TY  - JOUR
N2  - The stability of quartz in a multi-phase system of kaolinite and Al (hydr)oxides and quartz has been addressed in quite a few studies. However, the impact of pH on these multi-mineral interactions has not been elucidated. Therefore, this study shows the different dissolution behaviour and surface morphology of quartz admixed with hydrous kaolinite and aluminium (hydr)oxides under variable pH conditions. This will enhance the predictability of silica behaviour in natural rock weathering and reservoir systems. Scanning electron microscopy characterization shows that kaolinite and Al (hydr)oxides exhibit high-quality coating of quartz surface at acidic and alkali pH by creating a surficial secondary layer that allows agglomeration of other minerals, while Fourier transform infrared analysis showed shifts in peak positions of Siâ??O quartz from 691 cmâ??1 and 692 cmâ??1 at pH 5 and 7 to 686 cmâ??1 at pH13, and broadening of characteristic hydroxide and siloxane peaks as well as the formation of new Siâ??Oâ??Al bonds at pH 13, suggesting structural changes in hydrous aluminosilicates and Al hydroxides (broken bonds of Alâ??Oâ??Si, Alâ??Oâ??Al and Siâ??Oâ??Si) and Al substitution for Si in tetrahedral sheets. The dissolved silica in quartzâ??kaoliniteâ??Al (hydr)oxides interactions is relatively lower under alkali conditions compared to acidic pH. Quartz dissolution was highest at pH 7; signifying the interaction of quartz with Al (hydr)oxides and kaolinite is favourable for quartz dissolution at neutral pH range. The results indicate that quartz interaction with kaolinite and Al (hydr)oxides is dependent on pH. Quartz coating by kaolinite and Al (hydr)oxides is more effective under alkali pH conditions, given the low solubility of Al within this pH range. © 2019, Springer Nature Switzerland AG.
SN  - 25233971
Y1  - 2019///
KW  - Aluminum coatings; Aluminum metallography; Dissolution; Hydraulic servomechanisms; Kaolinite; Morphology; pH; Quartz; Scanning electron microscopy; Silicon; Surface morphology; System stability; Weathering
KW  -  Dissolution behaviour; Fourier transform infra reds; High quality coatings; Mineral interactions; Multi phase systems; Quartz dissolution; Reservoir systems; Tetrahedral sheets
KW  -  Aluminum compounds
IS  - 5
TI  - Effect of pH on the stability of quartz in a multi-phase system of kaolinite, hydrous Al (hydr)oxide and quartz
UR  - https://www.scopus.com/inward/record.uri?eid=2-s2.0-85100721142&doi=10.1007%2fs42452-019-0398-3&partnerID=40&md5=932fc20fc413a48aeab2d38b966b34c7
A1  - Ali, A.M.
A1  - Padmanabhan, E.
A1  - Mijinyawa, A.
A1  - Kwaya, M.Y.
N1  - cited By 3
ID  - scholars11597
PB  - Springer Nature
JF  - SN Applied Sciences
AV  - none
VL  - 1
ER  -