Abstract: A method and apparatus allow for continuous removal of contaminants from solder. The solder is pumped from a main solder pot to an auxiliary solder pot through a skimmer valve which is heated to keep the solder molten. In the auxiliary pot, the solder is cooled so that dissolved contaminants such as copper precipitate out and are removed from the pot. The purified solder is then returned to the main pot, for example, by a gravity feed.

Abstract: Molten metal containing suspended liquid particles is passed preferably generally upwardly through a porous media so constructed and arranged such that the movement of the molten metal therethrough renders the suspended liquid particles gravity separable. The gravity separable liquid particles rise upwardly or settle downwardly so as to be removable from said molten metal for subsequent removal therefrom. An associated apparatus is also provided.

Abstract: Particles or inclusions are removed from a molten alloy by contacting the molten alloy with a material selected from the group consisting of aluminium silicate, magnesium silicate, zirconium oxide or a mixture of alumina-calcia and alumina-magnesia.

Abstract: A melt is stored in a vessel. A lower half of a degassing member is immersed in the melt. The degassing member has a cylindrical form with the lower end closed, and the lower half section is made of a porous material which is permeable to gas and impermeable to melts as molten metal, molten slag, or molten matte. This lower half section is a partitioning member. When an internal space inside the degassing member is sucked to realize vacuum or reduced pressure atmosphere, gas producing components in the melt pass through the partition member of the degassing member, and are exhausted to inside the degassing member, thus being separated from the melt. Also, by making the degassing member rotate or move in a horizontal or vertical direction, the melt is stirred. With these features, gas-producing components in the melt can be removed at a high efficiency.

Abstract: An apparatus for filtering molten material, such as a molten metal-ceramic particle mixture, includes a porous cloth filter located so that the mixture must pass through the cloth filter, and a mechanical filter shaker that prevents the accumulation of filtered solids on the porous cloth filter. Where a further degree of filtration is required, there is a second filter located so that material leaving the porous cloth filter passes through the second filter after it passes through the porous cloth filter, and a mechanism that prevents an accumulation of filtered solids on the second filter. The second filter is desirably a porous media filter.

Abstract: A tundish baffle having a plurality of fluted openings is provided. The fluted openings interrupt and remove inclusions from molten metal passing through the baffle, using a plurality of obstructive peaks and valleys located at the perimeters of the openings. The fluted openings also include central portions which are not obstructed by the flutes, through which molten metal can flow in a regular fashion.

Abstract: An apparatus for filtering a molten solder bath comprises, a housing having an entrance end and an exit end enclosing a channel means extending from the entrance end to a filter means adjacent the exit end. The channel means being configured for receiving molten solder at the entrance end and directing the solder to the filter means in a turbulent flow. The filter means being configured to filter particles from the flow and direct the filtered flow to the exit end. A cooling means is positioned on the housing for cooling solder flowing through the channel means without reacting with the solder. A method for filtering a molten solder bath comprises, directing solder from the bath in a turbulent flow and cooling the flow to form a precipitate of an impurity in the molten solder. The cooled flow is filtered to remove particles and form a high-purity solder, and the high-purity solder is returned to the bath. Preferably, the molten solder is protected by an inert atmosphere that does not react with the solder.

Abstract: A method of treating molten aluminum containing a suspension of finely divided salt particles remaining after filtering molten aluminum is disclosed. The method comprises providing a body of molten aluminum containing the suspension of molten salt particles entrained therein and passing the molten aluminum into a medium substantially unwettable by the molten salt particles. The particles of salt are collected on the medium and permitted to agglomerate so as to be removed to the surface of the molten aluminum by gravity.

Abstract: A process for the econimic recovery of metallic fractions generated during operation of a cupola furnace comprises the steps of the separating filter dust containing metal fractions from an off-gas stream and recirculating the metal fraction back to the cupola furnace for combustion with additional feedstock so as to enrich the metallic concentration of the filter dust to a level where economic recovery of the metallic fraction can occur.

Abstract: The process for purifying a metal melt operates with an active gas introduced into the lower region thereof and consisting of an inert carrier gas and an active, gaseous halogen which are introduced under control into a vessel with the stagnant or flowing metal melt.The active, gaseous halogen is generated at a controlled rate in at least one gas evolution cell and introduced into the carrier gas. The active gas mixture is passed directly into the metal melt. The gas feed line of the halogen does not have any control element.The gas evolution cell for generating the halogen is preferably an exchangeable electrolysis cell, gas being produced only when the electrolysis current is switched on, which follows a nominal curve proportionally to the current intensity.

Abstract: The filtration of molten ferrous metal is accomplished by providing a porous ceramic filter preferably comprising particles of alumina and partially stabilized zirconia that are spaced by interconnected cells to form circuitous and tortuous pathways throughout the ceramic body. The filter is a disc-like structure that can have different surface configurations such as corrugations or a waffle design. The filter can be flat-surfaced with an array of cylindrical openings or counterboard openings extending completely through the filter, or with openings extending partially into the filter from the upper and lower sides of the filter. Several relatively thin filters can be arranged in tandem, if desired.

Abstract: The filtration of molten ferrous metal is accomplished by providing a porous ceramic filter preferably comprising particles of alumina and partially stabilized zirconia that are spaced by interconnected cells to form circuitous and tortuous pathways throughout the ceramic body. The filter is a disc-like structure that can have different surface configuration such as corrugations or a waffle design. The filter can be flat-surfaced with an array of cylindrical openings or counterbored openings extending completely through the filter, or with openings extending partially into the filter from the upper and lower sides of the filter. Several relatively thin filters can be arranged in tandem, if desired.

Abstract: The effluent from mercury collected during the photochemical separation of the .sup.196 Hg isotope is often contaminated with particulate mercurous chloride, Hg.sub.2 Cl.sub.2. The use of mechanical filtering via thin glass tubes, ultrasonic rinsing with acetone (dimethyl ketone) and a specially designed cold trap have been found effective in removing the particulate (i.e., solid) Hg.sub.2 Cl.sub.2 contaminant. The present invention is particularly directed to such filtering.

Abstract: The present invention relates to a ceramic body suitable for use in molten metal filtration applications having a built-in preheat indicator and method for forming such a ceramic body. The preheat indicator comprises a dye having a burnoff temperature substantially equal to the desired preheat temperature applied to a surface of the ceramic body. In a preferred embodiment, the dye comprises an aniline dye such as Backmeier's crystal violet.

Abstract: The present invention relates to wax impregnated filters for use in investment casting applications and a method for forming them. The filters are characterized by a wax impregnated ceramic substrate, wax layers bonded to two opposed surfaces of the substrate, and peripheral edges having exposed ceramic surfaces which can be adhered to the ceramic liner of an investment casting apparatus. The method comprises providing a sheet of ceramic foam filter material, impregnating the sheet with sufficient liquid wax to form a wax layer of desired thickness bonded to each of two opposed surfaces of the sheet, allowing the wax to solidify, and precision cutting the impregnated sheet into filters having a desired set of dimensions. The method further comprises exposing the peripheral edges of each filter to allow the ceramic shell building or liner in the investment casting apparatus to bond directly to the filter.

Abstract: A molten metal pump includes a filter that prevents ingestion of foreign material such as dross from molten metal within which the pump is immersed. The filter is a large structure that is secured to the base of the pump surrounding the pump's inlet. The filter forms a cavity adjacent the pump's inlet. The ratio of the surface area of the filter to the inlet area of the pump is very large; the filter has a low porosity while maintaining a high flow rate for the pump.

Abstract: The present invention relates to an improved molten metal filtration system. The system comprises at least one filtration assembly positioned within a filter chamber intermediate a molten metal inlet and a molten metal outlet and a dam wall positioned intermediate each filtration assembly and each molten metal outlet. Each dam wall prevents the initial molten metal used to prime the filter(s) in each filtration assembly from proceeding directly to the outlet. Instead, the dam wall collects the initial molten metal and forms it into a pool of heated molten metal. This pool has been found to reduce the amount of heat loss during the filtration process. A process for using the filtration system of the present invention is also described.

Abstract: Shaped, porous filter members having a size and shape adapted for the filtration of liquid metals, e.g., the configuration of a honeycomb, are comprised of a porous alveolar ceramic material including from 10 to 20% SiO.sub.2, from 50 to 60% Al.sub.2 O.sub.3 and from 20 to 40% ZrO.sub.2, each percentage being by weight with respect to the total weight of said oxides, said Al.sub.2 O.sub.3 and SiO.sub.2 being present in the form of mullite, 3Al.sub.2 O.sub.3 /2SiO.sub.2, and the combined weight of the zirconia and mullite comprising at least 90% by weight of said alveolar ceramic material.