Electrokinetic Properties of Kaolins, Sodium Feldspar and Quartz
Sitthisak Prasanphan and Apinon Nuntiya** Author for corresponding; e-mail address: anuntiya@chiangmai.ac.th
Volume: Vol.33 No.2 (MAY 2006)
Research Article
DOI:
Received: 28 December 2005, Revised: -, Accepted: 12 April 2006, Published: -
Citation: Prasanphan S. and Nuntiya A., Electrokinetic Properties of Kaolins, Sodium Feldspar and Quartz, Chiang Mai Journal of Science, 2006; 33(2): 183-190.
Abstract
Zeta potential of three kaolins (Ranong, Lampang and Narathiwat), sodium feldspar and quartz were determined as a function of pH and in the presence of sodium silicate. From the experimental results, it was found that the increase of the suspension pH resulted in an increase in the negative charge of the three kaolins, sodium feldspar and quartz. Furthermore, when sodium feldspar and quartz were added to either of the kaolins, it was found that the zeta potential of the mixtures decreased (being less negative) as the concentration of sodium feldspar and quartz increased. The results also indicate that the zeta potential of the 25wt% sodium feldspar-25wt% quartz-50wt% kaolin mixtures were more negatively charge than those of sodium feldspar and quartz, but less negatively charge than that of the kaolins. The addition of sodium silicate into the suspensions provided higher negative zeta potential. The three kaolins and sodium feldspar did not show any isoelectric point, but quartz showed isoelectric points at pH about 2.13 and 2.77 in the absence and presence of sodium silicate in suspensions, respectively.