Recovering Value from Waste Rock: White Roach Molybdenum Case Study
Sensor-Based Ore Sorting at White Roach Molybdenum Mine
Guangdong Hengxing Economic Development Co., Ltd. operates the White Roach molybdenum operation, processing a +15–40mm ore fraction with a raw grade of 0.175% molybdenum. At this grade, the majority of run-of-mine material carries little to no recoverable metal, so separating that barren rock from the ore-bearing fraction before it reaches downstream processing has an outsized effect on plant economics. John Finlay delivered this installation, using sensor-based ore sorters to reject the barren fraction from the +15–40mm feed and lift the ore grade before further processing.
Project Overview
| Operator | Guangdong Hengxing Economic Development Co., Ltd. |
|---|---|
Site | White Roach Molybdenum Mine |
Ore Type | Molybdenum |
Feed Material | +15–40mm, raw ore grade 0.175% Mo |
Waste Rock Rejected | 400,000 t/a |
Challenge | A large share of run-of-mine material is barren rock; separating it from the ore-bearing fraction without sacrificing recovery of the contained molybdenum |
Solution
Sensor-based ore sorters were installed to pre-concentrate the +15–40mm fraction, rejecting more than 85% of feed as barren waste rock while holding onto the mineralized fraction for further processing.
Equipment and Performance
1. Sensor-Based Pre-Concentration
● Machines Used: Sensor-based ore sorters
● Feed Particle Size: +15–40mm
● Function: Removes low-grade waste rock from +15–40mm feed ahead of downstream processing
Sorting Results
● Raw Ore Grade: 0.175% Mo● Concentrate Grade: 0.731% Mo
● Waste Rock Grade: 0.015% Mo
● Rejection Rate: ≥85%
● Recovery Rate: 93.37%
Benefits and Outcomes
● Economic Efficiency: Rejecting more than 85% of run-of-mine feed while still recovering 93.37% of the contained molybdenum means downstream processing only has to handle a small, upgraded fraction of the original tonnage, sharply cutting cost per unit of recovered metal.
● Environmental Impact: With roughly 400,000 t/a of waste rock rejected before it reaches the processing plant, tailings storage requirements are reduced substantially.
● Operational Efficiency: Concentrate grade rises more than fourfold, from 0.175% to 0.731% Mo, giving the downstream circuit a smaller, far more consistent, higher-grade feed to work with.
Conclusion
At White Roach, the sensor-based sorting system rejects more than 85% of the run-of-mine feed as barren rock, while still recovering 93.37% of the contained molybdenum, which increases the concentrate grade more than fourfold before the ore reaches downstream processing. It shows that aggressive, selective rejection and high metal recovery aren’t a trade-off when the sorting technology can tell ore from waste at this resolution.
Are you considering pre-concentration for a molybdenum, copper, or polymetallic operation?
Talk to John Finlay’s ore sorting team about a feasibility assessment for your ore body.
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