Preparation of an activated carbon involving magnetic properties

Abstract

Magnetic activated carbon composite (MAC) was successfully prepared from olive residues and hematite (Fe2O3/AC). MAC was prepared based on a wet impregnation method followed by carbonization, under different operating conditions. Specifically, two different MACs were prepared by altering the temperature ramp rate during the carbonization procedure (5 and 20 min/°C), designated here as MAC5 and MAC20, respectively. The increased magnetic capacity of the two MACs (as evidenced by the measured permanent magnetism of 30 mT), allowed their easy separation by utilizing a simple magnetic separation technology. The efficient impregnation of the iron oxide on the two MACs was confirmed by Fourier transform infrared spectroscopy (FT-IR), while scanning electron microscopy (SEM) was used to characterize the morphology of the composites. FT-IR measurements showed the appearance of new peaks, between 500 and 700 cm−1 which is evidence of the effective binding of iron onto AC (C/Fe). The SEM images offered an insight to the size and the distribution of the pores on the MAC, which appeared to be much better than the pure AC. The magnetic separation was examined through mass balances, before and after applying the magnetic field. The results showed that the magnetic efficiency of MAC5 is higher compared to that of MAC20. The magnetic properties of the produced MAC pave the way for their utilization in magnetic separation methods.