Použití uhličitanu vápenatého jako činidla pro neutralizaci kyselých důlních vod

Zpravodaj Hnědé uhlí 2013, 53(2)

Using calcium carbonate as neutralisation agent of acid mine water

Ing. Iva Bestová, Ph.D.¹, Ing. Silvie Heviánková, Ph.D.¹, Ing. Miroslav Zechner, Ph.D.²: ¹ VŠB-TU Ostrava; ² Sokolovská uhelná, právní nástupce, a.s.

Neutralisation of acid mine drainage together with removal of iron, a part of manganese and heavy metals present in dissolved state is a basic step of its treatment before releasing it to a recipient. Hydrate of lime as lime milk is most often used for neutralisation. Hardness increase of treated water and creation of hard drainable sludge is a negative consequence of the use of lime hydrate which could be partially solved by using calcium carbonate, eventually by both agent combination. An effect of calcium carbonate in acid mine water from the Jiří open pit mine locality near the Sokolov town was observed in this work. Our attention was focused to testing economically favourable and technologically efficient ways of neutralisation. Time run of pH changes, initial and final concentrations of iron and manganese were measured in samples. An economic aspect was evaluated while respecting agent current prices, not at last. Cost savings of neutralising agents are ca 30% with both agent combination, using calcium carbonate alone showed as economically unprofitable.