Author(s): Shah, Syed Sikandar [UNESP] ; Palmieri, Mauricio Cesar ; Sponchiado, Sandra Regina Pombeiro [UNESP] ; Bevilaqua, Denise [UNESP]
Date: 2020
Persistent ID: http://hdl.handle.net/11449/200433
Origin: Oasisbr
Subject(s): Aluminum recovery; Aspergillus niger; Bioleaching; Low-grade bauxite; Molasses; Aluminum recovery; Aluminum recovery; Aspergillus niger; Aspergillus niger; Bioleaching; Bioleaching; Low-grade bauxite; Low-grade bauxite; Molasses; Molasses
Made available in DSpace on 2020-12-12T02:06:29Z (GMT). No. of bitstreams: 0 Previous issue date: 2020-08-01
Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
In this study, an economical and sustainable bio-hydrometallurgical route was evaluated for the recovery of aluminum from low-grade bauxite using the marine-derived fungus Aspergillus niger. Firstly, four different solid media were tested for high-yield spore production. Organic acid production capacity by A. niger was also evaluated in a medium supplemented with glucose or low-cost molasses as a carbon source using fungal spores or pellets as inoculum. The concentrations of the produced organic acids were determined by High-Performance Liquid Chromatography (HPLC). The results showed that oat-agar can be used as an inexpensive solid medium for greater fungal sporulation, while the liquid medium supplemented with molasses as a low-cost carbon source can be used for higher organic acids production. Among the conditions tested, A. niger spore inoculum showed the highest yield of the total produced organic acids (122.40 g L−1 or 81.6% (grams of sucrose used per grams of total acid) and also the highest (1.02 ± 0.02 g L−1 h−1) acids production rate using molasses as an inexpensive carbon source. This cultivation condition was selected for the bioleaching studies with low-grade bauxite. Among the three different bioleaching methods tested, the direct two-steps bioleaching process resulted in higher aluminum leaching (91.2%) compared to indirect (84.8%) and direct one-step (82.8%) bioleaching process. According to the results obtained using marine-derived A. niger under the established culture conditions, proved to be an eco-friendly and cost-effective way for aluminum recovery from low-grade bauxite ore and has the potential to be adopted on a pilot scale.
Department of Biochemistry and Chemical Technology São Paulo State University (UNESP) Institute of Chemistry Araraquara
Department of Chemistry Bacha Khan University, KPK
Itatijuca Biotech
Department of Biochemistry and Chemical Technology São Paulo State University (UNESP) Institute of Chemistry Araraquara
FAPESP: 2015/24757-9
