Bio-extraction of phosphorus from goethite ore with alkali addition

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Department of Chemical Engineering


Phosphorus has been long recognized as an unwanted element in steelmaking, which should be kept as low as possible. In current study, bio-extraction of phosphorus from goethite ore by naturally existed alkaline-tolerant microorganisms was investigated. The microbial growth, medium pH, and phosphorus extraction were monitored. It was found that alkali addition did not possess any positive effect on either microbial growth or phosphorus extraction as a whole. Medium pH was readily reduced from initial 8.5 to 4–6, on the other hand, constant alkaline condition was observed to largely inhibit most of microbial activities. A negligible amount of phosphorus was detected in liquid medium, therefore most of the phosphorus removal was attributed to phosphorus uptake for cell growth. Completing 45-day of incubation, the phosphorus content were reduced from initial 0.73% P to an average of 0.59% and 0.63% P by microorganisms obtained from two different sites, which were equivalent to 19% and 14% phosphorus removal. The highest phosphorus removal (38.4%) was correlated to a “massive” biomass development. It was also observed that fungus were favored over bacterium when pH was below 6.5. However, there are still some questions and uncertainties remaining in future regarding bio-beneficiation including: the complexity of microbial growth and reproducibility concern, lack of quantitative analysis and control methods, and the organic carbon requirement.

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© 2019 Elsevier Ltd. All rights reserved. Publisher’s version of record: https://doi.org/10.1016/j.mineng.2019.105850

Publication Title

Minerals Engineering