The mining of chemical raw materials and common minerals
Underground melting
Sulfur has an important role in extraction of chemical raw materials in Poland. Mines and Sulfur Chemical Plants ‘Siarkopol” with residence in Grzybów is the only enterprise running the exploitation of sulfur. The production of this mineral is concentrated in sulfur mine “Osiek” in Świętokrzyskie voivodship. The exploitation of sulfur is done by the method of underground melting consisting in delivery to a deposit of technological water with temperature of about 160 o C and withdrawal of liquid sulfur to the surface via 60 bore-holes, The extracted sulfur is stored and transported in a liquid form. The last year production of this raw material was in excess of 853 Thos. tons. The company engages about 3000 employees
Highways have increased production
Perceptible development of building industry and roads construction in recent years stimulated the production of the so called common minerals, exploited by an opencast method. Natural aggregates as well as road and building stones predominate in this group of minerals followed by, limestone and marl, silica and moulding sands but also - in proportionally small quantities - these minerals include gypsum and anhydrite, ceramic and stoneware clays, chalk, - proof quartzite, vein quartz, slates, magnesite, koalin and other glass making raw materials. Besides already mentioned building industry and civil engineering common minerals find their application especially (in the form of backfilling material) in other branches of mining, casting, glass - ceramic industries and paper one.
At present about 4 500 mining enterprises deal with opencast exploitation of common minerals in Poland. Their total production exceeds 214 Thos. tons annually. This mining is predominated - let us repeat - by production of natural aggregates. As many as 78 per cent of this group of enterprises concentrate on aggregate production. Last year they delivered to the market almost 117 Thos. tons of aggregate. Common minerals mining in Poland employs in total about 18 Thos. people. Usually those are small mining enterprises. Hardly 5,3 per cent of them employ more than 20 persons whereas almost 45 per cent of active plants engage up to 2 workers.
Deep salt mine „Kłodawa” extracts annually more than half a million tons of rock salt.