In this study, the effect of an external magnetic field on cationic flotation of quartz from magnetite was investigated by using a magnetic micro-flotation column. For this purpose, a micro-flotation column jacketed with three coils was fabricated to create a funnel-shaped magnetic field. Both the theoretical magnetic field strengths and the magnetic forces were calculated. The results from flotation experiments with 6 x 10(-5) M dodecylamine as collector using a binary mixture of quartz and magnetite as a feed material show that the separation efficiency increased from 0% without the magnetic field to 88% in the presence of the magnetic field. The significant enhancement in separation efficiency is evident. (C) 2010 Elsevier Ltd. All rights reserved.