ROLE OF MAGNETITE AND SODIUM OLEATE IN THE HIGH-GRADIENT MAGNETIC SEPARATION OF CALCITE USING MAGNETIC COATING OF THE SURFACE

Calcite, which is essentially nonmagnetic, has been coated with magnetite, which is ferromagnetic. The coated calcite can be obtained as the magnetic fraction in high-gradient magnetic separation. The roles of magnetite and sodium oleate added during coating have been investigated using SEM/EDAX, magnetic susceptibility, electrokinetic experiments, and FTIR. The magnetite particles stick to the surface only at a few points and sodium oleate helps the process of heteroflocculation by chemical interaction in which polymerization between oleate chains takes place by the formation of -C-O-C- bonds. © 1993 by Academic Press, Inc.