Abstract: An apparatus for collecting ferromagnetic particles distributed in metal or metal alloy material is disclosed. A tank containing an electrolyte is provided to electrochemically dissolve the metal or metal alloy material without substantial dissolving of the particles. A support surface is provided within the electrolyte for supporting the dissolving metal material and collecting undissolved particles. The support surface further comprises the working electrode in conjunction with the metal material. A magnetic field forming device is associated with the support surface for magnetically adhering undissolved particles to the support surface so as to maximize recovery of the particles.

Abstract: The method for preventing the inclusion of slag into the molten steel tapped from a converter is disclosed. Such method comprises immersing an elongated stopper in a molten steel contained in the converter until the stopper is positioned at a predetermined height above the inside opening of a tap hole, directing the elongated stopper to the inside opening irrespective of tilting of the converter such that the stopper could maintain the predetermined position while allowing a constant flow-out of the molten steel into the tap hole through the space formed between the stopper and the inside opening of the tap hole, and lowering the elongated stopper to close the tap hole when the slag floating above the molten steel is about to flow into the tap hole through the space, whereby the inclusion of the slag into the tapped molten steel can be prevented effectively. The apparatus which can efficiently conduct the above method is also disclosed.