The following is a description of coal’s life cycle:
- Exploration
Coal exploration includes gathering data that permits judgments to be made on whether additional exploration is desirable, the technical feasibility of mining, and the economic feasibility – including the size of the mine and the quality of the coal.
- Mine construction
Surface mining or underground mining can be used to harvest coal from the earth. In open-pit coal mining, a pit is created in an area, which forms the open-pit mine, also known as a quarry. Open-pit mines can grow to enormous sizes until the coal deposit is depleted or the cost of transportation becomes too expensive.
- Mining in open pits
Surface mining accounts for 53% of South Africa’s coal production, using open-cast or open-pit mines. This is due to the fact that the coal is only 60 meters below the surface.
Bord-and-pillar mining, stopping, and longwall mining account for 47% of South Africa’s coal production. These underground extraction methods reach coal up to 300 meters underground. Miners use lifts to travel down mine shafts to reach the mine’s depths, or they enter through decline shafts or adits for shallower mines. They operate heavy machinery that collects and transports coal above ground.
- Ventilation
Underground ventilation delivers oxygen to miners while also diluting, rendering harmless, and transporting harmful accumulations of gasses and dust. For every tonne of coal produced, more than six tonnes of air are cycled through the mine in some of the gassiest mines. Air circulation is accomplished by using fans to create a pressure difference between the mine workings and the surface. Fresh air is also provided near the production faces, which may change place numerous times during a shift.
- Control and monitoring
Sensor technology advancements, as well as advances in computer hardware and software capabilities, are finding increased application in underground coal mines, particularly in the monitoring and management of ventilation, haulage, and machine condition. Machines can be controlled remotely, and continuous miners have automatic controls as well. The atmospheric environment is monitored remotely for air velocity, gas concentrations, and airborne dust; fans and pumps are also continually monitored for operating status and characteristics.
- Haulage
Coal haulage, or the transportation of mined coal from working faces to the surface, is a significant aspect in underground mining efficiency. It is divided into three stages: face haulage, which transports coal from working faces; intermediate haulage, which transports coal to the main haulage system; and main haulage, which transports coal from the mine. Haulage methods vary depending on the situation and stage, and may include electric-powered, rubber-tyred trucks, chain haulage, armoured face conveyors, and mine cars propelled by electric- or diesel-powered locomotives.
- Preparation of coal
Impurities are present in coal that is mined directly. Buyers may request specific requirements based on the intended use of the coal, which may include utility combustion, carbonization, liquefaction, or gasification.
- Transporting
After preparation, higher grades of coal are sent to export markets, while lower grades are purchased by Eskom and burned in specially built power plant boiler hearths.
- Rehabilitation
Backfilling, regrading the final surface, and revegetating and rehabilitating the land for future use are all part of the reclamation process. These activities are undertaken concurrently with the mining operation in order to prevent erosion and sediment discharge, slope instability, and water-quality issues.
In South Africa, how is coal produced?
South Africa’s two primary mining technologies are surface (opencast) mining and deep underground mining. Approximately 51% of South African coal mining is done underground, while the remaining 49% is done using open-cast techniques.
What is the procedure for processing coal?
Some coal is pulverized and mixed with water before being delivered via pipelines. Crushing, screening, and beneficiation are all steps in the coal processing process. Coal processing is the process of converting run-of-mine (ROM) coal into a product that fits the needs of the consumer. Mined coal may have lumps.
What is the purpose of coal in South Africa?
The remaining coal production in South Africa is utilized to fuel various local sectors: 53% is used for electricity generation, 33% for petrochemical industries (Sasol), 12% for metallurgical industries (Arcelor-Mittal), and 2% for residential heating and cooking.
How much coal does South Africa still have?
South Africa has proven reserves of 173.3 times its yearly consumption. This means it has around 173 years of coal remaining (at current consumption levels and excluding unproven reserves).
