Swiss Aluminium Ltd.

Robert K Preuss

John C Yarwood

James E Dore

The disclosure teaches an improvement in the filtration of molten metal especially aluminum using a removable vertically disposed filter plate and at least one fluxing gas inlet positioned in such a manner so as to introduce fluxing gas into the filter plate. The filter plate is provided with a bevelled peripheral surface mating with a like bevelled surface in a filter chamber so that the filter plate can be conveniently inserted in the chamber and removed therefrom. Fluxing gas is provided to the melt through the inlet and flows through the filter plate so as to assure extensive contact with the melt. Dissolved gases and non-metallic inclusions are thereby abstracted and removed from the melt.

Filtering and inline degassing of molten metal

The disclosure teaches an improvement in the filtration of molten metal, especially aluminum, using a removable filter plate. The filter plate is provided with a bevelled peripheral surface mating with a like bevelled surface in a filter chamber so that the filter plate can be conveniently inserted in the chamber and removed therefrom.

Filtering of molten metal

Ceramic foams possessing controlled permeability and uniformity are prepared by a combined rolling operation of impregnating an open-celled organic polymer foam material possessing a predetermined permeability and resilience with a fluid aqueous slurry of a thixotropic ceramic composition and immediate passage through at least two controlled roll gaps, wherein the rolls are preset to effect a temporary compression ranging from about 50 to 90% for the first pass and 70 to 90% for the second pass. The resulting material is thereby uniformly impregnated with the required amount of slurry, and is then dried and heated to remove the organic foam component. The foams prepared in accordance with the present invention are useful as filters for molten metals, especially aluminum and its alloys.

Method of preparation of ceramic foam

The disclosure teaches an improvement in the degassing and filtration of molten metal, especially aluminum, using an apparatus which employs a pair of sequentially placed, removable filter-type plates and at least one fluxing gas inlet positioned therebetween. Fluxing gas is provided to the melt through the inlet and flows upward through the first of said plates into counter-current contact with the melt. Said plate serves to break up said fluxing gas into a fine dispersion to assure its intimate and extensive contact with the melt. Dissolved gases and non-metallic inclusions are thereby abstracted and removed from the melt.

Method for in-line degassing and filtration of molten metal

Apparatus and method for in-line degassing and filtration of molten metal

Ceramic foams possessing controlled permeability and uniformity are prepared by the impregnation of an open-celled organic polymer foam material possessing a predetermined permeability and resilience with a aqueous slurry of a thixotropic ceramic composition while shearing said slurry an amount sufficient to maximize said impregnation, and expelling excess slurry from said material by conducting at least two passes of said material through preset rollers to effect a temporary compression ranging from about 50 to 90% for the first pass and 70 to 90% for the second pass. The resulting material is then dried and heated to remove the organic foam component. The foams prepared in accordance with the present invention are useful as filters for molten aluminum.

Ceramic foam and method of preparation

The disclosure teaches an improved ceramic foam filter particularly useful for filtering molten metal, and also a method for filtering molten metal. The filter is characterized by a combination of properties which makes it particularly suitable for use in filtering molten metal.

Growing community of inventors

Middletown, CT, United States of America

Robert K Preuss