改性电炉钛渣酸解法制备沸腾氯化炉料新工艺研究

A novel process for preparation of boiling chlorinated charge frommodified electric furnace titanium slag by acid dissolution method

以改性电炉钛渣为原料,采用硫酸浸出-氟化氢铵浸出-盐酸浸出三段联合新工艺制备满足沸腾氯化要求的炉料,从热力学和浸出行为两方面对沸腾氯化炉料新工艺进行研究。研究结果表明:硫酸浸出可分解黑钛石相,并生成Ti OSO_(4),经水洗后TiOSO_(4)进入到滤液中。在酸矿比为1.7,熟化温度为250℃、熟化时间为2 h的条件下,Al、Ca、Mg、Si和Fe的浸出率分别为84.90%、26.90%、82.70%、12.03%和89.13%,Ti O_(2)品位和回收率为72.58%和42.41%。钙镁硅酸盐可以被氟化氢铵分解并生成CaMg_(2)Al_(2)F_(12)沉淀。在NH_(4)HF_(2)质量分数为15%、液固比为10:1、浸出时间为2 h、浸出温度为25℃的条件下,Al、Ca、Mg、 Si和Fe的浸出率分别为29.21%、 2.25%、 2.32%、 98.01%和26.74%, Ti O_(2)品位和回收率分别为82.31%和89.60%。氟化氢铵浸出渣中的钙镁氟化盐可以被盐酸浸出分解。在盐酸质量分数为15%、液固比为10:1、酸浸温度为25℃、酸浸时间为4 h的条件下,Al、Ca、Mg、Si和Fe的浸出率分别为91.24%、93.15%、92.89%、1.29%和70.12%,获得最终产品二氧化钛品位超过94.36%,杂质氧化钙和氧化镁质量分数分别为0.32%和0.14%的沸腾氯化炉料。

A novel process for preparing boiling chlorinated charges from modified electric furnace titanium slag by a three-stage combined process of sulfuric acid leaching,ammonium hydrogen fluoride leaching,and hydrochloric acid leaching was proposed.The process of boiling chlorinated charge was studied in terms of both thermodynamic and leaching behavior.The results show that the anosovite can be decomposed to form TiOSO_(4),which enters the filtrate after water washing.The leaching efficiencies of Al,Ca,Mg,Si,and Fe are 84.90%,26.90%,82.70%,12.03%and 89.13%,respectively,in process of sulfuric acid leaching at 250℃for 2 h when the concentrated sulfuric acid to titanium slag liquid-solid ratio is 1.7.In this stage,the grade and recovery of TiO_(2) are 72.58%and 42.41%.The calcium and magnesium silicates can be decomposed to form CaMg2Al2F12 precipitates by ammonium hydrogen fluoride leaching.The leaching efficiencies of Al,Ca,Mg,Si,and Fe are 29.21%,2.25%,2.32%,98.01%,and 26.74%,respectively,in the ammonium hydrogen fluoride leaching at 25℃for 2 h when the concentration of ammonium hydrogen fluoride is 15%,and the liquid-solid ratio is 10꞉1.In this stage,the grade and recovery of TiO_(2) are 82.31%and 89.60%.The calcium and magnesium fluoride salts in the leaching residue of ammonium bifluoride can be decomposed by leaching with hydrochloric acid.The leaching efficiencies of Al,Ca,Mg,Si,and Fe are 91.24%,93.15%,92.89%,1.29%,and 70.12%,respectively,in the hydrochloric acid leaching at 25℃for 4 h when the concentration of hydrochloric acid is 15%,and the liquid-solid ratio is 10꞉1.A boiling chlorinated charge with a final product grade of 94.36%TiO_(2) and impurities of 0.32%CaO and 0.14%MgO is obtained.