Abstract: The invention refers to a dimensionally stable roller shutter slat consisting of an aluminium strip plastic-coated on one side at least in part, and roll-formed into a hollow section 18 with the coated side inwards, the hollow section featuring upper and lower connecting areas with double-layer aluminum strip and an inside wall 14 as well as an outside wall 13, said hollow section featuring for the increase of the longitudinal stiffness and durability of the roller shutter slat at least one contact point 15, at which at least two aluminum strip layers are bonded connected with one another.

Abstract: In a die-casting machine for producing castings from metals or metal alloys, which castings have a low content of gas, pores and oxides, melt is drawn by means of a vacuum out of a holding device (10) via a suction tube (11) into a casting chamber (3). A casting plunger (7) closes the inlet opening (16) to the casting chamber (3). In order to achieve as low as possible mechanical surface pressure due to flow of the melt, and fluviatile erosion of the die-side end of the inlet opening (16), and thus avoid high wear of this inlet edge or of the casting chamber with casting plunger, a planar or linear inlet cross-section (24, 27) as well as a curved deflection surface (20) on the casting plunger (7) are provided.

Abstract: Disclosed is a molded aluminosilicate catalyst, including a zeolite powder and a SiO.sub.2 -containing powder. The SiO.sub.2 -containing powder includes SiO.sub.2 particles of from about 0.1 to about 5 microns in average diameter. The aluminosilicate catalyst includes from about 5 to about 70 percent by weight of the SiO.sub.2 -containing powder.

Abstract: A process for the production of large boehmite crystal aggregates, useful for soft polishing applications is provided herein. A caustic aluminate liquor is contacted with an oxygen-containing gas at elevated temperatures and pressures in the presence of about 1-50 mg/L of copper ions. The liquor is oxidized until a molar ratio of Na.sub.2 O.sub.free to Al.sub.2 O.sub.3 of less than or equal to 1 is achieved, and the oxidized liquor is cooled under quiescent conditions of little or no agitation which causes the crystallization and precipitation or novel large boehmite particles.

Abstract: The invention concerns a process for producing aluminum by molten salt electrolysis, whereby a melt consisting of alkali halides and/or alkali earth halides is used as electrolyte and a mixture containing aluminum oxide and carbon is used as the anode.

Abstract: A die casting process for making castings by means of a horizontally oriented cold-chamber die casting machine comprises the steps of advancing a casting piston in the casting chamber from a starting position for ejecting the molten metal dosage from the casting chamber; and withdrawing the casting piston into the starting position. The withdrawing step includes the step of passing over metal residues adhering to walls of the casting chamber. Subsequent to the withdrawing step and prior to the charging step of a successive cycle, the casting piston is advanced in the casting chamber void of molten metal dosage for ejecting the metal residues by the casting piston from the charging chamber and returning the casting piston into its starting position.

Abstract: A process of leaching ores, ore concentrates, intermediate metallurgical products and the like, which contain acid-soluble constituents, by a treatment in an acid aqueous solution under pressure in a tubular reactor. The slurry contains suitably 300 to 1100 g starting material per liter of water and a velocity of flow of 0.5 to 4.0 m/sec. is suitably maintained throughout the flow path in the tubular reactor of the slurry and of the leached suspension.

Abstract: Hydrogen fluoride is removed from gases by introducing the gases into a fluidized-bed reactor to form a gas-solid suspension, entraining a major part of the solids in an upward direction separating the solids entrained by the gases without prior removal of the solids from the gas-solid suspension, by means of an electrostatic precipitator.