Update on Mini-Pilot Plant Work for Lithium Recovery Process
Pure Energy Minerals Limited (the
“Company” or “Pure Energy”) is pleased to provide an update regarding its Mini-Pilot Plant work with Tenova Bateman Technologies (TBT) at their research and development centre in Katzrin, Israel and at other off-site locations. The Pure Energy and TBT team has achieved several intermediate milestones on the preliminary process engineering work for the Clayton Valley South (CVS) lithium brine project:
* Brine pre-treatment (LiP) testing exceeded expectations for lithium recovery and rejection of magnesium and calcium. Two membranes have been
short-listed and are undergoing additional testing;
* Confirmed initial favorable results from the solvent extraction lithium recovery circuit (LiSX) – highly efficient lithium recoveries into solvent and very low levels of lithium in residual brine;
* Successful conversion of lithium sulphate into lithium hydroxide by electrolysis (LiEL) – achieving higher current efficiencies than
The CVS Mini-Pilot Plant program is beyond its halfway point and progress has been excellent. This larger scale study of Pure Energy’s proposed processing technology route for the CVS Project is on track to highlight the advantages of a real-time new technology approach to lithium recovery. The team is advancing simultaneously on several areas of the program, as described in more detail below. All of these data will be integrated into the process design flow sheet and engineering studies that will comprise the Company’s forthcoming Preliminary Economic Assessment (PEA).
Patrick Highsmith, Pure Energy Minerals CEO commented, “We are very excited by our progress with Tenova Bateman Technologies on the Mini-Pilot Plant. Last year’s preliminary test results showed the solvent extraction technology to be viable at bench-scale, and this work is confirming success at a much larger scale while also providing engineering design data. As we reported in April of this year, the brine from our CVS Project has among the lowest magnesium contents of any lithium brine resource in the world. This makes it well suited for new direct lithium extraction technology,such as the TBT process. We look forward to building on this interim technical success to highlight its potential for low-cost, highly sustainable and environmentally friendly lithium production technology.”
Pure Energy’s proposed lithium recovery process consists of four main stages, as discussed below.
Pre-Treatment – The primary purpose of the pre-treatment stage is to remove alkaline earth elements (Ca, Mg and Sr) using either membranes (LiP; TBT’s process, being\ tested in Katzrin) or via direct chemical precipitation (being tested at SGS Canada Inc.’s hydrometallurgy laboratory in Lakefield, Ontario). TBT has completed the initial phase of membrane selection, which consisted of testing eight potentially suitable membranes using a flat-sheet configuration test rig. After analysis of brine flux rates, lithium recovery and alkaline earth rejection, the team selected the two best-performing membranes. These two membranes are currently being tested in a larger, spiral-wound test rig using 6.4 cm (2.5 inch) diameter units. This phase of work entails passing approximately 200 L of brine solution through the membranes in each test run. Work is ongoing, but preliminary data suggest that the membranes are providing better than expected performance in terms of lithium recovery and alkaline earth element rejection.
In addition, work completed at SGS has shown promising results using conventional direct chemical precipitation of unwanted alkaline earth impurities, by raising the pH through addition of sodium hydroxide and soda ash. The work completed to date has demonstrated rapid removal of Mg, Ca and Sr, with effectively zero loss of lithium during this precipitation process. Test work continues at SGS on solid-liquid separation and other aspects of the chemical precipitation option.
Solvent Extraction – This stage takes the pre-treated lithium brine and uses solvent extraction technology (LiSX) to selectively extract lithium from the brine into the organic phase. That organic is then chemically scrubbed to remove co-loaded impurities and then stripped to produce a concentrated high-purity lithium sulphate solution. Testing at TBT’s mini-pilot facility has focused on optimizing several aspects of the proven solvent extraction technique. The plant operators are employing their 40 mm (1.6 inch) diameter columns to determine and optimize the chemical conditions needed to gain maximum transfer of the lithium from the brine into the solvent, while they utilize their 100 mm (4 inch) diameter columns to assess and optimize the hydraulics of the transfer process. Initial results from the mini-pilot plant are very encouraging, showing that the transfer of lithium from the brine into the solvent is highly efficient, and that the “waste” brine (which is otherwise chemically
unchanged) contains near zero residual lithium. These results confirm the favorable LiSX results reported from the bench-scale testing in April 2015. Test work is ongoing to define and optimize the scrubbing and stripping of lithium from the Li-rich solvent to make a high purity lithium sulphate solution. This is being performed in the same test column apparatus.
Electrolysis – An electrochemical cell converts the lithium sulphate solution into a concentrated high-purity lithium hydroxide solution (LiEL). This stage of process test work was completed at a dedicated testing facility with specialty expertise in electrolysis. The work assessed two possible membranes for use in the cell, and examined a wide range of electrical, chemical and physical conditions in order to optimize lithium hydroxide production. Initial data from the testing work show that very high current efficiencies were achieved operating at high current densities during the successful conversion of lithium sulphate into lithium hydroxide. This should translate to smaller equipment needed at full-scale, and result in lower than expected capital and operating costs for this part of the process, though this is still subject to confirmation in the PEA.
Crystallisation – The final stage of the process is to concentrate the lithium hydroxide solution in order to crystallize out a high purity lithium hydroxide solid product. This part of the mini-pilot testing is being completed at a dedicated testing facility in Plainfield, IL. Test work is underway and should be completed in the next several weeks, with results also being incorporated into the PEA. Data and knowledge derived from the completed Mini-Pilot Plant will be integrated by Pure Energy’s engineering team into estimates of capital (CAPEX) and operating (OPEX) costs for the production of high-purity lithium hydroxide from a plant situated in Clayton Valley, Nevada. These data will be core to Pure Energy’s plan to produce a Preliminary Economic Assessment (PEA) later this year.
Dr. Ron Molnar, Professional Metallurgical Engineer (Ontario P.E.#100111288), is a qualified person as defined by NI 43-101, and has reviewed and approved the scientific and technical information that forms the basis for this news release. Dr. Molnar is independent of the Company.
About Pure Energy Minerals Ltd.
Pure Energy is a lithium-brine resource developer that is driven to become the lowest-cost lithium supplier for the burgeoning North American lithium battery industry. Pure Energy is currently focused on the development of our prospective CVS Lithium Brine Project, which has the following key attributes:
* A large land position with excellent existing infrastructure in a first-class mining jurisdiction: Approximately 9,324 acres in three main claim groups in the southern half of Clayton Valley, Esmeralda County,Nevada;
* Adjacent to the only producing lithium operation in the United States (Albemarle’s Silver Peak lithium brine mine);
* An inferred mineral resource of 816,000 metric tonnes of Lithium Carbonate Equivalent (LCE), reported in accordance with NI 43-101;
* Metallurgical and process studies underway to better understand the feasibility and economics of using modern environmentally-responsible processing technology to convert the CVS brines into high purity lithium products for new energy storage uses.
On behalf of the Board of Directors,
Chief Executive Officer
Forward Looking Statements: The information in this news release contains forward looking statements that are subject to a number of known and
unknown risks, uncertainties and other factors that may cause actual results to differ materially from those anticipated in our forward looking statements. Factors that could cause such differences include: changes in world commodity markets, equity markets, costs and supply of materials relevant to the mining industry, change in government and changes to regulations affecting the mining industry. Forward-looking statements in this release may include statements regarding mineral processing,
adaptation of test work to larger scale and/or future operational scales, estimates of reduced future capital and operating expenses, delivery of a preliminary economic assessment, future exploration programs, operation plans, geological interpretations, and mineral tenure issues. Although we believe the expectations reflected in our forward looking statements are reasonable, results may vary for reasons outside the control of the Company, and we cannot guarantee future results, levels of activity,
performance or achievements.
Neither TSX Venture Exchange nor its Regulation Services Provider (as that term is defined in the policies of TSX Venture Exchange) accepts responsibility for the adequacy or accuracy of this release.
Pure Energy Minerals Limited