Bioprocessing of Natural Phosphate Ore With Staphylococcus Aureus Bacteria

Abstract

Phosphate ores are in high demand around the world because they are the primary raw materials used in the manufacturing of phosphatic fertilizers and other chemicals. Since the grade of the ore is gradually declining, it is becoming economically viable to mine and beneficiate numerous lower-grade deposits, and a significant number of precious minerals are discarded due to the inadequacy of new technological advances. Thus, biological processes are becoming more appealing in mineral processing due to their lower operating costs and potential applications to beneficiate low-grade complex ores through the interaction of bacteria and mineral surfaces, resulting in surface modification and mineral separation via bio-flotation. Staphylococcus aureus was supplied by the mineral bioprocessing lab, CMRDI. Bacterial adhesion measurements revealed a higher affinity for apatite than quartz. A binary mixture containing 12.5% P2O5 and 42.5% SiO2 yielded a concentrate containing 20.15% P2O5 and 33.5% SiO2. Using the bio-flotation process with Staphylococcus aureus and the optimal conditions on natural phosphate ore, a concentrate with 30.25% P2O5 was obtained from a feed containing 21.89% P2O5.

The Role of Biomodification in Mineral Processing

“…Pseudomonas songnenensis was shown to improve apatite flotation in phosphate ore at pH 6.5, but it also did not have a significant change in calcite recovery [64]. Furthermore, another bacteria, S. aureus, was found to preferentially adsorb on apatite, increasing its hydrophobicity and allowing selective separation from quartz at pH 6-7 [65]. Similar observations have been reported for apatite and quartz conditioned with Bacillus cereus.…”