Empress Catherine II Saint Petersburg Mining University (Saint Petersburg, Russia)
Aleksandrova T. N., Head of Chair, Doctor of Engineering Sciences, Corresponding Member of the Russian Academy of Sciences, Professor, Aleksandrova_TN@pers.spmi.ru
Aburova V. A., Postgraduate Student, aburovaleria@gmail.com
Nikolaeva N. V., Associate Professor, Candidate of Engineering Sciences, Associate Professor, nadegdaspb@mail.ru
Struk G. V., Postgraduate Student, s245018@stud.spmi.ru

The high energy consumption associated with mineral processing has driven interest in methods that can reduce energy demands during ore preparation. One promising approach involves the use of energy-based treatments, such as microwave exposure, to alter the mechanical properties of raw mineral materials. This study investigates the potential for microwave radiation to modify the strength characteristics of sedimentary gold-bearing ore, with an average gold content of 2–3 g/t. The treatment exploits the differential response of ore and gangue minerals to microwave energy, which leads to the formation of micro- and macrocracks. These internal fractures contribute to a reduction in the material’s strength parameters. Prior to treatment, the ore was classified as moderately hard, with a strength criterion value of k = 37.9, and exhibited low abrasiveness (AI = 0.0555 g). Microwave processing was carried out at a power level of 600 W for 2 minutes, parameters selected to enable standardized testing using the drop weight method and to determine the Bond abrasiveness index. Post-treatment results showed a slight decrease in abrasiveness to AI = 0.0373 g (a reduction of 0.0182 g). More significantly, the strength criterion increased to k = 43.6, a shift of 5.7 units, indicating a structural weakening of the ore. The specific energy consumption for this process was 1.10 kWh/t. As a result of the treatment, the ore’s strength classification shifted from moderately hard to medium-hard. Taking into account the specific energy used for microwave exposure, the overall difference in total energy consumption before and after treatment (SCSE + microwave) amounted to 0.12 kW·h/t.
This research was supported by the Russian Science Foundation (grant No. 23-47-00109).

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