6
iron leaching started slowly but peaked at 619 mg/L, with
29% iron dissolved over 368 days at a pH range of 4.3 to
5.94.
It was also observed that reductive bioleaching dissolved
more iron from goethite-rich Source A than hematite-rich
Source B, as hematite’s crystalline structure makes it more
resistant to microbial attack. Additionally, the higher dis-
solved iron concentrations in Source A compared to Source
B can be attributed to the finer particle size in Source A,
which increases surface area and microbial accessibility,
enhancing bioleaching efficiency.
ACKNOWLEDGMENT
The author would like to thank the ARPA-E US Department
of Energy for providing funds (ARPA-E Award No.
DE-AR0001336) to carry out this research successfully.
REFERENCES
[1] Norton, M. G. 2021. ‘Iron-The Material of Industry.’
in, Ten Materials That Shaped Our World (Springer
International Publishing: Cham), pp. 45–63.
[2] United States Geological Survey. 2024. ‘Iron
Ore Statistics and Information’, Accessed
09/28/2024. https://www.usgs.gov/centers/national
-minerals-information-center/iron-ore-statistics
-and-information.
[3] Nkuna, R., Ijoma, G. N., Matambo, T. S., and
Chimwani, N., 2022. ‘Accessing metals from low-
grade ores and the environmental impact consider-
ations: a review of the perspectives of conventional
versus bioleaching strategies’, Minerals, 12 (5): 506.
[4] Akbari, H., Noaparast, M., Shafaei, S. Z., Hajati, A.,
Aghazadeh, S., and Akbari, H., 2018. ‘A beneficiation
study on a low grade iron ore by gravity and magnetic
separation’, Russian Journal of Non-ferrous metals, 59:
353–363.
[5] Filippov, L. O., Severov, V. V., and Filippova, I. V.,
2014. ‘An overview of the beneficiation of iron ores
via reverse cationic flotation’, International Journal of
Mineral Processing, 127: 62–69.
[6] Ogbezode, J. E., Ajide, O. O., Oluwole, O. O., and
Ofi, O. 2023. ‘Recent trends in the technologies of
the direct reduction and smelting process of iron ore/
iron oxide in the extraction of iron and steelmak-
ing.’ in, Iron Ores and Iron Oxides-New Perspectives
(IntechOpen), pp. 1–27.
[7] Haque, N. 2022. ‘Life cycle assessment of iron ore
mining and processing.’ in, Iron Ore (Elsevier),
pp. 691–710.
[8] Eisele, T. C., and Gabby, K. L., 2014. ‘Review of
reductive leaching of iron by anaerobic bacteria’,
Mineral Processing and Extractive Metallurgy Review,
35 (2): 75–105.
[9] Bale, C. W., Chartrand, P., Degterov, S., Eriksson,
G., Hack, K., Mahfoud, R. B., Melançon, J., Pelton,
A., and Petersen, S., 2002. ‘FactSage thermochemical
software and databases’, Calphad, 26 (2): 189–228.
[10] Cameselle, C., Ricart, M. T., Nunez, M. J., and Lema,
J. M., 2003. ‘Iron removal from kaolin. Comparison
between “in situ” and “two-stage” bioleaching pro-
cesses’, Hydrometallurgy, 68 (1–3): 97–105.
[11] Castro, L., García-Balboa, C., González, F., Ballester,
A., Blázquez, M. L., and Muñoz, J. A., 2013.
‘Effectiveness of anaerobic iron bio-reduction of
jarosite and the influence of humic substances’,
Hydrometallurgy, 131: 29–33.
[12] Nasab, M. H., Noaparast, M., Abdollahi, H., and
Amoozegar, M. A., 2020. ‘Indirect bioleaching of Co
and Ni from iron rich laterite ore, using metabolic
carboxylic acids generated by P. putida, P. koreensis,
P. bilaji and A. niger’, Hydrometallurgy, 193: 105309.
[13] Alibhai, K. A. K., Dudeney, A. W. L., Leak, D. J.,
Agatzini, S., and Tzeferis, P., 1993. ‘Bioleaching and
bioprecipitation of nickel and iron from laterites’,
FEMS microbiology reviews, 11 (1–3): 87–95.
[14] Rouchalova, D., Rouchalova, K., Janakova, I., Cablik,
V., and Janstova, S., 2020. ‘Bioleaching of iron, cop-
per, lead, and zinc from the sludge mining sediment
at different particle sizes, pH, and pulp density using
Acidithiobacillus ferrooxidans’, Minerals, 10 (11): 1013.
[15] Hosseini, M., Pazouki, M., Ranjbar, M., and
Habibian, M. R., 2007. ‘Bioleaching of iron from
highly contaminated kaolin clay by Aspergillus niger’,
Applied Clay Science, 37 (3–4): 251–257.
Table 3. X-ray diffraction analysis of the iron ore tailings
before and after the leaching process
Iron Ore
Tailing
Source
Mineral
Phases
Weight %in
Tailings Before
Leaching
Weight %in
Residue After
Leaching
A Goethite
(FeOOH)
19.3 12.1
Hematite
(Fe2O3)
5.9 4.8
Quartz (SiO
2 )74.8 80.4
Siderite
(FeCO
3 )
— 2.7
B Hematite
(Fe2O3)
15.1 11.9
Quartz (SiO2) 84.9 88.1
iron leaching started slowly but peaked at 619 mg/L, with
29% iron dissolved over 368 days at a pH range of 4.3 to
5.94.
It was also observed that reductive bioleaching dissolved
more iron from goethite-rich Source A than hematite-rich
Source B, as hematite’s crystalline structure makes it more
resistant to microbial attack. Additionally, the higher dis-
solved iron concentrations in Source A compared to Source
B can be attributed to the finer particle size in Source A,
which increases surface area and microbial accessibility,
enhancing bioleaching efficiency.
ACKNOWLEDGMENT
The author would like to thank the ARPA-E US Department
of Energy for providing funds (ARPA-E Award No.
DE-AR0001336) to carry out this research successfully.
REFERENCES
[1] Norton, M. G. 2021. ‘Iron-The Material of Industry.’
in, Ten Materials That Shaped Our World (Springer
International Publishing: Cham), pp. 45–63.
[2] United States Geological Survey. 2024. ‘Iron
Ore Statistics and Information’, Accessed
09/28/2024. https://www.usgs.gov/centers/national
-minerals-information-center/iron-ore-statistics
-and-information.
[3] Nkuna, R., Ijoma, G. N., Matambo, T. S., and
Chimwani, N., 2022. ‘Accessing metals from low-
grade ores and the environmental impact consider-
ations: a review of the perspectives of conventional
versus bioleaching strategies’, Minerals, 12 (5): 506.
[4] Akbari, H., Noaparast, M., Shafaei, S. Z., Hajati, A.,
Aghazadeh, S., and Akbari, H., 2018. ‘A beneficiation
study on a low grade iron ore by gravity and magnetic
separation’, Russian Journal of Non-ferrous metals, 59:
353–363.
[5] Filippov, L. O., Severov, V. V., and Filippova, I. V.,
2014. ‘An overview of the beneficiation of iron ores
via reverse cationic flotation’, International Journal of
Mineral Processing, 127: 62–69.
[6] Ogbezode, J. E., Ajide, O. O., Oluwole, O. O., and
Ofi, O. 2023. ‘Recent trends in the technologies of
the direct reduction and smelting process of iron ore/
iron oxide in the extraction of iron and steelmak-
ing.’ in, Iron Ores and Iron Oxides-New Perspectives
(IntechOpen), pp. 1–27.
[7] Haque, N. 2022. ‘Life cycle assessment of iron ore
mining and processing.’ in, Iron Ore (Elsevier),
pp. 691–710.
[8] Eisele, T. C., and Gabby, K. L., 2014. ‘Review of
reductive leaching of iron by anaerobic bacteria’,
Mineral Processing and Extractive Metallurgy Review,
35 (2): 75–105.
[9] Bale, C. W., Chartrand, P., Degterov, S., Eriksson,
G., Hack, K., Mahfoud, R. B., Melançon, J., Pelton,
A., and Petersen, S., 2002. ‘FactSage thermochemical
software and databases’, Calphad, 26 (2): 189–228.
[10] Cameselle, C., Ricart, M. T., Nunez, M. J., and Lema,
J. M., 2003. ‘Iron removal from kaolin. Comparison
between “in situ” and “two-stage” bioleaching pro-
cesses’, Hydrometallurgy, 68 (1–3): 97–105.
[11] Castro, L., García-Balboa, C., González, F., Ballester,
A., Blázquez, M. L., and Muñoz, J. A., 2013.
‘Effectiveness of anaerobic iron bio-reduction of
jarosite and the influence of humic substances’,
Hydrometallurgy, 131: 29–33.
[12] Nasab, M. H., Noaparast, M., Abdollahi, H., and
Amoozegar, M. A., 2020. ‘Indirect bioleaching of Co
and Ni from iron rich laterite ore, using metabolic
carboxylic acids generated by P. putida, P. koreensis,
P. bilaji and A. niger’, Hydrometallurgy, 193: 105309.
[13] Alibhai, K. A. K., Dudeney, A. W. L., Leak, D. J.,
Agatzini, S., and Tzeferis, P., 1993. ‘Bioleaching and
bioprecipitation of nickel and iron from laterites’,
FEMS microbiology reviews, 11 (1–3): 87–95.
[14] Rouchalova, D., Rouchalova, K., Janakova, I., Cablik,
V., and Janstova, S., 2020. ‘Bioleaching of iron, cop-
per, lead, and zinc from the sludge mining sediment
at different particle sizes, pH, and pulp density using
Acidithiobacillus ferrooxidans’, Minerals, 10 (11): 1013.
[15] Hosseini, M., Pazouki, M., Ranjbar, M., and
Habibian, M. R., 2007. ‘Bioleaching of iron from
highly contaminated kaolin clay by Aspergillus niger’,
Applied Clay Science, 37 (3–4): 251–257.
Table 3. X-ray diffraction analysis of the iron ore tailings
before and after the leaching process
Iron Ore
Tailing
Source
Mineral
Phases
Weight %in
Tailings Before
Leaching
Weight %in
Residue After
Leaching
A Goethite
(FeOOH)
19.3 12.1
Hematite
(Fe2O3)
5.9 4.8
Quartz (SiO
2 )74.8 80.4
Siderite
(FeCO
3 )
— 2.7
B Hematite
(Fe2O3)
15.1 11.9
Quartz (SiO2) 84.9 88.1