The April 2012 preliminary economic assessment for Globex Mining, Drinkard Metalox and Worldwide Magnesium plans a 500,000 t/y plant producing 137,060 t/y of talc and 118,293 t/y of magnesium oxide near Timmins, Ontario.
A Preliminary Economic Assessment for the Timmins Talc-Magnesite Deposit, Timmins, Ontario, Canada, dated April 16, 2012, was prepared for Globex Mining Enterprises Inc., Drinkard Metalox Inc. and Worldwide Magnesium Corporation. The plant design is based on a block flowsheet and design criteria from Globex and Drinkard Metalox (DMI), refined by Aker Solutions (Jacobs), which also built a Metsim mass and heat balance model. The plant produces two products from one ore: talc recovered by flotation, and magnesium oxide recovered by leaching the magnesite in the flotation tails.
Critical Data
| Parameter | Value | Unit | Notes |
|---|---|---|---|
| Report date | April 16, 2012 | Not applicable | PEA for Globex, Drinkard Metalox and Worldwide Magnesium |
| ROM feed rate | 500,000 | dry t/y | 365 days a year |
| Operating availability | 85 | % | Not applicable |
| Feed talc grade | 35.6 | % | Not applicable |
| Feed magnesite grade | 52.1 | % | Not applicable |
| Leach conditions | 105°C, atmospheric pressure | Not applicable | Not applicable |
| Overall talc recovery | 73.6 | % | Not applicable |
| Overall MgO recovery | 95 | % | Not applicable |
| Talc production | 137,060 | t/y | Purity above 97% |
| Magnesium oxide production | 118,293 | t/y | Purity above 98% |
| Enclosed plant footprint | About 24,000 | m² | Heated, except evaporators and kiln |
| Power supply | 115 kV line | Not applicable | A few kilometres west of the site |
Overview
The process has three divisions: talc processing; magnesite leaching, thermal processing and reagent regeneration; and utilities for water, chillers and cooling. A mining contractor crushes, screens and stockpiles the ore, and mining trucks deliver it to the plant stockpile on a private road. The main plant is housed in heated buildings, apart from the evaporator units and the kiln.
Talc is recovered in rougher and cleaner flotation, then dried, micronized and stored in silos. The flotation tails, which carry the magnesite, go to the leach circuits. There the magnesium is dissolved, impurities are precipitated, and the purified solution is concentrated, thermally decomposed to active MgO and finally dead-burned in a shaft kiln. The leaching reagent is recovered and recycled.
Key Process Stages
Crushing and grinding. After contractor crushing and screening, reclaimed ore goes to a tertiary crusher and a closed-circuit ball mill with cyclones and magnetic separation.
Talc flotation. Rougher and cleaner flotation, with magnetic separation, cyclones and regrinding between stages, recover talc to the concentrate. Concentrate is thickened, filtered and dried, then finished in hammer mills and fluid energy mills before packaging. Magnetic and ferruginous sands are stored and handled separately.
Magnesite leaching. Flotation tails are thickened and leached in primary and secondary stages at 105°C and atmospheric pressure to dissolve the magnesite and other minerals.
Impurity removal and evaporation. Iron, manganese and nickel impurities are precipitated and removed, and a multi-effect evaporator removes excess water.
Decomposition and dead-burning. The concentrated solution flows by gravity to thermal decomposition units that produce active magnesium oxide. The MgO is briquetted and screened, then dead-burned in a shaft kiln, and the dead-burned magnesia (DBM) is stored in a bunker. Rejected fines from the briquetter screen are crushed and returned to the impurity precipitation step.
Reagent regeneration. The leaching reagent is recovered from the decomposition off-gas and recycled to the leach, with make-up as needed.
Additional Interesting Data and Summary
The site plan includes a 900 m² administration complex with stores, offices and a change room, and a 2,000 m² unheated area for product storage and load-out. No truck shop is planned on site: mobile equipment is to be serviced in Timmins. Existing roads, power, gas and communication lines are close by. Given the cold climate, the water system is protected from freezing by electrical tracing or backup power for critical pumps. The design must also comply with the Ontario Fire Code, which a local inspector is to review in later engineering.
In summary, the 2012 Timmins Talc-Magnesite PEA is a two-product flowsheet: flotation for high-purity talc, and leaching and thermal decomposition of the magnesite-rich tails for dead-burned magnesia, at 73.6% talc and 95% MgO recovery.
Key Processes
- Contractor crushing and screening, tertiary crushing
- Ball milling with cyclones and magnetic separation
- Rougher and cleaner talc flotation with regrind
- Talc drying, hammer milling and fluid energy milling
- Atmospheric leaching of flotation tails at 105°C
- Iron, manganese and nickel impurity precipitation
- Multi-effect evaporation
- Thermal decomposition to MgO, briquetting and shaft kiln dead-burning
- Reagent recovery and recycle
Source: A Preliminary Economic Assessment for the Timmins Talc-Magnesite Deposit, Timmins, Ontario, Canada, for Globex Mining Enterprises Inc., Drinkard Metalox Inc. and Worldwide Magnesium Corporation, April 16, 2012.
Earlier report summaries
Earlier versions of this profile, based on older technical reports, are retained below for source traceability. Dates and figures reflect each report’s own effective date and are superseded by the current information above.
Timmins Talc-Magnesite Mine — 2010 Technical Report
This report presents the initial mineral resource estimate and processing considerations for the Timmins talc-magnesite deposit in Ontario, Canada, as documented in a February 24, 2010 technical report.
Report context
The technical report, dated February 24, 2010, was prepared for Globex Mining Enterprises Inc., Drinkard Metalox Inc., and Worldwide Magnesium Corporation. It documents the initial mineral resource estimate for the Timmins talc-magnesite deposit located in Ontario, Canada. The report was issued under the project title "Technical Report on the Initial Mineral Resource Estimate for the Timmins Talc-Magnesite Deposit." The document includes sections on property description, geological setting, mineralization, exploration, drilling, sampling, data verification, and mineral processing. This review focuses on the processing and metallurgical testing content presented in Section 16.0 of the original report.
Processing route
Historical Overview
The report provides a historical perspective on processing activities at the Timmins talc-magnesite deposit. The historical overview section establishes the basis for understanding earlier processing attempts and sets context for the 2009 testing program. The report indicates that prior operations or studies informed the current understanding of how the talc and magnesite materials respond to various processing methods. The historical data serves as a reference point against which the 2009 testwork results are compared, although the original report does not provide specific details of what those historical processing methods entailed in terms of flowsheet configuration or performance metrics.
The processing discussion is organized around three distinct but related areas: historical processing experience, the current 2009 talc testing program, and the magnesia recovery work conducted between 2008 and 2009. This structure shows the progressive development of process understanding from earlier operations through to the most recent testwork.
Current 2009 Talc Testing Program
Talc Recovery
The 2009 talc testing program addressed talc recovery from the Timmins material. The report describes testwork focused on establishing the recovery characteristics of talc from the deposit's feed material. The testing program was designed to generate data on how effectively talc could be concentrated through physical separation methods applicable to the deposit's ore type. The report presents these findings as the results of a specific test program, without extrapolating to full-scale plant design or expected commercial performance. The recovery testwork provides the technical basis for understanding the amenability of the material to talc concentration, representing the most recent data available on this aspect of the processing flowsheet.
Talc Recovery from Leach Residue
A second component of the 2009 program examined talc recovery from leach residue. This testwork addressed the potential to recover talc from the solid material remaining after leaching operations, which represents a by-product or secondary recovery opportunity within the overall processing concept. The report presents this as a distinct area of investigation within the 2009 program, indicating that the leach residue still contained sufficient talc values to warrant recovery testing. The results of this testing would inform whether a flowsheet incorporating both leaching and subsequent talc recovery from the residue would be technically viable.
Magnesia Recovery from Timmins Talc-Magnesite Samples
Magnesia Flowsheet Development
The processing discussion includes the development of a magnesia flowsheet for the Timmins material. The report describes the conceptual approach to recovering magnesia from the talc-magnesite samples, which represents the higher-value product stream within the overall processing concept. The flowsheet development work was directed at identifying suitable process routes for extracting and purifying magnesia from the deposit's feed material. No specific process steps or equipment details are provided in the available report section, indicating that the flowsheet development was at a conceptual or preliminary stage at the time of reporting.
Testwork Review 2008-2009
The report documents a magnesia testwork review covering the 2008-2009 period. This review consolidated the findings from magnesia recovery testwork conducted during this timeframe, providing the technical basis for the proposed processing approach. The review would have examined the results of various test programs designed to establish the recovery parameters for magnesia from the Timmins material. The consolidation of this work into a single review shows the development stage of the project at the time the report was written, where sufficient testwork data had accumulated to support initial process conclusions.
Key reported parameters
| Parameter | Value | Basis |
|---|---|---|
| Report date | February 24, 2010 | Document date |
| Talc recovery testwork | 2009 program | Testwork |
| Magnesia testwork period | 2008-2009 | Testwork review |
| Talc recovery scope | Whole ore and leach residue | Testwork programs |
| Deposit type | Talc-magnesite | Geological classification |
Project website: https://globexmining.com/property/timmins-talc-magnesite-deposit/
Technical qualifications
The original report does not provide sufficient processing data within the sections examined to establish specific design parameters for a commercial plant. The talc recovery testwork results are presented as the product of a specific 2009 program without extrapolation to plant-scale performance expectations. Similarly, the magnesia flowsheet development is described as being at a development stage rather than a demonstrated commercial process. The historical processing overview provides context but does not include reported operational performance data from previous operations that could be verified against the 2009 testwork results. The report does not indicate that any pilot-scale or demonstration-scale testwork had been completed on the Timmins material, meaning all process conclusions are drawn from laboratory-scale testing. The absence of stated recovery percentages, product grades, or process mass balances in the sections reviewed means that no processing performance metrics can be confirmed from this report alone.
Source: Timmins Talc-Magnesite Deposit Technical Report, February 24, 2010, Section 16.0 Mineral Processing and Metallurgical Testing.
