The road ahead
Jastrzębie-Zdrój, Poland. There are no dragons here. No dwarfs or ogres either, but from the dark depths of the Borynia-Zofiówka-Jastrzębie coal mine in Poland, 21,700 tonnes of coking coal are expertly and efficiently extracted every day.
The Borynia-Zofiówka-Jastrzębie coking coal mine sits in Jastrzębie-Zdrój, the heart of coking coal mining in Poland, about 60 kilometres southwest of Katowice. Huge deposits were found in the area’s picturesque green hills during the 1960s, and over the course of 12 years five mines were set up. Coking coal is used predominantly to make coke, an essential component for producing steel from iron ore.
As its name implies, Borynia-Zofiówka-Jastrzębie is actually three coking coal mines (Borynia, Zofiówka and Jas-Mos) that were combined into one in January 2013. The mine is operated by state-owned Jastrzębska Spółka Węglowa S.A. (JSW SA) and was strategically integrated to make better use of the coking coal deposit and production assets, incorporate the best design solutions, implement the best organizational practices into everyday work and optimize employment resources. Borynia-Zofiówka-Jastrzębie currently employs 10,560 people and has an average daily net extraction of around 21,700 tonnes of coking coal.
About JSW SA
Established in April 1993, JSW SA comprises five mines that extract coking coal and steam coal: Borynia-Zofiówka-Jastrzębie, Budryk, Krupiński, Pniówek and Knurów-Szczygłowice. The company processes about 50 percent of the coking coal it produces, enabling JSW SA to offer a more processed, higher-value final product. In 2013, JSW SA’s mines produced 9.8 million tonnes of coking coal (including 7.8 million tonnes of hard coking coal) and 3.8 million tonnes of steam coal. In the same year, JSW SA’s coking plants produced 3.9 million tonnes of coke.
The sprawling Borynia-Zofiówka-Jastrzębie site, covering 66 square kilometres, is home to a processing facility, administrative offices, storage and such shipping infrastructure as mining elevators, rails, trains and trucks. The mine itself is a vast interconnected network of tunnels and caverns, some of which are 1,200 metres deep.
One deep dive
It takes about 25 minutes to get from the surface to the belly of the mine. First the miners equip themselves with a variety of safety equipment, from lights, helmets, masks, goggles and boots to the life-saving breathing apparatuses that are vital in the event of a methane leak or underground fire. Then they take a two-minute ride on a high-speed elevator 600 metres down into the earth. After that a small, four-car train that runs throughout the mine’s labyrinth of tracks and corridors transports them further downward for about 10 minutes until they reach paths that are accessible only on foot.
It’s at this point that the heat, which has been steadily rising during the descent, reaches temperatures around 30 degrees Celsius. It is also very dark. At some points, the only light available to the descending miners emanates from the lamps on their helmets, which gives their approach an otherworldly feel, as if they were exploring an unknown planet or the bottom of the sea. This feeling is compounded by the utter silence (all sound is insulated and dampened by the rock face) and the puffs of dust each footstep produces. This beige powder is the product of rock dust brought in to trap the flammable coal dust. Still, the miners are in good spirits. Despite working in dark, confined spaces, their sweaty, swarthy faces smile readily, and they address one another with a tip of the hard hat or a handshake and a hearty “Szczęść Boże” (“God bless”).
After a 15-minute walk downward, the sounds of the drills and conveyor belts that carry the coke coal rise, their din indicating the location of the day’s activities that involve developmental work on the rock wall.
“I lead a group of about 350 people,” says Zbigniew Czarnecki, developmental mining manager at Borynia-Zofiówka-Jastrzębie. “I plan and manage the preparatory work at the mine, which involves cutting through the sandstone to expose the coal. We excavate a lot of coke coal here, which is later cleaned and treated at our processing plant.”
Sandvik MR340 roadheader
Sandvik MR340: max. cutting height 4.87 m
- Total weight 52 t
- Total length 10,300 mm
- Height over canopy 1,850 mm
- Width over loading table 2,800 mm
- Ground pressure 0.13 MPa
- Electrical system 1000 V/50 Hz
- Cutter motor 200 kW
- Hydraulic power pack motor 63 kW
- Loader motors 2 x 36 kW
Power supply demand
- Via transformer 630 kVA
- Via generator set 800 kVA
- Loader star drive via conveyor motors
- Chain speed 1.1 m/s
- Capacity of conveyor max. 400 m3/h
- Height 4,870 mm
- Width 7,400 mm
- Undercut 350 mm
- Negotiable gradients +/- 20 gon
- Speed of cutter head 2.3 m/s
- Tramming speed 0 – 8.8 m/min
Sandvik TriSpec tools
Sandvik TriSpec tools are equipped with a carbide ring placed slightly below the tip to prevent body wear and maximize carbide tip use. Each tool is available with either an insert or cap carbide tip. Sandvik TriSpec tools are the top of the line in high body-wash conditions.
Tough tools for hard work
Czarnecki’s team employs Sandvik MR340 and Sandvik AM75 roadheaders to build galleries along the coal bed for future extraction. It is hard work; each shift of miners cuts around 80 centimetres in a cycle before steel-arch supports need to be erected to protect against a cave-in. Where the rock is too hard for the roadheader, the team uses a drill and explosives, which limit the amount of hard manual labour required.
“We have a face with a lot of hard rock to work through,” says Pawel Stepowy, a muscular roadheader operator with a decade of underground mining experience. “The rock is both up and down in the excavation’s cross section. A big advantage with this roadheader, other than its toughness, is the visualization it offers. It really helps with excavating the rock when dust limits visibility. And then there are the resilient cutting tools it uses to strip away the sandstone.”
One of the most important considerations at Borynia-Zofiówka-Jastrzębie is productivity. The robustness of the rock tools used at the mine is directly correlated to downtime, lost production and higher labour costs. Sandvik TriSpec tools are equipped with double carbide rings that substantially improve wear resistance, an essential feature in the harsh environment of a coal mine.
“Before Sandvik won the contract, each potential supplier was asked to participate in a number of obligatory tests even before actual negotiations commenced,” says Przemysław Brychy, Sandvik regional sales director. “Our products performed extremely well in these tests, outperforming competing products by 150 percent.”
Janusz Piechoczek, another roadheader operator with eight years on the roadway development team, knows how important it is to have robust cutting tools. “We use around five Sandvik TriSpec tools for every 20 metres of excavation,” Piechoczek says. “The quality of the tools is excellent, and these ones don’t get worn out quickly, so they have to be changed less frequently. It makes the whole project go much faster.”
Czarnecki was also impressed with the performance of the tools . “The tools the mine used earlier wore out very quickly,” he says. “With the new Sandvik TriSpec tools , the efficiency of the process was raised by some 50 to 80 percent, and the process of excavating the rock became more productive. The interruptions for the change of tools are shorter and fewer. The cutter drums are also protected, and this is comforting for the operator, who does not have to worry about what is going on at the front of the face and can concentrate on the excavation process.
The cooperation between Sandvik and Borynia-Zofiówka-Jastrzębie extends well beyond the supply of robust tools, and looks to continue for some time in the future.
“My experience with Sandvik has been very positive,” Czarnecki says. “Each and every time I have a remark about anything, there is always a quick reaction from their side. We definitely see a continued partnership going forward.”
Once the difficult work of clearing the rock away is complete, the excavation of the coking coal can commence. When the mine is running at full capacity, express elevators ship around 15 tonnes of coking coal up to the surface every 30 seconds. After that, the coking coal is processed and prepared for shipping to the coke plant, all run by JSW. It is an efficient process, one dependent on the developmental phase, which is made even more productive when the tools are right and strong enough to tackle hard rock deep down inside the mine.
The Sandvik solution
Along with Sandvik AM75 and Sandvik MR340 roadheaders, the Borynia-Zofiówka-Jastrzębie mine also operates a loader from Sandvik. But it’s the Sandvik TriSpec cutting tools that keep this mine humming at an efficient pace. These tools have improved operations by increasing production, offering better cost-per-tonne efficiency, improved process cost savings and enhanced energy efficiency.