Alcan International Limited

Ghyslain Dube

Serge Eugene Lavoie

Claude Dupuis

Jean-Paul R Huni

Wesley D Stevens

Gilles R Turcotte

Francois Tremblay

Joseph Langlais

Sylvain Trottier

Stephane Rompre

Don Allen Doutre

Peter D Waite

Bruno Gariepy

Jean-Pierre Martin

Sebastien Fafard

Adam J Gesing

Martin R Reeve

Marc Auger

Yves Caron

Robert Dumont

Jean-Yves Fortin

Gaston Riverin

Gaetan Chauvette

Marko Litalien

Roger Pelletier

Zhou Wang

Friedrich Muller

Jean Pare

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.

Process for cleaning and purifying molten aluminum

Process and apparatus for cleaning and purifying molten aluminum

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 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.

Production of granules of reactive metals, for example magnesium and magnesium alloy

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. The invention also relates to apparatus for carrying out the above method and to a method of measuring the surface temperature.

Method and apparatus for controlling the temperature of an ingot during

Production of granules of reactive metals, for example magnesium and

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%.

Gas treatment of molten metals

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.

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. The use of the fluoride improves the rate of recovery of the metal content of the dross without producing environmental difficulties either during the heating operation or during the disposal or use of the dross residue.

Recovery of non-ferrous metals from dross

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.

Method and apparatus for recovery of non-ferrous metals from dross

Decontamination and/or surface treatment of metals

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. If a limited amount of oxygen is introduced into the bed, a combustible gas is produced that can be burned to extract its energy or can be stored for later use.

Process for combined decoating and melting of aluminum scrap

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.

Jet flow device for injecting gas into molten metal and process

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.

Treating aluminium with chlorine

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.

Process for producing mineral fibers incorporating an alumina-containing

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. The head consists of a monolithic or integral body of a porous gas-permeable material of sufficient porosity, pore size and permeability to permit the necessary gas diffusion in a reasonable period of time. If the test is to be carried out in a stationary body of molten metal, the probe may be vibrated or the metal may be stirred.

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Chicoutimi, Canada

Ghyslain Dube