METHOD FOR REMOVING IMPURITY ELEMENT IN MOLTEN COPPER OR COPPER ALLOY AND REFINING AGENT

摘要

PROBLEM TO BE SOLVED: To remove impurity elements such as Cr, Zr, melted in molten metal by covering the surface of molten copper or copper alloy with a coating agent substantially composed of at least one kind of borax and boric acid and the balance of at least one kind selected from among specific ratios of lithium oxide, potassium oxide and sodium oxide contained in the borax. ;SOLUTION: At the time of covering a molten metal surface with a refining agent with addition of an oxide such as lithium oxide to borax and/or boric acid, these mixed powders are melted with the molten metal surface to prevent oxidation from the atmosphere by covering this surface. At the same time, these oxides and Cr and Zr in the molten metal react to form complex oxide and this oxide is absorbed into a coating agent, and Cr and Zr in the molten metal can be reduced. This refining agent does not react with Sn, P, Zn, Ni, etc., and Cr, Zr, etc., are selectively removed. The content of the oxide of the lithium oxide, etc., is made in the range of 5 mol.% to less than 40 mol.%.;COPYRIGHT: (C)1999,JPO