Preparation of magnetic coal-based activated carbon

Magnetic coal-based activated carbons (MCAC) were prepared from Datong bituminous coal in the presence of different amounts of Fe₃O₄. Their pore structures were characterized by N₂ adsorption isotherm, and their iodine value, methylene blue value and magnetic properties were determined. The results show that Fe₃O₄ in the raw material is of importance to mesopores formation, and the ratio of mesopore volume reaches up to 76.0% when the mass fraction of Fe₃O₄ in the raw material is 10%. The iodine value decreases by 25.5% and the methylene blue value increases by 79.9% for the activated carbon with 7% Fe₃O₄ compared with common activated carbon without additives. A proper amount of Fe₃O₄ in the raw material makes it possible to grant the activated carbon with a higher magnetism and a bigger magnetoconductivity:MCACs derived from the raw materials containing 4% Fe₃O₄ and 7% Fe₃O₄ possess the magnetizations greater than common activated carbon by 24.4 times and 44.5 times, respectively.