Method for manufacturing needle-shaped or rod-shaped porous iron powder and needle-shaped or rod-shaped porous iron powder manufactured thereby

Abstract

The present invention relates to a method for manufacturing a needle-shaped or rod-shaped porous iron powder. Specifically, the present invention provides a method for manufacturing a needle-shaped or rod-shaped porous iron and a needle-shaped or rod-shaped porous iron powder manufactured thereby, the method comprising the steps of: preparing a ferrous chloride dehydrate by concentrating a ferrous chloride aqueous solution; solid-liquid separating the ferrous dichloride to prepare ferrous chloride dehydrate powder; oxidizing the ferrous chloride dehydrate powder; and reducing the oxidized ferrous chloride powder.

1 . A method for manufacturing a needle-shaped or rod-shaped porous iron powder, the method comprising:
 concentrating a ferrous chloride aqueous solution to prepare a ferrous chloride dihydrate;   subjecting the ferrous chloride dihydrate to a solid-liquid separation to prepare a ferrous chloride dihydrate powder;   oxidizing the ferrous chloride dihydrate powder; and   reducing the oxidized ferrous chloride dehydrate powder.   
     
     
         2 . The method for manufacturing a needle-shaped or rod-shaped porous iron powder of  claim 1 , wherein the ferrous chloride aqueous solution has a concentration of 20 to 625 g/L. 
     
     
         3 . The method for manufacturing a needle-shaped or rod-shaped porous iron powder of  claim 1 , wherein the concentrating of the ferrous chloride aqueous solution is carried out by evaporative concentration at a temperature of 72 to 125° C. 
     
     
         4 . The method for manufacturing a needle-shaped or rod-shaped porous iron powder of  claim 1 , wherein the oxidizing of the ferrous chloride dihydrate powder is carried out by calcination at a temperature of 200 to 1300° C. in an oxygen atmosphere. 
     
     
         5 . The method for manufacturing a needle-shaped or rod-shaped porous iron powder of  claim 1 , wherein the reducing of the oxidized ferrous chloride dihydrate powder is carried out at a temperature of 400 to 1300° C. under a reducing atmosphere. 
     
     
         6 . The method for manufacturing a needle-shaped or rod-shaped porous iron powder of  claim 5 , wherein the reducing atmosphere is an atmosphere of hydrogen, carbon monoxide, or a mixed gas thereof. 
     
     
         7 . The method for manufacturing a needle-shaped or rod-shaped porous iron powder of  claim 6 , wherein the reducing of the oxidized ferrous chloride dihydrate powder is carried out at a temperature of 600 to 800° C. in the case of the hydrogen atmosphere. 
     
     
         8 . The method for manufacturing a needle-shaped or rod-shaped porous iron powder of  claim 6 , wherein the reducing of the oxidized ferrous chloride dihydrate powder is carried out at a temperature of 700 to 1000° C. in the case of the carbon monoxide atmosphere. 
     
     
         9 . A needle-shaped or rod-shaped porous iron powder manufactured by the method of  claim 1 . 
     
     
         10 . The needle-shaped or rod-shaped porous iron powder of  claim 9 , wherein the iron powder has a specific surface of 0.3 to 3 m 2 /g.