Before casting, continuous casting, and other uses, molten metals containing small amounts of dissolved, particulate and gaseous impurities (such as aluminum and aluminum alloys) are placed in online degassing equipment.
The aluminum metal flows through the trough and launder at the inlet and flows out at the outlet, and this occurs in a substantially continuous manner. The aluminum online degassing equipment is usually installed between a heated vessel (such as a casting furnace) and a casting machine. The treatment aims to remove: dissolved hydrogen, solid non-metallic particles, such as aluminum oxide and magnesium oxide, and dissolved impurities, such as Na, Li and Ca.
Traditionally, this refining process is done using chlorine or a mixture of chlorine and inert gas (such as argon). This refining process is often referred to as “metal degassing“, although it should be understood that it can not only be used for metal degassing, because it can also remove other contaminants.
The online method for refining molten aluminum or aluminum alloy, the molten aluminum or aluminum alloy having a metal liquid level, the method comprising: adding an inert gas and at least one metal halide into the reactor salt. The molten aluminum or aluminum alloy is lower than the metal level at the upstream disperser. An upstream disperser is used to disperse the inert gas and at least one metal halide salt into the flowing molten aluminum or aluminum alloy, and in the downstream disperser, only the inert gas is added to the molten aluminum or aluminum alloy below the metal liquid level. A downstream disperser is used to disperse the inert gas into the molten aluminum or aluminum alloy flowing in.
Refining molten aluminum and/or aluminum alloy online without any chlorine. On-line refining is understood to be a substantially continuous process in which impurities in aluminum or aluminum alloys are removed. As mentioned earlier, these impurities are: dissolved gases, such as hydrogen; particles, such as insoluble oxides and dissolved alkali metals.
Online degassing refining is carried out between the casting (or metal holding) furnace and the casting machine. Such a metallurgical tank may have a slight inclination from the casting furnace to the casting machine, and is suitable for flowing molten metal from the casting furnace to the casting machine.