【摘要】 本文以山西某地高铁一水硬铝石为原料,结合氧化铝生产实践,开展了预脱硅、拜耳法溶出和赤泥沉降分离试验,考察了配料赤泥铝硅比（A/S）和石灰添加量（按石灰中CaO_合占矿石总量的质量分数计,下同）对矿石溶出效果、赤泥沉降性能等的影响.结果表明:高铁铝土矿在100℃下预脱硅8 h,预脱硅率(η_Si)和预脱钛率(η_Ti)随石灰添加量的增加而增大,石灰添加量达15%时,η_Si和η_Ti分别为31.63%和20.51%;预脱硅后矿浆在270℃下溶出40 min,石灰添加量由9%增大到15%时,溶出液苛性比值（α_k）由1.42增加到1.48,溶出赤泥钠硅比（N/S）由0.26降至0.06,Al₂O₃实际溶出率（η_实）由81.88%降至78.48%;当料浆Al₂O₃质量浓度为170 g/L、添加质量浓度为0.1 g/L的Nacol 9779絮凝剂3 mL、石灰添加量由9%增大到15%时,赤泥10 min时的沉降速度由11.6 mm/min增至12.4 mm/min,压缩液固比（L/S）由6.55降至4.12,上清液清澈透明;配料赤泥A/S对溶出效果和赤泥沉降性能影响不大.更多还原

【Abstract】 With high-iron diasporic bauxite from Shanxi as raw materials, the effects of the ingredients alumina-silica ratio A/S of red mud and lime dosage（according to the mass fraction of the total amount of Ca and Mg in lime to the total amount of ore, the same below） on pre-desilication, Bayer digestion and sedimentation were investigated.At 100 ℃, the rate of desilication and detitanation was 31.63% and 20.51%, respectively, when pre-desilication for 8 h and adding 15% lime, and moreover the rate of desilication and detitanation increased with increasing lime addition. Additionally, the amount of lime addition had significant effects on the digestion liquor caustic ratio α_k,the ratio of digestion red mud sodium oxide to silica N/S, and the actual rate η of Al₂O₃ dissolution. When the ore pupl after pre-desilication was dissolved for 40 min at 270 ℃, the digestion liquor caustic ratio α_k increased from 1.42 to 1.48, the ratio of digestion red mud sodium oxide to silica N/S decreased from 0.26 to 0.06, the actual dissolution rate η decreased from 81.88 % to 78.48% with increasing lime addition from 9% to 15%. Similarly, under the conditions of the Al₂O₃ mass concentration in slurry of 170 g/L, the 0.1 g/LNacol 9779 flocculant addition of 3 mL, when increasing lime addition from 9% to 15%, the settling velocity of red mud increased from 11.6 mm/min to 12.4 mm/min, the liquid-solid ratio of compression decreased from 6.55 to 4.12 and the supernatant was clear and transparent. Finally, the ingredients alumina-silica ratio A/S of red mud has unobvious effects on digestion and sedimentation.更多还原