Abstract: A shaking table for ore-dressing, having riffles on its deck, has circular orbital motion imposed on it to cause the riffles to oscillate, and for a standing wave to be created between the riffles. The continued circular motion acting on the standing waves causes sharp separation of the material fractions which are discharged continuously from the deck. The slope of the deck and riffles and the configuration of the riffles are critical. The slope of the deck is set empirically by estimating the approximate slope appropriate to the parameters of the material being treated and of the motion imparted to the deck; and the final adjustment is made by slewing the deck in its own plane to obtain an optimum result. For a frusto-conical deck, the adjustment is made on a flat deck and the frusto-conical deck is constructed accordingly. The deck may have rectilinear or curvilinear motion imparted to it, superimposed upon the circular motion.

Abstract: Oxidation in a leuco indigo dyebath is decreased by enclosing the air-liquor interface whereby enclosed air is depleted of oxygen by the dyebath components.

Abstract: The invention relates to a method of producing a graphite die for use in continuous casting of non-ferrous metals. The die has wearing surfaces which, in accordance with the invention, are coated, using either plasma-combustion flame or liquid-spraying techniques, with a first layer consisting of a metal or a metal plus a ceramic material and then with a second layer of ceramic material. The coating materials are applied as a suspension in a liquid medium by painting or spraying techniques or they must be applied by plasma or combustion flame spraying techniques.The first layer may comprise one or more of the following substances: silicon, iron, nickel, chromium, molybdenum, tungsten or their alloys or any other metal which can be subsequently carburized by heating with graphite in an inert or reducing atmosphere.Alternatively the first layer may be either aluminium, an aluminium alloy, an aluminium-metal composite or a mixture of the metal(s) and alumina and the second layer is preferably alumina.