Method for producing platinum group metal or platinum group-based alloy

Abstract

An object of the present invention is to provide a molten ingot of a platinum group metal or a platinum group-based alloy having a high material yield by suppressing a scattering phenomenon during heating and melting in a method for producing a platinum group metal or a platinum group-based alloy. The method for producing a platinum group metal or a platinum group-based alloy according to the present invention includes a preparing step of weighing a raw material that is partially or entirely of powder and, when the alloy is to be produced, mixing the weighed raw material to obtain a powder mixture, a molding step of molding and solidifying the prepared raw material to obtain molded bodies, a sintering step of sintering the molded bodies to obtain a sintered body, a melting step of melting the sintered body to produce a molten ingot, and a deformation processing step of processing the molten ingot. In the sintering step, the molded bodies are sintered in a stacked state to produce a sintered body as a joined body.

1 . A method for producing a platinum group metal or a platinum group-based alloy, comprising:
 a preparing step of weighing a raw material that is partially or entirely of powder and, when the alloy is to be produced, mixing the weighed raw material to obtain a powder mixture;   a molding step of molding and solidifying the prepared raw material to obtain molded bodies;   a sintering step of sintering the molded bodies to obtain a sintered body;   a melting step of melting the sintered body to produce a molten ingot; and   a deformation processing step of processing the molten ingot,   wherein, in the sintering step, the molded bodies are sintered in a stacked state to produce the sintered body as a joined body.   
     
     
         2 . A method for producing a platinum group metal or a platinum group-based alloy according to  claim 1 , wherein, in the molding step, the molded bodies are substantially in the shape of a rectangular parallelepiped. 
     
     
         3 . A method for producing a platinum group metal or a platinum group-based alloy according to  claim 1  wherein, in the melting step, a pressure during the melting is 1 Pa or higher. 
     
     
         4 . A method for producing a platinum group metal or a platinum group-based alloy according to  claim 3 , wherein, in the melting step,
 a plasma arc melting furnace with a water-cooled copper crucible having a through cavity is used,   a molten pool of a molten metal of the sintered body is formed in the cavity, and   a bottom portion of the molten pool in the cavity is pulled down to obtain the molten ingot.   
     
     
         5 . A method for producing a platinum group metal or a platinum group-based alloy, comprising:
 a preparing step of weighing a raw material that is partially or entirely of powder and, when the alloy is to be produced, mixing the weighed raw material to obtain a powder mixture;   a molding step of molding and solidifying the prepared raw material to obtain molded bodies;   a sintering step of sintering the molded bodies to obtain sintered bodies;   a melting step of melting the sintered bodies using energy beam melting that uses a boat-shaped water-cooled copper crucible having a cavity formed therein to produce a molten ingot; and   a deformation processing step of processing the molten ingot,   wherein, in the sintering step, a shape and dimensions of the sintered bodies are determined so as to conform to the cavity, and   wherein, in the melting step, the sintered bodies conforming to the cavity are densely arranged in the cavity of the boat-shaped water-cooled copper crucible to produce the molten ingot.   
     
     
         6 . A method for producing a platinum group metal or a platinum group-based alloy according to  claim 2 , wherein, in the melting step, a pressure during the melting is 1 Pa or higher.