Wirtgen surface miners maximize coal output

India’s Bhubaneswari opencast mine using seven 220 SM 3.8 surface miners to mine coal

INDIA’s extensive coal reserves are the country’s most important source of energy, covering about half of its primary needs. One of the country’s largest coal mines is the Bhubaneswari open-pit operation, near the town of Talcher, in the eastern Indian state of Odisha.

Here, Indian company Bhubaneswari Coal Mines Ltd (BCML) have been operating the mine since 2011, with mining taking place 24 hours a day to supply nearby coal-fired power plants and resulting in the extraction of more than 25 million tonnes of coal each year.

To mine the coal, which has a uniaxial compressive strength of up to 35MPa, BCML have refrained from the use of drilling and blasting and instead rely on seven Wirtgen 220 SM 3.3 surface miners to cut the soft rock.

Bairagi Sahu, associated vice-president of BCML, is highly satisfied with the machines: ‘When it comes to performance, the Wirtgen surface miners are simply the best on the market,’ he said. ‘We sometimes cut up to 1,800 tonnes of coal per hour with one surface miner.’

With an operating weight of 58 tonnes, the Wirtgen 220 SM 3.8 is powered by a fuel-efficient, 708kW Cummins diesel engine. The machine’s 2,300-litre capacity diesel tank makes it possible to operate around the clock with only one refuelling stop per day.

The 220 SM 3.8 is designed for the mining of all types of soft rock. This is particularly evident in the design of the 3.80m wide cutting drum with its narrow holder bases that ensure the material flows smoothly while requiring minimal energy.

Moreover, the shape of the holders in combination with the arrangement of the cutting tools minimizes the amount of fines in the material, which is continuously deposited in a windrow directly behind the machine.

‘With this mining method we can clearly see the quality of the coal due to the difference in colour between the coal and the lighter-coloured overburden, allowing us to mine the material cost-effectively,’ said Om Prakash, chief operating officer of BCML.

With reliability and availability being crucial in open-pit mining, all of the 220 SM 3.8 surface miner’s components are designed for demanding opencast applications. For example, additional filters in all of the machine’s hydraulic circuits as well as a pressurized hydraulic reservoir ensure maximum purity in the hydraulic system for smooth operations and extended service life of downstream components.

The 220 SM 3.8 also stands out in terms of occupational safety. The standard ROPS-FOPS operator’s cabin features additional soundproofing and vibration isolation, allowing the operator to work with maximum focus for many hours without risk of fatigue.

The ergonomically designed and clearly arranged controls are integrated into the armrests of the driver’s seat and all of the machine’s key functions are logically incorporated into the multifunctional joysticks, allowing the operator to operate the machine intuitively whilst fully concentrating on high-precision mining.

For optimum visibility, the spacious, fully air-conditioned cabin features generously sized windows and is positioned so that the operator always has a clear view of the cutting edge. Moreover, an optional camera system gives the operator an excellent overview of the work area, even behind the machine.

The 220 SM 3.8 is also designed to be easy to service and maintain. All of the maintenance and service points are easily accessible from the ground or inside, whilst the walk-in engine compartment makes it possible to quickly and easily inspect the engine. The machine’s air, fuel, and hydraulic oil filters are also directly accessible.

‘The Wirtgen surface miner has fully met our expectations and proven itself across the board at our Bhubaneswari coal mine,’ said chief operating officer Om Prakash.