McCreedy West Copper Mine Recovery Methods & XRT Ore Sorting

Source: Magna Mining Inc (2026)
Website: https://magnamining.com/about/mccreedy-west-project/

Critical Data

Overview

Located in the Sudbury Basin of Ontario, Canada, the McCreedy West Copper Mine is operated by Magna Mining Inc. The mine employs a multi-stage recovery strategy that integrates run-of-mine crushing, XRT (X-ray transmission) ore sorting, and rigorous sampling protocols to produce high-value copper and nickel ore for offsite processing. The surface facility, established in the early 2010s and upgraded in 2018 with a Steinert XRT sorter, is designed to handle ore from underground stoping operations (longhole and mechanized cut-and-fill). The recovery sequence begins with primary jaw crushing to minus 6 inches, followed by secondary cone crushing to minus 1.5 inches. When head grades warrant, the crushed material is screened at ½ inch, with coarse feed sent to the XRT sorter at 40 tons per hour. The sorter upgrades the ore by rejecting non-sulphide gangue, reducing transportation and milling costs while improving downstream metal recoveries. Accepts and fines are combined and passed through a sample tower that produces representative subsamples for assay determination of pay metals (Cu, Ni, Co, Pt, Pd, Au, Ag) and deleterious elements. Ore lots of 2,000–4,000 wet metric tonnes are dispatched to third-party mills—Vale’s Clarabelle Mill or Glencore’s Strathcona Mill—where copper and nickel-copper bulk concentrates are produced. This integrated recovery approach allows Magna Mining to economically extract value from variable-grade orebodies while maintaining strict quality control and environmental stewardship through lined containment pads and dust mitigation measures.

Key Process Stages

• Stage 1: Run-of-Mine Crushing – Ore from the McCreedy West underground is stockpiled on an engineered lined pad. Oversize material is reduced by an excavator-mounted 8,500 ft-lb rock breaker. A front-end loader feeds the primary jaw crusher, reducing ore to minus 6 inches. The crushed material is then conveyed to a secondary cone crusher enclosure, where it is further reduced to minus 1.5 inches.
• Stage 2: XRT Ore Sorting – When head grades require upgrading, minus 1.5-inch product is screened at ½ inch. The minus ½ inch fines bypass the sorter directly to the sample tower. The plus ½ inch material is fed into a Steinert XRT sorter at 40 tph. The sorter uses X-ray transmission to differentiate ore from waste, producing an upgraded ‘accept’ stream and a ‘reject’ stream (waste rock used as underground backfill). Wash deck fines are recovered and combined with the accepts.
• Stage 3: Sample Tower Sampling – The combined upgraded ore (accepts plus fines) enters a sample tower where primary and secondary linear samplers extract an approximately 1.5 wmt representative subsample. The subsample is rolls-crushed to 100% passing 9.5 mm. A tertiary rotary sampler then splits duplicate subsamples of ~340 kg each, sealed in 180-litre labelled drums (‘A’ and ‘B’) with an embossed metal tag for traceability.
• Stage 4: Sample Preparation and Assay – The ‘A’ sample is dispatched to a third-party preparation facility (e.g., SGS) where it is dried at ≤105°F for 24 hours, weighed for moisture content, then crushed and pulverized to 90% passing 106 µm. Four representative subsamples are split into one-litre bottles and submitted to SGS and Vale Copper Cliff for assay of pay metals and deleterious elements. Magna’s QA/QC program includes reference materials, blanks, and check assays at 2–7% frequency.
• Stage 5: Ore Sales and Offsite Milling – Processed ore lots (2,000–4,000 wmt) are loaded into trucks, weighed, and shipped to Vale’s Clarabelle Mill or Glencore’s Strathcona Mill in Sudbury. The mills produce copper concentrate and a separate nickel-copper bulk concentrate after pyrrhotite rejection. Settlement follows standard NSR (net smelter return) terms with smelter recovery rates, treatment charges, and refining charges for each metal.

Additional Interesting Data and Summary

The McCreedy West recovery system is designed for flexibility and economic optimization. The XRT ore sorter operates intermittently based on run-of-mine head grades, allowing Magna Mining to upgrade lower-grade material when it provides a net financial benefit by reducing transportation and milling costs, removing problematic non-sulphide gangue, and improving downstream mill head grades and metal recoveries. The sorter’s capacity of 40 tph is the current optimal rate for balancing productivity and waste rejection. Wash deck fines (minus ⅛ inch) from the sorter are pumped underground to weirs on 300 level for decantation, then hauled back to surface and combined with the sorter accepts fraction, ensuring no metal value is lost. The reject waste rock is returned underground for use as roadbed or backfill, supporting sustainability by minimizing surface waste storage. The sample tower protocol includes strict lot size limits of 2,000–4,000 wet metric tonnes and a maximum of 7 continuous days of processing for contact nickel ore to mitigate sulphide oxidation; copper footwall ores are deemed non-oxidizing and can be stockpiled longer. Moisture determination via 24-hour drying at ≤105°F ensures accurate metal accounting. Quality control is robust: Magna’s QA/QC includes reference materials, blanks, and 2% check assays at ALS Global historically, while SGS runs duplicate samples at ~7%. The analytical results feed into a standard ore sale arrangement where the mill’s recovery relationships (confirmed in testing) determine payable metals, and smelter terms calculate net smelter return with treatment and refining charges. Environmentally, the engineered lined containment pad mitigates noise, metal dust, and runoff. From a future outlook, the sorter and sampling infrastructure are expected to continue supporting variable-grade orebodies as exploration upgrades Inferred Resources to Indicated. The facility’s flexibility—able to bypass the sorter when grades are high—ensures economic resilience. Overall, McCreedy West’s recovery methods represent a modern, adaptable approach to processing complex copper-nickel ores in the historic Sudburg mining camp.

Key Processes: Crushing

Target Commodities: Copper, Nickel