Abstract: A refining hearth. The refining hearth comprises an open vessel defining a first deep zone having a predetermined depth, a second deep zone having a predetermined depth, and a shallow zone intermediate the first deep zone and the second deep zone, wherein the shallow zone has a predetermined depth less that of the first deep zone and less than that of the second deep zone. A furnace for refining metal is also disclosed which employs a similarly constructed hearth. A method of refining metal is also disclosed. The method includes depositing molten metal in a first deep pool, passing the molten metal through a shallow pool having a depth less than the depth of the first deep pool, directing an energy source at the molten metal, and passing the molten metal into a second deep pool having a depth greater than the depth of the shallow pool.

Abstract: Apparatus and methods for limiting interaction of electron beams produced by adjacent electron bean guns mounted within a vacuum chamber of a furnace. The apparatus may include one or more barriers that are suspended within the vacuum chamber between adjacent electron beam guns. The methods may include suspending one or more vertically extending barriers with the vacuum chamber between adjacent electron beam guns.