High purity iron, method of manufacturing thereof, and high purity iron targets

Abstract

High purity iron with a very few content of impurities such as copper, a method of manufacturing thereof, and high purity iron targets are provided. The iron containing impurities such as copper is dissolved in a hydrochloric acid solution, and the concentration of the hydrochloric acid of the aqueous solution of iron chloride is adjusted to 0.1 kmol/m 3 to 6 kmol/m 3 . Then, iron is added in the aqueous solution of iron chloride, and an inert gas is injected into the solution with agitating, in order to convert the trivalent iron ions and divalent copper ions contained in the aqueous solution of iron chloride respectively to divalent iron ions and monovalent copper ions. Then, the aqueous solution of iron chloride is fed into a column filled up with the anion exchange resins. The divalent iron ions are not absorbed on the anion exchange resins although the monovalent copper ions are absorbed on the anion exchange resins. Therefore, copper can be separated from the aqueous solution of iron chloride. And then, the aqueous solution of iron chloride is evaporated to dryness, oxidized and heated in a hydrogen atmosphere to generate iron.

What is claimed is:  
     
         1 . High purity iron with 99.99 mass % or more in purity wherein a copper impurity content is 50 mass ppb or less.  
     
     
         2 . High purity iron wherein a residual resistivity ratio thereof is 3000 or more, and a copper impurity content is 50 mass ppb or less.  
     
     
         3 . A method of manufacturing high purity iron comprising the steps of; 
 converting trivalent iron ions and impurity divalent copper ions contained in an aqueous solution of iron chloride respectively to divalent iron ions and monovalent copper ions;    adjusting a concentration of hydrochloric acid in a range of 0.1 kmol/m 3  to 6 kmol/m 3 ; and    separating the monovalent copper ions from the aqueous solution of iron chloride by using ion exchange resins.    
     
     
         4 . A method of manufacturing high purity iron according to  claim 3 , comprising the steps of; 
 converting trivalent iron ions and impurity divalent copper ions contained in an aqueous solution of iron chloride respectively to divalent iron ions and monovalent copper ions;    adjusting a concentration of hydrochloric acid in the aqueous solution of iron chloride in a range of 0.1 kmol/m 3  to 6 kmol/m 3 ; and    contacting the aqueous solution of iron chloride with anion exchange resins to separate the monovalent copper ions from the aqueous solution of iron chloride after the steps of converting the trivalent iron ions and the divalent copper ions respectively to the divalent iron ions and the monovalent copper ions and adjusting the concentration of hydrochloric acid.    
     
     
         5 . A method of manufacturing high purity iron according to  claim 3 , wherein the converting step comprises the steps of; 
 injecting an inert gas into the aqueous solution of iron chloride; and    converting trivalent iron ions and divalent copper ions contained in an aqueous solution of iron chloride respectively to divalent iron ions and monovalent copper ions by contacting the aqueous solution of iron chloride with iron.    
     
     
         6 . A method of manufacturing high purity iron according to  claim 3 , wherein at least one of impurities selected from the group consisting of zinc, gallium, niobium, technetium, ruthenium, rhodium, palladium, silver, cadmium, indium, tin, antimony, tellurium, tantalum, tungsten, rhenium, osmium, iridium, platinum, gold, mercury, thallium, lead, and bismuth is separated from the aqueous solution of iron chloride in the step of separating the copper.  
     
     
         7 . A method of manufacturing high purity iron according to  claim 3 , further comprising the steps of; 
 adjusting the concentration of hydrochloric acid in the aqueous solution of iron chloride in a range of 2 kmol/m 3  to 11 kmol/m 3 ;    contacting the aqueous solution of iron chloride with the anion exchange resins to absorb the iron of trivalent ions thereon and separate at least one of impurities selected from the group consisting of lithium, beryllium, sodium, magnesium, aluminum, silicon, phosphorus, potassium, calcium, scandium, titanium, vanadium, chromium, manganese, cobalt, nickel, rubidium, strontium, yttrium, zirconium, cesium, barium, lanthanoids, hafnium, francium, radium and actinoids contained in the aqueous solution of iron chloride, from the aqueous solution of iron chloride; and    eluting the iron from the anion exchange resins with a hydrochloric acid solution.    
     
     
         8 . A method of manufacturing high purity iron according to  claim 7 , wherein a hydrochloric acid solution having a concentration of 0.1 kmol/m 3  to 2 kmol/m 3  is used for eluting the iron from the anion exchange resins in order to separate the iron from at least one of impurities selected from the group consisting of zinc, gallium, niobium, molybdenum, technetium, ruthenium, rhodium, palladium, silver, cadmium, indium, tin, antimony, tellurium, tantalum, tungsten, rhenium, osmium, iridium, platinum, gold, mercury, thallium, lead, bismuth and polonium absorbed on the anion exchange resins.  
     
     
         9 . A method of manufacturing high purity iron according to  claim 3 , further comprising the steps of; 
 obtaining iron oxide from the aqueous solution of iron chloride which the impurity copper are separated therefrom; and    heating the iron oxide in a hydrogen atmosphere to obtain iron.    
     
     
         10 . A method of manufacturing high purity iron according to  claim 9 , further comprising the step of melting the iron obtained in the heating step with plasma arc using a plasma generation gas containing active hydrogen in order to remove at least one of impurities selected from the group consisting of oxygen, nitrogen, carbon, sulfur, halogen, alkaline metals, and alkaline-earth metals.  
     
     
         11 . A method of manufacturing high purity iron comprising the steps of; 
 converting trivalent iron ions in an aqueous solution of iron chloride to divalent iron ions;    adjusting a concentration of hydrochloric acid in a range of 0.1 kmol/m 3  to 6 kmol/m 3 ; and    separating at least one of impurities selected from the group consisting of zinc, gallium, niobium, technetium, ruthenium, rhodium, palladium, silver, cadmium, indium, tin, antimony, tellurium, tantalum, tungsten, rhenium, osmium, iridium, platinum, gold, mercury, thallium, lead, and bismuth from the aqueous solution of iron chloride by using the anion exchange resins.    
     
     
         12 . High purity iron targets with 99.99 mass % or more in purity wherein a copper impurity content is 50 mass ppb or less.  
     
     
         13 . High purity iron targets wherein a residual resistivity ratio is 3000 or more, and a copper impurity content is 50 mass ppb or less.