As companies push the boundaries of mining exploration, digging deeper and in more remote locations, temperature control and ventilation take on an ever increasing level of importance, says temporary power and temperature-control solutions provider Aggreko Southern Africa local business head Martin Foster.

He says that fast depleting mineral resources are forcing miners to dig deeper and in more disparate locations. 

“For these sites to be safe and productive it is imperative that temperatures are controlled and regulated, with moisture and contaminants extracted from the air. The continued analysis and development of such technology is essential to the future of the mining industry,” states Foster.

He stresses that consistent ventilation and temperature control are essential to miners’ welfare.  Fractional changes in the temperature or air quality inside an underground mine can damage site equipment or reduce its performance, which can leave miners susceptible to harmful contaminants.

Foster adds that temperature control has become even more important as climates have become more volatile and the surface temperatures of mine locations rise.

Where surface temperatures rise unexpectedly, on-site permanent cooling equipment used for regulation can become less effective, resulting in adverse changes to temperature management underground. Even small variations to heat control can result in heat exhaustion, dehydration and heat cramps, all of which have an adverse effect on miners’ welfare and productivity.

He states that alongside controlling temperature, ventilation systems are crucial in removing harmful fumes that occur during the extraction process from the mine.

Foster highlights that in the case of coal mines, gasses can be combustible and, therefore, a fire risk. In the case of uranium mining, radioactive radon gas can also be harmful to the health of workers, as exposure to it presents a lung cancer hazard. 

Moreover, he points out that drills, pumps, load haul dumps and other mobile devices that are often powered by diesel, which can all contribute to increased air temperature and decreased air quality underground.

“Essentially, an effective cooling and ventilation system reduces these risks, while allowing for optimum productivity in challenging conditions,” states Foster.

He comments that mine cooling and refrigeration technology, particularly where the application of chilled water and compound air is concerned, is at a mature stage in the market.

However, Foster notes that it is the application of this technology that continues to evolve.

“The fact that this technology can be applied in a variety of ways is where the real challenge arises within the mining environment,” he says.

Efficiency is key and the technology in question requires heavy maintenance and competency checks to manage the innovation in the most effective manner, states Foster.

“There are full-service solutions that can help to evaluate these but, even so, it is a critical area that should not be overlooked or underestimated,” he emphasises.

With significant depth increases come significant temperature increases and this means serious occupational hazards can present themselves. Heat exhaustion in deep underground mines, for example, becomes more common as the temperature rises, with dehydration and heat cramps not uncommon.

In deep mining, where ventilation and temperature control systems are an essential part of the permanent production infrastructure, fractional increases in climatic conditions on the surface can add significant stress to existing equipment, resulting in decreased performance levels. 

Foster asserts that air cooling power is a major contributing factor in the overall improvement in working conditions underground.

“Scientific research and common practice have shown that heat exhaustion is far less likely to occur if ventilation and refrigeration achieves air cooling power greater than 250 W/m2 at an underground work site.”

He says that in the event of an extraordinary rise in surface temperature, where existing equipment is unable to reliably produce the increased cooling or ventilation, miners face possible shut-downs unless they have a back-up plan in place.

JSE-listed gold miner Harmony Gold’s Phaksia mine, in Free State, South Africa is one of the world’s deepest gold mines, reaching a depth of 2 400 m.

Harmony is required to manage the associated temperature issues of mining at such a depth.

However, Foster says that when recently the commissioning of a cooling system was delayed, and the summer months were approaching, Aggreko provided a solution with a fully integrated, turnkey cooling package, which effectively bridged the gap until a permanent cooling package was installed.

“Aggreko, therefore, played a vital role in terms of health and safety, as well as ensuring the effective operation of the mine,” he enthuses.

Foster says that a worst case scenario for mining businesses would be for it to be rendered operationally unsafe during extreme peaks in temperature.

“With above ground temperatures in the likes of Australia or South Africa often reaching beyond 45 ºC, health, safety and productivity at mines can all be in jeopardy.

“Therefore, controlling and regulating temperatures underground as well as extracting contaminants go a long way to ensuring that, when the boundaries of mining exploration and activities are pushed, miners’ welfare and productivity do not suffer as a consequence,” he concludes.