Microwave Treatment of Ores

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Microwave test work is the newest addition to Sepro Labs. Microwave treatment offers several unique benefits due to the differences in heating response between valuable minerals and waste minerals.

Different minerals have different heating responses when subjected to microwave energy, and valuable minerals often heat more quickly than waste minerals. This unique heating behaviour creates thermal stress and fractures along grain boundaries of target and waste minerals. The result is reduced ore competency and improved mineral liberation, which allows for a coarser grind compared to untreated ores. Differential heating patterns can also be detected with a thermal camera. Our proprietary sorting algorithm uses this heating information to reject barren rocks prior to grinding.

The coarser grind size, improved mineral liberation, and higher ore grade can improve downstream processes such as gravity concentration, flotation, cyanidation, dewatering, and tailings management. The overall benefits of microwave treatment include increased plant throughput, reduced water use and GHG emissions, and potential energy savings of over 50%.

To find out more about how we can apply microwave technology to your project, reach out to our team at Sepro Labs. We are happy to discuss the various aspects of our test program and how we can tailor our approach to each of your projects. We also have an existing database on the microwave response of dozens of ores, so even with limited mineralogical information, we can provide an educated guess about the microwave response of the ore and what the potential benefit could be.

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Phased Testwork Program

Phase 1: Evaluation of Microwave Amenability

In the first phase of testing, we determine the microwave amenability of your ore by generating a standardized microwave heating curve using a bench-scale laboratory microwave. We also complete a comprehensive chemical and mineralogical analysis of the sample. Data generated from these tests is then compared to our proprietary microwave treatment database to determine the amenability of the sample to microwave treatment. If the results are positive, we move to Phase 2 of our testing program.

Phase 2: Comparative Testing of Downstream Processes

The second phase of testing investigates downstream processes with and without microwave treatment. To start, we evaluate the effect of microwave pretreatment on downstream processes by running comparative tests on treated and untreated samples. Downstream processes can include ore sorting, coarse and fine comminution, gravity concentration, flotation, cyanide leaching, or other processes as determined by client needs. If the results from this phase demonstrate a significant improvement in process performance, we move to Phase 3 of our testing program.

Phase 3: Pilot Plant Testing

The third phase of testing uses a 150 kW, 915 MHz industrial-scale microwave system to confirm the bench-scale results at high power with large ore samples. The pilot testing results are used to complete a techno-economic assessment and estimate the industrial-scale benefits of microwave technology for your specific ore.