A Complex Use of the Materials Extracted from an Open-Cast Lignite Mine

Abstract

Abstract The company Sokolovská uhelná, was the largest producer of city gas in the Czech Republic. After its substitution by natural gas the gasification technology became the basis of the production of electricity in the combine cycle power plant with total output 400 MW. For the possibility of gasification of liquid by- -products forming during the coal gasification a entrained-flow gasifier capable to process also alternative liquid fuels has been in installed. The concentrated waste gas with these sulphur compounds is conducted to the desulphurisation where the highly desired, pure, 96 % H2SO4 is produced. Briquettable brown coal is crushed, milled and dried and then it is passed into briquetting presses where briquettes, used mainly as a fuel in households, are pressed without binder in the punch under the pressure of 175 MPa. Fine brown coal dust (multidust) is commercially used for heat production in pulverized-coal burners. It forms not only during coal drying after separation on electrostatic separators, but it is also acquired by milling of dried coal in a vibratory bar mill. Slag from boilers of classical power plant, cinder form generators and ashes deposited at the dump are dehydrated and they are used as a quality bedding material during construction of communications in the mines of SUAS. Fly ash is used in building industry for partial substitution of cement in concrete. Flue gases after separation of fly ash are desulphurized by wet limestone method, where the main product is gypsum used, among others, in the building industry. Expanded clays from overburdens of coal seams, that are raw material for the production of “Liapor” artificial aggregate, are used heavily. This artificial aggregate is characterized by outstanding thermal and acoustic insulating properties.