In Poland, brown coal deposits occur in young geological formations, mainly the Tertiary. Older brown coal deposits are known to occur also in the Jurassic, Carboniferous and locally even Cretaceous and Triassic in several places in the world. The brown coals are intermediate in qualification between hard coal and peat. Their characteristics and properties were markedly influenced by the type of parent plant material and environment in which they originated.
Brown coal deposits originated both in platform areas and sedimentary basins in orogenic belts. The coals form extensive seams or lenses a few meters to several dozen meters in thickness. Thickness of overburden is usually quite small which makes possible opencast mining of the deposits.
There are brown coal deposits occurying in Poland presented on the map.
Seams of older brown coals are often situated too deep underground for opencast mining and require underground mining. This is also the case of coal seams occurring in glacitectonic folds. The methods of underground mining were lately used in Poland to mine coals in the Babina and Sieniawa deposits.
Brown coal resources are calculated to the maximum depth of deposit base of 350 m, the minimum brown coal layer thickness in bed of 3 m and maximum overburden/deposit thickness ratio of 12 : 1. The minimum weighted-average calorific value in bed (with intercalations) should equal 6.5 MJ/kg (at brown coal humidity of 50 %) and maximum medium sulphur content equal 2 % (for brown coal bed with intercalations and at humidity of 50 %). These are the basic balance criterias for energy coals which are common in Polish deposits.
At the end of 2012 Poland’s anticipated economic resources of brown coals amounted to 22,583.83 million tonnes. The resources comprise 0,8 million tonnes of bituminous coal, about 2,390 million tonnes of coals usable for production of briquettes and about 1,418 million tonnes of coals suitable for production of coal tar and liquid through distillation. Nevertheless, all these coals are used and treated as energy coals only. The Bełchatów brown coal deposit from the Piotrków Trybunalski area is the largest and most important and accounts for more than 62 % of domestic production of this raw material. The remaining demand for brown coal is covered by production from the Turów open cast mine in vicinities of Bogatynia and the Pątnów and Adamów mines in the Konin area. Works preceding start of exploitation are being continued at the Szczerców brown coal field of the Bełchatów deposit.
Table 1 shows resources and the current state of exploration and development of brown coal deposits in Poland.
Anticipated economic resources were equal 22,583.83 million tones as of 31.12.2012 and decreased by 79,23 million tonnes in comparison with the previous year due to the production and losses in several deposits – Bełchatów-pole Bełchatów, Pątnów, Drzewce, Koźmin, Turów, Bełchatów-pole Szczerców and Adamów (the result of better deposits explorations). In 2012 the Pątnów III – socz. Danków deposit was crossed out from "The balance…”.
Anticipated economic resources within exploited deposits amounted to 1,590.76 million tonnes (7 % of total anticipated economic resources).
Strip mining of brown coal of the Czempin, Krzywin and Gostyń deposits with total reserves of 3,690 million tonnes is nowadays precluded on environmental grounds and in connection with high class and value of agricultural lands in area of the planned open strip mine. Table 2 shows basic parameters of major non-exploited deposits with anticipated economic resources over 75 million tonnes.
Production amounted to 64,297 thousand tonnes in 2012, being 1,408 thousand tonnes higher than in the previous year. The most important is Bełchatów-pole Bełchatów deposit (29.19 million tonnes - 45 % of domestic production) and Bełchatów-pole Szczerców deposit (with production equal 10.97 million tonnes – 17 % of domestic production). Almost the whole production of the largest brown coal strip mines (Bełchatów, Turów, Adamów and Konin) was used as energy coal in power plants.
The figure given below shows changes in resources and production of brown coal in Poland in the years 1989-2012.
Economic resources of brown coal as of 31.12.2012 amounted to 1,219.12 million tonnes and decreased by 67.91 million tonnes.
Prepared by: Janina Dyląg