High performing longwalls in Russia
Two SUEK mines in Russia’s Kuzbass region have produced outstanding performances in August, with more than 1 million tonnes of saleable coal from their longwalls for the month.
Kotinskaya mine produced 1,050,452t from the first panel in a new seam.
This seam is 3.8m thick with moderate inclinations, and has already been over-worked by a seam approximately 40m above.
The wall is 300m in length, and the panel is 2400m long and contains 3.9Mt.
The longwall equipment consists of a set of Joy supports that have been in use for about 12 year years, a Cat PF6 armoured face conveyor and a new Eickhoff SL900 shearer.
This seam is equipped with a new conveyor line with four 1600 mm wide belts. These variable speed drive conveyors were designed and made in Russia by a SUEK company.
This is only the second month of production from Seam 50. In the first full month of production this longwall produced 800,000t.
SUEK’s second longwall to produce more than 1Mt is Taldinskaya Zapadnaya No.1.
This mine produced 1,020,109 t in August using a 300m longwall with DBT supports, a PF6 AFC and a Joy 7SL6 shearer.
This mine operates in a 4.5m thick seam and it is also extracting the first panel in a newly developed seam. This is the third seam to be extracted in this mine.
The runs in this mine are short with reserves of about 3Mt per panel, but the mine has been a consistent high performer, and a technical innovator.
All SUEK longwalls are conventional retreat panels. They are developed using twin entries with one bolter miner in each entry.
Pillars of approximately 30m are left between the entries.
Conditions are relatively difficult in development and extraction. Developments must be bolted after each cut, normally with six roof bolts and two to four bolts per side.
Longwalls must operate with very tight face to tip clearances, and still have to leave a skin of coal on the roof.
Faces are salvaged using Huesker mesh, roof bolts and cable bolts.
During salvage a diesel monorail is installed right through the face, so locomotives can drive a circuit through the salvage face, through the installation face and back, thus enabling multiple locomotives to be used.
All equipment is transported intact, except for the shearer, which normally has the drums and arms removed.
SUEK longwalls use state-of-the-art gas drainage, safety and production systems, blending best international equipment with very advanced Russian designed and made equipment.
Kotinskaya has very wet conditions so SUEK and local manufacturers designed, built and proved a system to dewater the coal on the gate road conveyors to stop wet coal sliding back down the slope conveyors.
Panels are accessed by twin roads and are conventional design except that an angled road has to be driven across the panel at intervals of about 1km Russian legislation, to guarantee an escapeway.
The longwalls cut through these roadways, often with no loss of production. The roads are angled so that only about four supports are within the roadway at any time. Other significant factors are seasonal cold and steep gradients.
The mines are located in Siberia (SUEK stands for Siberian Coal Energy Company) and winter temperatures are down to -40 C, so massive boilers must be used to heat the air before it enters the mines. These operate for five months of the year.
Gradients within the seams are highly variable, and can be up to 26 degrees along the longwall faces.
These gradients mean rubber tyred transport is not used. Instead all materials and equipment must be transported using roof-mounted monorail systems with diesel locomotives.
This has a serious impact on longwall transfers and greatly reduces the ease of transport of men and materials within the mines.
Source: Mining Monthly