Abstract: An extruded drill blank which has uniform pitch of grooves or lands on the circumference thereof and flushing bores of uniform diameter. A tool and process for producing the extruded drill blank comprises heating a hard metal or ceramic material to the extrusion temperature thereof, pressing the heated metal or ceramic material through the space defined by a mandrel and a nozzle and twisting the blank helically during the extrusion, whereby the billet is guided in the direction of the extrusion by at least one land or groove extending helically and provided on the inside surface of the nozzle, and contemporaneously forming bores on the blank with at least one elastic center pin secured onto the mandrel and spaced apart by a spacing corresponding to the flushing bore; the mandrel terminating prior to the nozzle, and the center pin protruding into the nozzle interior and having a diameter corresponding to the diameter of the flushing bores.

Abstract: A process for the production of ferrochromium from iron-containing chromium ores, in which the reduction of the ore, which is mixed with coal and slag-forming constituents, is conducted in a rotary kiln at 1480.degree. to 1580.degree. C. in the presence of a CO-containing atmosphere from 20 to 240 minutes, and in which melting follows in a melting furnace at 1600.degree. to 1700.degree. C. By this process, the greatest part of the gangue of the ore can be separated off before melting the reduced ore.

Abstract: A process for the production of ferromanganese from iron-containing manganese ores, in which the reduction of the ore, which is mixed with coal and slag-forming constituents, is conducted in a rotary kiln at 1200.degree. to 1350.degree. C. in the presence of a CO-containing atmosphere for 20 to 240 minutes, and in which melting follows in a melting furnace at 1400.degree. to 1600.degree. C. By this process, the greatest part of the gangue of manganese ore can be separated off before melting the reduced ore.

Abstract: An impact crusher, especially for crushing stone, includes a housing (1) which comprises a delivery chute (5) for supplying the material to be crushed to a rotor (3) which has beater blades (4), rotates about a horizontal axis and with which rebound walls (7) are associated, which rebound walls (7) approach the rotor (3) in the region of the upper quadrant of the descending side of the rotor (3) and form, with the latter, a delivery opening (8) for the crushed material. One or more slipways (11, 12) project in the region of the delivery opening (8) from the rebound wall (7) towards the rotor (3) and form, with their upper edge, a guideway which extends from the delivery-opening (8) at a slight angle towards the horizontal and is guided upwards in a direction over the rotor (3).