The nickel ores of Sudbury contain substantial amounts of the gangue minera
l pyrrhotite (Fe8S9) which causes certain difficulties in The milling of th
ese ores. This paper proposes a process called "magnetoflotation" as an eff
ective means of dealing with pyrrhotite. The method reduces the pyrrhotite
content of concentrates by applying a magnetic field on the froth product a
s it leaves the flotation cell.
Successful performance of magnetoflotation requires the optimization of sev
eral variables. In this study, three of the variables (frother concentratio
n, collector concentration, air flowrate) were investigated by Box-Wilson e
xperimental design, and others (magnet speed, grind size, pulp density, flo
tation time) were examined individually. The process was tested on a Falcon
bridge nickel ore, assaying 1.92% Ni, and under the best operating conditio
ns, a concentrate was obtained with 13.56% Ni grade and 74.32% recovery in
a single step. Further improvements to grade and recovery were possible by
cleaning and scavenging. The same ore was also tested with conventional met
hods for comparison, and results indicated that magnetoflotation performed
better.