Huge mining equipment
Today mining is undertaken on a massive scale and the operations involve the use of huge mining equipment. This is a far cry from the days of hand-held drills and wheelbarrows. Some of the heavy machines commonly used in mining are described below:
Ground preparation prior to mining involves the use of earth moving equipment like bulldozers, loaders and diggers to clear the overlying ground cover. Massive drills are used in underground mining to construct the shafts to reach the ores. Cranes assist in lifting and demolition work. Haul trucks and sump trucks are used to transfer ores and waste materials to their next destination for processing or disposal. Excavators are used to remove earth in order to extract minerals below the surface. There are several types of excavators suitable for mining including dragline excavators, hydraulic excavators and bucket wheel excavators. Replacing the shovels used initially, they have dramatically speeded up operations as some of the very large excavators can lift several hundred tons in a single scoop.
Conveyers are used in both surface and underground mining. They help in directing the flow of materials from the mining site onwards for further processing. There are many varieties of conveyer belt systems available depending on the type of mining, the machines being used to mine and the loads produced. Some of them include face conveyers and entry conveyers. Used along with feeder breakers, they can efficiently direct mined materials to their destination.
Some large equipment particular to underground mining include longwall miners and continuous miners. Longwall miners consist of multiple shearers mounted on a series of hydraulic self advancing ceiling supports which are connected to a conveyer belt system. As the longwall miner advances along the rock surface, the shearers cut away the deposits which then fall on the conveyer belts. The ceiling supports also advance and the roof behind the miner is allowed to collapse in a pre-determined manner. The entire process is mechanized. Continuous miners are huge machines which have revolutionized the underground mining industry by dramatically increasing productivity. A continuous miner consists of a large rotating steel drum set with tungsten carbide spikes which cut away at the mine surface to extract the ores or coal. They work in a room and pillar system where a network of chambers is constructed. Today remote controlled miners are increasingly used, especially when mining in difficult and dangerous underground terrain. Robotic versions which have their own navigation systems and internal diagnostic systems are also available.
To transport miners around the site, large vehicles are often required. Trams and trucks are often employed to move miners and their equipment in surface mining. Shuttle cars can be used to transport ores and minerals. Articulated trucks are especially suited for underground mining since they are easier to manoeuvre through the underground chambers.
Once the ores are retrieved, they are sent to huge processing plants where machines like roasters, magnetic separators, crushers etc will be used to refine them.