The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jan. 14, 1992
Filed:
Nov. 05, 1990
Robert Provencher, Jonquiere, CA;
Gaston Riverin, Jonquiere, CA;
Alcan International Limited, Montreal, CA;
Abstract
A process is described for removing all reinforcing particles contained in metal matrix composite scrap materials. This new technique involves providing a treatment vessel for holding a melt of an aluminum matrix composite to be recycled. Heating means are provided for heating the contents of the vessel to a temperature in the range of 700.degree.-750.degree. C. Mixing of the melt is carried out by means of a power driven vaned rotary impeller and this impeller is operated under different conditions for different stages of the process. In the first mixing stage, the impeller is operated under vortex-forming conditions and a fluxing salt is added to the melt while a gas is injected through a gas outlet beneath the surface of the melt and near the rotating impeller. This causes the salt to rapidly mix with the melt and the inlet gas, providing a uniform distribution through the melt of gas bubbles each surrounded by a layer of liquid salt. As a second stage of the treatment process, the impeller is operated at a high differential velocity between the impeller and the melt. These conditions cause collisions between the salt-coated bubbles and wetted reinforcing particles such as to de-wet the reinforcing particles and cause the reinforcing particles and salt flux to rise to the surface of the melt. The surface layer that is formed is essentially a powder which can easily be removed leaving a substantially pure metal with its chemical composition unchanged.