The surface miner is a mobile milling machine with a mechanically driven cutting drum. The drum is located between two sets of individual height adjustable crawler tracks, and a two-stage conveyor system is used to directly load trucks. Surface miners cut, crush and load the material in one single pass. The primary conveyor picks up the material in the drum housing and transports it towards the rear of the machine, where it is then accepted by the sewable and height-adjustable discharge conveyor. The discharge conveyor loads the material into trucks or dumpers or discharges it to the side of the miner. The discharge height can be adjusted to the height of the transport vehicles. Surface miner eliminates drilling blasting and primary crushing units and thus reduces their associated environmental hazards. Apart from this, the sized excavated material increases the transport/conveying efficiency and thus saves the energy requirement in transportation.
Surface Miners are used for the extraction of a wide range of primary resources by cutting in open cast mines. Thanks to selective extraction, they achieve high degrees of material quality and enable optimal exploitation of mineral deposits. In contrast to drilling and blasting, the use of surface miners makes mining vibration-free and significantly reduces noise and dust emissions. As a result, the material can be mined close to industrial sites and other infrastructure facilities such as pipelines, railroad tracks, or high-voltage lines that cannot be exposed to vibrations. This improves the exploitation of the deposit and with it, the overburden-to-coal ratio, allowing the operator to generate additional revenues. Various types of surface miners are available, with or without a loading conveyor belt, which can be mounted at the front or back of the machine. Different types of models are used across different parts of the country for various project requirements.
Different types of surface miner used in India
Surface miner for soft rock
The latest model of surface miner selectively mines raw materials with a wide cutting drum designed specifically for soft-rock mining. The cutting drum is designed specifically for demanding windrow applications in soft rock, such as coal or salt. Maximum cutting performance combined with the ideal use of engine power and low specific fuel consumption allows raw materials to be mined in an extremely cost-effective process. Six different adjustable cutting drum speeds ensure that the machine can be perfectly adapted to the material being extracted.The high-pressure injection and intelligent engine management, the engine is extremely fuel-efficient. A cooling system with a demand-driven fan speed also helps to reduce fuel consumption and at the same time reduces noise emissions. As such, high, narrow holder bases on the drum ensure that the material flows smoothly while requiring minimal energy. In addition, the shape of the holders in combination with the arrangement of the cutting tools minimizes the number of fines in the material, which is continuously deposited in a window directly behind the machine.
Surface miner for rough terrain
Surface Miner models are designed to address the toughest terrain. An emergency drive system is activated in case of main drive failure during operation, providing temporary power. Water sprinkling system suppresses dust generated during cutting of material by sprinkling water on all four sides – front, sides and rear. Critical drive units for oil lubrication are provided with an external oil cooler and oil filter to maintain an operating temperature within safe limits. Automated safety features ensure retraction of cutting drum to avoid tramp while mining. Closed loop hydrostatic drive with variable displacement axial piston pumps and variable displacement axial piston motors ensure smooth travel of the miner. There are 3 speed modes depending on operation along with speed control through joy stick, eases operation. Closed-loop hydrostatic drive with variable displacement axial piston pumps and variable displacement axial piston motors ensures smooth travel of the miner. Extra rugged machine frameworks provide stability amidst extreme cutting forces. Water sprinkling system suppresses dust generated during cutting of material by sprinkling water on all four sides – front, sides and rear.
Surface miner for depth crushing
Latest surface miners are used for depth crushing. Built-in features ensure high-quality product sizing and mixing, and level benches ensure minimal wastage and safe operation. The built sturdy box frame integrated with side plates and lifting jack cylinder to withstand extreme shock loads. Four-track steering is provided for efficient steering and control. Height adjustment is electro-hydraulic for achieving fine settings. Undercarriage & Tracks The under-carriage & track assemblies provided are the heavy-duty type with a wider footprint to provide extra tractive effort needed to ensure effortless movement while cutting to the set depth and provide optimized ground pressure for working in soft ground conditions. This ensures greater depth of cut and the rated production and required productivity from the overall system. Cutting/milling drum Very robust drum-type roll design, wear-resistant set with up-milling configuration to achieve a uniform depth of cut The engine chamber is sound-proofed to keep noise level under allowable limits. Air intake through turbo-separator/air-pre cleaner arrangement to ensure long engine life is provided.
Conclusion
Surface Miners are increasingly finding their way into applications where drilling and blasting are prohibited or costly. They are found to be highly productive and economical in selective mining of coal, limestone and other minerals. Using surface miners allows operators to cut material along contact zones with an accuracy of just a few centimeters. It creates many opportunities to reduce ore loss and minimise dilution improving ore quality and more effective recovery of the mineral resource. In some cases, these factors will help determine the feasibility of a mining operation.
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