Title: Effects of bioleaching on the chemical, mineralogical and morphological properties of natural and waste-derived alkaline materials
Authors: Chiang, Yi Wai ×
Santos, Rafael
Monballiu, Annick
Ghyselbrecht, Karel
Martens, Johan
Mattos, Maria Laura T.
Van Gerven, Tom
Meesschaert, Boudewijn #
Issue Date: Jul-2013
Publisher: Pergamon Press
Series Title: Minerals Engineering vol:48 pages:116-125
Abstract: Bioleaching is a potential route for the valorisation of low value natural and waste alkaline materials. It may serve as a pre-treatment stage to mineral carbonation and sorbent synthesis processes by increasing the surface area and altering the mineralogy of the solid material and by generating an alkaline rich (Ca and Mg) aqueous stream. It may also aid the extraction of high value metals from these materials (e.g. Ni), transforming them into valuable ore reserves. The bioleaching potential of several bacteria (Bacillus circulans, Bacillus licheniformis, Bacillus mucilaginosus, Sporosarcina ureae) and fungi (Aspergillus niger, Humicola grisea, Penicillium chrysogenum) towards the alteration of chemical, mineralogical and morphological properties of pure alkaline materials (wollastonite and olivine) and alkaline waste residues (AOD and BOF steel slags, and MSWI boiler fly ash) at natural pH (neutral to basic) was assessed. Bioleaching was conducted using one-step and two-step methodologies. Increased solubilisation of alkaline earth metals and nickel were verified. Alteration in basicity was accompanied by alteration of mineralogy. AOD slag experienced solubilisation-precipitation mechanism, as evidenced by the decline of primary phases (such as dicalcium-silicate, bredigite and periclase) and the augmentation of secondary phases (e.g. merwinite and calcite). Nickel-bearing minerals of olivine (clinochlore, lizardite, nimite and willemseite) significantly diminished in quantity after bioleaching. Altered mineralogy resulted in morphological changes of the solid materials and, in particular, in increased specific surface areas. The bioleaching effect can be attributed to the production of organic acids (principally gluconic acid) and exopolysaccharides (EPS) by the microorganisms. The similarities between fungal and bacterial mediated bioleaching suggest that biogenic substances contribute mostly to its effects, as opposed to bioaccumulation or other direct action of living cells.
ISSN: 0892-6875
Publication status: published
KU Leuven publication type: IT
Appears in Collections:Process Engineering for Sustainable Systems Section
Microbial and Molecular Systems - miscellaneous
Centre for Surface Chemistry and Catalysis
Technologiecluster Bioengineering Technologie
Bioengineering Technology TC, Technology Campus Ostend
× corresponding author
# (joint) last author

Files in This Item:
File Description Status SizeFormat
Chiang2013_MinEng.pdfPublished article Published 2192KbAdobe PDFView/Open Request a copy
Chiang2013_MinEng_author accepted manuscript.pdfAccepted Manuscript Published 1262KbAdobe PDFView/Open

These files are only available to some KU Leuven Association staff members


All items in Lirias are protected by copyright, with all rights reserved.

© Web of science