Abstract: Iron ore concentrate is converted to magnetic gamma hematite in an autogenous roasting operation which is self-sustaining. The iron ore concentrate is preheated and contained magnetite is oxidized to hematite. Hematite is reduced to magnetite using carbon monoxide. After cooling, the magnetite is oxidatively exothermically converted to magnetic gamma hematite. The thermal energy resulting from the latter step is recycled to the preheating and reduction steps while thermal energy resulting from the cooling step also is recycled to those steps. The magnetic gamma hematite may be subjected to magnetic separation to produce a very low silica high purity iron oxide concentrate, which may be blended with high silica concentrate to provide a pellet feed for making blast furnace feed pellets.

Abstract: Steel sheet is formed directly from iron ore concentrate by reducing a bed of iron ore concentrate, particularly high purity magnetized magnetic gamma hematite, to a low density hot cake of carburized metallic iron and then hot rolling the hot cake to a metallic sheet of full density (meeting market specification).

Abstract: Iron ore concentrate is converted to magnetic gamma hematite in an autogenous roasting operation which is self-sustaining. The iron ore concentrate is preheated and contained magnetite is oxidized to hematite. Hematite is reduced to magnetite using carbon monoxide. After cooling, the magnetite is oxidatively exothermically converted to magnetic gamma hematite. The thermal energy resulting from the latter step is recycled to the preheating and reduction steps while thermal energy resulting from the cooling step also is recycled to those steps. The magnetic gamma hematite may be subjected to magnetic separation to produce a very low silica high purity iron oxide concentrate, which may be blended with high silica concentrate to provide a pellet feed for making blast furnace feed pellets.

Abstract: A procedure for stopping and starting a D.C. ferrite toroid motor so as to ensure that the rotor always rotates in the correct direction on starting. The windings in the stator are arranged in a plurality of circuits. Upon opening of the power switch to the motor, activation of one of the stator circuits only results in magnetic poles which attract the rotor poles, thereby slowing and stopping the rotor. Upon activation of the other of the stator circuits, an attractive stator pole is established ahead of a rotor pole and a repulsive stator pole is established behind the rotor pole, thereby ensuring rotation in the desired direction.

Abstract: Reactions between solid materials to form useful products, for example, strontium ferrites, are effected by heating a primary solid feed material with a plasma gas stream to melt the primary feed material and then contacting a secondary solid feed material with the molten primary feed material and the plasma gas stream to melt the secondary feed material and enable reaction among the reactants to occur. The method of the invention simplifies the effecting of solid-solid reactions using plasma gas streams and permits the use of impure materials as the secondary feed material, strontium carbonate or strontium oxide and ferric oxide (hematite), so as to form a strontium ferrite.

Abstract: Permanent magnets are used to perform useful work. The field of a first permanent magnet is diverted by electromagnetic coils to such a low value that another opposing permanent magnet can approach the first magnet without the application of undue force. The field in the first magnet is restored to act on the second magnet so as to repel it. The force which results may be harnessed to effect reciprocal or rotary motion.

Abstract: Electrically-conducting particles may be separated from mixtures thereof containing non-conducting particles by conveying the mixture through a magnetic field oriented angularly with respect to the part of conveyance. The magnetic field induces magnetic poles in the conducting particles, causing them to deflect from the path of movement of the mixture as they attempt to move in the angular orientation of the magnetic field. The non-conducting particles are unaffected, so that a separation may be achieved. The invention is applicable to a wide variety of materials, such as ores or tailings which contain desired electrically-conducting particles, such as, iron oxide, and unwanted gangue constituents.