Century Lithium Corp. (TSXV: LCE) (OTCQX: CYDVF) (Frankfurt: C1Z) (Century Lithium or the Company) is pleased to report testing results at Saltworks Technologies, Inc. (Saltworks) in Richmond, Canada, and additional production of high-purity lithium carbonate (Li2CO3) using product solutions from the Company's Lithium Extraction Facility (Pilot Plant) in Amargosa Valley, Nevada, USA. The solutions tested at Saltworks were derived from leaching of claystone from the Company's 100%-owned Clayton Valley Lithium Project (Project) in Nevada; and processed at the Pilot Plant via direct lithium extraction (DLE) to produce an intermediate concentrated lithium solution (DLE eluent).
"It is very positive to see consistency in our high-purity, 99.87%, lithium carbonate product grades from our Pilot Plant this year" stated Bill Willoughby, President, and CEO of Century Lithium. "The highlight though, is the almost five-fold increase in lithium grade in the concentrated lithium solution generated at the Pilot Plant. This was achieved through collaboration with Koch Technology Solutions and their Li-ProTM system, and its integration into Century Lithium's chloride-based leaching process."
Highlights
- Repeated production of high-purity (99.87%) battery-grade lithium carbonate
- Improved lithium concentrations in DLE eluent
- Reduced volume of solution in downstream treatment and recycling
- Potential to eliminate evaporation from the post DLE process flowsheet
- Active testing underway to further improve DLE eluent grade
- Lithium Carbonate Assay Results
Saltworks has once again produced battery-grade lithium carbonate (Li2CO3) from the DLE eluent produced at the Pilot Plant. The table below is a comparison of Saltworks' 2023 results for Li2CO3, DLE eluent Batch 2, with the previously reported results from DLE eluent Batch 1 (see May 25, 2023 news release). Also shown are the constituent levels for battery grade Li2CO3, as published by two major producers. The assays results were finalized by Saltworks and independently assayed by SGS Canada, Inc. These results show consistency in composition of both the DLE eluent produced by the Pilot Plant earlier in the year and the resulting Li2CO3 product produced by Saltworks, achieving 99.871% content versus 99.875% reported previously.
Lithium in DLE Eluent
As recently reported (see August 9, 2023 news release), Century Lithium collaborated with Koch Technology Solutions (KTS), a Koch Engineered Solutions' (KES) company, and integrated KTS' Li-ProTM system into the DLE stage of the Pilot Plant. This work has increased the grades of the DLE eluent (intermediate lithium product solution) several fold. These changes are outlined in the table below, as reported by analyses from Saltworks.
Batches 1, 2 and 3 are DLE eluents produced during the first quarter of 2023. Li2CO3 production was carried out to completion in batches 1 and 2 but the processing of Batch 3 was put on hold due to its similarity to batches 1 and 2 and the improvements seen in the grades of batches 4 and 5. These improvements in lithium grade from 1,430 parts per million (ppm) to 6,780 ppm, increase in the ratio of lithium to total dissolved solids (TDS) from 0.018 to 0.085, and reduction in sodium from 25,850 ppm to 8,220 ppm all occurred with the introduction of KTS' Li-ProTM system into the DLE stage of the Company's Pilot Plant.
Implications for Lithium Carbonate Production
The increase in lithium (Li) grade and the Li:TDS ratio has positive implications for the size and costs of the lithium carbonate production portion of the lithium extraction process at the Project. Within the Saltworks flowsheet, these higher values equate to a lower volume of solution to be treated and a proportionate decrease in the amount of water that must be removed (evaporated) prior to lithium carbonate precipitation. This will also affect the recycled solutions within the lithium carbonate production stage by reducing the volume of solutions moved in this stage and other leaching areas of the processing plant.
The information derived from the Pilot Plant, including the test results from the combination of Century Lithium's DLE process and KTS' Li-ProTM system, and recent component changes at the Saltworks laboratory, is supplemental to the Feasibility Study for the project. The design basis for the Feasibility Study was established at a Li:TDS ratio of 0.02.
The Saltworks flowsheet targets a lithium grade of 10,000 to 20,000 ppm (10-20 g/L) for precipitation. Work with KTS at the DLE stage at the Pilot Plant has seen preliminary, internally assayed, lithium solution grades of over 8,000 ppm in the DLE eluent. Work is continuing within the DLE area to further increase lithium grades in solution, creating the scope to reduce solution volumes and the potential to eliminate a major evaporation step from the process flowsheet. As a supplement to the Feasibility Study, the Company is pursuing these potential cost and size savings with Saltworks.
Moving Forward
Work on the Feasibility Study continued throughout the six months ended June 30, 2023, with more than 20,000 consultant hours expended since its commencement. Following receipt of initial values from our consultants, Wood PLC and thyssenkrupp nucera, the Company is conducting internal reviews to assess optimization and cost reduction opportunities; work which is underway. In June 2023, the Company engaged Kiewit Industrial Group in Lone Tree, Colorado to assist with the review of project designs and estimates with attention to site development, material and supply costs, and construction methods. One optimization opportunity, reducing or eliminating the use of thickeners for tailings separation in the process configuration, was implemented and is under trial at the Pilot Plant.
The Company's collaboration with KTS is underway, utilizing KTS' Li-ProTM equipment in the DLE section of the Pilot Plant, where lithium is selectively recovered from the leach solution while deleterious elements are rejected. Testing with KTS is expected to continue through the 3rd quarter while KTS collects information to prepare an engineering design and cost estimate for a full-scale deployment of Li-ProTM system which will supplement the Company's Feasibility Study.
Qualified Person
Todd Fayram, MMSA-QP and Daniel Kalmbach, CPG, are the qualified persons as defined by National Instrument 43-101 and have approved the technical information in this release.