焙烧-湿法预脱硅工艺处理高硫低铝硅比铝土矿石的试验研究及效果——以贵州务川大竹园铝土矿区矿石为例

An experimental study of treating the high-sulpfur low-alumina silicified bauxitic ore with the pre-desilicification technology of firing-wet method: a case study of the alumyte ore from Dazhuyuan,Wuchuan County,Guizhou Province

DS1试样主要化学成分为Al2O3 64.31%,SiO2 8.92%,A/S 7.11,TS 0.30%;该试样经焙烧-湿法预脱硅处理后,A/S由7.11提高到26.37,Al2O3由63.41%升高到78.53%,TS从0.30%降低到0.11%;焙砂在温度280℃,时间60 min,配料比αk 1.45,碱浓度为220 g/l,石灰添加量4%的最佳溶出条件下,Al2O3的绝对溶出率为95.52%,相对溶出率99.59%;Ga的溶出率91.63%,溶出物在1100℃下锻烧2 h,可获得Al2O3>99%,其他各项指标均优于YS/T274-1998AO-1行业标准的氧化铝产品。

The major chemical components of DS1 samples are Al2O3 64.31%,SiO2 8.92%,A/S 7.11,and TS0.30%.After this sample was treated by the roasting wet pre-desilicification method,the A/S ratio increased from 7.11% to 26.37%,Al2O3 increased from 63.41% to 78.53%,and TS decreased from 0.30% to 0.11%.The roasting temperature was 280 ℃ and the time span was 60 minutes,the ingredient ak was 1.45 and the alkali concentration was 220 g/l.Under the best stripping condition in which the lime additive amount is 4%,the absolute stripping rate of Al2O3 was 95.52% and the relative rate was 99.59%,the stripping rate of Ga was 91.63%.More than 99% Al2O3 could be obtained when the dissolved substance was sintered at the temperature of 1100 ℃ for 2 hours.All the other indexes were better than the indexes of aluminium oxide of industrial standard YS/T274-1998AO-1. The GS1 sample,after roasting wet pre-silicification treatment,A/S increased from 5.31 to 18.88,Al2O3 increased from 61.37% to 80.09%,SiO2 decreased from 11.55% to 4.26% and TS decreased from 1.20% to 0.16%.These data suggest that,after the treatment,the high-sulfur low-alumina silicified bauxitic ore absolutely can attain the requirement for aluminum-silicon ratio and sulfur content of Bayer process,indicating the application prospect of the high-sulfur low-alumina silicified bauxitic ore.