Mining is an essential process that has become even more critical as the world moves towards a greater energy transition. Minerals are a crucial competent in clean energy technologies such as electric vehicles, solar panels, and batteries, and the demand for these minerals and mine operations is increasing. According to the International Energy Agency (IEA), the demand for some minerals to support the transition is projected to increase more than twentyfold by 2040.
Meeting global carbon reduction targets is essential to mitigate the effects of global climate change and the mining industry will play a key role in this effort. Mining practices must adapt and evolve to be more environmentally friendly to decarbonise. In line with global efforts to meet the Paris Agreement objective, mining companies are setting targets to reduce their greenhouse gas (GHG) emissions.
A PwC survey of CEOs in 2021 showed that 76% of global mining and metals executives said they were concerned about climate change and environmental damage, up from 57% a year earlier. And 70% of global mining executives plan to increase their long-term investments in sustainability and environmental, social, and governance (ESG) initiatives.
Challenges in decarbonising the industry
There are several ways that mines can reduce their carbon footprint, but moving to a 100% electric mine would represent a transformational shift for underground mine operations where diesel engines have dominated for over 100 years. Working underground diesel equipment is one of the biggest environmental challenges a mine faces. Switching to an electric energy source can significantly impact mines, reducing their ventilation shaft and tunnel sizes; the size of their fans and heating and cooling systems; their carbon footprint; and their capital investment.
Diesel equipment can also be a significant financial burden regarding a mine's ventilation costs, so moving to electric while updating ventilation solutions can be highly effective for improving overall environmental credentials. While progress has been made, which will result in future benefits, there are opportunities for the mining industry to reduce energy consumption and emissions through a combination of advanced sustainable technologies, actionable insight into mine operations, and automation - solutions that exist today.
Energy efficiency in mining
Digital advancements are enabling the industry to become more efficient, safe, and productive by collecting, analyzing, and implementing data to make mine conditions, processes, and maintenance decisions. Digital technologies and automation can also be applied to ventilation.
Ventilation is one of the most vital processes in a mine's operation. It is necessary for providing fresher air and, in some instances, cooling the working environment, clearing blast fumes, and diluting exhaust fumes and gases generated by the seams; it needs to run consistently and reliably. This can lead to substantial operating costs and up to 40-50% of a mine's total energy consumption. Advanced technology and more efficient ventilation systems can reduce costs and significantly contribute to a mine's carbon reduction objectives.
The primary goals of ongoing mine ventilation developments are to mitigate environmental impact, as already outlined, by reducing GHG emissions and improving underground air quality. They are also necessary to create efficiency that is sustainable and reliable, so a mine continues to produce energy savings throughout its lifecycle. Optimising overall health and safety models is crucial, which rely on automation for unprecedented operational capabilities.
There are several solutions to support these goals, including electric mine air heating, which provides a simple and safe mine air heating solution with zero emissions. Through a modular design approach, these systems use industrial grade, Incoloy tubular elements selected for optimal functionality and maintenance.
Optimised ventilation systems are also available to drive energy savings contributing to net zero commitments. Products like Ventsim™ CONTROL utilize intelligent software that communicates to hardware devices monitoring remotely, control and automate airflow and heating and cooling systems.
Thermal heat recovery can result in operational flexibility and reduced emissions. Employing a system of heat transfer coils, liquid pumping stations, and control and automation technology, the mine can generate heat recovery using potential sources like waste heat from mine exhaust air, central boilers, power generators, and compressors, or green sources such as geothermal energy.
Ammonia refrigeration systems offer a sustainable solution with no harmful CO2 or HFC emissions.. Ammonia is considered the "Green refrigerant" And has been used for many years; however, it is now coming into its own with the demands for reducing the footprint of hydrocarbon and HCFC refrigerants that can damage the atmosphere.
Demonstrable ventilation success
Companies like Howden have been successfully supplying these green mine ventilation solutions for years, and the tangible results are clear.
The Oyu Tolgoi mine in Mongolia required a new indirect air heating, ventilation, and filtration solution. Howden developed a unique thermal heat recovery solution that included airlock access, pipe work engineering, main & bypass damper, and fan outlet. Howden's solution can be used as a reference for the remainder of the mine's development. Each heater house was designed to capture 22MW waste heat from the hot water system.
An electric heating system was supplied to a high-grade underground mining operation located in Northern British Columbia, Canada. The system included two direct-fired, hybrid M.I.D mine air heaters and enabled the mine's electric mine air heating system to take advantage of low electricity prices.
Ventilation automation has been a part of several large-scale mine operations and mining for decades, and some mines have experienced reductions of more than 50-60% in energy consumption and 11,500 tonnes of CO2 power emissions.
The Newmont Éléonore mine in Quebec, Canada, brought in a Ventsim™ CONTROL system, which included ventilation monitoring stations and the automation of all ventilation equipment. To date, there has been a 43% reduction in mine heating costs, a 56% drop in underground ventilation electricity costs, and a 73% decrease in the cost of surface ventilation electricity. To recognize the proven benefits of Howden's Ventilation on Demand (VOD) system, Newmont – Eleonore won the Eureka Prize from Écotech Québec.
As the pioneer, Howden engineered an ammonia refrigeration system in mines during the 1970s. Recently the company supplied ammonia screw chillers at Prominent Hill mine in South Australia for OZ Minerals. In partnership with the customer, Howden created solutions for their needs that are of the highest functionality while supporting their net-zero targets.
As environmental pressure builds on companies and industries globally, and especially on mining, now is the time to implement proven solutions to support a cleaner energy future.