PROCESS FOR DECOMPOSING CALCIUM SULFATE

摘要

1346659 Calcium sulphate decomposition; sulphur dioxide GRAIN PROCESSING CORP 29 July 1971 [29 July 1970] 35771/71 Heading C1A SO 2 and CaO are obtained by decomposing a bed of CaSO 4 by means of a fluidizing gas mixture of air and a reducing gas wherein (a) the CaSO 4 has a particle distribution such that at least 90% of the particles are larger than 30 U.S. mesh, (b) the flow velocity of the gas mixture through the bed is at least 1À0 ft./sec. and (c) the flow velocity is in the range of 20-130% of the minimum flow velocity of the gaseous mixture which will support fluidization. The particles preferably have a size in the range 8-24 mesh. The flow velocity may be in the range 3-4 ft./sec. The reducing gas may be a CO/H 2 mixture or partially burnt fuel, e.g. CH 4 , preferably being passed, together with air, into the fluidized bed at a temp. of 2150-2280‹ F.