Apparatus for purifying ruthenium using ozone

Abstract

The present invention relates to an apparatus for obtaining high purity ruthenium metal without the need for high temperature processing, expensive reagents, complex series of wet processes, or expensive equipment. According to the present invention, a gas stream including ozone (O 3 ) is brought into contact with a ruthenium source in one or more reaction vessels. The ozone reacts with the ruthenium source to form ruthenium tetraoxide (RuO 4 ), a compound that is a gas at the reaction conditions. The ruthenium tetraoxide, along with unreacted ozone and the remainder of the gas stream is then fed into a collection vessel where a major portion of the m gaseous ruthenium tetraoxide is thermally reduced to form ruthenium dioxide (RuO 2 ) deposits within the collection vessel. The deposited ruthenium dioxide is then reduced to produce highly pure ruthenium metal.

What we claim is:  
     
         1 . An apparatus for the manufacture of high purity ruthenium comprising: 
 an oxygen source, an ozone generator, a first container, a heated collection vessel, a nitrogen source, and a hydrogen source;    the oxygen source being connected to the ozone generator for supplying a stream consisting essentially of oxygen to the ozone generator;    the ozone generator operating on the stream of oxygen to produce a mixed gas stream consisting essentially of oxygen and ozone;    the first container designed to contain a ruthenium source and promote the mixing of the ruthenium source and the mixed gas stream, the reaction of the ozone and the ruthenium source producing a reaction gas stream comprising oxygen, ozone, and ruthenium tetraoxide;    the heated collection vessel comprising heated collection surfaces, the collection surfaces being maintained at a temperature sufficient to cause the spontaneous reduction of the ruthenium tetraoxide in the reaction gas stream to form deposits of ruthenium dioxide on the collection surfaces;    the nitrogen source connected to the heated collection vessel for purging the collection vessel to remove essentially all of the remaining portion of the reaction gas stream; and    the hydrogen source connected to the heated collection vessel for selectively introducing hydrogen gas into the collection vessel for reducing the deposited ruthenium dioxide to form highly pure ruthenium.    
     
     
         2 . An apparatus for the manufacture of high purity ruthenium according to  claim 1  wherein the first container comprises a series of perforated trays for supporting the ruthenium source and permitting the flow of the mixed gas stream.  
     
     
         3 . An apparatus for the manufacture of high purity ruthenium according to  claim 1  wherein the first container comprises a fluidized bed in which pieces of the ruthenium source are suspended in and agitated by the flow of the mixed gas stream.  
     
     
         4 . An apparatus for the manufacture of high purity ruthenium according to  claim 2  wherein the ruthenium source comprises ruthenium sponge.  
     
     
         5 . An apparatus for the manufacture of high purity ruthenium according to  claim 4  wherein the ruthenium sponge is characterized by a purity of at least 99.5%.  
     
     
         6 . An apparatus for the manufacture of high purity ruthenium according to  claim 3  wherein the ruthenium source is selected from a group consisting of ruthenium powder, ruthenium shot, ruthenium pellets and crushed ruthenium sponge.  
     
     
         7 . An apparatus for the manufacture of high purity ruthenium according to  claim 3  wherein the ruthenium source comprises ruthenium provided on particles of an inert carrier.  
     
     
         8 . An apparatus for the manufacture of high purity ruthenium according to  claim 7  wherein the inert carrier comprises a ceramic material.  
     
     
         9 . An apparatus for the manufacture of high purity ruthenium according to  claim 1  further comprising a second container designed to contain a second ruthenium source and promote mixing of the second ruthenium source and the reaction gas stream.  
     
     
         10 . An apparatus for the manufacture of high purity ruthenium according to  claim 9  wherein the second container further comprises an inlet for the mixed gas stream, the design of the second container promoting mixing of the mixed gas stream, the reaction gas stream and the ruthenium source to form a second reaction gas stream that is fed into the heated collection vessel.  
     
     
         11 . A method for manufacturing high purity ruthenium dioxide the steps of: 
 placing a ruthenium source in a first container;    feeding an ozone-containing gas stream into the first container;    forming a reaction gas stream comprising ozone, oxygen, and ruthenium tetraoxide;    feeding the reaction gas into a collection vessel;    reducing the ruthenium tetraoxide to form ruthenium dioxide deposits within the collection vessel;    purging the collection vessel to remove essentially all remaining reaction gas; and    removing the highly pure ruthenium dioxide from the collection vessel.    
     
     
         12 . A method for manufacturing high purity ruthenium dioxide according to  claim 11 , wherein the highly pure ruthenium dioxide is at least 99.99% pure.  
     
     
         13 . A method for manufacturing high purity ruthenium dioxide according to  claim 12 , wherein the highly pure ruthenium dioxide is characterized by a predominate crystalline morphology.  
     
     
         14 . A method for manufacturing high purity ruthenium dioxide according to  claim 12 , wherein the predominate crystalline morphology is a crystalline needle.