1 Breath of fresh air With no aspect of underground mine safety more fundamental than proper ventilation, various modern systems are being used to ensure airflow is safe for workers BY BREE FREEMAN When it comes to underground mine workings, few things are more important than adequate ventilation. Every year enormous efforts are made to maintain and improve airflow to working areas. This is to dilute emissions below statutory limits, render the air harmless, carry away hazardous contaminants and provide necessary levels of oxygen for the miners. As a result, ventilation systems form a crucial pan of the design of any mine, the layout of which is determined by the orebody geology, legislation, available manpower, mining methods and the equipment used. Specific environmental issues such as virgin rock temperatures, spontaneous combustion and dust control further complicate theoretical ventilation systems. Moreover, whatever system is eventually planned will inevitably suffer from imperfect implementation and control because of the day-to-day complexities of the extraction operation. “Ventilation in the modem mine is an essential prerequisite, perhaps even more so than in the past.Apart from the obvious biological aspect of preventing depletion of oxygen and the build-up of carbon dioxide in the air, the mine-ventilation system must be able to keep quantities of contaminants below harmful levels,” says Mike Beare, principal mining engineer for consultancy SRK. He explains: “A modern mine has many sources of harmful substances, including fumes from explosives, dust from broken rock and gases present in the rocks themselves. in addition to these, the modem approach to mining (including the use of diesel-engine...
