Project duration: 10 May 2019 – 31 December 2019

Objective

A considerable amount of energy is used by mining and mineral processing sector to mine and process the raw materials for further applications. The industry consumes 6-7% of total world energy, from which almost half goes for size reduction/comminution. Furthermore, it is estimated that the industry consumes 6-8 Billion m3 of water per annum. The industry, therefore, facing challenges including improving process and resource efficiency, access to energy and water, reduce carbon footprint as well as acceptance by the society (i.e., social license to operate), etc. Therefore, inventing and developing technologies, machinery, and processes to help in overcoming the challenges are paramount important. In one hand almost 50% of the energy consumption in mining goes to size reduction and on the other hand, the energy in comminution per ton of extracted ore increases as deeper and more competent ores are being extracted. That really motivates the mining industry to look at eco-efficient processes.

Comminution (size reduction) starts from extraction (drilling and blasting) to end of fine milling to provide appropriate particle sizes in each step for the downstream process(es). To improve resource efficiency and to reduce energy consumption, different strategies must be considered. One appropriate and promising technology is Microwave. The technology has revealed promising prospects in rock processing by taking to advantages over the variations among the electrophysical properties of minerals and rocks.

Engineering efforts have paved our way to develop techniques and apparatus for efficient microwave energy at significantly low level to be implemented in different areas of mining and mineral processing that includes; comminution, drying, magnetic and electrical separation, flotation, leaching/hydrometallurgy, roasting, vitrification, etc. Possibly the most interesting and challenging area is to seek for weakening/pre-weakening of rocks/slabs during mining and extraction and to prospect the effect of microwave technology in hard rock mining. In hard rock mining, the cyclic mining operation associated with high energy consumption and relatively high wear rate on the cutting tools and other extraction and comminution equipment. Comminution is extremely energy intensive and costly with high wear rates.

The main objectives herein are to collect all the information and know-how on microwave application in extracting and comminuting raw materials and to test and evaluate the potential of microwave assisted technology towards eco-efficient mining activities (i.e., effective excavation and comminution). That means from circular economy perspective, not only reductions in energy and water consumption are considered, but also a reduction in consuming wear material in machinery should be aimed (e.g., reducing wear in cutting tools and media consumption in crushing and grinding).

For decades, efforts were made to test and implement potential game-changing technologies for smart and innovative mine of the future. In long term strategy, developing and implementing f high-tech fully automated and continuous mining machinery with complete data collecting and digitalization infrastructure are the keys to have safe, lean and green mining activities that need investments in technologies and talents

The solution (technology)

The final outcomes would be collecting all intelligence, knowledge and know-how in the field of microwave application(s) and how the technology can be adapted or implemented towards resource efficiency, i.e., improving productivity, reducing energy and water consumption. The study will cover and elaborate all parameters (both instrumental design and raw material characteristics ones) that affecting microwave treatment of the raw materials to improve/optimize the processes of microwave processing. Furthermore, the report will touch and compare some other potential technologies that can compete with microwave technology, particularly, in the field of comminution.

The final report could be served as a guideline/roadmap to be used by EIT RawMaterials to proceed and define R&D and RTD projects for further development of microwave application in the mining industry.

Outcomes in Summary:

  • Collecting know-how and procedures to show how the technology can assist excavation and comminution characteristics of rocks
  • Impact of microwave on size reduction, energy consumption and equipment wear in extraction and comminution processes
  • Predicting the effect of microwave irradiation on rock characteristics

Partnership

  • Sandvik SRP AB, Sweden (Lead Partner)
  • McGill University, Canada
  • University of British Columbia, Canada