Abstract: Method and apparatus for the direct chill casting of non-ferrous metals comprises varying the chill depth of the mould independently of the level or quantity of liquid metal in the mould by relatively moving the mould and a "hot-top" which may be a sleeve of refractory material during the casting, which may comprise semi-automatic or automatic casting.

Abstract: Alloys having a composition suitable for superplastic deformation usually require heat treatment after casting and mechanical working in order to produce in the alloy the necessary fineness of grain stucture to permit such deformation to occur. It has now been found that some such alloys including in particular ranges of aluminum alloys containing zirconium (or Nb, Ta or Ni) may be heated to a superplastic forming temperature and non-superplastically deformed at that temperature to induce dynamic recrystallisation and simultaneously produce a fine recrystallised grain structure and superplastic deformation.

Abstract: A method of recovering gallium from sodium aluminate solutions comprises extracting gallium from aluminate solution by electrolysing the solution with a current density of at least 0.002 A/cm.sup.2 and a cathodic potential relative to a saturated calomel electrode of at least 1.5 volts, using an anode made from a metal which does not produce undesirable impurities in the aluminate liquor under the conditions of electrolysis and a solid cathode made of a metal into which gallium diffuses, while maintaining the temperature of the aluminate solution in the range 25.degree.to 80.degree.C until the gallium has diffused into the cathode to give a gallium content in the surface layers of at least 0.10%. The cathode metal is preferably tin, lead, indium, zinc and alloys of tin and lead. The preferred current density range is 0.005 to 0.05 A/cm.sup.2 while the preferred temperature range is 35.degree.to 65.degree.C. The gallium is subsequently separated from the cathode metal.

Abstract: A method of removing gallium from tin, lead or tin-lead alloy in which the molten metal containing gallium is treated with a molten flux of alkali metal hydroxide, alkali metal carbonate or a mixture of such constituents where the alkali metal is lithium, sodium, potassium or a mixture of these. Preferably the metal and flux are stirred together, then separated, and the flux dissolved in water and gallium recovered from the solution by electrolysis.