文献类型：期刊文献

英文题名：Green recovery of potassium and aluminum elements from alunite tailings using gradient leaching process

作者：Luo, Mengjie[1];Liu, Chenglin[1];Jiang, Youfa[1];Xue, Jin[1];Li, Ping[1];Yu, Jianguo[1]

机构：[1]East China Univ Sci & Technol, Coll Chem Engn, State Key Lab Chem Engn, Natl Engn Res Ctr Integrated Utilizat Sait Lake Re, Shanghai 200237, Peoples R China

年份：2017

卷号：168

起止页码：1080

外文期刊名：JOURNAL OF CLEANER PRODUCTION

收录：;EI(收录号：20174104256338);WOS:【SCI-EXPANDED(收录号:WOS:000414817700099)】；

基金：The authors wish to acknowledge National Nature Science Foundation of China (Grant 21376085, 21276080) and the Fundamental Research Funds for the Central Universities (Grant 22A201514058) for the financial support.

语种：英文

外文关键词：Alunite tailing; Green recycling; Gradient leaching; Thermodynamics; Process optimization

摘要：In this work, a gradient leaching process is proposed to treat alunite tailings in order to recover potassium and aluminum. Thermodynamic analysis on the reactions of alunite tailings with potassium hydroxide in the leaching process over the temperature range of 30-120 degrees C is accomplished. In the gradient leaching process, the main mineral of potassium alunite from alunite tailings is extracted into the concentrated potassium hydroxide solution, while kaolinite and quartz are still remained in the leaching residues. The proposed leaching process is demonstrated to be feasible based on the leaching ratio of potassium, aluminum, silicon elements in the leaching solution by ICP-OES and the mineralogical characterizations of the leaching residues by XRD, IR and Raman spectrometers. Furthermore, the gradient leaching conditions, such as alkali-to-ore mass ratio, leaching temperature, leaching time and potassium hydroxide concentration, are optimized using the response surface method to recover potassium and aluminum from alunite tailings as many as possible and to extract silicon as small as possible. Under the optimal leaching conditions of alkali-to-ore mass ratio 3.3, temperature 81.8 degrees C, time 41.6 min, and potassium hydroxide concentration 53.9 wt%, the leaching ratio of potassium and aluminum reaches 99.5% and 84.0%, and the leaching ratio of silicon is controlled in 5.6%, respectively. All the obtained results could contribute to affording a green and closed-loop recovering process for potassium and aluminum elements from alunite tailings. (C) 2017 Elsevier Ltd. All rights reserved.