Coal Bay deposit

The field is located in the intermountain depression, open from the sea. The surface of the depression is a hilly plain, densely dissected by a network of shallow streams and ravines, in the eastern part of which coal seams come to the surface along the valleys of the Ugolnaya, Kanaevka rivers and their tributaries. From the exits, the coal seams are hollow within the site to a depth of 270 m. The thickness of loose loose sediments is 0.1-15 m. The alluvial deposits are composed of pebbles, eluvium and deluvium - loams mixed with detrital rock material. The host rocks (medium and strong) are mainly represented by sandstones (up to 90%), less often siltstones and mudstones (10-18%). Fine-grained sandstones from weak to strong, relatively stable, and medium abrasiveness lie mainly in the roof of coal seams. The soils of the strata are composed of siltstones, weakly stable, with horizontal stratification, with a thickness of 0.2-10 m. Intra-layer interlayers are composed of siltstones, mudstones and fine-grained sandstones. Coal seams make up 7-10% of the section. Their total power varies from 0.5 to 3.5 m.

The total thickness of coal deposits is 470 m, where there are 13 coal seams, 5 of which are working capacity. 3 adjacent layers of the middle horizon (Quarry, Double and Powerful) are being developed with a prevailing thickness of 1-2 m.

Coals belong to soft rocks. Fracturing of 3-5 tr / m is developed for 3 systems. All rocks of the coal-bearing stratum and coals contain moisture (up to 5.5-10%). According to the degree of pore development, the rocks are finely porous, the bulk weight of wet rocks is 2.1-2.53 g / cm³. In terms of density, the rocks are classified as medium (2.65-2.69 g / cm³), and coal - to light (1.32-1.47 g / cm³).

Coals of the deposit are mostly shiny (31-82%), semi-shiny (13-55%), semi-matte and matte (0-14%); belong to the class of humolites, brand “G”, group “1G”, subgroup “1GV”. The calorific value is high. Low and medium ash coals (8-16%), the yield of volatiles varies from 32 to 57%. The average sulfur content in the reservoir is 1.10-1.93%. Coals are unsalted or slightly salted, medium-ash, medium-sulfur, moderately slagous with high polluting ability. Ashes: silica (from 33.9 to 48.8%), alumina (not more than 30%), alkali metals (1-7.2%), titanium dioxide (0.3-5%). The density of coal is 1.22-1.49 g / cm³, the average value is 1.36 g / cm³. The grindability ratio is 0.79-1.12.

Coals according to spontaneous combustion are non-hazardous (Powerful, Double, Quarry strata), low-hazardous coals (Double, Quarry strata) and hazardous (Quarry stratum); by their tendency to oxidation are classified as unstable with increased activity to oxidation.

Coal mining is carried out by the mine method (up to 70 m deep) in the permafrost zone, the average thickness of which is 90 m. Modern developments are also carried out in flooded taliks. The mining conditions are silico-hazardous , coal dust is anthracose-hazardous and explosive. Gas content in the permafrost does not exceed 1.5 m³ / t, in the talik permafrost - up to 10.7 m³ / t.

Since the beginning of commercial operation, the field has produced more than 16 million tons of coal ^[3] .

Explored reserves in 1980 were estimated at 58 million tons, preliminary estimates - 471 million tons ^[4] .

According to modern data, within the boundaries of the Nagornaya mine, the balance reserves are 45 million tons ^[3] .

In 1886, the clipper “Cruiser” entered the bay under the leadership of Captain A. A. Ostolopov, the landed expedition discovered the release of coal seams to the surface. Having examined the samples, the expedition noted the good quality of the mineral ^[5] . In 1912, the geologist Polevoy P.I. determined the age of the deposit by analogy with the geology of the Anadyr brown coal deposit . The first attempts to organize detailed exploration at the seams were undertaken in 1921-1922. The Russian-Japanese mining corporation, however, the work was not further developed.

By the beginning of the 1930s. With the development of the Northern Sea Route , new fuel supply points for ships were required. In 1934, a small expedition of the Arctic Research Institute led by MP Kudryavtsev was sent to Ugolnaya Bay, which carried out geological survey work ^[6] . Six coal seams with a thickness of 0.5-6 m were identified, reserves for the Karyernoye seam were estimated at 2663.4 thousand tons. In May 1940, the first coal was obtained. On March 15, 1941, the Bukhtugol mine department was formed, and in the same year, construction of a mine for industrial production began. In 1945, the construction of the Kapitalnaya No. 1 mine with a production capacity of 100 thousand tons of coal was started on the Main section, however, due to difficult geological conditions, coal mining was stopped there in 1958, and construction of the mine was started at the field No. 2 “Beringovskaya” with a production capacity of 200 thousand tons.

In subsequent years, production at the field was constantly growing, and by 1990, the largest coal mine in the North-East of the USSR was operating here. Reconstruction was carried out at a capacity of 1 million tons of coal per year, and design work was underway to increase the capacity to 2 million tons. However, the post-Soviet socio-economic crisis put an end to these plans. Extraction fell sharply, by 1999 it was reduced by 10 times ^[7] .

In the 2000s production at the field has stabilized. Plans for a multiple increase in production with the goal of exporting coal to the Asia-Pacific countries reappeared ^[8] . For this, reconstruction of the existing Nagornaya mine was planned along with the development of the nearby Amaam deposit ^[9] .

As of the beginning of 2015, due to the lack of potential consumers of coal, due to its high cost, production at the field is being curtailed ^[10] .

• Mine "Nagornaya"