This Preliminary Economic Assessment describes a proposed open pit mining and processing operation to produce 30,000 tonnes per year of 99.94% purity graphite concentrate from a hydrothermal vein-type deposit in northern Ontario.
Report context
This Technical Report, dated July 9, 2015, and prepared for Zenyatta Ventures Ltd., presents a Preliminary Economic Assessment (PEA) for the Albany Graphite Project located in the Porcupine Mining District of northern Ontario, Canada, within the Hudson Bay-James Bay Lowlands. The Project is situated approximately 30 km north of the Trans-Canada Highway, west of the communities of Constance Lake First Nation and Hearst, Ontario. The report conforms to NI 43-101 Standards of Disclosure for Mineral Projects and is considered by the authors to meet the requirements of a Preliminary Economic Assessment. The economic analysis contained in this report is preliminary in nature and based on Mineral Resources that are not Mineral Reserves, and therefore do not have demonstrated economic viability.
Processing route
Beneficiation by flotation
Development testwork forming the basis of the PEA conceptual flowsheet and design was carried out at SGS Canada Inc. in Lakefield, Ontario, using representative mineralized samples from the Albany graphite deposit. The primary steps in beneficiation include crushing, grinding, and concentration by flotation. The crushing, grinding, flotation, and purification processing facility is designed to operate for 350 days per year at a design throughput of 983,000 tpa for the first 22 years of the mine life. The average design throughput of the processing facility is 270 tpd of flotation concentrate.
Purification by caustic leaching
The primary steps in purification include alkaline (NaOH) treatment comprising one caustic leaching stage on each side of a low temperature baking stage at 350 °C, followed by a mild hydrochloric acid (HCl) leach to produce a purified graphite product. The graphite product will be filtered, washed, dried, and bagged for sale and transportation to market.
Testwork results
Metallurgical testing was conducted in three flotation stages followed by three purification leaching stages. The average graphite purity and recovery achieved in various stages of metallurgical testing were used for PEA design and economic analysis. Testwork results show flotation achieving 88.6% Cg purity at 84.54% recovery in the first stage, progressing to 99.94% Cg purity at 99.90% recovery in the third purification leach stage. The overall process achieved 99.94% Cg purity at 75.40% overall recovery.
Key reported parameters
| Parameter | Units | Value | Basis |
|---|---|---|---|
| Processing facility design throughput | tpa | 983,000 | Design |
| Processing facility operating days | days/year | 350 | Design |
| Average flotation concentrate throughput | tpd | 270 | Design |
| Final graphite product purity | % Cg | 99.94 | Testwork |
| Overall process recovery | % | 75.40 | Testwork |
| Flotation concentrate purity (Stage 1) | % Cg | 88.6 | Testwork |
| Flotation recovery (Stage 1) | % | 84.54 | Testwork |
| Purification leach purity (Stage 3) | % Cg | 99.94 | Testwork |
| Purification leach recovery (Stage 3) | % | 99.90 | Testwork |
| Mine life | years | 22 | Design |
| Potential annual graphite production | tpa | 30,000 | Design |
| Base case graphite price | US$/t | 7,500 | Assumption |
| Total initial capital cost | US$ millions | 411.5 | Estimate |
| Total operating cost | US$/t processed | 61.96 | Estimate |
Project website: https://geotech.ca/papers/finding-graphite-vtemmax-albany-graphite-project-northern-ontario-2/
Technical qualifications
This report is a Preliminary Economic Assessment as defined in Canadian NI 43-101 regulations. The economic analysis contained in this report is preliminary in nature and based on Mineral Resources that are not Mineral Reserves, and therefore do not have demonstrated economic viability. There is no certainty that economic forecasts on which this PEA is based will be realized. The PEA is based on open pit mining and processing of approximately 2,800 tpd via flotation, followed by purification. Capital costs have been estimated based on comparable projects, subscription-based cost services, and information within RPA's project database. Operating costs have been estimated for the Project and allocated to mining, process, and general and administration. The PEA projected mine life is 22 years, with good potential for more via pit expansions, processing of low-grade stockpiles, or underground mining.
Source: Zenyatta Ventures Ltd. – Albany Graphite Project, Technical Report NI 43-101, July 9, 2015, Sections 1, 2, 13, 17.
