2014-Sustainable Industrial Processing Summit
SIPS 2014 Volume 2: Mineral Processing
| Editors: | Kongoli F |
| Publisher: | Flogen Star OUTREACH |
| Publication Year: | 2014 |
| Pages: | 446 pages |
| ISBN: | 978-1-987820-04-1 |
| ISSN: | 2291-1227 (Metals and Materials Processing in a Clean Environment Series) |
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Microbial Bio-Amphiphiles: Environmentally Benign Flotation Agents for the Selective Separation of Mineral Particles
Chih-Wei Liao1; Ya-Wen Yah1; Hassan El-Shall1; Laurie Gower1;1UNIVERSITY OF FLORIDA, Gainesville, United States;
Type of Paper: Regular
Id Paper: 132
Topic: 2
Abstract:
A challenge for sustainability in the mining industry is the use of toxic or harsh reagents for separation of mineral components. We present here a biotechnology approach which has the potential to improve mineral separation efficiencies, while also using biodegradable flotation agents that are effective at neutral pH conditions. The biotechnology approach is based on phage display, where phage (virus particles) are genetically modified to 'display' a different peptide on their 'tail' proteins, with around 109 different peptide combinations available from a commercial phage library. This library of phage clones can be placed in a solution containing the target material of interest, where the phage that happen to bind to the target are collected, and then subjected to another 'biopanning' round in order to 'evolve' a set of phage clones that have strong binding affinity to the target. From this group of clones, one can then chose the clones that do not bind to the undesired material, in order to achieve a specificity in binding. We demonstrate this biotechnology approach using a specific example based on the Florida phosphate mining industry, which is concerned with the separation of dolomite (CaMg(CO3)2) contaminants from the desired francolite mineral (a fluorapatite (Ca5(PO4)3(F,OH)), which have similar surface chemistries, and are therefore notoriously difficult to separate. Using phage display, we screened for phage clones that had a strong and preferential binding affinity to Francolite, relative dolomite. The coat proteins of phage are relatively hydrophobic, which enabled the phage to be used as bioamphiphiles for flotation, where they concentrated the content of francolite relative to dolomite from 25% to 42% in a bench-top flotation apparatus. The potential for using this biotechnology approach for commodity applications is discussed, where we believe that phage can provide a renewable 'surfactant' for environmentally-benign particle processing.