Abstract: The present invention provides a process for the preparation of pre-melted calcium aluminate for iron and steel treatment and protection by the fusion of aluminum dross residues, usually referred to as non-metallic products (NMP) containing variable levels of aluminum (Al) and aluminum nitride (AlN) with calcium carbonate at high temperature, under oxidizing atmosphere. It further relates to the purification of the molten calcium aluminate from some contaminants present in the dross residue.

Abstract: The present invention provides a process for the preparation of pre-melted calcium aluminate for iron and steel treatment and protection by the fusion of aluminum dross residues, usually referred to as non-metallic products (NMP) containing variable levels of aluminum (Al) and aluminum nitride (AlN) with calcium carbonate at high temperature, under oxidizing atmosphere. It further relates to the purification of the molten calcium aluminate from some contaminants present in the dross residue.

Abstract: A method is described for improving neutron absorption in aluminum-based cast composite material, which comprises preparing a molten composite from an aluminum alloy matrix and aluminum-boron intermetallics containing relatively large boron-containing particles, and either (a) heating the composite and holding for a time sufficient to partially dissolve the boron-containing particles and then adding titanium to form fine titanium diboride particles, and casting the composite, or (b) adding gadolinium or samarium to the molten composite or to the aluminum alloy matrix and casting the composite to precipitate fine particles of Gd—Al or Sm—Al within the cast composite, said fine particles filling gaps around the large boron-containing particles with neutron absorbing material.

Abstract: A process is described for treating molten metal with a particulate treating agent. A melt of a metal, e.g. aluminum, is provided in a treatment vessel such as a ladle and a mixing impeller is positioned substantially below the surface of the molten metal. The impeller comprises a plate with a series of spaced blades extending from the surface of the plate. This impeller is adapted to provide high shear mixing with minimum vortex. While rotating the impeller on a substantially vertical axis, particulate treating agent is fed by way of an injection tube below the surface of the molten metal and into the region between the axis and periphery of the impeller. This causes a high shearing action in the region of the blades whereby the treating agent is quickly broken down into finely divided droplets that are at least partially molten and which are circulated within the molten metal.

Abstract: A process is described for treating molten metal with a particulate treating agent. A melt of a metal, e.g. aluminum, is provided in a treatment vessel such as a ladle and a mixing impeller is positioned substantially below the surface of the molten metal. The impeller comprises a plate with a series of spaced blades extending from the surface of the plate. This impeller is adapted to provide high shear mixing with minimum vortex. While rotating the impeller on a substantially vertical axis, particulate treating agent is fed by way of an injection tube below the surface of the molten metal and into the region between the axis and periphery of the impeller. This causes a high shearing action in the region of the blades whereby the treating agent is quickly broken down into finely divided droplets that are at least partially molten and which are circulated within the molten metal.

Abstract: A process is described for treating molten metal with a particulate treating agent. A melt of a metal, e.g. aluminum, is provided in a treatment vessel such as a ladle and a mixing impeller is positioned substantially below the surface of the molten metal. The impeller comprises a plate with a series of spaced blades extending from the surface of the plate. This impeller is adapted to provide high shear mixing with minimum vortex. While rotating the impeller on a substantially vertical axis, particulate treating agent is fed by way of an injection tube below the surface of the molten metal and into the region between the axis and periphery of the impeller. This causes a high shearing action in the region of the blades whereby the treating agent is quickly broken down into finely divided droplets that are at least partially molten and which are circulated within the molten metal.

Abstract: A process is described for treating molten metal with a particulate treating agent. A melt of a metal, e.g. aluminum, is provided in a treatment vessel such as a ladle and a mixing impeller is positioned substantially below the surface of the molten metal. The impeller comprises a plate with a series of spaced blades extending from the surface of the plate. This impeller is adapted to provide high shear mixing with minimum vortex. While rotating the impeller on a substantially vertical axis, particulate treating agent is fed by way of an injection tube below the surface of the molten metal and into the region between the axis and periphery of the impeller. This causes a high shearing action in the region of the blades whereby the treating agent is quickly broken down into finely divided droplets that are at least partially molten and which are circulated within the molten metal.

Abstract: A process of producing granules of a reactive metal. The process comprises providing a source of molten reactive metal (41), forming discrete droplets (53) of the molten metal, contacting the droplets while still substantially molten with a fluidized bed of particles (12) maintained at a temperature substantially below the solidus temperature of the metal and freezing the droplets as discrete granules of the reactive metal in the fluidized bed. The invention also provides apparatus for carrying out the method and product produces by the method, including a magnesium-containing additive for aluminum alloying. The use of a fluidized bed for cooling and freezing the droplets avoids problems encountered in prior methods and also makes it possible to provide coatings of various kinds on the surfaces of the granules, if desired.

Abstract: A method of controlling a temperature of a surface of a direct chill cast ingot cast in an open-ended mold provided with a bottom block during early stages of casting as the ingot emerges from the open-ended mold. The method involves the steps of directing a flow of a coolant onto at least one surface of an ingot emerging from an open-ended mold to impinge on the surface at a normal impingement point and to cool the surface, measuring a surface temperature on the emerging ingot at at least one measurement location which is at a predetermined position close enough to the normal impingement point to be affected by the secondary coolant, to generate a measured surface temperature, determining the displacement of the bottom block of the casting machine from its initial position at the start of the cast, corresponding to each the surface temperature measurement, and using the measured surface temperature to control a casting variable and thereby to control the temperature of the surface.

Abstract: An apparatus for producing coated metal granules is disclosed. The apparatus includes a source of molten metal, a device for forming droplets of the molten metal, a bed of particles for receiving the droplets and a means for introducing a gas to fluidize the bed, cooling equipment to maintain the bed below the solidus temperature of the metal, and a separator for separating solidified granules of the metal from particles of the bed. This apparatus can produce an alloying additive which comprises magnesium granules 1-10 mm in size, at least partially coated with particles of a chloride salt which are attached to the granules by being physically embedded into a surface of the granules. The salt particles remain unmelted or only partially melted during formation of the additive.

Abstract: A method of and apparatus for treating molten metal to achieve effective removal of such unwanted inclusions as gases, alkali metals, entrained solids, and the like. The method comprises continuously introducing molten metal into a container forming a trough or trough section, such as the trough provided between a melting furnace and a casting machine, providing at least one mechanically movable gas dispenser submerged within the metal in the container and introducing a gas into the metal adjacent to the gas disperser in a part of the trough forming a treatment zone such that the gas is broken into smaller bubbles by the gas dispenser and dispersed through the treatment zone. The trough or trough section is such that it exhibits a static to dynamic metal holdup of less than 50%.

Abstract: A process of producing granules of a reactive metal. The process comprises providing a source of molten reactive metal, forming discrete droplets of the molten metal, contacting the droplets while still substantially molten with a fluidized bed of particles maintained at a temperature substantially below the solidus temperature of the metal and freezing the droplets as discrete granules of the reactive metal in the fluidized bed. The invention also provides apparatus for carrying out the method and product produced by the method, including a magnesium-containing additive for aluminum alloying. The use of a fluidized bed for cooling and freezing the droplets avoids problems encountered in prior methods and also makes it possible to provide coatings of various kinds on the surfaces of the granules, if desired.

Abstract: A process of recovering a non-ferrous metal from a dross containing the same. The process involves introducing into a rotary furnace the dross and a fluoride compound which becomes substantially molten above the melting point of the metal, heating the dross and fluoride compound to a maximum temperature above the melting point of the metal, using a heating device which substantially maintains a non-oxiding atmosphere in the furnace, rotating the furnace until the dross reaches the maximum temperature, removing the molten metal thereby separated from a solid dross residue and removing the solid dross residue from the furnace. The fluoride compound, which may be, for example, cryolite, recovered cryolite, AlF.sub.3 or NaF, or a mixture thereof, is such that it remains in the dross during the process and does not make the dross become sticky.

Abstract: A method and apparatus for treating non-ferrous metal drosses in order to recover the free metal contained therein. The dross is heated by a plasma torch in a rotary furnace, preferably to a temperature above 800.degree. C. The plasma heating and rotary motion make it possible to recover metal from the dross without employing the conventional salt bath. This means that the gases exiting the furnace can be treated more easily to remove pollutants and the solid residues can be discarded without risk of causing environmental pollution. By controlling the speed of rotation of the furnace, large dross lumps can be accommodated and so the conventional grinding and screening procedure of the dross can advantageously be eliminated.

Abstract: The invention relates to a process of decontaminating metal (especially aluminum or aluminum alloy) scrap contaminated with organic material. The problem with such methods is that undue oxidation of the metal may take place as the decontamination proceeds, leading to reduced recovery rates. The process involves heating the scrap in a fluidized bed of solid particles fluidized by a fluidizing gas to a decontaminating temperature high enough to consume the organic material but below the melting point of the metal. The heating step is carried out in the presence of a protective material which protects the aluminum or aluminum alloy against substantial oxidation while the scrap is held in the bed at the decontaminating temperature. Preferred protective materials include organic and inorganic fluorine-containing compounds, particularly AIF.sub.3. The process is particularly effective for the treatment of aluminum alloys containing magnesium, which are especially susceptible to oxidation.

Abstract: A method of recovering an aluminum-containing metal from a scrap material containing the metal and an organic contaminant, such as paper, plastics, lacquer, paint or oil. The method involves creating a fluidized bed of solid particles, maintaining a zone of the bed at a temperature in the range of the melting point of the metal to 1000.degree. C., introducing the scrap material into the fluidized zone to cause decoating of the metal within a time in the range of 1 to 40 seconds, at least partially melting the metal, and removing the metal material from the fluidized bed. In this way, decoating and at least partial melting is achieved essentially at the same time for improved efficiency. Metals of different melting point may also be separated from each other by providing a series of temperature zones in the fluidized bed (or in a series of fluidized beds) of progressively increasing temperature.

Abstract: A device is described for injecting gas into molten metal, e.g. molten aluminum, in a furnace chamber. It comprises: (a) a stirring apparatus having a reservoir chamber separate from the furnace chamber, a connector portion with an orifice connecting the interior of the furnace and the reservoir for the passage of the molten metal between them through the connector portion, vacuum/pressure generating means connected to the reservoir chamber interior for alternatively and successively producing therein a vacuum for drawing molten metal into its interior from the furnace chamber and a positive pressure for expelling the molten metal therefrom into the furnace chamber through the orifice in the form of a high velocity stirring jet, and (b) gas injector means adapted to inject gas into the high velocity stirring jet such that the gas is broken down into a large number of small bubbles which are circulated throughout the furnace chamber with the stirring jet.

Abstract: When molten aluminium is treated with chlorine to remove alkali and alkaline earth metals and hydrogen, there is formed a brittle oxide crust which does not protect the metal from oxidation. This problem is solved by admixing with the chlorine a minor proportion of a gaseous compound of fluorine, preferably sulphur hexafluoride, which can form alkali or alkaline earth metal fluorides in the presence of molten aluminium. The proportion of sulphur hexafluoride to chlorine gas is preferably from 0.01 to 1.0. Ingots cast using the treated metal are free of oxide patches on their surface.

Abstract: A process for producing mineral fibers and the fibers thus produced are disclosed. The process involves forming a melt comprising an alumina-containing residue from a metal melting operation and one or more mineral raw materials suitable for forming mineral fibers, dividing the melt into streams and cooling the streams to produce the fibers. The residue from the metal melting operation acts as an inexpensive, substantially non-polluting source of alumina which can be used to increase the alumina content of the fibers and thus improve their properties, or which can be used as a replacement for more expensive or less desirable sources of alumina.

Abstract: The invention provides a new method for the determination of the concentration of gas dissolved in a molten metal or metal matrix composite employing a new immersion head probe in apparatus employing the method. Such determinations are needed to facilitate removal of the gas, which can cause loss of desirable properties and/or bubbles in the solidified material and subsequent processing difficulties. This determination is particularly difficult with metals containing high concentrations of particulate additions, such as metal matrix composites, since it is necessary to avoid deposition of the particulates and consequent inaccurate readings. The method employs apparatus which circulates an inert carrier gas through the probe in gas exchange contact with the molten metal to entrain dissolved gas until an equilibrium mixture is obtained; the concentration of the dissolved gas in the mixture then is representative of its concentration in the molten metal.