Journal
WASTE MANAGEMENT
Volume 95, Issue -, Pages 549-559Publisher
PERGAMON-ELSEVIER SCIENCE LTD
DOI: 10.1016/j.wasman.2019.06.044
Keywords
Acid baking water leaching; Bayer process; Bauxite residue; Red mud; Oxonium-ion iron double sulfates; Waste valorization
Categories
Funding
- Rio Tinto [503532]
- Natural Sciences and Engineering Research Council of Canada (NSERC) [503534]
Ask authors/readers for more resources
The current study put the emphasis on developing a novel and environmentally friendly waste valorization process, called acid-baking water-leaching, to recover scandium from bauxite residue produced by the aluminum industry. In this process, bauxite residue is mixed with concentrated sulfuric acid, baked in a furnace at 200-400 degrees C, and leached in water at ambient conditions. Compared with direct acid leaching processes, the developed process offers the advantages of less acid consumption, less wastewater generation, and fast kinetics. With fundamental investigation into the reaction mechanism, acid baking temperature was shown to be the controlling factor that dictates the final phases of the process. Baking at 200 degrees C results in the formation of (H3O)Fe(SO4)(2) that leaches in water rapidly (<5 min), but extraction efficiency is low (58% scandium). In contrast, baking at 400 degrees C results in the formation of Fe-2(SO4)(3) that leaches at slower kinetics (>45 min), but results in higher extraction efficiency (80% scandium). The acid baking water leaching process proves to be a promising technique as the first step of a potential nearzero-waste integrated process for the sustainable valorization of bauxite residue to help build the circular economy. (C) 2019 Elsevier Ltd. All rights reserved.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available