title: Feasible conversion of solid waste bauxite tailings into highly crystalline 4A zeolite with valuable application.
abstract: Bauxite tailings are a major type of solid wastes generated in the flotation process. The waste by-products caused significant environmental impact. To lessen this hazardous effect from poisonous mine tailings, a feasible and cost-effective solution was conceived and implemented. Our approach focused on reutilization of the bauxite tailings by converting it to 4A zeolite for reuse in diverse applications. Three steps were involved in the bauxite conversion: wet-chemistry, alkali fusion, and crystallization to remove impurities and to prepare porous 4A zeolite. It was found that the cubic 4A zeolite was single phase, in high purity, with high crystallinity and well-defined structure. Importantly, the 4A zeolite displayed maximum calcium ion exchange capacity averaged at 296 mg CaCO3/g, comparable to commercially-available zeolite (310 mg CaCO3/g) exchange capacity. Base on the optimal synthesis condition, the reaction yield of zeolite 4A from bauxite tailings achieved to about 38.43%, hence, this study will provide a new paradigm for remediation of bauxite tailings, further mitigating the environmental and health care concerns, particularly in the mainland of PR China.
authors.affiliation: State Key Laboratory of Advanced Metallurgy, University of Science and Technology Beijing, Beijing 100083, China.
authors.forename: Dongyang
authors.initials: D
authors.lastname: Ma
authors.affiliation: State Key Laboratory of Advanced Metallurgy, University of Science and Technology Beijing, Beijing 100083, China.
authors.forename: Zhendong
authors.initials: Z
authors.lastname: Wang
authors.affiliation: State Key Laboratory of Advanced Metallurgy, University of Science and Technology Beijing, Beijing 100083, China.
authors.forename: Min
authors.initials: M
authors.lastname: Guo
authors.affiliation: State Key Laboratory of Advanced Metallurgy, University of Science and Technology Beijing, Beijing 100083, China. Electronic address: zhangmei@ustb.edu.cn.
authors.forename: Mei
authors.initials: M
authors.lastname: Zhang
authors.affiliation: The Department of Chemistry, Texas A&M University-Kingsville, Kingsville, TX 78363, USA; The Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA.
authors.forename: Jingbo
authors.initials: J
authors.lastname: Liu
mesh_terms: D000537:Aluminum Oxide / Q000737:chemistry*; D002118:Calcium / Q000737:chemistry; D007220:Industrial Waste / Q000032:analysis*; D007474:Ion Exchange; D008906:Mining; D059027:Recycling; D062611:Solid Waste / Q000032:analysis*; D017641:Zeolites / Q000737:chemistry*
chemical_list: D007220:Industrial Waste; D062611:Solid Waste; D017641:Zeolites; D000537:Aluminum Oxide; D002118:Calcium
keywords: 4A zeolite; Alkali fusion; Bauxite tailings; Calcium ion exchange capacity; Crystallization