MILLING AND WASHING METHOD OF FINE METALLIC GRAIN

摘要

PURPOSE:To strip away the impurity layer on the surface of fine metallic grains in a short period by charging said grains together with media made of a magnetosensitive material into a cylindrical vessel and rotating the grains at a high speed while exerting load thereto from above then washing the grains. CONSTITUTION:The fine metallic grains such as steel balls having the impurity layer on the surfaces are charged together with the media 5 made of the magnetosensitive material into the cylindrical vessel 1. A drop cap 2 is imposed thereon and the load is exerted thereto from above by a heavy material. A vertical revolving shaft 3 is rotated at a high speed to rotate the metallic grains and media 5 at a high speed by a plate-shaped rotating vane 4. Powerful impact force is thereby exerted to the fine metallic grains and the impurity layer sticking thereto is stripped away. The cap 2 and the load are removed upon ending of the milling stage. A required washing liquid is then fed through a lower supply port 6 and the vane 4 is gently rotated while the liquid is made to overflow from an upper overflow port 7. Electricity is conducted to an electromagnet 8 to take out the stripped impurities.