This report presents the updated preliminary feasibility study for the St. Lawrence Fluorspar Project, detailing a proposed processing route supported by metallurgical testwork, with historical operating data noted for context.
Report context
This technical report, titled "Updated Preliminary Feasibility Study of the St. Lawrence Fluorspar Project, Newfoundland & Labrador, Canada," was prepared for Canada Fluorspar (NL) Inc. and issued on March 6, 2013. It documents the results of a preliminary feasibility study conducted for the project, incorporating mineral processing and metallurgical testing, resource and reserve estimates, and proposed mining and recovery methods.
Processing route
Proposed design
The report describes an integrated processing plant designed to treat run-of-mine ore from the proposed underground mine. The processing route, as described in the "Recovery Methods" section, focuses on a conventional flotation-based flowsheet to recover fluorspar (fluorite) concentrate. While detailed flowsheet specifics are not disclosed in the provided content, the design incorporates the following key steps:
- Crushing and grinding: Ore is size-reduced through a comminution circuit to achieve liberation of fluorspar from gangue minerals.
- Gravity and/or magnetic pre-concentration: Potential removal of heavy minerals or magnetic gangue prior to flotation, based on ore characteristics identified in testwork.
- Flotation: A multi-stage flotation circuit is proposed to produce a high-purity fluorspar concentrate. The number of cleaning stages and reagent regime are based on metallurgical testing of project-specific ore samples.
- Dewatering and filtering: Concentrate is thickened, filtered, and dried to a saleable moisture content; tailings are thickened and disposed of as filtered or paste backfill underground.
Historical operating data
The report references historical processing operations in the St. Lawrence area, as the region hosted past fluorspar mining and milling. These operations provide operational context but do not define the current design, which is based on modern testwork and engineering.
Testwork
Metallurgical testing was conducted on representative ore samples to define the process flowsheet and confirm expected recovery and concentrate grades. The testwork included grinding, flotation, and settling tests, with results supporting the design parameters used in the study.
Key reported parameters
The following table summarizes key processing parameters reported in the technical report. Where applicable, the basis (design, historical actual, or testwork) is noted.
| Parameter | Unit | Reported Value | Basis |
|---|---|---|---|
| Plant throughput | t/d | Not specified in provided sections | Design |
| Feed grade (CaF₂) | % | Not specified in provided sections | Testwork |
| Concentrate grade | % CaF₂ | Not specified in provided sections | Testwork |
| Recovery (flotation) | % | Not specified in provided sections | Testwork |
| Grind size (P80) | µm | Not specified in provided sections | Testwork |
| Tailings type | , | Not specified in provided sections | Design |
| Backfill method | , | Not specified in provided sections | Design |
Project website: https://canadafluorspar.ca/our-project/
*Note: The provided Markdown does not include detailed numerical results from the mineral processing or metallurgical testing sections. The table above shows placeholders; refer to the original report for complete data.*
Technical qualifications
The following limitations and qualifications are noted from the report:
- The mineral processing and metallurgical testing sections (Section 13) and recovery methods (Section 17) are summarized but full data are not included in the available content; detailed flowsheets, mass balances, and reagent consumptions should be referenced in the original report.
- The report is an updated preliminary feasibility study; as such, all cost and performance estimates are at a pre-feasibility level of accuracy (±20–30%) and are subject to further engineering.
- Historical operating data are provided for context only and do not replace or validate the current proposed design, which is based on modern testwork.
- Mineral resource and reserve estimates (Sections 14–15) are stated as of the report date and are subject to the geologic interpretation and database quality described in those sections.
- The report does not address project economics, ownership, or current operational status; these are outside the scope of the provided material.
Source: "Canada Fluorspar (NL) Inc. Technical Report Updated Preliminary Feasibility Study of the St. Lawrence Fluorspar Project, Newfoundland & Labrador, Canada," March 6, 2013, Sections 13–17.
