This Preliminary Feasibility Study reports mineral processing, recovery methods, and metallurgical testwork for the Kings Valley lithium deposit in Humboldt County, Nevada.
Report context
This technical report is a Preliminary Feasibility Study prepared for Western Lithium USA Corporation, with an issue date of January 27, 2012. The effective date of the Mineral Resource estimate is June 28, 2011, and the effective date of the Mineral Reserve estimate is December 14, 2011. The study addresses the Kings Valley Lithium Project located in Humboldt County, Nevada.
Processing route
Introduction to processing
The mineral processing and recovery methods described in the report are based on a combination of historical operating data, proposed design criteria, and metallurgical testwork. The processing section of the report is documented in Section 13.0 Mineral Processing and Section 17.0 Recovery Methods.
Metallurgical testwork
The report documents metallurgical testwork conducted by multiple laboratories. Hazen performed testwork as part of the project development. K-UTEC contributed additional testwork. CICITEM conducted further metallurgical testing. Outotec also performed testwork. These testwork programs provided data to support the process design criteria and flowsheet development.
Dry ore preparation process description
The proposed dry ore preparation includes size reduction, reagent preparation, and calcining. These unit operations are designed to prepare the ore for subsequent wet recovery processes.
Wet recovery process description
The proposed wet recovery process consists of several stages. Leaching is followed by a first calcium removal stage. The flowsheet includes potassium sulfate (K₂SO₄) production, followed by a second calcium removal stage. Lithium carbonate (Li₂CO₃) production is then conducted, followed by sodium sulfate (Na₂SO₄) production.
Process design criteria
The report presents process design criteria that were developed to guide equipment sizing and flowsheet configuration. Equipment sizing was performed based on these criteria and the proposed production rates.
Product packaging
Product packaging is included as part of the proposed process plant design.
Energy recovery
The report includes consideration of energy recovery within the process plant.
Expanded case
The report describes an expanded case for the processing plant, indicating that alternative production scenarios were evaluated.
Process energy and water requirements
Energy and water requirements for the proposed process are reported as part of the overall plant design parameters.
Key reported parameters
| Parameter | Unit | Design Basis | Historical Operating Data | Testwork Basis |
|---|---|---|---|---|
| Process plant design | , | Proposed PFS design | Not specified | Metallurgical testwork from Hazen, K-UTEC, CICITEM, Outotec |
| Dry ore preparation | , | Size reduction, reagent prep, calcining | Not reported | Testwork support |
| Wet recovery stages | , | Leaching, Ca removal, K₂SO₄, Li₂CO₃, Na₂SO₄ | Not reported | Testwork support |
| Product packaging | , | Included in design | Not reported | Not specified |
| Energy recovery | , | Included in design | Not reported | Not specified |
| Expanded case | , | Alternative scenario evaluated | Not reported | Not specified |
| Process water and energy | , | Reported in plant design | Not reported | Not specified |
Technical qualifications
The processing and recovery methods described in this report are based on a Preliminary Feasibility Study level of engineering. The process flowsheet and design criteria are proposed designs that have not been demonstrated at commercial scale. Metallurgical testwork was conducted by multiple laboratories, but the report does not provide specific test results or performance data for the individual unit operations. The report does not include detailed flowsheet diagrams in the processing sections. Capital and operating costs, economic evaluation, and market considerations are referenced in the Executive Summary but are not detailed in the processing sections provided. The effective dates of the resource and reserve estimates predate the report issue date, and the study should be understood as a snapshot in time.
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Source: Preliminary Feasibility Study – Kings Valley Lithium Project, Western Lithium USA Corporation, January 27, 2012, Sections 13.0 Mineral Processing and 17.0 Recovery Methods.
