Tuesday, August 6, 2013
Greening the Mining Industry – Part 1
Comment by Dennis Franklin
For the last 100 years, the mining industry has been responding to changing community attitudes about the environment and sustainability. The considerable interest and debate around the globe on climate change means proactive action is very important, In this article I hope to highlight some of those impacts, and in later follow up articles, I will discuss impacts and responses in more detail. I won’t reproduce all of the work that is being published, but I will point to some of the emerging trends and insights into the role and contribution of Information Technology (IT). In particular, I’ll be highlighting some of the areas where IT can help to support the industry’s response and management of “sustainability”.
Today, not a single project can proceed without an understanding of its impacts on the environment. Now the growing community interest on a global scale means that the mining industry, indeed all industries, need to understand their specific and general impacts on the global environment. The industry’s contribution is through emissions resulting from the mining process, and through the production of raw materials that contribute to the main causes of global emissions. Legislation to minimise those impacts is already being enacted or drafted in many jurisdictions. Even though the mining industry is an important contributor to the economy and our lifestyles, it is, by its very nature, an industry whose emissions will be subject to increased scrutiny.
Where are the impacts across the life cycle of a mine?
Most of the recent press on environmental impacts is about the generation of greenhouse enhancing gases. The main contributors here are Carbon Dioxide (CO2), Methane, and Nitrous Oxide . These contributions are different at different stages of the life cycle of a mine.
The use of fuels, power, and water and the possible introduction of contaminants have impacts that exist across the whole life-cycle. The obvious response to all of this is to use those resources more efficiently and so use less of them. Optimising mine operations through smart design during the concept and pre-feasibility phases of a project can produce significant offsets.
Ensuring that new technologies in mining equipment which lead to reduced fuel usage, more effective tyre wear, and automation and optimisation of their use through fleet management can deliver significant whole-of-life cost savings and can reduce carbon emissions per ton of product. Just as the public are moving towards energy efficiency in their homes through the use of energy saving lighting and appliances, so the mining industry can reduce its energy usage through smart selection of equipment and consumables.
The Build Phase
Perhaps the best time to affect the life-cycle impacts of anything is during the design stage. Minimising the embodied impacts of building a new mine can best be addressed during design. For example, the production of concrete has relatively low embodied energy (energy used to produce the material) but it tends to be used in large quantities . On the other hand, concrete production produces up to 3000 kg/tonne of CO2 and so the carbon contribution is significant.
In domestic applications, however, both of these issues can be traded off against the benefits that concrete slabs can provide. Good design turns concrete slabs into heat sinks that reduce the need for power usage for heating and cooling. So while the interactions are complex, there is a case for good design turning an initial high contribution to environmental impacts into a long term beneficial outcome.
Another example is the use of an in-pit crusher and conveyor to offset the needs for a large diesel truck fleet in an open pit operation. Emissions from the extra trucks is much greater that the carbon footprint of the conveyor system.
The same is true for many other aspects of mine design, mine planning and mining process design where a detailed understanding of the environmental impacts could contribute to a better long term outcome.
The Operate Phase
Good design can go a long way to minimising impacts from operational processes but there are ways to improve existing operations without major capital upgrades. These include better power management, optimising algorithms for mobile equipment, and almost any application of Lean Manufacturing techniques for reducing wasteful effort in the production processes.
The more significant issue during the operational phase of a mining operation is the end-user impact of the raw materials being produced. The obvious example is coal, the burning of which contributes a significant amount of CO2 to the atmosphere. While the argument about whether anthropogenic CO2 is the cause of climate change is controversial, the industry needs to take a position on this issue simply because the political landscape requires it. Besides, any rational approach to risk management would dictate the need to act on the risk anyway, regardless of the likelihood of the risk, simply because the size of the projected global impacts is huge.
The responses to the liberation of CO2 to the environment by burning coal and other carbon fuels tend to be technological. Now, many are researching processes that capture liberated CO2 and turn it into a form that can be stored for long periods, for instance Geo-sequestration. Sequestration seeks to inject CO2 back into the geological strata to remove it from the short-term carbon cycle. Research into these technologies is in its infancy, but most large mining companies and most governments are contributing funds to the research. Another approach is to offset emissions by parallel activities that remove CO2 from the atmosphere, such as reforestation. In time, the establishment of carbon trading markets will allow nett emitters to offset against the activities of others.
The Retirement Phase
The retirement phase of a mining operation includes all of the activities discussed with the life-cycle but offers some interesting opportunities for offsetting emissions as the environmental repatriation activities are progressed. Where appropriate reforestation of mine sites is progressed, carbon offsets should be claimable. Here are also gains to be made through the optimal dismantling of the infrastructure and the reuse of equipment. One option is the mothballing of operations until a time when the technology advances have addressed the problem, similar to the practice of mothballing operations during times of low prices. The threat of this possibility is enough to give the mining industry a strong motivation to be an active participant of the technology development.
The issues at question for the mining industry are not trivial, and the interrelationships between the natural processes are complex. Most of the research on the impacts is detailed and well understood but the necessary responses that need to be taken are not yet well researched. Even so, there are many activities that can be commenced, not just because they make environmental sense, but because they can make business sense as well. Already, in other industries, innovations that reduce energy use are being instituted because they save money. Smart design can help to deliver both energy savings and operational benefits; they are worth doing for their own sake.