Production of granules for acidic gas removal

摘要

Production of granules for removal of acidic gases with the aid of hydrated lime comprises mixing the lime with soft brown coal in the form of raw fine coal, the brown coal functioning as dispersant and stabiliser. The granules are produced by: (1) crushing the raw brown coal to a grain size of 0-3 (0-0.3) mm; (2) intensively mixing the crushed brown coal with finely ground hydrated lime to a homogeneous mixture so that the lime is distributed on the surface of the crushed coal and, by penetrating the crushed coal, into the water-rich soft brown coal; (3) granulating the mixture with addition of water and/or condensed water vapour to granules of suitable grain size (distribution), in which only small amounts of hydrated lime are found on the outer surfaces of the granules; (4) irreversibly converting the moist crushed brown coal into a solid porous water-resistant matrix structure with the embedded hydrated lime by drying at /- 75 deg C to a relative water content of <= 25% (preferably 15%); and (5) re-moistening the solidified granules with water.