American Lithium Corp. has announced an updated mineral resource estimate (MRE) that significantly increases the contained lithium resources for the Tonopah Lithium Claims (TLC) project located in the Esmerelda lithium district northwest of Tonopah, Nevada. This MRE was completed as part of the process of compiling the maiden preliminary economic assessment (PEA) on TLC and will be incorporated into the Mine Plan within the PEA scheduled to be completed and announced.
Simon Clarke, CEO of American Lithium states, “We are very pleased with the results of our 2022 drill programs culminating in a much larger mineral resource at TLC which underlines our position as one of the largest lithium projects in North America. In addition, the higher-grade shallow lithium mineralisation identified in our core Measured resource area provides focus for early production that should have a positive impact on the economic potential of TLC. This will be reflected in a robust maiden PEA, which we are in the process of completing in conjunction with DRA Global and should help fast-track the Project’s move through feasibility.”
“Of equal importance, the mineral resource block model and extensive new drilling has increased our geological understanding of the complexity, geometry, depth and location of the TLC mineralised claystone and has confirmed to us that American Lithium holds the most prospective ground for the location of shallow lithium-rich claystone in the TLC sub-basin,” Clarke adds.
- Measured + indicated resource LCE increases 64% from original April 2020 Mineral Resource Estimate.
- Measured resource – 4.2 Mt lithium carbonate equivalent (LCE) (860 Mt @ 924 ppm Li).
- Indicated Resource – 4.63 Mt LCE (1192 Mt @ 727 ppm Li).
- Measured + Indicated Resource – 8.83 Mt LCE (2052 Mt @ 809 ppm Li).
- Inferred Resource – 1.86 Mt LCE (486 Mt @ 713 ppm Li).
- Base case cut-off of 500 ppm Li employed – up from 400 ppm Li in the original resource due to anticipated increased processing cost inflation between 2020 and 2022.
- Infill RC and Diamond drilling validates size and scale of existing measured core resource, expands the core resource and defines areas of high-grade shallow mineralisation.
- Using a 1200 ppm Li cut-off: Measured + Indicated mineral resource contains 1.60 Mt LCE comprising 214 Mt averaging 1,402 ppm Li, which should positively impact project economics.
- RC exploration drilling highlights deeper lithium mineralisation to the west and northwest of the core Measured resource and thinner, lower grade sections to east and south next to the sub-basin edge.
Mineral resource estimation calculation methodology
The geologic model used for reporting of lithium resources was developed using Hexagon Mining’s geological modelling and mine planning software, MinePlan version 16.0.4. The geologic model from which lithium resources are reported is a 3D block model developed using the Nevada State Plane Central Zone NAD83 coordinate system and US customary units. Block size is 50 ft-X, 50 ft-Y and 20 ft-Z. Modelling method and approach is similar to that described in the prior Technical Report (Loveday, 2020) but with a re-interpretation of geologic controls on mineralisation using the additional exploration data and increased model size covering the expanded mineral claim boundary. A significant new addition to the resource is the recognition of an additional lithium clay resource below a tuffaceous marker horizon.
A base case lithium resource cut-off grade has been calculated based on the economics of a medium size (100 Mtpa) run-of-mine (ROM) surface mining operation that does not require blasting. Processing of the mineralised material would be onsite extracting lithium from claystone using an acid digestion method. Resources are reported from within an economic pit shell at 45-degree constant slope using Hexagon mining Pseudoflow algorithm. Maximum pit depth is limited to 304.8 metres below surface. No underground mining is considered.