SYSTEM FOR PRODUCING ALKALINE SOIL-IMPROVING MATERIAL, COMBINED WITH FLUE-GAS DESULFURIZATION

摘要

PROBLEM TO BE SOLVED: To build a system for producing a good-quality alkali soil-improving material in which amount of Ca such as lime used is slight and desulfurization can economically be carried out in high efficiency and unreacted Ca and heavy metal are scarcely mixed, in a dry type fuel-bas desulfurization method suitable for dried areas.;SOLUTION: A fluid medium consisting mainly of Ca is fed to the uppermost stage of a multi-stage fluidized bed and the feed is successively moved to the lower stage and flue gas in which fly ash is removed is fed from a gas chamber in the lower part of the lowermost stage and the flue gas is repeatedly brought into contact with the fluid medium in each stage and Ca is substantially completely converted to calcium sulfite or gypsum by SOx in the flue gas while controlling residence time of the fluid medium and then, the calcium sulfite or gypsum is pulled out from the lowermost stage. As a result, flue gas desulfurization is carried out and at the same time, the good-quality soil-improving material scarcely containing a heavy metal and an alkali component is produced.;COPYRIGHT: (C)2007,JPO&INPIT