Process for recycling of tungsten carbide alloy

Abstract

The present disclosure is a process for the recycling of tungsten carbide alloy. Tungsten carbide alloy scrap is heated in an oxidizing atmosphere and the oxidized material is pulverized by grinding. The powder material is treated with a carburizing mixture for reducing and carburizing the powdered tungsten oxides and other metal oxides. The method is cost effective and environment friendly.

1 . A process for the recycling of tungsten carbide alloy comprising acts of:
 a) oxidizing the tungsten carbide alloy to obtain tungsten oxides and other metallic oxides;   b) grinding the tungsten oxides and other metallic oxides to obtain a powder; and   c) treating the powder with a carburizing mixture for reducing and carburizing the powdered tungsten oxides and other metallic oxides to obtain the purified tungsten carbide alloy powder.   
     
     
         2 . The process as claimed in  claim 1 , wherein the oxidation is carried out in an oxidation furnace at a temperature ranging from about 400° C. to about 1000° C., preferably at about 950° C. 
     
     
         3 . The process as claimed in  claim 1 , wherein the oxidation is carried out using oxidizing agent selected from a group comprising air and oxygen, preferably air. 
     
     
         4 . The process as claimed in  claim 1 , wherein the grinding is carried out by a method selected from a group comprising ball mill, Attritor Mill, High Speed Intensive mill; preferably ball mill. 
     
     
         5 . The process as claimed in  claim 1 , wherein the grinding is carried out for a period ranging from about 0.5 h to about 10 h, preferably for about 2 h. 
     
     
         6 . The process as claimed in  claim 1 , wherein the carburizing mixture is selected from a group comprising air, hydrogen, nitrogen, carbon monoxide, methane, carbon dioxide, compressed natural gas (CNG), liquefied petroleum gas (LPG) and mixtures thereof. 
     
     
         7 . The process as claimed in  claim 6 , wherein the carburizing mixture is a combination of about 10% liquefied petroleum gas and about 90% nitrogen. 
     
     
         8 . The process as claimed in  claim 1 , wherein the treatment with the carburizing mixture is carried out for a period ranging from about 1 h to about 15 h, preferably 3 h. 
     
     
         9 . The process as claimed in  claim 8 , wherein the treatment with the carburizing mixture to obtain the purified tungsten carbide alloy powder is carried out in a reduction furnace at a temperature ranging from about 800° C. to about 1400° C., preferably at about 1050° C. 
     
     
         10 . The process as claimed in  claim 9 , wherein the purified tungsten carbide alloy powder is cooled to a temperature ranging from about 300° C. to about 200° C. preferably about 200° C. in nitrogen, and then to about 40° C. to about 20° C., preferably about 25° C. in air.