Australian Environment minister Greg Hunt recently told the UN that Australia is 78 million tonnes ahead of its 2020 emissions reduction target which is a dramatic increase on the initial 28 million tonnes target projected last December. Australia has also committed to cut its emissions to five per cent by 2020 and by 26 per cent to 28 per cent to 2030.
With an ever increasing number of vehicles across all sectors including mining, vehicle emissions have a significant impact on the environment. These can be in the form of vibration, heat, noise, and exhaust emissions – ultimately having a direct impact the vehicle and workers.
In terms of underground operations, these issues are compounded by the effect of diesel particulate matter (DPM) which includes fine carbon particles and poly-aromatic hydrocarbons (PAHs), which adhere to the surface of these carbon particles.
DPM can act like a gas and stay airborne for long periods of time and can penetrate deep into the lungs because of the small size of the particles. According to Safe Work Australia, exposure to diesel exhaust can cause both short term (acute) and long term (chronic) health effects.
Futhermore, DPM affects vehicle performance, as higher DPM levels mean the engine is not combusting at optimal levels, causing it to be less efficient, and leading to potential breakdowns. It can be emitted during vehicle usage, maintenance, and even during the vehicle’s final decommissioning and recycling.
Thus, machine design and service support is important;regular maintenance, proper operational training, and aftermarket support can also lead to lower emissions. However the most important part of any vehicle’s performance is the engine, so choosing the right engine is the first step in ensuring low emissions.
The main criterion for choosing the right engine option is the sulphur content of the diesel fuel and the availability of AdBlue/DEF exhaust additive. If ultralow sulphur fuel (15ppm & below) and AdBlue are available, then a Tier 4 low emission engine should be the preferred choice.
If ultra-low sulphur fuel and AdBlue are not available; fuels with a higher sulphur content cannot be used in a Tier 4 engine. In which case, a Tier 2 engine with exhaust after-treatment is the preferred option.
Sandvik’s different tiered solutions:
Tier 4 Engine Solution
Sandvik Mining and Rock Technology Australia is a fleet owner for Volvo Penta. Overcoming any perceived challenges of making Tier 4 technology work underground, Sandvik introduced the Volvo D13 and D16 Tier 4 interim engines (ideal for underground mining conditions) into loaders and trucks in 2011. The Tier 4 final engines arrived in 2014, using the Selective Catalytic Reduction (SCR) system that is central in the reduction of emissions in the Tier 4 engine.
It involves the ADblue additive being injected into the exhaust gas stream where it reacts with the NOx in the SCR catalytic converter to produce nitrogen and water. At the same time, light/hot EGR recirculates a small amount of a hot exhaust gas back into the engine to further meet Tier 4 final requirements.
These fit-for-the-purpose and easy-to-maintain machines come with all the required certifications – MSHA, CANMET and Euro Stage 4 and are compliant with all the Tier 4 final requirements.
At the present, Sandvik is the only Original Equipment Manufacturer (OEM) to provide Tier 4 solutions for emissions on underground trucks and LHDs in Australia.
Tier 2 Engine Solution
Sandvik has developed a Diesel Particulate Filter (DPF) system optimised for use on the Volvo Tier 2 engine. Particularly when ultra-low sulphur fuels are not available and the Tier 4 engine cannot be selected. The Sandvik DPF targets a 99 per cent diesel particle reduction, using a reliable filter system that is easy to maintain and does not require any special tools. This reduces the particulate matter down to the same level or even below that of equivalent Tier 4 engines.
Sandvik provides Tier 2 Volvo engines in its loaders and trucks when Tier 4 cannot be selected. The Tier 2 engines offer low fuel consumption, with a simple construction that does not require EGR. The transient fuelling has also been optimized to minimise transient smoke. They are specially designed for high altitude, severe conditions and have been tested up to 4500m above sea level.
For more information on Sandvik’s emission solutions, click here