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8h,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40min,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,Al_(2)O_(3)实际溶出率(η_(实))由81.88%降至78.48%;当料浆Al_(2)O_(3)质量浓度为170g/L、添加质量浓度为0.1g/L的Nacol9779絮凝剂3mL、石灰添加量由9%增大到15%时,赤泥10min时的沉降速度由11.6mm/min增至12.4mm/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.
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 αk,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 αk 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.
作者
王红伟
马春玉
马科友
张学英
Wang Hongwei;Ma Chunyu;Ma Keyou;Zhang Xueying(Metallurgical and Chemical Department,Jiyuan Vocational and Technical College,Jiyuan 459000,China)
出处
《材料与冶金学报》
CAS
北大核心
2021年第1期45-49,共5页
Journal of Materials and Metallurgy
关键词
高铁铝土矿
高压溶出
赤泥沉降分离
high-iron bauxite
high pressure digestion
sedimentation and separation of red mud
