| 摘要 |
<p>Ferro-magnetic particles are produced by electrolytic deposition from electrolyte containing iron on the surface of a liquid metal cathode, e.g. mercury, and introducing below the liquid metal surface a supply of the liquid metal whereby the floating layer of deposited magnetic particles overflows and is then separated into magnetic and non-magnetic material. A cell 1 filled with electrolyte to level 30 is provided with an inner open top cathode vessel 2 containing mercury and above which is mounted an anode 4. A vertical tube 33 discharges mercury fed from a reservoir 15, by a solenoid-operated valve 26, below the surface of the mercury in the vessel 2, and the floating layer runs off through an S-bend 5 into a magnetic separator 32. This separator comprises an inclined rotating screw conveyer 6 having notches at the edge of the screw and mounted in a casing surrounded by magnets 7. The magnetic particles are caught in the notches of the conveyer, and the separated mercury flows into a reservoir from which it is pushed up a tube 13 by water pressure. The magnetic particles progress to the left through a furnace 8 where they are age-heated at 200 DEG C. for a few minutes and any occluded mercury is distilled off. Cooling condensers are mounted <PICT:0977459/C6-C7/1> at 9, and an inert gas is introduced to the separator at inlet 11. The ferro-magnetic particles which are either iron or iron-cobalt alloy have a ratio L/W of 1.5 to 1 and are of width 100-1000</>rA. They are mixed with a non-magnetic material, e.g. a thermoplastic resin, lead or lead alloy, the particles are then orientated, and then pressed to form a compact body. In a modified apparatus a series of cathode vessels 2 are used and the mercury feed from reservoir 15 is controlled by a rotating funnel-shaped member having an outlet at its shallow end which is eccentric and passes over a series of feed tubes supplying mercury to the series of cathode vessels at regular intervals.</p> |
