PURPOSE: To remove P from a powdery or granular Mn alloy efficiently by heat treating the Mn alloy together with a specified flux for dephosphorization at a temp. between the m.p. of the flux and a temp. below the m.p. of the Mn alloy.

CONSTITUTION: A flux for dephosphorization contg. an inorg. salt which generates an oxidizing gas by heat treatment as the principal component is added to a powdery or granular Mn alloy. The flux has a lower m.p. than the Mn alloy and may contain the carbonate of an alkali or alkaline earth metal such as Na2CO3, K2CO3 or Li2CO3 as the principal component. The Mn alloy is heat treated together with the flux at a temp. between the m.p. of the flux and a temp. below the m.p. of the Mn alloy.