School of Chemistry and Chemical Engineering, Henan Polytechnic University, Jiaozuo, 454000, Henan, China.
State Environmental Protection Key Laboratory of Mineral Metallurgical Resources Utilization and Pollution Control, Wuhan University of Science and Technology Wuhan, Hubei, 430081, China.
Environ Sci Pollut Res Int. 2022 Oct;29(49):74264-74275. doi: 10.1007/s11356-022-21081-5. Epub 2022 May 30.
Titanium white waste acid (TWWA) was used to dissolve the representative elements from red mud (RM) to achieve the goal of "treating waste with waste." The leaching parameters on the leaching efficiency of Na, Sc, and Al were investigated, in which the analysis of XRD and SEM-EDS on RM and leaching residue was performed. The leaching kinetics of Na, Sc, and Al was studied with unreacted shrinking core model (USCM). The results show that the dealkalization efficiency was close to 100%, and the leaching efficiency of Sc and Al was 82% and 75%, respectively. Cancrinite was dissolved from RM, and then the elements such as Na, Al, and Ca reacted with HSO of TWWA. Na existed in the leaching liquor in the form of ions. Ca reacted with sulfuric acid to form anhydrite, which existed in the leaching residue. The particles of RM became smaller and dispersed with each other by acid leaching. The leaching apparent activation energy of Na, Sc, and Al was 4.947 kJ/mol, 6.361 kJ/mol, and 31.666 kJ/mol, respectively. The leaching kinetic equation of Na, Sc, and Al was 1 - (1 - a) = 0.084·exp[- 595.05/T]·t by external diffusion, 1 - 2a/3 - (1 - a) = 0.021·exp[- 765.16/T]·t by internal diffusion, and ln(1 - a)/3 + (1 - a) - 1 = 67.12·exp[- 3808.8/T]·t by joint action, respectively.
钛白废酸（TWWA）用于溶解赤泥（RM）中的代表性元素，以实现“以废治废”的目标。研究了浸出参数对 Na、Sc 和 Al 浸出率的影响，并对 RM 和浸出残渣进行了 XRD 和 SEM-EDS 分析。采用未反应收缩核模型（USCM）研究了 Na、Sc 和 Al 的浸出动力学。结果表明，脱碱效率接近 100%，Sc 和 Al 的浸出率分别为 82%和 75%。方钠石从 RM 中溶解，然后 Na、Al 和 Ca 等元素与 TWWA 中的 HSO 反应。Na 以离子形式存在于浸出液中。Ca 与硫酸反应生成存在于浸出残渣中的无水石膏。酸浸使 RM 的颗粒变小并相互分散。Na、Sc 和 Al 的浸出表观活化能分别为 4.947 kJ/mol、6.361 kJ/mol 和 31.666 kJ/mol。Na、Sc 和 Al 的浸出动力学方程分别为外部扩散的 1−(1−a)=0.084·exp[−595.05/T]·t、内部扩散的 1−2a/3−(1−a)=0.021·exp[−765.16/T]·t 和联合作用的 ln(1−a)/3+(1−a)−1=67.12·exp[−3808.8/T]·t。
