Energy efficiency has long served as a goal for environmentalists as well as those businesses that make a priority of cutting costs. Those companies that invest in energy efficiency enjoy a competitive advantage over others through reduced overhead costs. Technological advances and industry efficiency studies regularly uncover new ways for mining companies to reduce waste in production.
As the mining industry grows more competitive, companies will feel increased pressures to reduce energy waste and promote efficiency. When companies examine their equipment and processes to find areas to increase efficiency, they will often save money as well.
Mines face a number of energy challenges that have kept them from operating at peak efficiency. First, many mines operate in remote areas. Many in these areas lack sufficient access to the electrical grid and have to rely more on diesel or other fuels to keep running.
Ore concentration in surface mines has grown into a challenge, causing deep mine operations to seek better concentrations at deeper depths. This leads to increased reliance on cooling systems to maintain healthy levels of temperatures in the mine. One of the main challenges, according to a University of Wollongong study, lies in the increased distance between surface Bulk Air Cooling (BAC) units and miners. The study suggests that BAC units, or at least parts of them, should be placed underground to decrease the distance between the machine and miners while increasing energy efficiency.
Process chillers may also deliver more energy efficiency than traditional air conditioners. They use condensation and evaporation processes that work much in the same way as sweat evaporation cools skin. Chillers require less energy than typical air conditioner units.
Engixo works with mining operations across Australia. We provide expert advice on how to upgrade, repair, or replace inefficient running systems with those that save both energy and money. This includes the use of chillers where appropriate.
We also work with companies to re calibrate their current systems to promote more energy efficient cool air distribution.
Mining operations often lose a great deal of efficiency in lighting. Our specialists have experience in putting together lighting solutions that save money. Whether in a traditional deep mine on land or an undersea operation, we can use LED and natural sources to reduce energy usage.
We can recommend the strategic positioning of skylights to maximise use of natural light, reducing dependence on electric power.
Cooling systems can also enjoy better efficiencies when they use natural hydrocarbon-based coolants. Propane and other hydrocarbon-based substances have proven themselves more energy efficient and have less impact on the environment than traditional CFCs.
Our team work regularly with companies, helping them to adopt cleaner and greener refrigerant solutions that have minimal impact on the Earth's ozone layer.
Ore concentration issues have hit many Western Australian mining operations, leading to other energy efficiency challenges. Many mining operations in Western Australia have witnessed declining ore concentrations. Companies still need to produce and profit, so many will have to work harder just to deliver even the same quantity of product. This has already resulted in the doubling of overburden and halving of grade in the past 30 years.
When companies work harder to achieve the same results, they must find ways to save on energy costs, especially concerning their heavy reliance on diesel, natural gas, and grid electricity.
Better insulation in key areas of a mining operation can boost cost savings and energy efficiency by keeping air colder for longer periods of time. It also reduces the strain on air conditioning or chiller systems.
One way to increase energy efficiency and lower costs lies in using renewable sources of energy. Western Australia offers numerous opportunities to use solar and wind-generated power. Perth, for example, experiences an average of 265 days of sun per year. Rockingham has 285. This demonstrates that solar power has strong viability in Western Australia with the added benefit of low operating costs once installed. Approximately four-fifths of Western Australia rate as “excellent” in government studies for solar use with the southern tier listed as “very good.”
Government studies also indicate that southwestern, southern, and much of the central part of the territory rates as “very good” for use of solar with small pockets of excellent conditions.
Our team design solar energy solutions for mining and other industrial operations. Next generation photovoltaic solar panels provide some of the best levels of efficiency seen in solar energy production.
As renewable energy develops, mines will likely use a hybrid approach between traditional and energy-efficient renewable sources.
Every mining operation seeks better ore concentration. Improved ore concentration translates directly to less energy used to obtain the same level of production. The challenge, however, lies in finding ways to improve ore concentration in an era of declining natural concentrations.
Better technology and techniques can help mining operations to better pinpoint the best possible ore concentration. Companies can make more informed decisions whilst implementing a smart blasting approach that will result in energy and other savings. Using data that creates 3D models of the mining site will improve the concentration of ore collected. The use of better technology, data, and analytics can reduce energy usage by between 10 and 50 percent. Even the low end of energy savings can result in significant cost reductions for the operation.
The comminution process can also develop energy efficiencies by analysing the equipment used. Just as in your own car, old or improperly maintained equipment may not run at its top level of energy efficiency. An audit of machine operation can identify how to repair or replace equipment to restore optimal function and energy efficiency. Some operations have seen an efficiency increase of up to 40 percent, which translates into solid efficiencies and cost reductions.
Additionally, some operations have turned away from the SAG mill equipment currently dominating the industry. They have found that using a high pressure grinding roll boosts energy efficiency. Under some conditions, the SAG has a 40 percent energy efficiency rating while an HPGR unit can achieve up to 80 percent. These results may not occur in every operation, but the results for some make it worthwhile exploration for all.
Other methods of using fine grinding to improve efficiency include:
• Reducing primary and secondary recirculating loads and using the right-sized mill for the job
• Creating a steeper distribution of particle sizes, which frees desired materials more easily and leads to more efficient processing
• Reducing the need for other grinding equipment with high energy requirements
Increasing grinding efficiency also has two important positive side effects. It decreases wear and tear on equipment, helping machines last longer. Also, it reduces heat generation. Less heat means reduced reliance on energy-consuming cooling systems.
Improvements in technology and technique can help to offset the increased cost of mining in increasingly challenging fields. It will also help to reduce mining companies’ environmental impact while increasing sustainability in energy and other important economic sectors. Companies need not continue to lose money on outdated equipment and processes that waste time, money and energy.
Efficiency represents a win-win for the cause of environmentalism and saving companies money. Owners and managers should research their operations and even hire outside consultants to find ways to save.
Engixo brings decades of experience to helping mining operations save energy and money. Whether your mine is a traditional deep mine, a surface operation, or extracts materials under the sea bed, our team can help you save time, energy, and money.
Image: Shane McLendon