Innovation

Green mining: An oxymoron

by Samar Al-Montser

Though green mining sounds like an oxymoron, mining companies are slowly acquiring technologies that can minimise their environmental impact. Here are a few mining attempts to go green or at least ways that are helping to minimise mining’s damaging to the environment.

Building a future is one thing but making sure it’s sustainable in the long term is another. For mining companies, that’s hard to achieve. The reason is that an essential part of mining is to extract minerals from the earth which disrupts the lands’ natural ecosystem. The damage is not only the loss of minerals but the irreversible condition of many other resources such as water. However, research has provided ways of how the productivity of the land may still be preserved after it has been mined.

Mining activities are considered essential for many manufacturers for things we find essential. So, the need is there but the pressure to go green is on. Here are six practices that can help reduce mining activities environmental footprint.

1. Energy efficient machines
According to a report by one of the world’s largest aluminium producers, Alcoa, has set a greenhouse management plan to address environmental issues and reduce greenhouse gas emissions. According to an Australia Aluminium Industry Study, commissioned by the Commonwealth Government, in 2003, Alcoa’s goal to reduce 25 per cent of its direct greenhouse gases worldwide was met and in 2014, it was 25.9 per cent less greenhouse gases than in 2005.

Alcoa achieved this partly by pioneering an energy efficient jet engine with the world’s first manufactured hybrid-metallic fan blade by Pratt & Whitney. This made the engines much lighter and energy efficient. Other ways Alcoa’s reducing energy consumption is through Alcoa’s Rope Conveyor (RopeCon) system at Jamalco’s mines. According to BusinessWire, this transport system saves over a thousand truck journeys a day, CO2 emissions, noise and dust. The way it does this is by generating electricity while it’s being transported downhill to the mine.

2. Water management
Due to water being vital for the mining process, companies have been forced to look into ways to better manage their water use. Ecosphere Technologies, a water services company, is one of the latest in technological developments that help clean high volumes of wastewater produced from mining. Its Ozonix water treatment technology is a chemical-free alternative that offers safe ways of recycling wastewater. It even works in real-time processing and can bring back 100 per cent of flow back water from about 38 thousand barrels.

According to MiningFacts.org, in the late 90s, active water treatment systems were seen to be cost-effective. However, at the time, it removed only 99.2 per cent of metals in the water. Though it wasn’t considered to be a viable solution, it was valuable research that resulted in restoring the natural wetland and developed it into a recreation area and park. This water treatment which involved oxidation and lime treatments in active and passive forms was piloted in the Wheal Jane mine in the United Kingdom.

3. Mine restoration
Mine restoration is not an easy task at all after the land has been mined, its complete natural revival is close to impossible. Currently, research shows that preserving the ecosystem by protecting the few species left can revive the land to some degree. This near-natural restoration is better than technical intervention.

In the Czech Republic, many spoil heaps are often left after coal mining, some of which have been left and dedicated to spontaneous succession. This means the heap can be left alone for several years and decades until it naturally revives itself. One of the most favourable and natural ways to help conserve and restore the land is to prepare the heap with soil layers such as humus, plant a few trees and also include invasive species.

4. Reducing vibrations and energy consumption
Though technology isn’t always the solution, some innovative technologies can help reduce the extent of the mining impact on the environment. WIRTGEN, a technology developing company, developed the Surface Miner 2200 SM to effectively reduce harmful effects of mining technologies. Unlike conventional technological methods of mining, this technology attempts to reduce the heavy vibrations, noise and dust pollution of conventional technologies.

Another example is the Australian company, Emergent Mining Technologies (EMT), that’s developing various energy efficient mining technologies. This green sector in mining technologies is fast developing and opening up new business opportunities.

5. Waste reduction
After all the waste has been dumped around the mine, what’s usually left is hazardous and often useless. With copper mining, pollution or corrosive acid is usually left as waste. These piles of mine waste can actually be reused and reproduced for other uses such as energy. Current biomining research is trying to find effective ways of mining to help advance these solutions.

According to a BBC News article, Codelco, which is the world’s largest copper mining company, has set up a biotechnology venture called Biosigma. Codelco, with Nippon Metals and Mining, is trying to introduce a solution of microbes that can help clean up waste, reduce harm to the environment and use less energy to extract copper. In Canada, Natural Resources Canada (NRCan) is producing an environment-friendly binder out of waste rock from mines. The binder, made of a composition of slag, is used for mine shafts instead of cement.

6. Energy recycling
Another ongoing project to reuse mining waste as energy is in the coal mining company, Consol Energy. According to PR Newswire, Consol is using Ventilation Air Methane (VAM) abatement equipment to destroy methane released during the mining process. Methane can then be burned to produce valuable fuel and electricity.

Methane mitigation is also underway in Kazakhstan which has the eighth largest reserve of coal in the world. According to the United States Environmental Protection Agency (EPA), Kazakhstan is a member of the Global Methane Initiative (GMI) which promotes best practices to reduce methane emissions.

Last words
While mining technologies first and foremost benefit the companies using them, mining companies could collectively contribute to a substantive reduction in environmental impact. Most mining companies have targeted to reduce their greenhouse gases by over 20 per cent and they did achieve those goals. If at least 20 per cent of greenhouse gases were reduced by all companies in the mining industry, the degree of impact on Earth could be greatly significant. However, how these green attempts and technologies translated into slowing down damage to the global environment is yet to be measured in its totality. One thing these technologies had proven is that they can save businesses some money. The mining industry remains the main sector that needs to continue addressing its environmental effects which leave its doors open for further innovations.

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22 May 2018
Last modified: 16 Jul 2018
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