Summary
This review surveys online resources relevant to ventilation systems in underground mines. It lists ventilation software, publications, courses, consultants, and suppliers. Topics discussed include the basics of ventilation systems, regulations, and design principles.INTRODUCTION
Ventilation is a basic part of all underground mine operations. Ventilation is undertaken in order to introduce fresh, cool air to the workings and to remove stale, affected air from the workings. In this technology review, we look at the basics of ventilation, the regulations, and the people, companies, and equipment you may need for installing, operating, and maintaining a ventilation system at your mine. The need for ventilation in an underground mine is described thus by Hardcastle, Kocsis, and Lacroix in a paper from the CIM 2007 conference, entitled Strategic mine ventilation control: A source of potential energy savings.Ventilation in underground mines is required to dilute and remove hazardous substances, control the thermal environment, and provide oxygen for humans and engine combustion. In Canadian mines, the most common considerations are the control of diesel engine exhaust emissions and mineral dust concentrations, to within prescribed levels for humans to work in that environment. A lesser concern is the clearance of blast fumes which is normally when the mine is not occupied. In a smaller number of mine radiation and other gases, such as methane may also need consideration. A new and increasing concern as Canadian mines go deeper is the control of heat exposure to the degree that it requires more air to control the temperature of the working environment than is needed for other concerns.Mine ventilation system is said to be homotropal when the movement of the fragmented ore is in the same direction as the fresh air, while an antitropal ventilation system is one wherein the movement of the fragmented ore is opposite to the direction of movement of fresh air. Ascentional ventilation takes the advantage of the tendency of warm air to move upwards through inclined workings and utilizing natural ventilation effects. Descentional ventilation system is employed where the air can enter the mine at a higher elevation where its cooler and drier.
BASICS
A ventilation system is basically a combination of pipes and ducts, fans, cooling and heating systems, and possibly air cleaning equipment. Air introduced into the mine workings via the pipes and ducts, and from natural openings and shafts into the mine workings flows through the workings, is affected by dust, gas, heat, or other constituents and is then removed (or exists naturally) from the workings. Thus the information you will need to design, install, and operate a cost-effective and technically efficient ventilation system includes: surface temperatures and humidity; underground rock strata temperatures and moisture contents; rock fracture patterns to the extent they affect the air permeability of the rock; the layout of the mine workings, include options for ventilation shafts, bulkheads, and partitioning of the workings into areas for separate ventilation control; the mine operations as they will affect underground air quality including blasting and equipment emissions; the air quality standards that have to be met for human health and safety in the ventilated workings; and finally the nature and cost of energy sources to run and operate the ventilation system.Mine ventilation system run the full spectrum of shafts and tunnels so configured that natural air drafting is sufficient to move and clean the air; to the most sophisticated modern systems where wireless sensors monitor air quality and temperatures and control systems to ventilate only specific areas when needed such as after blasting or just before the entry to the area of miners.
As noted, the system supplying air to the workings generally includes fans, ducts, and piping. Cooling and filtering equipment may also be needed. The specifics of such equipment are multiple and complex. Best you contact the manufacturers and suppliers for specific equipment facts and statistics.
A ventilation system, at is simplest, is but a pipe network through which air flows. There are many computer codes to undertake the simple, but repetitive calculations required to quantify the performance of such a system. Most computer codes incorporate the many coefficients that generally govern the flow of air in pipes, through mine tunnels, and into and out of the valves and doors that control flow. We do not repeat such flow parameters here-best buy the code and go for it.
The evaluation of a mine ventilation system can be best expresses by calculating the volumetric efficiency. It relies on the simple formula as given below:
Ventilation Efficiency (%) = 100 x Total Quantity of Air 'Usefully Employed' / Total Quantity of Air Supplied through the Main Fan(s)
HISTORY
The best work on the history of mine ventilation I found is by Reed and Taylor: Factors affecting the development of mine face ventilation systems in the twentieth century.REGULATIONS
Regulations for ventilation systems vary from jurisdiction to jurisdiction and mine type to mine type. In the United States, MSHA sets the standards, guidelines, and criteria for most mines. In both Canada and Australia, there is particular attention paid to ventilation for air quality control in uranium mines. See the World Nuclear Association for more on this topic.In Canada, the provincial Occupational Health & Safety codes govern the mine ventilation systems, their requirement and monitoring.
The South African Department of Minerals and Energy site provides links to relevant South African laws and regulations.