products such as potash as fertilizer and rubidium hydroxide for industrial applications. The overall impurities level in the aqueous solution obtained to date, through roasting and water leaching, presents a legitimate alternative route to producing battery-grade lithium chemicals from TLC claystone mineralization.
Additional test work is underway to build on these initial results and further investigate the roasting process-route at Hazen and at TECMMINE and the results will be fully compared to sulfuric acid leaching once sufficient data is compiled. American Lithium plans to compare the roasting option to acid leaching both in terms of capex, opex, environmental footprint and economic performance.
As previously announced on March 23, 2021, TLC claystones can be upgraded by up to 66%, in terms of lithium grades, using hydrocyclones and centrifuges. The preliminary test work on roasting was performed on non-upgraded claystones and further progress and efficiencies are anticipated from testing upgraded samples.
In parallel, hydrochloric acid leaching test work has started with TECMMINE. TECMMINE was instrumental in optimizing the leaching and precipitation of battery grade lithium from the Company’s high-grade Falchani project in Peru and will be a key player in the optimization of flowsheets for TLC.
Dr. Laurence Stefan, COO of American Lithium, concluded “As we continue to optimize processes for the extraction of lithium from TLC claystone mineralization, we will be comparing overall environmental and economic performance for all relevant routes. American Lithium is fortunate that we have so many excellent options from which to produce battery grade lithium compounds from TLC which will enable us to select the best overall route for feasibility and to have other options if needed in the future. We currently anticipate finalizing this process this Fall.”