A Zambian coal miner has become the first recipient of the Wirtgen 220 SM 3.8 surface miner. Supplied by Wirtgen Group Southern Africa, the 220 SM 3.8 surface miner is a completely new unit designed from the ground up, replacing the predecessor model, the 2200 SM. With a 3,8 m drum, the machine has been optimised for the mining of soft rock to ensure maximum productivity at minimum operating costs.
It is designed to utilise the Windrowing method which enables mined material to be deposited behind the machine in a continuous process, thus allowing the ore to be extracted in a single, environmentally sustainable way with no need for drilling and blasting, yielding material of high quality.
A huge benefit of the new unit, explains Waylon Kukard, sales manager at Wirtgen Group Southern Africa, is its intelligent maintenance concept. “Readily accessible points for maintenance and servicing, walk-in engine compartment, plain text displays on the control screen enabling quick, effective troubleshooting, easy cleaning of the cooling system and a removable hydraulic tank for cleaning purposes, all contribute to maximising utilisation of the machine, thus ensuring maximum productivity.”
Machine in detail
With an operating weight of 58 t, the Wirtgen 220SM3.8 surface miner is driven by a Cummins diesel engine with an output of 708 kW. Thanks to high-pressure injection and intelligent engine management, the engine is said to be highly fuel-efficient.
At the same time, the diesel tank with a capacity of 2 300 litres makes it possible to operate the machine around the clock with only one stop to refuel per day, resulting in greater productivity. A cooling system with a demand-driven fan speed also helps to reduce fuel consumption and at the same time reduces noise emissions.
The 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 minimises the amount of fines in the material, which is continuously deposited in a windrow directly behind the machine.
Uptake and technology benefits
Commenting on the uptake of the Wirtgen surface miner technology in southern Africa, Kukard says despite the initial slow uptake, interest is picking up dramatically as more and more contractors, mining houses and mine owners are starting to understand the benefits of the technology. A total of five units are to date operating in the local market. Wirtgen Group Southern Africa also has a trial/demo unit available for trials.
Outlining some of the benefits of surface miner technology compared with conventional mining methods, Kukard says surface miners extract primary resources in a selective operation, achieving high degrees of purity and maximising exploitation of the deposits.
“Selective mining considerably reduces equipment and time requirements as well as overburden volumes. The mining material is cut, crushed and if required, loaded straight into trucks or dumpers in a single operation, thus eliminating conventional primary crushing in an additional work step,” he says.
The surface mining process is much more economical than standard drilling and blasting methods which call for subsequent material loading and primary crushing, adds Kukard. Strict environmental standards in terms of noise and dust emissions make the vibration-free surface mining process attractive in comparison to drilling and blasting.
“The stable, precise and level surfaces produced in mining, earthworks and rock operations are suitable for immediate use as pavements, slopes or tunnel floors. In a nutshell, Wirtgen surface miner technology reduces four operating steps into one. It also reduces exhaust, noise and vibration emissions, while achieving high degrees of purity,” he says.
Due to the reduction in exhaust, noise and vibration emissions, the Wirtgen surface miner allows for better exploitation of current ore bodies due to the fact that the machine can work on current infrastructure such as roads, settlements and close to or under power lines, thus allowing the mine to extract ore bodies which they would normally not be able to exploit with conventional mining methods.
“Wirtgen surface miners can be utilised in a windrowing, side casting, stockpiling or direct loading application, thus making it way more flexible than any other surface mining technologies available in the market,” concludes Kukard.