Abstract: A method for extracting aluminum of substantial purity from furnace products resulting from carbothermic reduction of alumina-bearing ores and contaminated with up to about 30 weight percent of aluminum carbide is disclosed. The method involves contacting the furnace product with a high alumina-containing molten slag in the substantial absence of reactive carbon, so as to cause the alumina-containing slag to react with the aluminum carbide, thereby diminishing the aluminum carbide content of the furnace product to the level of 4-10% aluminum carbide by weight. It further involves heating the partially purified furnace product in the absence of both reactive carbon and slag, thereby reacting the self-contained alumina with the aluminum carbide contaminant to produce a purified aluminum.

Abstract: A batch method is described for decarbonizing aluminum primary furnace product from an aluminum carbide content of up to about 35% to a useful content of about 2% Al.sub.4 C.sub.3. The method maximizes mass transfer of the aluminum carbide from molten primary furnace product to molten slag and molten alumina in a decarbonization furnace which has elevatable electrodes and is operated in the extraction mode according to the equation:Al.sub.4 C.sub.3 +4Al.sub.2 O.sub.3 .fwdarw.Al.sub.4 O.sub.4 C.The method comprises forming an overlying molten layer of primary furnace product, preferably as an aluminum alloy containing 9.5% Al.sub.4 C.sub.3 and 12% Al.sub.2 O.sub.3 and at a temperature of about 2100.degree. C., and an underlying molten layer of slag, at a temperature of about 1900.degree. C., and then adding an alumina cover layer of granular alumina onto the overlying layer of alloy melt.

Abstract: A gauge for thickness measurement, being particularly adapted to measuring thickness within grooves, is disclosed. The gauge employs a reinforced blade as the groove entering element. This blade is designed to prevent penetration of the workpiece being measured, resulting in enhanced accuracy.

Abstract: A retortable membrane closure structure for containers is disclosed which includes a first adhesive layer, an intermediate layer, a second adhesive layer and an outer barrier layer. Bond strengths and tear strengths of the layers are selected such that upon peeling the membrane from a container to which it was sealed initial failure occurs within the intermediate layer, followed by failure between the second adhesive layer and the intermediate layer, providing a clean peel between the layers.

Abstract: In a process for purifying aluminum chloride made by the high temperature chlorination of an aluminum value containing material by distilling the aluminum chloride in a still, and separating the aluminum chloride the improvement comprising adding sufficient alkali chloride to the aluminum chloride as to provide an aluminum chloride/alkali chloride mixture having a conductivity sufficient to permit internal electrical resistance heating of the still when an electric current is applied across the still mixture.

Abstract: A selective solar coating for solar collectors is disclosed. The coating is characterized by its high absorptance and low emittance. The coating comprises an organic compound or substance having a high molecular weight and a high carbon content, such as a petroleum, vegetable or animal oil, fat or wax, which is pyrolyzed to produce a carbon black pigmented varnish.

Abstract: A method for producing alumina from a material containing alumina values via a chlorination step which process comprises the steps of:(A) dehydrating the material, if necessary, at a temperature of between about 500 and about 1300.degree. K.;(B) chlorinating the product of step (A) in the presence of chlorine and carbon at a temperature below about 1200.degree. K. and under conditions which provide chlorination of a majority of the iron present in the clay without substantial chlorination of titania values which may be present therein with concommittant formation of an iron chloride cloud above the surface of the chlorination reaction mixture;(C) introducing oxygen into the iron chloride cloud under conditions to cause oxidation of a majority of the iron chloride contained in the cloud;(D) chlorinating the non-gaseous product of step (B) in the presence of chlorine and carbon at a temperature above about 1300.degree. K.

Abstract: An acoustical enclosure system, particularly designed for overtable circular saws employed in cutting such materials as metal shapes, is disclosed. The system includes an acoustical enclosure covering the saw and a pair of vibration damping arms covering the workpiece being sawed. This combination of elements results in substantially reduced noise levels within the sawing environment.

Abstract: There is described a method for producing alumina from a material containing alumina values via a chlorination step which process comprises the steps of:(A) dehydrating the material, if necessary, at a temperature of between about 500 and about 1300.degree. K;(B) chlorinating the product of step (A) in the presence of chlorine and carbon at a temperature below about 1200.degree. K and under conditions which provide chlorination of a majority of the iron present in the clay without substantial chlorination of titania values which may be present therein with concommittant formation of an iron chloride cloud above the surface of the chlorination reaction mixture;(C) introducing oxygen into the iron chloride cloud under conditions to cause oxidation of a majority of the iron chloride contained in the cloud;(D) chlorinating the non-gaseous product of step (B) in the presence of chlorine and carbon at a temperature above about 1300.degree.

Abstract: A method for producing aluminum chloride suitable for direct introduction into an aluminum chloride reduction cell by treatment of the gas stream emerging from an aluminum value source chlorination process comprising the steps of:1. reducing and condensing iron chloride in one or more iron chloride condensation stages;2. absorbing the aluminum chloride contained in the gas stream under high temperature conditions with an alkali chloride or alkali chloride mixture to form an ionic alkali chloride-aluminum chloride complex; and3. selectively condensing the chlorides from the product by step (2) to produce a purified aluminum chloride-alkali chloride complex suitable for direct introduction into an aluminum chloride reduction cell.

Abstract: A conveyor system is disclosed in which a plurality of free-wheeling conveyor rollers are rotated by means of a driven belt which intermittently contacts the conveyor rollers when driven motion is desired. The rollers may also be braked by means of a second belt member which may contact the conveyor rollers at those times when the driven belt is out of contact with the rollers.

Abstract: An improved alumina reduction cell is described in which the carbonaceous cathode includes refractory hard metal tiles forming the surface in contact with molten aluminum formed in the cell and intermediate tiles separating the refractory hard metal tiles from the carbonaceous cathode to prevent reaction between refractory hard metal tiles and the carbonaceous cathode in the presence of the molten aluminum.

Abstract: In a metal strip rolling mill having a strip shape measuring means connected to adjust the mill to control the strip shape, improved strip shape control performance is achieved by mounting a hold-down roll between the measuring means and the take-up reel.

Abstract: A carbothermic reduction process is described for producing alumina metal containing about 10% Al.sub.4 C.sub.3. The process heats a descending charge by radiation at a rate of heat flux of 10-100 KW/sq. inch, to form a melt surface that is spaced from an open arc between a pair of electrodes. Additional alumina beyond the stoichiometric amount is preferably introduced into the reduction zone immediately surrounding the melt surface.A large moving-bed shaft furnace is utilized. This furnace comprises hearth shoulders and preferably also comprises alumina introduction ports and a charge shaping device that cooperatively interacts with the hearth shoulders to suspend the descending charge column above a pool of melted aluminum product therebeneath, whereby the aluminum product is able to flow and/or fall into the pool with minimum passage over unreacted charge.

Abstract: This invention concerns cathodes for alumina reduction cells, particularly drained cathodes, which present a refractory surface for contacting molten aluminum on the cell floor. This invention also concerns materials for constructing such cathodes.The cathodes described comprise a carbonaceous bed, preferably a graphite bed, and a composite tile. This tile is characterized by a layer of a refractory hard metal (RHM) material bonded to a base layer of a graphitic material, where the RHM layer comprises a hot pressed mixture of titanium diboride and aluminum nitride powders. The tile is further characterized by the bond between the RHM layer and the graphitic base layer, such bond having been produced simultaneously as the RHM layer is formed by hot pressing the mixture of titanium diboride and aluminum nitride powders directly against the graphitic base layer.