Industry body the Mine Ventilation Society of South Africa (MVS) says that the high energy prices and a lack of applied research and skills are affecting the development of novel technologies in this field of expertise and the effective management of safety and health measures in mining ventilation.
The MVS president, Dr Bharath Belle, says that from about 10% to 20% of global energy is attributed to moving air in one way or other, while, in particular, about 750 MW of power is attributed to mining ventilation in South Africa alone. Ventilation engineers have to think differently during the design process of mines in order to use energy efficiently.
“Ways of becoming more energy efficient with regard to mine ventilation engineering include using infrastructure and management of ventilation technology more efficiently, reducing leakages and using different mine fan techno- logy, including an improved aerodynamic design of fans, like composite blades, in order to save energy,” he says.
MVS honorary editor Marco Biffi says that ventilating and cooling only on demand, when workers are active in the mine, can have a signi- ficant impact on energy use in mines.
“Ventilation engineers are considering only ventilating a mine, or parts thereof, when there are workers in the mine. That way, fans and cooling equipment can be turned down or even switched off when there is no one in sections of a mine, leading to reduced energy use. How- ever, this method holds both safety and health risks, such as excessive gas build-up, which can affect workers’ safety and health once they enter the mine again. We are now looking at the use of variable-speed drives and modulating the use of power in order to save energy,” he explains.
Mine ventilation engineers are currently re-evaluating the way in which mine ventilation systems are designed. Biffi says that, in principle, the systems must be more energy efficient and would be more cost effective if less capital is invested upfront for a modular approach to match the different growth phases of modern mine design.
A significant challenge to the development of ventilation in mines is retaining the knowledge base of ventilation engineers and highlighting the importance of mine ventilation as a health and safety enabler. Belle says that about 70% to 80% of professionals in the ventilation discipline are nearing retirement, so it is important for engineering graduates to become involved in mine ventilation.
“The management of significant health and safety hazards both on surface and underground mines is enacted by good ventilation engineering and, if people do not realise the importance of this discipline, no solutions for safety and health hazards can be found,” he says.
Biffi adds that there is a tendency to mechanise this previously labour-intensive industry. The machinery, however, increases the level of fumes and dust, which challenges ventilation engineers to find a way to manage the air quality and to come up with ventilation designs that will still be sensible 20 years later, so that old challenges do not keep resurfacing.
Meanwhile, the MVS is bidding to host the 2013 International Mine Ventilation Congress, in South Africa. The society has obtained support from the Chamber of Mines and the Department of Mineral Resources, and is hopeful that the congress will rejuvenate the discipline of ventilation engineering in mining.