高硫铝土矿的焙烧预处理

Roasting Pretreatment of High-sulfur Bauxite

采用回转窑对我国高硫铝土矿进行焙烧预处理,考察了焙烧温度、焙烧时间对矿物中硫含量及氧化铝溶出性能的影响,利用SEM和XRD技术对焙烧矿的微观形貌、晶型结构变化进行了分析,并对高硫矿脱硫机理和焙烧机理作了探讨.结果表明,焙烧脱硫处理高硫型铝土矿是可行的,焙烧温度为750℃、焙烧时间为60min时,焙烧矿中硫含量低于0.7%,达到我国氧化铝生产的工业要求;焙烧矿在溶出温度220℃、溶出时间60min的条件下,氧化铝溶出率达到97%以上.

Roasting pretreatment of high sulfur bauxite was studied using a rotary kiln, and the effects of roasting temperature and roasting time on sulfur content and digestion performance of high sulfur bauxite were examined. Changes of microscopic appearance and crystal structure were analyzed with SEM and XRD techniques. The mechanism of desulphurization and roasting pretreatment was also studied. The experimental results indicate that the sulfur in bauxite was successfully discharged as gas form through roasting, the sulfur content of high sulfur bauxite met the industrial standard under the conditions of 750℃ roasting temperature and 60 min holding time. The digestion rate of alumina was above 97% under the conditions of 220℃digestion temperature and 60 min holding time.