*4.1.4 Effect of surface charge*

Yield stress measurements are used in combination with electrophoretic and zero charge point measurements as a function of solution pH to detect the surface charge characteristics of particles that play a very important role in froth flotation. Although the coagulation peak, the isoelectric point and the zero charge point all converge at the same value for isotropic minerals, they spread across a wide range of anisotropic minerals, and with the addition of anionic polymer as a dispersant to the mineral suspensions, this disparity between isotropic and anisotropic minerals is even accentuated.
