A method of melting an aluminum charge having no more that 4% salt by mass, including during a melting phase, introducing fuel and oxidant via a burner operating at a first firing rate, the fuel and oxidant reacting to form a combustion zone above the aluminum charge, terminating the melting phase and commencing a transition phase when the aluminum charge is nearly completely molten, during the transition phase, reducing the firing rate of the burner to a second firing rate lower than the first firing rate, introducing a non-oxidizing gas at a first velocity to form a non-oxidizing zone between the combustion zone and the aluminum charge, and allowing the aluminum charge to become completely molten, and terminating the transition phase and commencing a tapping phase after the aluminum charge has become completely molten, and during the tapping phase, pouring the molten aluminum charge out of the furnace.

A system for removing molten metal from a vessel is disclosed. The system includes a vessel having a first section and a second section and a pump positioned in the first section of the vessel. As the pump operates it moves molten metal through a pump discharge and through an opening into the second section of the vessel, where the molten metal reaches a vessel outlet and exits the vessel. The pump discharge is preferably formed at an angle to the vessel outlet. The outlet may be attached to a launder.

Aspects of the invention relate to a rotor for transferring molten metal. A powered device, such as a molten metal pump, which may be inside of a transfer chamber, includes a multi-stage rotor to move molten metal within a vessel. The molten metal may be moved out of the vessel and into another structure, which could be another vessel or a launder. The multi-stage rotor may have multiple blades with each blade having multiple surfaces.

A salt flux and method for use of the same in cleaning and purifying molten aluminum is disclosed. The salt flux includes an equal proportion of sodium chloride and potassium chloride in a range of ninety percent or more, by weight, of the salt flux. The salt flux further includes aluminum fluoride in a range of less than ten percent by weight. The salt flux is introduced into a furnace using a submergence system such as a side well with an impeller to submerge the salt flux under the surface of the metal bath. Oxides may be collected and removed to reduce inclusions, oxide, and magnesium levels within the metal bath.

A vortex chamber includes an outer circumference wall, a container, an annular shoal portion provided between the container and the outer circumference wall so as to encircle the outer circumference of the container, and a dam portion protruding upward from the upper surface of the outer circumference of the container so as to partition the container from the shoal portion. An undried nonferrous metal block is fed into the shoal portion, the block having such a size that is not completely submerged into the molten metal in the shoal portion. The fed nonferrous metal block is gradually melted to have a reduced volume of small pieces and particles of nonferrous metal, which are re-circulated in the shoal portion, flown over the dam portion, and dropped into the container, thereby forming a vortex in the container in which remaining small pieces and particles submerged into the molten metal are melted.

Apparatus and method for filtering molten metal, in particular aluminium, including a container (1) with an outer shell or casing of metal and an inner thermally insulated interior cladding or wall construction made of heat resistant insulation and refractory material. A removable lid (2) provided on top of the container to keep the container sealed (air tight) during operation, the container (1) being provided with an inlet chamber (3) having an inlet opening (4) receiving metal from a metal supply launder (10) and an outlet chamber (5) with an outlet opening (6) in which a ceramic or refractory filter (7) is mounted.

A system and method for transferring molten metal from a vessel and into a launder is disclosed. The system includes at least a vessel for containing molten metal, an overflow (or dividing) wall, and a device or structure, such as a molten metal pump, for generating a stream of molten metal. The dividing wall divides the vessel into a first chamber and a second chamber, wherein part of the second chamber has a height H2. The device for generating a stream of molten metal, which is preferably a molten metal pump, is preferably positioned in the first chamber. When the device operates, it generates a stream of molten metal from the first chamber and into the second chamber. When the level of molten metal in the second chamber exceeds H2, molten metal flows out of the vessel and into the launder. The launder has a horizontal angle of between 0 and 10 to help prevent dross from being pulled by gravity into downstream vessels.

A continuous aluminum melting furnace with a porous spray pipe heat exchanger, comprising a furnace body, combustion nozzles, a smoke pipeline and a heat exchanger. The heat exchanger comprises a smoke channel and heat exchange cylinders, wherein each of the heat exchange cylinders comprises a head end, a tail end, and a porous spray pipe in at least one of the cylinders. The porous spray pipe comprises a closed end and a pipe body, with several air spray holes provided on a peripheral wall of the pipe body so that cold air entering the at least one heat exchange cylinder is sprayed to an inner wall of the cylinder so as to exchange heat with high-temperature smoke which flows through an outer wall of the cylinder, thus keeping the temperature of the cylinder lower than the rated tolerant temperature of the material from which the cylinder is made.

To provide a technique that reliably and quickly melts conductive metal, there is provided a conductive metal melting method including: rotating a magnetic field device formed of a permanent magnet, which includes a permanent magnet, about a vertical axis near a driving flow channel of a flow channel that includes an inlet through which conductive molten metal flows into the flow channel from the outside and an outlet through which the molten metal is discharged to the outside and includes a vortex chamber provided between the driving flow channel provided on an upstream side and an outflow channel provided on a downstream side, and moving lines of magnetic force of the permanent magnet while the lines of magnetic force of the permanent magnet pass through the molten metal present in the driving flow channel; allowing the molten metal to flow into the vortex chamber by an electromagnetic force generated with the movement to generate the vortex of the molten metal in the vortex chamber into which the raw material is to be put; and discharging the molten metal to the outside from the outlet. The conductive metal melting method further includes driving the molten metal present in the outflow channel toward the outlet by an electromagnetic force generated with the movement of the lines of magnetic force as necessary.

The invention relates to systems for transferring molten metal from one structure to another. Aspects of the invention include a transfer chamber constructed inside of or next to a vessel used to retain molten metal. The transfer chamber is in fluid communication with the vessel so molten metal from the vessel can enter the transfer chamber. A powered device, which may be inside of the transfer chamber, moves molten metal upward and out of the transfer chamber and preferably into a structure outside of the vessel, such as another vessel or a launder.