Summary:
The coal mines of Qarmet JSC (former ArcelorMittal Temirtau) are located in the Karaganda Coal Basin. The basin is more than 3,000 square kilometers and was formed by strata of Upper Devonian and Carbonic ages, Mesozoic and Cainozoic formations. Due to structural peculiarities, the coal basin is divided into three geology-based mining areas. ArcelorMittal Temirtau's coal mining operations are performed in the three distinct mining areas: Karagandinskiy (Kostenko, Kuzembayeva, and Saranskaya mines), Sherubay-Nurinskiy (Abayskaya and Shakhtinskaya mines) and Tentekskiy (Kazakhstanskaya, Lenina, and Tentekskaya mines).
Karaganda basin is located on the area of the same name and in the center of this region. Four synclines are notable in the basin: Tentek, Sherubainur, Karaganda and Verkhnesokursk, first three of them make an industrial part of basin and are studied full enough up to the depths 700- 1300m.
Productive sediments are represented by Ashlyarik, Karaganda, Dolinsk and Tentek series which contain up to 30 coal seams with the total working thickness 40m, coal ash content varies within the limits of 10-35 % with the tendency of reduction upwards the section. The most-widely spread are coals of types from hvBb to mvb. Karaganda basin is considered as a high gas content and gas content seams intensively grow from the beginning of methane zone up to 400-500m reaching 15-20 m3/t, and are more stabilized on the depth within the limits of 22-27 m3/t. Gas weathering zone depth varies within the limits of 60-250 m.
Abaiskaya Coal Mine
The geological structure of the Abaiskaya mine (formerly the Kalinina mine) is represented by sedimentations of carbonic, paleogene, neogene, and quarternary age. The carbonic section is represented by a full section of Karaganda suite divided into three sub-suites: lower (seams K1-K6), middle (seams K7-K14), and upper (seams K15-K20). Lithological content of the strata is represented by interbedding of sandstones, siltstones, argillites, carbonaceous argillites, and coal seams. Thickness of the suite sedimentations is 750m. The field of the Abaiskaya mine is located in the Southern part of the northeastern flank of Sherubai-Nurinskaya synclinal as a big tectonic block limited by a series of overlap faultings. Slope of the seam mainly varies 10 to 25° to the northwest. The area is complicated with folds and disjunctive imperfections. Results of exploratory works have indicated 91 disjunctive faults and 82 low-swing imperfections with amplitude distortion of 3-5m spreading from 50 to 300m. Zones of the imperfections have intensive cleavage of the strata with trace of drifts along sliding surfaces.
Kazakhstanskaya Coal Mine
The Kazakhstanskaya mine has rights to develop the following coal seams: T3, T1, T11, D10, D9, D6, D5, D4, D3, and D1. Seams D6 and D11 are currently being developed, and D10 is being prepared for development. Seam D6 is the thickest and most stable seam of the Dolinskaya suite. Its effective thickness varies from 2.92 to 7.04 m, with an average thickness of 5.44m. The seam has a complex structure where up to 8-10 interlayers of strata of different thicknesses (usually not exceeding 0.2m) are being noted. The most stable is the waste strata interlayer of 0.05-0.20m, appearing in the upper part of the seam. The other strata interlayers are lens-shaped.
Seam D11 is relatively stable and of moderately complex structure. Its effective thickness varies from 0.7 to 1.69m, with an average thickness of 1.13m. Thin strata interlayers of 0.05 0.20m are noted in the upper part of the seam. The seam has a complex, easy-breaking roof, with a thickness of 0.5-0.7m.
Seam D10 is relatively stable and has a complex structure and thickness of 1.14m. The formation interlayer of 0.05-0.30m splits the seam into two banks, with the upper bank being 1.5-2 times larger than the lower one. In terms of continuity of thickness and structure, the coal seams are specified as follows:
• Continuous – D6
• Relatively continuous – T3, T1, D11, D10, D1
• Irregular seams – D9, D5, D4, D3.
Lenina Coal Mine
The field of Lenina mine is represented by an asymmetrical synclinal fold that is complicated by plicative and disjunctive imperfections and faults. The geological structure of coal-bearing strata is represented by argillites, siltstones and sandstones of carbonic age. The productive layer is presented by seams of Dolinskaya suite: D1, D3, D5, D6, D9, D10. All of the seams are considered dangerous with outbursts. The main coal grade is KZh with rare1K Coke and 2K Coke.
Tentekskaya Coal Mine
Technical borders of the Tentekskaya mine include the following 10 working coal seams: T3, T1, D11, D10, D9, D7, D6, D5, D4, D1.
Geological structure of the mine field is represented by sedimentations of over-karaganda, dolinskaya, and tentekskaya suites of carbonic age, overlaid by neogene, paleogene, and quaternary sedimentations of overall thickness from 7 to 86 m.
Over-karaganda suite is represented by argillites, siltstones, fine-grained sandstones, and lenses of coal interlayers.
Dolinskaya suite of overall thickness 520-550m is composed of argillites, siltstones, sandstones and coal seams D1-D11.
Coal seams and coal-bearing strata extend to the west with a 10°-20° angle. Slope angles in the central part of monoclinal increase up to 30°, and at the Northern part, up to 40°-50°.
The field of the mine is complicated by a significant number of disjunctive faults and plicative folding and limited by the big Churubai-Nurinskiy fault.
The Tentekskaya mine is considered dangerous with spontaneous coal and gas outbursts. Coal seams T1 and D6 (south, center) are dangerous at a depth of 350 m and seam D6 (north) – at a depth of 230 m.
The mine is noted for danger from dust.
Coals of the seam D6 are noted for spontaneous combustions.
The seam D6 is a subject to fire risk.