title: Zirconia enrichment in zircon sand by selective fungus-mediated bioleaching of silica.
abstract: One of the important routes for the production of zirconia is by chemical treatment and removal of silica from zircon sand (ZrSixOy). We present here a completely green chemistry approach toward enrichment of zirconia in zircon sand; this is based on the reaction of the fungus Fusarium oxysporum with zircon sand by a process of selective extracellular bioleaching of silica nanoparticles. Since this reaction does not result in zirconia being simultaneously leached out from the sand, there is a consequent enrichment of the zirconia component in zircon sand. We believe that fungal enzymes specifically hydrolyze the silicates present in the sand to form silicic acid, which on condensation by certain other fungal enzymes results in room-temperature synthesis of silica nanoparticles. This fungus-mediated twofold approach might have vast commercial implications in low-cost, ecofriendly, room-temperature syntheses of technologically important oxide nanomaterials from potentially cheap naturally available raw materials like zircon sand.
authors: Nanoscience Group, Materials Chemistry and Biochemical Sciences Division, National Chemical Laboratory, Pune - 411 008, India.
authors: Vipul
authors: V
authors: Bansal
authors: Asad
authors: A
authors: Syed
authors: Suresh K
authors: SK
authors: Bhargava
authors: Absar
authors: A
authors: Ahmad
authors: Murali
authors: M
authors: Sastry
mesh_terms: D004798:Enzymes / Q000737:chemistry*; D005670:Fusarium / Q000201:enzymology*; D053758:Nanoparticles / Q000737:chemistry / Q000648:ultrastructure; D010316:Particle Size; D017640:Silicates / Q000737:chemistry*; D012822:Silicon Dioxide / Q000737:chemistry*; D017550:Spectroscopy, Fourier Transform Infrared; D013057:Spectrum Analysis; D013499:Surface Properties; D014965:X-Rays; D015040:Zirconium / Q000737:chemistry* / Q000302:isolation & purification
chemical_list: D004798:Enzymes; D017640:Silicates; C003784:zircon; D012822:Silicon Dioxide; D015040:Zirconium; C028541:zirconium oxide