Study on the roasting and leaching behavior of high-sulfur bauxite using ammonium bisulfate
Study on the roasting and leaching behavior of high-sulfur bauxite using ammonium bisulfate
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DOI：
10.1016/j.hydromet.2016.01.018
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发表时间：
2016-10-01
期刊：
影响因子：
4.7
通讯作者：
Zhai, Yuchun
中科院分区：
文献类型：
--
作者：
Lou, Zhenning;Xiong, Ying;Zhai, Yuchun
高硫是我国难选铝土矿加工的难题之一。研究了以高硫铝土矿为原料，采用NH 4 HSO 4焙烧法制备氧化铝的新工艺。本文提供了一种可能的替代方法，可以提高整体工艺的经济性和环境影响。研究了硫酸氢铵的加入量、焙烧温度和焙烧时间等因素对焙烧机理的影响。结果表明，焙烧过程的控制步骤为化学控制，在623 ~ 648 K的反应温度范围内，表观活化能为65.74 kJ/mol。研究了温度、液固质量比和时间对熟料水浸出动力学的影响。动力学数据分析表明，铝土矿的溶出过程受收缩核控制，符合表面反应模型。在323 ~ 363 K范围内，浸出过程的表观活化能为37.94 kJ/mot。在最佳条件下，铝的溶解率最大可达93%左右。本文旨在为高硫铝土矿的开发和应用的进一步研究和实践提供一些启示和指导。(C)2016爱思唯尔B. V.保留所有权利。
High sulfur content is one of the many challenges in processing the refractory bauxites of China. A new method to prepare Al2O3 from high-sulfur bauxite with the NH4HSO4 roasting process was studied. The paper offers a possible alternative method for desulfurization of bauxite that may improve overall process economics and environmental impact. The roasting mechanism and various parameters including the amount of the ammonium bisulfate addition, roasting temperature and roasting time were investigated. The results showed that the control step of the roasting process was chemical control and the apparent activation energy was 65.74 kJ/mol over the reaction temperature range from 623 to 648 K. The leaching kinetics of the sintered clinker by water was investigated, which was affected by temperature, mass ratio of liquid to solid and time. Analysis of the kinetic data indicates that the dissolution of bauxite ore was controlled by the shrinking core with surface reaction model. The apparent activation energy of the leaching process was found to be 37.94 kJ/mot from 323 to 363 K. The maximum aluminum dissolution ratio reaches about 93% under the optimal condition. This paper aims at giving some revelation and instruction for the further research and practice on high sulfur bauxites development and application. (C) 2016 Elsevier B.V. All rights reserved.