2483
Investigation of pH Conditions Effect on Xanthate,
Dithiocarbamate and S-Triazine Collectors Performance on
Platarsite and Sperrylite Minerals
Bradley Nemutudi, Peace Mkhonto, Phuti Ngoepe
Materials Modelling Centre, University of Limpopo, Sovenga, South Africa
Sophia Pikinini, Belinda McFadzean
Centre for Minerals Research, University of Cape Town, Rondebosch, South Africa
Xingrong Zhang
College of Chemical Engineering, Qingdao University of Science and Technology, Qingdao, China
State Key Laboratory of Mineral Processing, BGRIMM Group, Beijing, China
ABSTRACT: There is still a huge challenge in efficiently recovering the arsenides platinum group minerals
(PGMs) in particular the platarsite and sperrylite minerals that are largely concentrated in the Platreef Bushveld
Complex. Therefore new collectors are required to improve the recovery separation of arsenides. In this study,
the density functional theory (DFT) and experimental (microcalorimetry and microflotation) methods were
adopted to investigate the performance of the well-known normal butyl xanthate (NBX) and normal butyl
dithiocarbamate (NBDTC) in comparison with the novel 2,6-dithio-4-butylamino-1,3,5-triazine (DTBAT)
collector under different pH conditions on platarsite and sperrylite minerals. The collectors were computationally
adsorbed on dry and hydrated surface under neutral and acidic conditions on sperrylite, while on platarsite only
the dry condition was considered. It was found that the adsorption energies on platarsite followed the decreasing
order as: DTBAT NBDTC NBX, under both neutral and acidic conditions, indicating that the DTBAT
had strong exothermic adsorption. The adsorption energies on dry and hydrated sperrylite surface followed
the decreasing order as: NBDTC DTBAT NBX under acidic condition, while under neutral condition
the order followed as: DTBAT NBDTC NBX. The sperrylite minerals adsorptions were complemented
by microcalorimetry and microflotation. It was noted that the neutral condition was in agreement with the
microcalorimetry heats of adsorption trend (DTBAT NBDTC NBX), while the acidic condition agreed
well with the microflotation recoveries (NBDTC DTBAT NBX). It was noted that under acidic condition
sperrylite gave higher recoveries compared to neutral conditions. These results suggested that the NBDTC may
be highly selective in improving the flotation of the slow floating sperrylite mineral under acidic condition,
while SDTBAT would perform better under neutral conditions. Therefore, these results paved a way for design
of novel collector for platarsite and sperrylite minerals to improve their recovery.
Investigation of pH Conditions Effect on Xanthate,
Dithiocarbamate and S-Triazine Collectors Performance on
Platarsite and Sperrylite Minerals
Bradley Nemutudi, Peace Mkhonto, Phuti Ngoepe
Materials Modelling Centre, University of Limpopo, Sovenga, South Africa
Sophia Pikinini, Belinda McFadzean
Centre for Minerals Research, University of Cape Town, Rondebosch, South Africa
Xingrong Zhang
College of Chemical Engineering, Qingdao University of Science and Technology, Qingdao, China
State Key Laboratory of Mineral Processing, BGRIMM Group, Beijing, China
ABSTRACT: There is still a huge challenge in efficiently recovering the arsenides platinum group minerals
(PGMs) in particular the platarsite and sperrylite minerals that are largely concentrated in the Platreef Bushveld
Complex. Therefore new collectors are required to improve the recovery separation of arsenides. In this study,
the density functional theory (DFT) and experimental (microcalorimetry and microflotation) methods were
adopted to investigate the performance of the well-known normal butyl xanthate (NBX) and normal butyl
dithiocarbamate (NBDTC) in comparison with the novel 2,6-dithio-4-butylamino-1,3,5-triazine (DTBAT)
collector under different pH conditions on platarsite and sperrylite minerals. The collectors were computationally
adsorbed on dry and hydrated surface under neutral and acidic conditions on sperrylite, while on platarsite only
the dry condition was considered. It was found that the adsorption energies on platarsite followed the decreasing
order as: DTBAT NBDTC NBX, under both neutral and acidic conditions, indicating that the DTBAT
had strong exothermic adsorption. The adsorption energies on dry and hydrated sperrylite surface followed
the decreasing order as: NBDTC DTBAT NBX under acidic condition, while under neutral condition
the order followed as: DTBAT NBDTC NBX. The sperrylite minerals adsorptions were complemented
by microcalorimetry and microflotation. It was noted that the neutral condition was in agreement with the
microcalorimetry heats of adsorption trend (DTBAT NBDTC NBX), while the acidic condition agreed
well with the microflotation recoveries (NBDTC DTBAT NBX). It was noted that under acidic condition
sperrylite gave higher recoveries compared to neutral conditions. These results suggested that the NBDTC may
be highly selective in improving the flotation of the slow floating sperrylite mineral under acidic condition,
while SDTBAT would perform better under neutral conditions. Therefore, these results paved a way for design
of novel collector for platarsite and sperrylite minerals to improve their recovery.