What are the energy management challenges?
The long-term decline in base and precious metal ore grade is a key driver of the downward trend in Australia’s mining productivity. Declining ore grade, using current processing strategies, suggests breaking, sorting, processing and moving more rock before saleable ore leaves the mine gate. This influences key production metrics such as tonnes of material moved (TMM) as a ratio of saleable ore tonnes (TMM/t). As a result, ore grade has a direct impact on the energy intensity of production.
For mine sites with declining ore grade, an increase in energy consumption is needed just to maintain output levels - unless processing strategies are adapted.
Mining energy productivity is also impacted by increasingly remote sites, as more complex operating environments and mine geology also drive up development and operating costs. The energy associated with moving people and production inputs to the sites, and mining products to markets drives up costs.
What is the size of the energy productivity opportunity for mining?
Energy costs represents between 10–20% of operating costs on most mine sites (Energetics, 2014). At a company level, institutional investors are increasingly taking note of how miners manage their energy (Smith, 2013).
However, energy is a manageable cost, with demonstrable savings of 5–30% in energy use possible across core processes such as comminution and haulage.
Energy management should be an integral part of responding to competitive pressures through the deployment of alternative businesses models and the optimisation of mineral production processes. Energy productivity can be influenced by enhancing existing processes, such as adopting best practice, increased gangue rejection, ore sorting technology, and grade engineering. Improving ore quality shipped to smelters can also reduce downstream energy consumption and air pollution associated with removing impurities during smelting.
What are the elements of an energy productivity program?
1. ‘Traditional’ energy management – ore characterisation and feed preparation, comminution processes, froth flotation and mineral separation, hauling and materials movement, ventilation, fuel switching, data and management practices
2. Systems optimisation – smart blasting, characterisation of ore and mineral size, optimal processing strategies, whole of site operations.
3. Business model transformation – autonomous mines, truckless mines, real time big data transformation
Note: The text above is an extract from the A2SE's "Doubling Australia’s energy productivity by 2030: Re-energising the mining sector to improve its competitiveness". Energetics' Anita Stadler was the lead author, with contributions from a broader team which included Dr Fiesal Musa and Dr Mary Stewart also from Energetics.
Access the report: 2XEP Mining Sector Overview
Talk to one of Energetics experts about the energy productivity opportunity for your mining operation.
Watch Dr Mary Stewart's presentation at the World Resources Forum, June 2015