The first Wirtgen 2200 SM 3.8 surface miner is being used in the Chinese province of Xinjiang, replacing the conventional mining equipment used locally. Wirtgen experts are providing support for the project.
Situated in the north-west of China near the borders with Russia, Kazakhstan and Mongolia, the Yihua Xinjiang Wucaiwan coal mine is being mined by contractor Xinjiang Jianyun Engineering Co. Ltd. for the past one-and-a-half years, making use of the eco-friendly surface mining technology from Wirtgen. The mine operator was previously using conventional methods such as drilling and blasting to mine coal, which often resulted in fires as the coal was highly flammable at the open coal faces damaged by blasting.
With a view to increasing safety at the mine, the mine operator decided to replace the conventional techniques with advanced surface mining technology from Wirtgen, simultaneously boosting safety, cost-effectiveness and quality of mining.
According to Chen Jianyun, the owner of Xinjiang Jianyun Engineering Co. Ltd., the Wirtgen specialists provided them with in-depth advice and assistance right from the start to develop the most appropriate solution for their mine site.
Manoeuvrability of the machine was a key factor in mining this particular area as it measured 2 x 300 x 35 m. The mine operator also wanted to increase production from 3,000 t to 7,000 t per day to meet the enormous demand from their main customers, who operated a cogeneration plant and a fertiliser plant under construction. Since the grade of coal was extremely fragile and fine-grained, it produced a great deal of dust, which also had to be taken into consideration in addition to various requirements on the gradation of the cut material and the coal seam with a thickness range of 1.3m to 10.63m.
Bernhard Schimm, Manager of the Mining Division of Wirtgen GmbH explained that Wirtgen recommended the new 2200 SM 3.8 surface miner to their customer after taking stock of the underlying conditions. Based on the same machine concept as the 2200 SM/3800, the new surface miner’s production capacity is approximately 25% higher and the specific fuel consumption approximately 15% lower. The advanced machine selectively mines soft rock, maximising both performance and cost efficiency.
Chen Jianyun said they decided on the 2200 SM 3.8 after analysing the results of tests with the prototype of the new 3.8 generation in an Indian coal mine.
The centrepiece of the compact, yet powerful 2200 SM 3.8 surface miner is the 3.8m-wide cutting drum that cuts coal or salt with unconfined compressive strengths of up to 35 MPa and deposits the material in three windrows behind the machine resulting in maximum cutting performance with optimum utilisation of engine capacity. Key benefits also include low fuel consumption, optimised use of cutting tools and minimised content of fines due to the gentle material transport system. The modified drum speed combined with a reduced cutting depth and travel speed enables the grain size distribution to be additionally optimised on site and the fines content reduced by a further 10%.
The cutting drum is reliably sealed by two side plates that can be raised and lowered hydraulically, reducing the formation of dust during milling considerably. The miner is also equipped with an additional dust protection plate for this application.
To operate efficiently in the confined space of the mine, the 2200 SM 3.8 surface miner features a smooth hydraulically adjustable all-track steering with a large steering angle resulting in a turning radius of just 2.5m.
Key features also include a crab steering mode allowing rapid manoeuvring; large ground clearance with individually height-adjustable crawler tracks allowing operation on uneven terrain and reversing; selectable hydraulic differential lock ensuring optimum traction on any surface; and enormous grade-ability and longitudinal slope of the surface miner allowing operation in difficult peripheral areas.
Surface miners are usually in operation round the clock, and it’s no different at the Zhundong coal field where the 2200 SM 3.8 works 24 hours a day for 330 days in a year. Consequently, a reliable supply with original parts and deployment of excellently trained Wirtgen service engineers are extremely important to ensure uptime. Chen Jianyun notes that every minute the surface miner is not working costs money and minimises profit. However, the knowledge that they could always rely on support from Wirtgen was a key factor in their choice of partner.