" DISCLAIMER: The ILO does not take responsibility for content presented on this web portal that is presented in any language other than English, which is the language used for the initial production and peer-review of original content. Certain statistics have not been updated since the production of the 4th edition of the Encyclopaedia (1998)."

Sunday, 13 March 2011 15:35

Types of Coal Mining

Written by
Rate this item
(0 votes)

The rationale for selecting a method for mining coal depends on such factors as topography, geometry of the coal seam, geology of the overlying rocks and environmental requirements or restraints. Overriding these, however, are the economic factors. They include: availability, quality and costs of the required work force (including the availability of trained supervisors and managers); adequacy of housing, feeding and recreational facilities for the workers (especially when the mine is located at a distance from a local community); availability of the necessary equipment and machinery and of workers trained to operate it; availability and costs of transportation for workers, necessary supplies, and for getting the coal to the user or purchaser; availability and the cost of the necessary capital to finance the operation (in local currency); and the market for the particular type of coal to be extracted (i.e., the price at which it may be sold). A major factor is the stripping ratio, that is, the amount of overburden material to be removed in proportion to the amount of coal that can be extracted; as this increases, the cost of mining becomes less attractive. An important factor, especially in surface mining, that, unfortunately, is often overlooked in the equation, is the cost of restoring the terrain and the environment when the mining operation is closed down.

Health and Safety

Another critical factor is the cost of protecting the health and safety of the miners. Unfortunately, particularly in small-scale operations, instead of being weighed in deciding whether or how the coal should be extracted, the necessary protective measures are often ignored or short-changed.

Actually, although there are always unsuspected hazards—they may come from the elements rather than the mining operations—any mining operation can be safe providing there is a commitment from all parties to a safe operation.

Surface Coal Mines

Surface mining of coal is performed by a variety of methods depending on the topography, the area in which the mining is being undertaken and environmental factors. All methods involve the removal of overburden material to allow for the extraction of the coal. While generally safer than underground mining, surface operations do have some specific hazards that must be addressed. Prominent among these is the use of heavy equipment which, in addition to accidents, may involve exposure to exhaust fumes, noise and contact with fuel, lubricants and solvents. Climatic conditions, such as heavy rain, snow and ice, poor visibility and excessive heat or cold may compound these hazards. When blasting is required to break up rock formations, special precautions in the storage, handling and use of explosives are required.

Surface operations require the use of huge waste dumps to store overburden products. Appropriate controls must be implemented to prevent dump failure and to protect the employees, the general public and the environment.

Underground Mining

There is also a variety of methods for underground mining. Their common denominator is the creation of tunnels from the surface to the coal seam and the use of machines and/or explosives to extract the coal. In addition to the high frequency of accidents—coal mining ranks high on the list of hazardous workplaces wherever statistics are maintained—the potential for a major incident involving multiple loss of life is always present in underground operations. Two primary causes of such catastrophes are cave-ins due to faulty engineering of the tunnels and explosion and fire due to the accumulation of methane and/or flammable levels of airborne coal dust.


Methane is highly explosive in concentrations of 5 to 15% and has been the cause of numerous mining disasters. It is best controlled by providing adequate air flow to dilute the gas to a level that is below its explosive range and to exhaust it quickly from the workings. Methane levels must be continuously monitored and rules established to close down operations when its concentration reaches 1 to 1.5% and to evacuate the mine promptly if it reaches levels of 2 to 2.5%.

Coal dust

In addition to causing black lung disease (anthracosis) if inhaled by miners, coal dust is explosive when fine dust is mixed with air and ignited. Airborne coal dust can be controlled by water sprays and exhaust ventilation. It can be collected by filtering recirculating air or it can be neutralized by the addition of stone dust in sufficient quantities to render the coal dust/air mixture inert.



Read 6579 times Last modified on Tuesday, 28 June 2011 12:17


Part I. The Body
Part II. Health Care
Part III. Management & Policy
Part IV. Tools and Approaches
Part V. Psychosocial and Organizational Factors
Part VI. General Hazards
Part VII. The Environment
Part VIII. Accidents and Safety Management
Part IX. Chemicals
Part X. Industries Based on Biological Resources
Part XI. Industries Based on Natural Resources
Iron and Steel
Mining and Quarrying
Oil Exploration and Distribution
Power Generation and Distribution
Part XII. Chemical Industries
Part XIII. Manufacturing Industries
Part XIV. Textile and Apparel Industries
Part XV. Transport Industries
Part XVI. Construction
Part XVII. Services and Trade
Part XVIII. Guides

Mining and Quarrying Additional Resources

Click the Button below to view additional resources for this topic.


Mining and Quarrying References

Agricola, G. 1950. De Re Metallica, translated by HC Hoover and LH Hoover. New York: Dover Publications.

Bickel, KL. 1987. Analysis of diesel-powered mine equipment. In Proceedings of the Bureau of Mines Technology Transfer Seminar: Diesels in Underground Mines. Information Circular 9141. Washington, DC: Bureau of Mines.

Bureau of Mines. 1978. Coal Mine Fire and Explosion Prevention. Information Circular 8768. Washington, DC: Bureau of Mines.

—. 1988. Recent Developments in Metal and Nonmetal Fire Protection. Information Circular 9206. Washington, DC: Bureau of Mines.

Chamberlain, EAC. 1970. The ambient temperature oxidisation of coal in relation to the early detection of spontaneous heating. Mining Engineer (October) 130(121):1-6.

Ellicott, CW. 1981. Assessment of the explosibility of gas mixtures and monitoring of sample-time trends. Proceeding of the Symposium on Ignitions, Explosions and FIres. Illawara: Australian Institute of Mining and Metallurgy.

Environmental Protection Agency (Australia). 1996. Best Practice Environmental Management in Mining. Canberra: Environmental Protection Agency.

Funkemeyer, M and FJ Kock. 1989. Fire prevention in working rider seams prone to spontaneous combustion. Gluckauf 9-12.

Graham, JI. 1921. The normal production of carbon monoxide in coal mines. Transactions of the Institute of Mining Engineers 60:222-234.

Grannes, SG, MA Ackerson, and GR Green. 1990. Preventing Automatic Fire Suppression Systems Failure on Underground Mining Belt Conveyers. Information Circular 9264. Washington, DC: Bureau of Mines.

Greuer, RE. 1974. Study of Mine Fire Fighting Using Inert Gases. USBM Contract Report No. S0231075. Washington, DC: Bureau of Mines.

Griffin, RE. 1979. In-mine Evaluation of Smoke Detectors. Information Circular 8808. Washington, DC: Bureau of Mines.

Hartman, HL (ed.). 1992. SME Mining Engineering Handbook, 2nd edition. Baltimore, MD: Society for Mining, Metallurgy, and Exploration.

Hertzberg, M. 1982. Inhibition and Extinction of Coal Dust and Methane Explosions. Report of Investigations 8708. Washington, DC: Bureau of Mines.

Hoek, E, PK Kaiser, and WF Bawden. 1995. Design of Suppoert for Underground Hard Rock Mines. Rotterdam: AA Balkema.

Hughes, AJ and WE Raybold. 1960. The rapid determination of the explosibility of mine fire gases. Mining Engineer 29:37-53.

International Council on Metals and the Environment (ICME). 1996. Case Studies Illustrating Environmental Practices in Mining and Metallurgical Processes. Ottawa: ICME.

International Labour Organization (ILO). 1994. Recent Developments in the Coalmining Industry. Geneva: ILO.

Jones, JE and JC Trickett. 1955. Some observations on the examination of gases resulting from explosions in collieries. Transactions of the Institute of Mining Engineers 114: 768-790.

Mackenzie-Wood P and J Strang. 1990. Fire gases and their interpretation. Mining Engineer 149(345):470-478.

Mines Accident Prevention Association Ontario. n.d. Emergency Preparedness Guidelines. Technical Standing Committee Report. North Bay: Mines Accident Prevention Association Ontario.

Mitchell, D and F Burns. 1979. Interpreting the State of a Mine Fire. Washington, DC: US Department of Labor.

Morris, RM. 1988. A new fire ratio for determining conditions in sealed areas. Mining Engineer 147(317):369-375.

Morrow, GS and CD Litton. 1992. In-mine Evaluation of Smoke Detectors. Information Circular 9311. Washington, DC: Bureau of Mines.

National Fire Protection Association (NFPA). 1992a. Fire Prevention Code. NFPA 1. Quincy, MA: NFPA.

—. 1992b. Standard on Pulverized Fuel Systems. NFPA 8503. Quincy, MA: NFPA.

—. 1994a. Standard for Fire Prevention in Use of Cutting and Welding Processes. NFPA 51B. Quincy, MA: NFPA.

—. 1994b. Standard for Portable Fire Extinguishers. NFPA 10. Quincy, MA: NFPA.

—. 1994c. Standard for Medium and High Expansion Foam Systems. NFPA 11A. Quncy, MA: NFPA.

—. 1994d. Standard for Dry Chemical Extinguishing Systems. NFPA 17. Quincy, MA: NFPA.

—. 1994e. Standard for Coal Preparation Plants. NFPA 120. Quincy, MA: NFPA.

—. 1995a. Standard for Fire Prevention and Control in Underground Metal and Nonmetal Mines. NFPA 122. Quincy, MA: NFPA.

—. 1995b. Standard for Fire Prevention and Control in Underground Bituminious Coal Mines. NFPA 123. Quincy, MA: NFPA.

—. 1996a. Standard on Fire Protection for Self-propelled and Mobile Surface Mining Equipment. NFPA 121. Quincy, MA: NFPA.

—. 1996b. Flammable and Combustible Liquids Code. NFPA 30. Quincy, MA: NFPA.

—. 1996c. National Electrical Code. NFPA 70. Quincy, MA: NFPA.

—. 1996d. National Fire Alarm Code. NFPA 72. Quincy, MA: NFPA.

—. 1996e. Standard for the Installation of Sprinkler Systems. NFPA 13. Quincy, MA: NFPA.

—. 1996f. Standard for the Installation of Water Spray Systems. NFPA 15. Quincy, MA: NFPA.

—. 1996g. Standard on Clean Agent Fire Extinguishing Systems. NFPA 2001. Quincy, MA: NFPA.

—. 1996h. Recommended Practice for Fire Protection in Electric Generating Plants and High Voltage DC Converter Stations. NFPA 850. Quincy, MA: NFPA.

Ng, D and CP Lazzara. 1990. Performance of concrete block and steel panel stoppings in a simulated mine fire. Fire Technology 26(1):51-76.

Ninteman, DJ. 1978. Spontaneous Oxidation and Combustion of Sulfide Ores in Underground Mines. Information Circular 8775. Washington, DC: Bureau of Mines.

Pomroy, WH and TL Muldoon. 1983. A new stench gas fire warning system. In Proceedings of the 1983 MAPAO Annual General Meeting and Technical Sessions. North Bay: Mines Accident Prevention Association Ontario.

Ramaswatny, A and PS Katiyar. 1988. Experiences with liquid nitrogen in combating coal fires underground. Journal of Mines Metals and Fuels 36(9):415-424.

Smith, AC and CN Thompson. 1991. Development and application of a method for predicting the spontaneous combustion potential of bituminous coals. Presented at the 24th International Conference of Safety in Mines Research Institutes, Makeevka State Research Institute for Safety in the Coal Industry, Makeevka, Russian Federation.

Timmons, ED, RP Vinson, and FN Kissel. 1979. Forecasting Methane Hazards in Metal and Nonmetal Mines. Report of Investigations 8392. Washington, DC: Bureau of Mines.

United Nations (UN) Department of Technical Cooperation for Development and the German Foundation for International Development. 1992. Mining and the Environment: The Berlin Guidelines. London: Mining Journal Books.

United Nations Environment Programme (UNEP). 1991. Environmental Aspects of Selected Non-ferrous Metals (Cu, Ni, Pb, Zn, Au) in Ore Mining. Paris: UNEP.