Effect of mechanical milling on particle size, magnetic susceptibility and dielectric of synthetic toner colorant magnetite extracted from Indonesian iron sand

As a colorant and additive substance for toner, magnetite (Fe₃O₄) has become main mineral that can produce electrical charge on printing process. In this research, we reports the effect of mechanical milling time to magnetic susceptibility, morphology and dielectric properties of synthetic toner The standard of the grain size of toner including of magnetite dissolved, are ranged from 2 to 10 micron or less, depending on the kind of toner. The results of this research show that the average of particle size decreases from 15μm to 5 μm by milling time between 6 hour to 9 hour and almost constant up to 12 hour. The magnetic susceptibility of the sample decreases as decreasing particle size, while the dielectric constant increases as decreasing particle size.