As the number of pieces of equipment or their capacity increases, and more underground production work areas are opened up, the demand for fresh air also increases. Mining equipment generates heat, dust and fumes while it is operating, and hence will require sufficient fresh air to dilute the contaminants to a safe level, specified by regulatory authorities such as the NOHSC (National Occupational Health and Safety Commission) and the Mines Safety and Inspection Act. These regulatory bodies require that workers operate in a healthy work environment that meets specified minimum standards.
Many underground operations find it difficult to achieve these minimum ventilation standards at all times and will, in some instances, compromise production to comply with the statutory requirements. Others, sadly to say, who also simply cannot meet the minimum ventilation standards, will compromise the working environment to achieve their business targets. In either case the problem is inadequate ventilation, which is brought about by lack of appropriate knowledge and poor or ineffective planning.
It is true to say that many underground planners do not see that ventilation forms a critical part of their mine planning process and often leave the ventilation details to the nominated statutory ventilation officer to handle, as if it is of secondary importance. It is also fair to say that most ventilation officers in Australia are junior engineers who have been nominated to fill in this role for short period of time, as a part of their postgraduate training before proceeding on with their career. A situation which is exacerbated by the fact that no mentorship in ventilation requirements is provided to these junior ventilation officers.
If senior and project management are intent on enhancing their business practice they would do well to consider the following questions and raise them with their subordinates to ensure acceptable ventilation practice is attained:
What is your underground ventilation compliance rating with respect to the Mines Safety and Inspection (MSI) Regulations?
Do you have adequate ventilation standards and procedures that are effective in preventing production and development losses, fatalities and serious health hazards from arising?
Has your mine design changed since the feasibility study, and does the current ventilation strategy reflect on changes to the underground plan and schedule?
Are you overlooking the critical link between ventilation design and underground mine design? Are you assuming you can resolve the ventilation issues when they arise?
Do you know whether your ventilation strategy is good, bad or otherwise, and whether you are compromising your productivity and ultimately the business plan?
Ventilation is an integral part of the underground planning process. It should be considered when the design changes, or is expanded to ensure the ventilation demand can be met. This way the cost of ventilation will not be overlooked, as is often the case in many projects, which will avoid the problem of under-budgeting which ultimately leads to a substandard ventilation system.
The occurrence of terrestrial gasses such as methane, high geothermal gradients or changes in material/rock properties, just to name a few, will also demand additional ventilation. Ventilation requirements may also dictate the type of explosive that must be utilised to reduce possibility of dust explosion, a problem encountered in mines that have a high sulphide content. All of these factors will have a detrimental impact on your project costs and business targets if they are not identified in time and managed appropriately. Regular ventilation system audits, other than those necessary for the minimum statutory compliance, should therefore also be conducted. This will identify all underground design changes so that implementations can be made to the underground ventilation plan and schedule. Any deficiencies can then be identified and rectified. Published in Australia's Mining Monthly
Junior Oding is a senior mining engineer with SRK Consulting. SRK has established a specialised team to service the practical training and guidance for site ventilation officers and to also conduct reviews in order to bring the ventilation systems, standards, procedures and management for all underground operations to a world best practice status.