Research Information System
PHYSICOCHEMICAL PROBLEMS OF MINERAL PROCESSING, vol.60, no.2, pp.1-14, 2024 (SCI-Expanded)
The objective of this research is to study the effects of feed particle size, splitter angle, and washing process on Fe2O3
removal efficiency in the separation of ferrous impurities from
halloysite ore by dry magnetic separation in order to increase the
purity of halloysite sample after crushing and blunging processes
separately. Firstly, after crushing ore in a jaw crusher and sizing to
-2+1 mm, -1+0.5 mm, and -0.5+0.212 mm fractions, the sized materials
were fed to REMS-type dry magnetic separator at a constant belt speed of
300 rpm with the splitter angles of 0, 15, 30º separately. Maximum Fe2O3
removal efficiency (FRE) (97.1%) was obtained in the nonmagnetic
product at -0.5+0.212 mm size fraction and 0º splitter angle. The
minimum Fe2O3 content (1.3%) was reached in the
nonmagnetic product obtained in the experiment with the feed size of
-2+1 mm and a splitter angle of 0º. Secondly, dry magnetic separation
was applied to the washed -2+0.212 mm size fraction after drying at room
temperature to evaluate the coarse particle-sized halloysite ore that
was gained by mechanical dispersion in the aqueous medium towards sodium
hexametaphosphate (SHMP), while a significant part of the clay minerals
went into fine size after the dispersion process. In the experiment
performed with a 0º splitter angle after washing, it was determined that
halloysite concentrate of 0.4% Fe2O3 content could be obtained with 98.8% Fe2O3 removal efficiency. As a result of dry magnetic separation experiments, it was seen that Fe2O3 removal efficiency decreased as the splitter angle increased, while Fe2O3
content in magnetic and nonmagnetic products increased. It was
determined that washing and cleaning of fine-sized minerals plastered on
particle surfaces after mechanical dispersion and particle release of
minerals with different magnetic properties increased the dry magnetic
separation efficiency, and nonmagnetic products with very low Fe2O3 (0.4%) and high Al2O3
(31.9%) content was obtained. The blunging process in the presence of
dispersant caused the dispersion of clay minerals and allowed to
liberating of the ferrous minerals from the halloysite ore, hence the
increase in the FRE for the magnetic separation.