TY - JOUR
T1 - Mineralogical and leaching characteristics of altered ilmenite beach placer sands
AU - Ramakokovhu, Munyadziwa Mercy
AU - Olubambi, Peter Apata
AU - Mbaya, Richard Kady Kadiambuji
AU - Mojisola, Tajudeen
AU - Teffo, Moipone Linda
N1 - Publisher Copyright:
© 2020 by the authors. Licensee MDPI, Basel, Switzerland.
PY - 2020/11
Y1 - 2020/11
N2 - In order to have a good understanding of the treatment process and improvement on the market value of ilmenite beach placer sands, knowledge of its mineral composition and phase distribution is fundamental. In this study, a combination of characterization techniques including high-resolution scanning electron microscopy (HR-SEM), high-resolution transmission electron (HR-TEM) microscope, and X-ray diffraction (XRD) techniques was used to understand the mineralogical characteristics of ilmenite beach placer sands obtained from Richards Bay, South Africa. The mineral phase constituents of the ilmenite beach placer sands were studied before pre-oxidation and additive leaching in a chloride environment. During observations using XRD and HR-SEM, the ilmenite beach placer sands exhibited signature rhombohedral crystal form and crescentic pits with evidence of alteration phases. The characterized pre-oxidized ilmenite showed the presence of a ferric oxide film deposit of the particles. The leaching characteristics of both raw and pre-oxidized ilmenite was studied in the presence of additives. The leaching efficiency of the pre-oxidized ilmenite in the presence of additives increased by 20% at atmospheric conditions. The characterized residues show the improved amenability of pre-oxidized leach in chloride media. The formation of new phases containing pseudo-rutile indicated crystallographic disintegration by the movement of atoms during dissolution. Some particles retained the crescentic pit and the subangular grain structure; however, the phase changes were observed at the grain boundaries and grain edges. The leached residue’s EDS results still indicated the presence of pseudo-rutile and some minor unreacted oxides such as SiO2, Al2O3, and other trace metals. The trace metals impurities present in the as-received ilmenite were reduced by 80% in the final residue after the leaching.
AB - In order to have a good understanding of the treatment process and improvement on the market value of ilmenite beach placer sands, knowledge of its mineral composition and phase distribution is fundamental. In this study, a combination of characterization techniques including high-resolution scanning electron microscopy (HR-SEM), high-resolution transmission electron (HR-TEM) microscope, and X-ray diffraction (XRD) techniques was used to understand the mineralogical characteristics of ilmenite beach placer sands obtained from Richards Bay, South Africa. The mineral phase constituents of the ilmenite beach placer sands were studied before pre-oxidation and additive leaching in a chloride environment. During observations using XRD and HR-SEM, the ilmenite beach placer sands exhibited signature rhombohedral crystal form and crescentic pits with evidence of alteration phases. The characterized pre-oxidized ilmenite showed the presence of a ferric oxide film deposit of the particles. The leaching characteristics of both raw and pre-oxidized ilmenite was studied in the presence of additives. The leaching efficiency of the pre-oxidized ilmenite in the presence of additives increased by 20% at atmospheric conditions. The characterized residues show the improved amenability of pre-oxidized leach in chloride media. The formation of new phases containing pseudo-rutile indicated crystallographic disintegration by the movement of atoms during dissolution. Some particles retained the crescentic pit and the subangular grain structure; however, the phase changes were observed at the grain boundaries and grain edges. The leached residue’s EDS results still indicated the presence of pseudo-rutile and some minor unreacted oxides such as SiO2, Al2O3, and other trace metals. The trace metals impurities present in the as-received ilmenite were reduced by 80% in the final residue after the leaching.
KW - Characterization
KW - Ilmenite
KW - Leaching
KW - Mineralogy
KW - Pseudo-rutile
UR - http://www.scopus.com/inward/record.url?scp=85096613548&partnerID=8YFLogxK
U2 - 10.3390/min10111022
DO - 10.3390/min10111022
M3 - Article
AN - SCOPUS:85096613548
SN - 2075-163X
VL - 10
SP - 1
EP - 18
JO - Minerals
JF - Minerals
IS - 11
M1 - 1022
ER -