This Preliminary Economic Assessment reports on the Record Ridge magnesium exploration project in British Columbia, Canada, based on laboratory leach testing and proposed mineral processing and recovery methods.
Report context
SRK Consulting (U.S.), Inc. prepared this NI 43-101 compliant Preliminary Economic Assessment (PEA) for West High Yield [W.H.Y.] Resources Ltd. for the Record Ridge Project in the Rossland Mining District, British Columbia, Canada. The report date is June 3, 2013, with an effective date of April 18, 2013. The Project is a magnesium exploration project that was mapped, surveyed, and drilled by WHY during 2007, 2008 and 2011. The PEA was prepared according to NI 43-101 guidelines.
Processing route
Metallurgical testwork background
Initial metallurgical results were provided by Met-Solve Laboratories in a report dated October 31, 2012, which indicated an open cycle laboratory leach testing metallurgical recovery to solution of magnesium from Record Ridge mineralization of approximately 60%. That report indicated these initial leaching recovery rates could likely be improved with additional metallurgical work. Subsequent testwork was conducted after the great majority of engineering and design work had been completed in 2012 based on the 60% recovery assumption. Met-Solve Laboratories completed this recommended work and reported on April 18, 2013, with an estimated improvement of open cycle laboratory leach testing Mg recovery to 80% to solution.
Proposed design basis
The body of the report was not altered to show the 80% leached Mg recovery improvement. The case presented in the PEA is conservative, using the initial 60% metallurgical recovery assumption for the initial resource statement and subsequent engineering. The improvements and associated additional operational and capital costs were incorporated into the technical economic model. The mineral resources have not been restated using a cut-off grade based on a metallurgical recovery of 80% Mg. The effect of the higher Mg recovery is expected to lower the cut-off grade for the stated mineral resources, thereby increasing tonnes and extending mine life.
Process description
Major design criteria and a process description are provided in Section 14 of the report. Key process assumptions, potential risks and further suggested work are documented. The process description covers recovery methods for the Project.
Further processing considerations
The report notes that the 80% open cycle laboratory leach testing Mg recovery is not a clear indication or confirmation of the overall Mg recovery to a final fused magnesia product, as this aspect of the process has yet to be tested in any manner.
Project infrastructure
Infrastructure components addressed include access road and transportation, power supply, water supply, a sodium sulfate bagging/warehouse facility, a tailings storage facility, and closure costs.
Key reported parameters
| Parameter | Value | Basis |
|---|---|---|
| Magnesium recovery to solution (initial testwork) | ~60% | Open cycle laboratory leach testing, Met-Solve Laboratories report October 31, 2012 |
| Magnesium recovery to solution (subsequent testwork) | 80% | Open cycle laboratory leach testing, Met-Solve Laboratories report April 18, 2013 |
| Mine life projection (based on stated resource and production scenario) | 42 years | Based on 60% metallurgical recovery assumption and current stated resource |
| Metallurgical recovery used in PEA base case | 60% | Conservative assumption used for initial resource statement and engineering |
Project website: https://whyresources.com/record-ridge-magnesium-project/
Project website: https://projects.eao.gov.bc.ca/p/662c34c8bd773100221ff9d4/project-details
Technical qualifications
The report explicitly states that the 80% open cycle laboratory leach testing Mg recovery is not a clear indication or confirmation of the overall Mg recovery to a final fused magnesia product, as this aspect of the process has yet to be tested in any manner. The mineral resources have not been restated using a cut-off grade based on a metallurgical recovery of 80% Mg. The PEA is a preliminary economic assessment, and the body of the report was not altered to show the 80% leached Mg recovery improvement.
Source: Record Ridge Project , 2013 Technical Report, NI 43-101 Technical Report Preliminary Economic Assessment, Report Date June 3, 2013, Effective Date April 18, 2013, Sections 11, 12, 13, 14, 15.
