Magnetic iron oxide, process for its production and the use thereof

A process for improving the triboelectric properties of magnetite particles which comprises combining magnetite particles consisting of magnetic iron oxide having an Fe content of 45 to 73% wt %, a luminance (L*) of 45.0 to 65.0 CIELAB units, a color cast (a*) of -0.5 to 1.5 CIELAB units, a color cast (b*) of -1.0 to -7.0 CIELAB units with one or more additional compounds trom the group consisting of oxides, hydroxides and hydrated oxides of the metals lithium, sodium, potassium, magnesium, calcium, strontium, barium, manganese and zinc, in a quantity of 0.1 to 5% wt. %, which increase the triboelectric charge of the starting material not containing any additives by at least 30%.