二段法溶出降低赤泥碱耗的研究

硕士学位论文第一章文献综述ABSTRACTThe most resource of production of alumina is bauxite.According tothe fast development of the alumina industry,the resource of high qualitybauxite is drying up.And the property of the bauxite resource of ourcountry is high-alumina high-silica.The high content of silica of thebauxite results in the problem of high-energy and high-soda consumption,which limit the use of the high-silica bauxite.So it is important for thegood use of bauxite and the alumina industry to develop a process thatcould reduce the soda consumption of high-silica bauxite which causedby the silica minerals of the bauxite.The two-stage digestion process could effectively reduce thefix-soda consumption of the red mud of the Henan and Pingguo bauxite.And the application of the two-stage digestion process in the Guizhoubauxite was investigated.In the optimum condition of the Guizhoubauxite two-stage digestion process were explored.The experimentresults showed that the fix-soda consumption of the red mud of theGuizhou bauxite reached to the lowest point under the digestion condition:the bauxite was predesilicated at 170C for 120 minutes in the first stageand than digested at 260C for 30 minutes,the N/S of the red mud was0.36.The XRD picture illustrated that the reduction of the fixed-sodaconsumption of the red was caused by the reduction of cancrinite andincrease of katoite in the red mud.It was found that the effect of the Pingguo bauxite two-stagedigestion process were different for different digestion equipment.Thepotential reasons were carefully researched.According to the results,thedifferent effect of two-stage digestion process between using steel bomband the autoclave were result from the better predesilication effect in thesteel bomb.In the same time,the steel balls in the steel bomb not onlystirred the slurry but also mechanically activated the reaction happened inthe steel bomb.By means of digested the roasted Pingguo bauxite withthe two-stage digestion process,the conclusion could be made that thepredesilication effect were result from the high level of alumina digestion