Abstract: A process for the production of alumina from siliceous minerals containing substantial quantities of combined aluminium and calcium comprises the steps of treating the finely divided mineral with a hot acid liquor containing chloride, fluoride and calcium ions to extract alumina values from the mineral; recovering aluminium chloride from the liquid extract; recycling one fraction of the spent extract to the mineral extraction stage; and treating another fraction of the spent extract to regenerate hydrogen chloride gas for re-use in the process.

Abstract: Lengths of material are collected in side-by-side relation in a group and delivered as a group to a receiving station by an apparatus which includes a support table constituted by a number of spaced parallel arms pivoted coaxially with each other about one end. Each arm has a finger which projects upward above the arm and which can be moved toward the pivot for moving the lengths laterally of themselves towards a stop adjacent the pivoted ends of the arms, and during this movement the arms are inclined downward towards their pivot at such an angle that the fingers need exert only a small force to move the lengths towards the stop.

Abstract: Anodized aluminium having an anodic oxide film of at least 3 microns thickness is colored by electrolytically depositing inorganic pigment from metallic salt solutions, particularly nickel, cobalt, tin and copper salts and mixtures. The pigment deposits are characterized by outer ends of an average size in excess of 260 A lying at a distance of 500 - 3000 A from the aluminium/aluminium oxide interface.In a preferred method of production the anodic oxide coating is formed under conventional anodizing conditions in a sulphuric acid-based electrolyte. The anodized aluminium is then treated in phosphoric acid at a voltage of 8 - 50 volts to enlarge the pores to above 260 A in a region at the base of the pores adjacent the barrier layer. The pigment is then deposited in the pores to the specified depth and interesting new color shades are obtained as a result of optical interference due to the presence of the large size shallow inorganic pigment deposits.

Abstract: In a large scale filtration apparatus filtration is performed in a vertical cylindrical vessel, in which a number of spaced filter leaves are suspended. The liquor to be filtered is introduced into the shell and the filtrate is led out from the interior of the individual leaves. The filter residues are removed from the leaves at intervals by means of a spray device located in the top of the shell above the leaves. A spray bar, having a downwardly facing elongated slit orifice and rotating slowly about the axis of the shell, is preferably employed for this purpose.

Abstract: A dispersion strengthened aluminum alloy is produced by continuously casting an aluminum alloy containing 4 - 15% Si and other optional constituents in the form of a slab at a growth rate in excess of 25 cm/min. to solidify silicon in the form of elongated rods in a size range of 0.05 - 0.5 microns diameter. The cast slab is then subjected to at least 60% reduction to fragment the elongated silicon rods into finely divided particles, at least the final part of the reduction being effected by cold rolling, the cold-rolled sheet being subjected to a final annealing treatment at a temperature in the range of 250.degree. - 400.degree. C.

Abstract: Aluminum alloy products having superplastic properties are prepared by casting an aluminum alloy containing calcium and zinc in near-eutectic proportions under conditions that develop a eutectic cast structure of fine Ca-Zn-Al intermetallic rods, and working the cast alloy mass to break up the rods into particles having an average diameter of less than two microns.

Abstract: A dispersion strengthened aluminum alloy sheet is produced by casting an Al-Fe 1.1 - 2.5% alloy optionally containing Si up to 2.0% and, optionally, proportions of other specified alloying constituents. The alloy is cast in the form of a slab at a growth rate in excess of 25 cm/min. at a thickness of less than 25 mm so that intermetallics are formed in the slab in the form of fine rods of a diameter of 0.05 - 0.5 micron. These rods are then segmented by reducing the slab by at least 60% by rolling to develop a dispersion of fine intermetallic particles. By final annealing the rolled sheet at a temperature in the range of 250.degree. - 400.degree. C a sheet having a good combination of yield strength and formability is obtained (as indicated by a yield strength of greater than 15 k.s.i. and tensile elongation greater than 15%).

Abstract: An aluminum alloy electrical conductor consisting essentially of 0.07 - 0.2% Mg, 0.02 - 0.05% Zr, balance Al with minor amounts of other elements, annealed at 200.degree. - 300.degree. C to precipitate ZrAl.sub.3 and having an electrical conductivity of at least 60% IACS.

Abstract: A sawing apparatus for sawing long lengths of material into shorter pieces having a predetermined length and discarding spoiled and short end pieces comprises a saw movable across a saw table formed in two parts which can be tilted independently of each other to tip sawn material into a receptacle. The downstream part has a nose piece projecting just beyond the saw to support the leading end of a length to be sawn. The apparatus also comprises exit and entry tables and a number of sensors for respectively detecting the leading and trailing ends of the lengths of material and for automatically initiating sequences of operations of releasable clamps for clamping the lengths of material, traversing movements of the saw, and the tiltable table parts.

Abstract: In a process for the production of aluminium a molten alumina slag, containing combined carbon is circulated through one or more alternately arranged relatively low temperature zones where carbon is added to increase the combined carbon content of the slag by reaction with the alumina slag and high temperature zones where aluminium metal is released by reaction of aluminium carbide and alumina in the slag with consequent depletion of the combined carbon content. Alumina is supplied to the slag at one or more locations. The energy to drive the reactions is preferably supplied by resistance heating of the slag particularly in transit from a low temperature zone to a high temperature zone although usually additional energy is supplied to the slag in the return from a high temperature zone to the next low temperature zone.In most instances the aluminium-liberating reaction is carried out in an upwardly inclined passage and the gas evolved is employed to achieve the circulatory movement of the slag.

Abstract: A process for the production of electroplated aluminium stock, such as strip or wire, comprises passing the stock continuously through a bath having a high dissolving power for aluminium oxide, such as strong aqueous sulphuric acid and phosphoric acid and subsequently through an electroplating bath, the first bath having a cathode electrode and the electroplating bath having an anode electrode so that the stock is anodic in the first bath. The stock may pass through one or more intermediate non-electrolytic treatment stages, such as immersion tinning or zincating. It may also pass through one or more electrolytic pretreatment stages during its passage between the first bath and the electroplating bath. In such pretreatment stages, such as the application of a bronze strike, there may be an anode electrode at the same potential as the anode in the electroplating bath.

Abstract: An apparatus for stretching an extruded length of metal comprises a plurality of sets of tailstock jaws mounted at fixed positions in line with and spaced from each other, and a set of headstock jaws mounted in line with the sets of tailstock jaws and movable towards and away from the sets of tailstock jaws by a motor. The sets of tailstock jaws are individually controlled by respective sensors which when energized emit a signal in response to the presence of the trailing end of an extruded length of metal travelling past the sets of tailstock jaws, and the sensor signal actuates closure of the associated tailstock jaws on the trailing end of the extruded length.

Abstract: In the production of alumina for supply to electrolytic reduction cells in the production of aluminum metal, alumina trihydrate is calcined in a calcination furnace to convert it to alumina, typically having a water content of less than 2%. In the course of this operation fine particles in a size range below 44 microns are separated from the exhaust gases from the calciner. In conventional procedures these particles which are only partially dehydrated, are either recycled to the calciner or directly added to the calciner product alumina. With the dual objective of reducing environmental pollution and saving valuable alumina the present invention converts these collected fines into compacted granules in a size range of 150-5000 microns for supply to an electrolytic reduction cell either directly or after readmixture with the calciner product alumina.

Abstract: In the production of aluminum ingots by the direct chill casting process, in which the conventional chilled mold is equipped with a thermally insulated "hot top," smooth surfaced ingots are produced under conditions obtained by correlating of the length of the chilled mold, the casting rate and the head of molten metal in the hot top. Preferably the values of chilled mold length and metalostatic head are selected so as to be tolerant of some variation of metalostatic head which is difficult to avoid in the simultaneous operation of a large number of molds under level pour conditions.

Abstract: Anodized aluminium having an anodic oxide film of at least 3 microns thickness is colored by electrolytically depositing inorganic pigment from metallic salt solutions, particularly nickel, cobalt, tin and copper salts and mixtures. The pigment deposits are characterized by outer ends of an average size in excess of 260 A lying at a distance of 500 - 3000 A from the aluminium/aluminium oxide interface.In a preferred method of production the anodic oxide coating is formed under conventional anodizing conditions in a sulphuric acid-based electrolyte. The anodized aluminium is then treated in phosphoric acid at a voltage of 8 - 50 volts to enlarge the pores to above 260 A in a region at the base of the pores adjacent the barrier layer. The pigment is then deposited in the pores to the specified depth and interesting new color shades are obtained as a result of optical interference due to the presence of the large size shallow inorganic pigment deposits.

Abstract: The invention relates to a method of joining together the ends of tubular metal members by explosive welding and to a permanent, self-aligning backing mandrel for use in the method. The mandrel is in the form of a tubular member having an outer face defining a cylindrical portion and an axially adjacent tapered portion, the maximum diameter of the tapered portion being greater than the diameter of the cylindrical portion. An annular shoulder extends outwardly between the cylindrical portion and the maximum diameter end of the tapered portion, which tapers inwardly away from the shoulder. One pipe end is outwardly flared and fits over the tapered portion of the mandrel and the other pipe end is non-flared and fits over the cylindrical portion, abutting the shoulder. The outer end of the flared pipe end overlaps the non-flared pipe, defining therewith an annular wedge-shaped outwardly-opening space. An explosive is located around this outer overlapping end and is detonated to weld the ends together.

Abstract: In apparatus for the continuous casting of metal in strip form between moving belts, belt support means comprising a multiplicity of elements that are distributed crosswise and lengthwise of a belt path area beside the mold space and are individually yieldable against a loading force, permit close belt stabilization to a selected path while yielding locally under excess outward force by the belt such as caused by solidified metal. Arrangement of belt support and cooling means along the mold space in successive sections each individually adjusted in respect to one or more of the conditions of belt path taper; degree of compliance, if any, in the retention of the belt against the support; and cooling action; are such that these features, as well as provision, if desired, of local yieldability, permit accommodation of the apparatus to various requirements of casting operation.

Abstract: For supporting and cooling the reverse surfaces of belts in apparatus for continuously casting metal strip between such belts, means enclosing the reverse surface of a belt includes a multiplicity of guiding faces that are distributed closely both crosswise and lengthwise of the belt to define an intended belt path, and that have nozzle openings through which liquid coolant is projected against the belt, rapidly flowing out in a layer over the guiding face and being withdrawn at localities close to all of the guiding faces. The belt, which may be forced toward the faces to stabilize it in its desired path, thus rests on a layer of rapidly moving liquid coolant, which affords efficient heat removal and an essentially complete liquid bearing, such apparatus and procedure being also deemed applicable to cooling other surfaces.

Abstract: In a rolling mill for reducing metal, having upper and lower work rolls between which the metal is passed and at least one back-up roll for the upper work roll, the combination of means for applying coolant to the surface of the upper work roll only on the outgoing side of the mill, casing structure enclosing the locality of coolant application and so arranged that a narrow gap is defined between the upper work roll and a transverse wall of the casing below the coolant-applying means, and means for creating a rapid flow of air along the upper work roll surface adjacent the gap in a direction to prevent exit of coolant through the gap from the casing structure while withdrawing air from the casing structure. The air-flow creating means may include means for maintaining the interior of the casing structure at subatmospheric pressure.

Abstract: A service unit capable of supplying sterile utilities including compressed air and water and preferably both hot and cold water, disinfectant and suction, is particularly adapted to be connected to machines for the packaging of foods, medicines and the like under aseptic conditions to provide servicing utilities. The service unit has the advantage of being capable of supplying sterile utilities to such aseptic packaging machines from outside the aseptic screen surrounding the packaging workspace and thus to be capable of providing sterile services to several packaging machines in turn.