Calcium sulfate process for the coproduction of Po

专利名称：Calcium sulfate process for the

coproduction of Portland cement clinkerand concentrated sulfur dioxide adequate tomanufacture sulfuric acid

发明人：Roger S. Ribas申请号：US07/206018申请日：19880610公开号：US05049198A公开日：19910917

摘要：This invention isolates in separate furnaces the three thermochemical processesrequired in manufacturing Portland cement and sulphur dioxide from a calcium sulfatesource so as to yield improved pyrometallurgical treatment for each individual process.Separating these processes facilitates selection of the most kinetically suitable reactionsby enabling the maintenance of optimum conditions for each process withoutcompromising the thermal or kinetic efficiencies of the other processes.

Only one fourth of the calcium sulfate is reduced to calcium sulfide in a separate adhoc reduction furnace specifically designed for achieving enhanced reduction parameterswhich results in minimized reduction equipment size. Treating most of the calcium sulfateelsewhere works to avoid side reactions and allows Portland cement raw mixcomponents to have an enhanced synergistic catalytic effect on reduction kinetics.Compounds deleterious to both Portland cement and sulfuric acid, such as alkalies andfluorides, are removed with the reduction furnace gases while high concentrations ofsulphur dioxide are achieved in the gases reporting to the sulfuric acid plant.

< P>Three fourths of the calcium sulfate is made to react separately and

simultaneously in a flash calciner with the calcium sulfide to produce sulphur dioxide andcalcium oxide. At the flash calciner heat of radiation from exothermic combustionreactions is applied directly to the highly endothermic desulfurization of calcium sulfateunder an oxidizing atmosphere. The calcium oxide and other Portland cement

components are then discharged onto a short rotary kiln where only clinkering reactionstake place at high thermal efficiencies for enhanced throughput, minimized furnace size,and lower burning zone temperatures.

申请人：RIBAS; ROGER S.

代理机构：Townsend and Townsend

更多信息请下载全文后查看