Roasting pretreatment of high sulfur bauxite of China

摘要

Effects of roasting temperaturernand time on desulphurization rate of highrnsulfur bauxite of China were studied byrnusing rotary tube furnace. Microscopicrnappearance and crystal structure changes ofrnroasted ore were analyzed by SEM andrnXRD. Digestion rate and settlingrnperformance of roasted ore were also tested.rnThe results indicate that the sulfur contentrnof roasted ore is lower than the industrialrnstandard after being roasted at 750□ forrn60mins, and its alumina digestion rate isrnabove 97% at 220□ for 60min. Red mud ofrnroasted ore becomes looser and morernporous, and goethite in high sulfur bauxiterntransforms into hematite after roasting.rnSettling performance of roasted ore isrnimproved, but will get worse if the roastedrnore is too loose and particle sizes of the redrnmud become smaller greatly. Compared tornthe digestion slurry of raw ore, therndigestion slurry of roasted ore has betterrnsettling performance.