PURPOSE: To inexpensively and efficiently obtain iron oxide having high purity by feeding air to an aq. acid iron chloride soln. added with a surface active agent and alumina granular particles to foam the soln. and floating and separating the silicon-components in the dissolved state.
CONSTITUTION: The surface active agent (e.g.: lauryl pyridinium chloride) and α-alumina granular particles as the adsorption assistant are added to the aq. acid iron chloride soln. which is waste liquid of pickling of steel products and after the soln. is stirred, the air is fed thereto for 30minW1hr at 5l/min to foam the soln. The various silicon-components in the dissolved state contained in the aq. soln. are floated and separated. The silicon-components (SiO2) in the aq. acid iron chloride soln. are thereby decreased to ≤20ppm.
NAKANE TAKEMI
IWAKI KAN
MORI KAZUTAKA
ITO YOSHIBUMI
