Patent ID: 6486822
Filing Date: 2002-11-26
Classification: H01F,H01Q

Abstract:
A method of producing coated particles, said method comprising:providing a rotatable retort mounted about a generally horizontal axis of rotation and having an outer wall; partially filling said retort by placing ferromagnetic particles selected from the group consisting of iron, carbonyl iron and alloys thereof into said retort; evacuating said partially filled retort; supplying a gaseous composition containing both silicon and oxygen as active elements at a controlled pressure within said evacuated retort; rotating said retort during the supply of said gaseous composition to fluidize said ferromagnetic particles; and heating the exterior of said retort while said retort is rotating to transfer energy through said outer wall of said retort and into said ferromagnetic particles, thereby producing coated particles by effecting deposition of said active elements within said gaseous composition onto the surface of said ferromagnetic particles.