Crystallization of gibbsite from synthetic chromate leaching solution in sub-molten salt process

作     者：张培育 魏广叶 郭强 曲景奎 齐涛 Pei-yu ZHANG;Guang-ye WEI;Qiang GUO;Jing-kui QU;Tao QI

作者机构：中国科学院过程工程研究所湿法冶金清洁生产技术国家工程实验室北京100190 中国科学院大学北京100049 

出 版 物：《Transactions of Nonferrous Metals Society of China》 (中国有色金属学报（英文版）)

年 卷 期：2015年第25卷第8期

页      面：2734-2743页

核心收录：

学科分类：081702[工学-化学工艺] 08[工学] 0817[工学-化学工程与技术] 

基　　金：Project(51125018)supported by the National Science Foundation for Distinguished Young Scholars of China Project(2011AA060704)supported by the National High-tech Research and Development Program of China Projects(51204153,21406246)supported by the National Natural Science Foundation of China 

主　　题：gibbsite secondary nucleation carbonization chromate leaching solution 

摘      要：For the clean and economical production of chromium compounds, it is crucial to remove aluminates from chromate alkali solutions and utilize aluminum-containing compounds. In this work, carbonization was used to remove aluminates from a synthetic chromate leaching solution containing a high K2O/Al2O3 mole ratio. The influence of reaction temperature, carbonization time, flow rate of carbon dioxide, and seed ratio on the precipitation of Al was investigated. The optimal output was obtained under the following experimental conditions： a reaction temperature of 50 °C, a carbonization time of 100 min, a carbon dioxide flow rate of 0.1 L/min, and a seed ratio of 1.0. Gibbsite was obtained following carbonization. The structure and morphology of the gibbsite were characterized by X-ray diffraction （XRD）, scanning electron microscopy （SEM）, and laser particle size analyzer. The particle size distribution and morphology of the gibbsite were significantly influenced by the experimental conditions. The gibbsite had a mean particle size （d50） of 16.72μm. The thermal decomposition of the gibbsite was analyzed by XRD and the decomposition path was determined. The obtained coarseα-Al2O3 precipitate, which contains 0.08% Cr2O3 and 0.10% K2O, was suitable for subsequent utilization.