A common problem for many mines is insufficient total primary airflow or insufficient airflow in the correct places as the mine changes over its life._x000D_
This has a number of impacts on the business operation and may result in the need for a major and unexpected capital upgrade of the system, cancellation of a planned production increase, reduction in production targets, increased operating costs, failure to provide contracted metals to customers or acceptance of substandard conditions in the workplace. In some cases, it can even result in premature closure of the mine._x000D_
In recent times, higher metal prices have given an expected economic boost to many mines, potentially prolonging their life but simultaneously requiring the mine to develop to deeper depths or requiring assets such as shafts and fans to have their service life extended._x000D_
Insufficient primary airflow is a particular problem in deeper mines as the ventilation circuits become longer, more convoluted, have higher shock losses and the actual airflow requirements increase due to a combination of leakage, dispersion of the workings and the problems of managing the additional heat loads due to higher virgin rock temperatures and autocompression._x000D_
This paper discusses the reasons why mines experience unexpected shortfalls in primary ventilation capacity with its associated impacts on metal targets, profits and frequently on the health, safety and morale of the workforce, as well as its productivity._x000D_
FORMAL CITATION:Brake, D J and Nixon, t, 2008._x000D_
Correctly estimating primary airflow requirements for underground metalliferous mines, in Proceedings Tenth Underground Operators' Conference 2008, pp 199-204 (The Australasian Institute of Mining and Metallurgy: Melbourne).