title: Proposal for management and alkalinity transformation of bauxite residue in China.
abstract: Bauxite residue is a hazardous solid waste produced during the production of alumina. Its high alkalinity is a potential threat to the environment which may disrupt the surrounding ecological balance of its disposal areas. China is one of the major global producers of alumina and bauxite residue, but differences in alkalinity and associated chemistry exist between residues from China and those from other countries. A detailed understanding of the chemistry of bauxite residue remains the key to improving its management, both in terms of minimizing environmental impacts and reducing its alkaline properties. The nature of bauxite residue and the chemistry required for its transformation are still poorly understood. This review focuses on various transformation processes generated from the Bayer process, sintering process, and combined Bayer-sintering process in China. Problems associated with transformation mechanisms, technical methods, and relative merits of these technologies are reviewed, while current knowledge gaps and research priorities are recommended. Future research should focus on transformation chemistry and its associated mechanisms and for the development of a clear and economic process to reduce alkalinity and soda in bauxite residue.
authors.affiliation: School of Metallurgy and Environment, Central South University, 932 Lushan South Road, Changsha, Hunan, 410083, People's Republic of China. sgxue70@hotmail.com.
authors.forename: Shengguo
authors.initials: S
authors.lastname: Xue
authors.affiliation: School of Metallurgy and Environment, Central South University, 932 Lushan South Road, Changsha, Hunan, 410083, People's Republic of China.
authors.forename: Xiangfeng
authors.initials: X
authors.lastname: Kong
authors.affiliation: School of Metallurgy and Environment, Central South University, 932 Lushan South Road, Changsha, Hunan, 410083, People's Republic of China.
authors.forename: Feng
authors.initials: F
authors.lastname: Zhu
authors.affiliation: Crop and Environment Sciences Department, Harper Adams University, Newport, Shropshire, TF10 8NB, UK.
authors.forename: William
authors.initials: W
authors.lastname: Hartley
authors.affiliation: School of Metallurgy and Environment, Central South University, 932 Lushan South Road, Changsha, Hunan, 410083, People's Republic of China.
authors.forename: Xiaofei
authors.initials: X
authors.lastname: Li
authors.affiliation: School of Metallurgy and Environment, Central South University, 932 Lushan South Road, Changsha, Hunan, 410083, People's Republic of China.
authors.forename: Yiwei
authors.initials: Y
authors.lastname: Li
mesh_terms: D000537:Aluminum Oxide / Q000737:chemistry*; D002681:China; D006863:Hydrogen-Ion Concentration; D007220:Industrial Waste / Q000032:analysis; D018505:Waste Management
chemical_list: D007220:Industrial Waste; D000537:Aluminum Oxide
keywords: Alkalinity transformation; Amelioration; Bauxite residue; Chemical mechanism; Neutralization; Waste management