Improving the air down there
Creating better air quality in underground mining environments is one of the most pressing issues facing mining companies today. Goldcorp’s Borden project in Canada is developing the world’s first all-electric mine using Sandvik Mining and Rock Technology equipment to help minimize emissions underground. More will have to be done, however, to combat the health risks associated with poor air quality. Solid Ground online spoke with Karen Hudson-Edwards, a professor of sustainable mining at the University of Exeter, to get her views on what can be done to help improve the air down there.
What are some of the health issues associated with poor air quality in underground mines?
Poor underground air quality caused by contaminants such as heat, humidity, dust and toxic, flammable, radioactive and suffocating gases can lead to a variety of health issues. These include loss of concentration, heat stress, respiratory tract irritations, poisoning and diseases such as pneumoconiosis, fibrosis, silicosis, black lung disease and lung cancer.
What are some of the hurdles to supplying underground environments with good-quality air?
One of the main hurdles mine operators face is to supply good-quality underground air in the most cost-effective manner. This requires a good understanding of the air volumes and velocities required, together with the potential contaminants produced. This is particularly true as mining moves deeper, because the geothermal gradient increases and ventilation systems must deliver more air or refrigeration over longer distances.
Which hazards that are controlled by ventilation affect air quality underground the most?
Ventilation systems can be associated with fires and gas outbursts. Power failures resulting in the shutdown of the systems can lead to a lack of oxygen and a build-up of toxic gases for mine workers. Underground dusts can accumulate on, and be redistributed by, ventilation components, or be produced by corrosion of these components by wear or reaction with contaminated air.
How can modern technology help improve air conditions underground?
Computer technology is increasingly playing a role in all underground mining activities, including ventilation. For example, Ventilation on Demand (VOD) systems are able to supply mine faces being worked with high-quality and efficient ventilation, while reducing or not ventilating those that are not being worked. The VODs operate through mine sensors that send data on air quality, personnel location and other factors to centralized computer systems that in turn adjust and supply the ventilation. This sustains good air circulation to workers while at the same time reducing costs. Other innovations include heat exchange ventilation, currently used at Vale’s Creighton mine in Ontario, and hydraulic compressed air cooling for deep mines.
What can be done to mitigate exposure to airborne contaminants?
Modern and well-maintained suppression, ventilation or exhaust-extraction systems are essential to eliminate or minimize airborne contaminants and ensure that fresh air is consistently supplied. Ideally these systems should adhere to legal frameworks, approved codes of practice and management plans for underground mining practice that aim to regulate and reduce workers’ exposure to these contaminants. To reduce diesel emissions, battery-powered electric vehicles and remotely controlled mobile machines are being increasingly used. These have many added benefits, including reduced emissions, costs, heat, noise and vibration.
Is there a modern-day version of the “canary in the coal mine”?
Smart technologies are the modern equivalents of the canaries in the coal mines. These can be used to monitor, detect, control and share information and be operated remotely and for 24 hours a day. The variety of such technologies is wide and growing. Examples include wireless sensor networks, radio frequency identification, smart grids, mobile sensing and cloud computing. The Internet of Things combines many of these technologies into a remotely controlled network.