• Diesel Particulates and Electric Mines

Diesel Particulates and Electric Mines

16 January 2020

Original content provided by BDO Australia

Is this the next big risk for mining companies...and how electrifying mines will play its part? 

What is the issue? 

Mining companies focus on how to build and operate a mine as efficiently and safely as possible.  Occasionally there is a sudden shock to the system such as a mine collapse or a tailings dam failure.  Fortunately, these are few and far between but when they do happen there is a swift review and much navel gazing across the industry.  Unfortunately, a safety issue that has a much longer and less dramatic gestation period has the potential to be a major risk for mining companies in the near future: that is the chronic health issues associated with the presence of nano diesel particulate (nDPM) matter in underground mines. 

What are diesel particulates and why are they an issue? 

nDPM has the potential to be a ticking time-bomb akin to ‘asbestos’ for the industry.  Diesel became prevalent in underground mines in Australia around 40 to 50 years ago and whilst there may be no immediate health effects on underground mine workers the long-term impact may be seen in the coming few years. 

There has been much written on why nDPM is so dangerous (lung cancer, bladder cancer, DNA damage) so we will not repeat it here.  Suffice to say that nDPM is unbelievably small – 160 times smaller than a red blood cell and around 40 times smaller than bacteria and as they accumulate in your body they can build to a level that is very bad for your health.  
What contributes to the issue? 

The health effects to underground miners where dieselpowered equipment predominate have many contributing factors such as the proximity of workers to the source of the diesel engine exhaust fumes; the level, duration and variability of exposure; the type, condition and age of the diesel engines; the quality of the ventilation system etc.  Reducing the number of nDPM in the air is key to reducing the health risk to mine workers.

What are the options? 

Oil security has proven to be a highly disruptive and expensive issue for many decades, particularly for the United States. As oil dependency reduces over the coming decade, oil security, mainly in the Middle East, will become less of an issue. But that raises an interesting question: will security of other materials, such as copper for electric vehicles and rare earth elements for defense-related technologies, result in increased conflict in nations that hold significant reserves of such materials?

The ultimate option is to close the mine down but let’s take that option off the table.  In reality the other three alternatives are to:

  • Move to electric, in total or in part
  • Improve ventilation
  • Filtration

The solution adopted will depend on the size, design, economics and life of the mine but will often include elements of all three.

Going electric is all the rage above ground and there are numerous studies predicting that the number of electric passenger vehicles will mushroom.  Underground it is a lot harder to move to electric, especially for existing mines.  We are starting to see the first all-electric mines coming on stream in Canada. However, whilst electric machinery can have reduced downtime and operating costs, at present the capital costs tend to make going electric prohibitive in most cases.  However, with improvements in technology and reduced costs, in the future it is very likely that it will be commonplace to see new mines being fully electric in Australia.

Ventilation can be an integral part of the solution. Underground mines commonly use the decline for primary fresh air ventilation, which is the same decline used by the diesel vehicles, thereby increasing the issue. Ventilation cannot solve the issue by itself.

In the short term filtration is the key solution.  Some of the very newest diesel engines that will be coming to the market soon, coupled with an effective Diesel Particulate Filter (DPF), can reduce the level of nDPM to acceptably low numbers.

For heavy machinery in existing mines, the solution is likely to be to buy and install effective DPFs or if such equipment is due to be replaced then replace them with new Stage V equipment fitted with a DPF. We have already seen trials of light electric vehicles in some underground mines in Australia.  Effective DPFs can be the immediate solution for LEVs too but given the advances in passenger electric vehicle technologies that we will see it is likely that electric LEVs will become commonplace underground more quickly that for heavy equipment.

Will we see fully electric mines in Australia?

The short answer is yes.  When is a more difficult question to answer.  It is likely that by 2035 electric mines will be the norm and we will be asking why diesel is being used.

What else should we consider?

We expect guidance to come from State governments on the lowering of acceptable nDPM levels with the Western Australian Government taking the lead.  To encourage this transition we would like to see Federal and State governments providing incentives such as grants and subsidies to encourage mining companies to address the issue.  

Training and retraining of future diesel mechanics is an interesting question.  There is no doubt that there will be plenty of work for diesel mechanics for the foreseeable future, but their skill sets will need to transition to include electric equipment in the medium to long term. This needs to be in the sights of those looking to join the industry and those who train them.

Whilst this is a lurking significant issue for mining companies the fear is that some may only sit up and pay attention when their significant investors insist that they do (as in the case of the Church of England Pensions Board and its Investor Mining & Tailings Safety Initiative) or when they are on the receiving end of class actions (similar to asbestos cases).  At that point the question of whether to face the costs of this will be taken from the remit of mine mangers and be placed into the Boardroom of mining companies where it belongs. Really change needs to happen before it gets to that point.

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