On the Conversion of Bauxite Ores to Highly Activated Alumina Media for Water Remediation

Abstract

Good quality drinking water is necessary to maintain a high quality of life. Millions lack access to clean and safe drinking water, and current trends suggest that billions will face acute water shortages in the coming decades. Development of new materials has led to technological impacts on water purification, from desalination membranes to atmospheric water scavenging. However, the most challenging aspect of technological solutions is cost: if the community being serviced cannot afford the solution, it is not likely to be sustainable. Repurposing Earth‐abundant materials to replace highly engineered solutions is an atractive solution. Herein, minimal processing of bauxite rocks produces a high‐porosity and reactive activated alumina in situ, without purification directly from the ore. This acid‐treated, thermally activated bauxite (ATAB) exhibits a high surface area of 401 ± 6 m2 g−1, a 40‐fold increase relative to its parent ore, and a 2× increase relative to the state‐of‐the‐art fluoride adsorbent, activated alumina. The composition, preparation, and mechanism of adsorption are studied by X‐ray diffraction, X‐ray photoelectron spectroscopy, and multiple‐quantum magic‐angle spinning 27Al nuclear magnetic resonance (NMR). The maximum adsorption density of ATAB is comparable with that of activated alumina, but ATAB requires fewer processing steps, thus warranting future consideration as a primary adsorbent of choice for fluoride removal from water.

Toward Greener and More Sustainable Manufacture of Bauxite-Derived Adsorbents for Water Defluoridation

“…28,29 and ATAB processes is from ref. 30 The actual values of carbon footprints are sensitive to the generation mix of input electricity. However, regardless of energy source, adsorbents manufactured in the ATAB process achieve the lowest carbon footprint among four major scenarios considered in this study.…”

Physicochemical Characterisation for Potential Uses as Industrial Mineral of Bauxite from Débélé, Guinea

“…Apart from the metallurgical usage, bauxite has found diverse applications in manufacturing vari-Journal of Materials Science and Chemical Engineering ous products like cement, abrasives, refractories, chemicals, etc. Recently, bauxite has been used as an additive in various material compositions, to improve functional properties or for alternative sustainable products [1]- [6]. The industrial use of bauxite and derivatives materials is mostly based on the high aluminum hydroxide content, as gibbsite or boehmite.…”

“…They decrease the fluxing role of alkaline minerals, favouring the high mechanical resistance of products [10] [11] [12] [13] [14]. Beyond, bauxite found further application in water treatment, satisfactory elimination of certain toxic elements such as fluorides was obtained thanks to the improvement of adsorbent properties through the chemical and heat activation [6].…”

Fabrication of Carbon–Alumina Composites via Catalytic Pyrolysis of Pine Sawdust on Aluminum Dross for Cr(VI) Removal

“… 4 Activated alumina is a state-of-the-art sorbent for its low cost, porous structure, and activated hydroxyl sites. 5 , 6 One of the wastes generated from the aluminum production industry, alumina dross (AD), 7 is also used directly as a sorbent for water purification by other researchers. 8 However, the exchangeable form of heavy metals in the AD may bring about land and water contamination.…”