Process Safety and Environmental Protection ( IF 7.8 ) Pub Date : 2021-11-27 , DOI: 10.1016/j.psep.2021.11.052 Yijuan Tian 1 , Xuejun Quan 1 , Gang Li 1 , Xiaoyu Tang 1 , Xianfeng Qin 1 , Haifeng Wu 1 , Kui Zeng 1 , Zhanghao Jiang 1
To establish a cleaner production technology of chromium salt, the pressurized leaching process of chromite ore in 60 wt% NaOH solution, subsequent separation of a chromium salt from the leached solution and Cr2O3 preparation from the intermediate product BaCrO4 were systematically investigated, and a new highly efficient and economical process for the production of Cr2O3 from chromite ore was established. The results showed that the decomposition of chromate ore could be significantly improved by increasing the temperature, and the Cr leaching rate reached 99% at 240 °C for 4 h. Meanwhile, the leaching process was controlled by surface chemical reactions with activation energy (Ea) of 34.3051 kJ/mol and a pre-exponential factor (A) of 6.9560. In the leached liquor, Na2CrO4 was transformed into BaCrO4 through its reaction with Ba(OH)2, Cr separation efficiency could reach as high as 89% in the undiluted leached liquor, while the separated alkali liquor could be effectively recycled for the leaching of chromite ore. Ultimately, a new method for the preparation of Cr2O3 from the intermediate product BaCrO4 was presented by the dissolution and reduction of BaCrO4 with HCl-CH3CH2OH as the reactant. The new cleaner process for Cr2O3 preparation from chromite ore provides an attractive alternative to upgrading the current chromate salt production processes.
中文翻译:
一种从铬铁矿中制备氧化铬的清洁方法
为建立铬盐清洁生产技术,系统研究了铬铁矿在60 wt% NaOH溶液中的加压浸出工艺,随后从浸出液中分离出铬盐,以及从中间产物BaCrO 4中制备Cr 2 O 3,以及一种高效、经济的生产 Cr 2 O 3的新工艺从铬铁矿成立。结果表明,提高温度可显着提高铬酸盐矿石的分解率,240℃下4h浸出率达到99%。同时,浸出过程受表面化学反应控制,活化能 (Ea) 为 34.3051 kJ/mol,指前因子 (A) 为 6.9560。在浸出液中,Na 2 CrO 4与Ba(OH) 2反应转化为BaCrO 4,未稀释浸出液中Cr的分离效率可达89%,而分离出的碱液可有效回收利用铬铁矿的浸出。最终,一种制备Cr 2 O的新方法3从中间产物BaCrO 4是由溶解和还原BaCrO呈现4用HCl-CH 3 CH 2 OH作为反应物。从铬铁矿中制备Cr 2 O 3的新清洁工艺为升级当前的铬酸盐生产工艺提供了一种有吸引力的替代方案。