Evaluation of hematite and quartz flotation kinetics using surfactant produced by Rhodococcus erythropolis as bioreagent

Carlos Alberto Castañeda Olivera,Maurício Leonardo Torem,Antonio Gutiérrez Merma

doi:10.1590/0370-44672018720162

Carlos Alberto Castañeda Olivera, Maurício Leonardo Torem + Show 1 more

Open Access

https://doi.org/10.1590/0370-44672018720162

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Abstract

Abstract The use of biosurfactants as reagents represents a promising alternative to the conventional surfactants used in the mineral industry because they may present low toxicity and high biodegradability. Therefore, this research studied the hematite and quartz flotation kinetics using surfactant produced by Rhodococcus erythropolis as bioreagent. The flotation kinetics of both minerals were evaluated under established conditions: biosurfactant concentration of 10 mg/L and solution pH of 3. The maximum floatability values were of 99.98% and 17.53% for hematite and quartz, respectively, after 2 minutes of flotation. Finally, the kinetics study indicated that the experimental data of hematite floatability was better fitted to both the first and non-integral order kinetics, while the experimental data of quartz floatability was better fitted to the non-integral order kinetic.

Highlights

The literature review has shown that some microorganisms can produce surface-active compounds that can vary in their chemical structure and size
Among the great variety of organic solvents that have been used in the biosurfactant extraction, include: Fe2O3 appears as the mineralogical phase of hematite, while SiO2 appears as the mineralogical phase of quartz
It was observed that the experimental data of hematite floatability was better fitted to both the first and non-integral order kinetics with a correlation coefficient (R2) of 0.97, while the experimental data of quartz floatability was better fitted to the non-integral order kinetic with a similar correlation coefficient (R2 = 0.97)

Summary

Introduction

The literature review has shown that some microorganisms can produce surface-active compounds that can vary in their chemical structure and size. These surfactants, often called microbial surfactants or biosurfactants, are considered nowadays as potential substitutes of conventional (chemically produced) surfactants due to their lower toxicity, environmentally friendliness, high biodegradability, and effectiveness over a wide range of temperatures and pH (Khoshdast et al, 2011). Biosurfactants are amphipathic molecules with both hydrophilic and hydrophobic moieties. They have the same characteristics of chemical surfactants, so they can be applied in metal treatment and processing industries (Olivera, 2018). The Rhodococcus erythropolis bacteria is a non-pathogenic Gram-positive microorganism found in a wide variety of sources such as soils, rocks, groundwater and marine sediments (Olivera et al, 2017)

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