Abstract: A filter system for removing solid impurities from molten metal is described comprising a housing containing vertically disposed rigid coarse filter facing the incoming flow of molten metal and capable of removing solids having a particle size of at least 10 microns and a rigid fine filter mounted vertically behind the coarse filter and capable of removing solids having a particle size as small as 1 micron. The apparatus further includes a heater for maintaining the temperature of the molten metal and a sparger mounted adjacent the front face of one filter to provide an intermittent gas flow over the face of the filter to dislodge solids on the filter as filter cake. In a preferred embodiment, the rigid filters are nested cylinders, and the molten metal is directed to the center of the smaller coarse filter cylinder from which it then flows through the coarse filter outward to and through the fine filter cylinder and then from the fine filter out of the filter housing.

Abstract: A process is described for producing an aluminum grain refiner, such as Al-Ti-B grain refiner. Molten aluminum is continuously flowed as a bottom layer along a substantially horizontal or slightly inclined trough. Titanium or boron compounds reducible by aluminum or a mixture of such compounds is added to the surface of the aluminum layer such that a discrete separate layer of these is formed on top of the aluminum layer. Reaction between the aluminum and the titanium and/or boron compounds occurs along the interface between the layers and this reaction may, if desired, be aided by providing relative movement between the layer of molten aluminum and the layer of titanium and/or boron compounds. A surface layer of spent reaction product is removed and a stream of aluminum alloyed with titanium and boron is collected.

Abstract: The toughness of Al-Li, Al-Mg and Mg-Li alloys is increased by a melting and refining process designed to reduce the concentration of alkali metal impurities below about 1 ppm and preferably below about 0.1 ppm. The hydrogen and chlorine gas constituents are also significantly reduced.

Abstract: A continuous process is described for the production of an aluminum master alloy, e.g. an Al-Ti-B grain refining rod, in which molten aluminum is continuously passed through a confined reaction zone. Particulate titanium and/or boron precursor compounds, e.g. salts, are continuously added to the molten aluminum in the reaction zone and the content of the reaction zone is continuously stirred to submerge the salts within the aluminum melt and form an alloy therewith. A mixture of formed molten alloy and entrained reaction products is continuously transferred from a lower region of the reaction zone into a refining zone, with reaction product slag being collected on the surface of the molten alloy in the refining zone. The molten alloy formed is continuously transferred via a transfer conduit from the refining zone to a casting station.

Abstract: This invention relates to a process and apparatus for treating molten aluminum prior to casting by adding a hydrogen-containing treating gas to the atmosphere over the molten aluminum during melting. A preferred treating gas is finely-atomized water vapor which is added to the fuel-air mixture to be delivered to burners to obtain a disassociation of water vapor into hydrogen and oxygen. The added hydrogen satisfies the affinity of molten aluminum for hydrogen, the addition being controlled to near the saturation point temperature of hydrogen within the molten aluminum. Improved casting properties are obtained in the molded parts which have smaller grain refinement and greater dispersion of shrinkage on cooling to solidification. The treating gas may also consist of hydrogen gas or ammonia gas, the hydrogen being supplied over the molter aluminum when heated to a temperature ranging from about 1200.degree. F. to 1480.degree. F.