Study on Zeta Potential of Micron-Size Tourmaline Powders

Zeta potential of micron-size tourmaline powders are studied using the laser granulometer and the Zeta potential analyzer. The result from the experiment shows, in the neutral condition, the micron-size tourmaline is negatively charged under water and Elbaite powder has the highest Zeta potential among all tested ones; the smaller the tourmaline powder is, the higher Zeta potential it has; heat-treated samples under reducing conditions have higher Zeta potential than those under oxidizing conditions by 4~5 mV; Dravites isoelectric point is 3.4, falling within the acid range.