Iron oxide-based nanomaterials prepared via ball milling process.

Milling process	Equipment/ball properties	Milling agent/solvents and conditions	Characteristics	Ref.
WBM	Planetary ball mill	DI water, 4 h, 500 rpm	High adsorption capacities of Cr(iv) qe = 48.1 mg g−1	34
DBM	Iron balls with 1.5 cm diameter	30 h and 90 h	31.48 emu g−1 and 37.80 emu g−1	81
DBM	Steel balls with 8 mm diameter	25 rpm, 60 min	Particle size = 45 nm	82
DBM	Planetary ball mill	30 min, 320 rpm	M s = 20.45 emu g−1	83