Abstract:
A method for refining a titanium metal containing ore such as rutile or ilmenite or mixtures to produce titanium ingots or titanium alloys and compounds of titanium involves production of titanium tetrachloride by processing the ore with a chlorinating procedure and removing various impurities by a distillation or similar procedures to form a relatively pure titanium tetrachloride. Thereafter, the titanium tetrachloride is introduced continuously into a reactor at the focal point of a plasma under atmospheric pressures of inert gas along with molten metallic reductant for the initial reduction of gas phase titanium tetrachloride into molten titanium drops which are collected in a set of skulled crucibles. Thereafter, further processing is carried out at atmospheric pressures in under inert gas where the titanium is heated by plasma guns to maximize titanium purity and, in a final optional stage, alloying compounds are added under the same controlled environment and high temperature conditions.

Description:
BACKGROUND OF THE INVENTION 
     The present invention relates to processing of titanium bearing ores and more specifically to an improved process for low cost and high speed extraction, production and refining of titanium and titanium alloys. 
     The present invention is a further improvement of Dr. Joseph&#39;s prior patents, U.S. Pat. No. 5,503,655 issued Apr. 2, 1995 and U.S. Pat. No. 6,136,060 issued Oct. 24, 2000, the disclosures of which are incorporated herein by reference. The first patent describes a process in which a liquid slag containing titanium dioxide is reduced to a mixture of titanium dioxide and iron; the iron is then separated out to produce about 95% pure titanium dioxide. In subsequent processing, the partially pure titanium dioxide is melted and processed to remove any residual iron and other impurities to form titanium dioxide powder. 
     The second patent discloses a process for production of titanium and titanium alloys using a reductive process under vacuum. The reduction step is carried out by molten metallic sodium, whereas in the present disclosure, the reductant could be any of magnesium, sodium, hydrogen, lithium, potassium, rubidium, cesium, francium, beryllium, calcium, strontium, barium or radium. 
     Canadian Patent No. 549299 to Gross et al. discloses the production of titanium metal by decomposing titanium halides under controlled temperatures. U.S. Pat. No. 4,793,854 to Shimotori et al. produces titanium by electrolysis of molten titanium slat followed by purification under high vacuum conditions. 
     A large number of prior art references describe various aspects of refining metals and particularly refining titanium. Great Britain Patent No 809,444 , U.S. Pat. No. 3,546,348 to DeCorso and U.S. Pat. No. 3,764,297 to Coad et al. describe the use of electric arcs under vacuum to melt metals. U.S. Pat. No. 2,997,760 to Hanks et al. describes melting metals under vacuum to remove volatile impurities. U.S. Pat. No. 3,237,254 (Hanks et al.), U.S. Pat. No. 3,342,250 (Treppschuh et al.) and U.S. Pat. No. 3,343,828 (Hunt) describe melting metals under vacuum with electron beam guns. U.S. Pat. No. 3,494,804 to Hanks et al. also describes vacuum heating with an electron beam gun and discloses the idea of using a “skull” to prevent contamination of a melt by the walls of a crucible. U.S. Pat. No. 4,027,722 to Hunt and U.S. Pat. No. 4,488,902, also to Hunt, describe additional details of electron beam based processes U.S. Pat. No. 3,210,454 to Morley and U.S. Pat. No. 4,838,340 to Entrekin et al. disclose the use of plasma torches to maintain metals in a molten state. 
     Titanium, especially some of its alloys such as titanium-aluminum-vanadium (Ti-6Al-4V) are important because they are ideally suited for a wide variety of applications in the aerospace, aircraft, military, and automotive fields. Titanium and its alloys, including that mentioned, combine the attractive properties of high strength and light weight with resistance to corrosion and stability under high temperatures. For example, titanium is very strong but only about 60% as dense as iron and parts made of titanium will weigh only 60% as much as the same part made of steel. While titanium is relatively easy to fabricate, there are numerous impediments to its widespread use. As demonstrated by the above cited references, refining titanium is energy intensive and involves significant costs in handling due to the need for toxic chemicals for its refining. Furthermore, in refining titanium, there may also be a high cost involved in disposing of the toxic byproducts produced in the refinery process. 
     Thus, it is a primary object of this invention to provide an improved and cost effective process for the production of high purity titanium and its alloys from a starting ore containing titanium, preferably in an oxide form. 
     Another object of the present invention is the conversion of a titanium bearing ore such as rutile or ilmenite to an essentially pure titanium tetrachloride followed by reduction to titanium which is then followed by refining of the titanium to a pure state and optionally alloying the same. 
     These objects and features of the present invention will become more apparent from the following detailed description which provides detailed information regarding both the process and apparatus and which is for purposes of illustration and should not be construed as a limitation on the present invention. 
     SUMMARY OF THE INVENTION 
     The present invention is a process for refining titanium containing ore and more particularly a sequence which involves converting the titanium ore to titanium tetrachloride, the latter continuously reduced to titanium metal in a plasma reactor in the presence of a metallic reductant under inert gas at atmospheric pressures. The resulting titanium is continuously fed and further processed to a relatively high purity while molten and under inert gas at atmospheric pressures followed optionally by alloying with other metals such as aluminum and vanadium. 
     First, titanium tetrachloride is produced from the ore and many of the impurities such as iron chloride and vanadium are removed in this step resulting in an intermediate with less than four parts per billion. 
     Then the titanium tetrachloride is reduced with molten magnesium or sodium, or alternatively with lithium, potassium, rubidium, cesium, francium, beryllium, calcium, strontium, barium or radium under inert gas at atmospheric pressures in a plasma reactor preferably using a hydrogen plasma. Thereafter, the molten titanium is processed in the presence of inert gas under atmospheric pressures (approximately 760 Torr ) and elevated temperatures. During this processing alloying optionally may take place. 
     An appreciation of the other aims and objectives of the present invention and an understanding of it may be achieved by referring to the accompanying drawings and description of a preferred embodiment. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a diagrammatic illustration of the general steps for production of titanium alloy from titanium ore in accordance with the present invention; 
     FIG. 2 is a process flow sheet for the production of titanium tetrachloride in accordance with this invention; 
     FIG. 3 is a sketch of the plasma reactor for the reduction of titanium tetrachloride in accordance with this invention; 
     FIG. 4 is an illustration of the titanium tetrachloride supply system used with the plasma reactor of FIG. 3 in accordance with this invention; and 
     FIG. 5 is an illustration of the apparatus for the steps of titanium alloying and purification following reduction. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     While the present invention is described herein with reference to illustrative embodiments for particular applications, it should be understood that the invention is not limited thereto. Those having ordinary skill in the art and access to the teachings provided herein will recognize additional modifications, applications, and embodiments within the scope thereof and additional fields in which the present invention would be of significant utility. 
     The process previously patented by Dr. Joseph utilizes sodium as a reductant, and produces high-grade titanium metal from titanium tetrachloride under vacuum conditions. In the improved process, magnesium, lithium, potassium, rubidium, cesium, francium, beryllium, calcium, strontium, barium or radium can also be used as the reductant instead of sodium. Because of cost and toxicity sodium or magnesium are preferred. 
     The choice of reductant between sodium and magnesium can be based on: 
     Suitability for reaction—thermodynamics and kinetics; 
     Cost of the reductant; 
     Ease of delivery or handling; 
     Disengagement of the products; and 
     Safety. 
     The following table of physical characteristics is useful for making this selection: 
     
       
         
               
               
               
               
             
               
               
               
               
             
           
               
                   
                   
               
               
                   
                 Component 
                 Melting Point ° C. 
                 Boiling Point ° C. 
               
               
                   
                   
               
             
             
               
                   
               
             
          
           
               
                   
                 Na 
                 98 
                 882 
               
               
                   
                 Mg 
                 650 
                 1105 
               
               
                   
                 Ti 
                 1667 
                 3285 
               
               
                   
                 TiCl 4   
                 −25 
                 137 
               
               
                   
                 NaCl 
                 801 
                 1465 
               
               
                   
                 MgCl 2   
                 714 
                 1418 
               
               
                   
                 TiCl 3   
                 730 
                 750 
               
               
                   
                   
               
             
          
         
       
     
     Thermodynamic analysis shows no real benefit of sodium over magnesium as reductant as far as can be discerned from equilibrium considerations. From the Kroll and Hunter processes (see  Hawley&#39;s Condensed Chemical Dictionary  (11th ed. 1987)) it appears that any of the reduction reactions is possible and no data have been found to support a preference for one reductant over the others. 
     Kinetic data in a publication by Tisdale et al. give some useful indicators that the reaction of titanium tetrachloride with magnesium metal is sufficiently fast in the vapor phase at 1150-1250° C. to preclude concerns over excessively long reaction times for a continuous process. “Vapor phase titanium production”, D. G. Tisdale, J. M. Toguri, and W. Curlook, CIM Bulletin, March 1997:159-163. 
     The cost of the reductant metal is a major consideration. Sodium and magnesium have similar atomic weights, but on a molar basis only one half as much magnesium is required. Therefore, there is less reductant to heat up to reaction temperatures with magnesium, thus lowering energy input. The fact that magnesium is currently in abundance and roughly half the cost of the sodium per pound or kilogram is an additional point in its favor. 
     Both magnesium and sodium are flammable and great care should be exercised in their handling. Sodium melts at a much lower temperature: so maintaining feed systems in the molten state is simpler. It is however more reactive with water and has to be stored under paraffin, as it will oxidize rapidly in air. Magnesium on the other hand can be delivered as ingots or “bricks” and is stable at room temperature. The products of the reactions have their respective advantages and disadvantages. The reactor has to be held above the condensation point of the reactants and products to enable good separation of the products. Reference to the database of physical properties allows one to estimate optimal reaction temperatures for any set of reactants. 
     To evacuate the process stream of product chloride and metal requires an operating temperature of at least 1465° C. Alternatively, sufficient flushing gas such as argon must be provided to assure that the walls of the vessel are above the dew point determined by the vapor pressure of any residual chloride or metal in this gas stream. While sodium metal is clearly more volatile than magnesium and therefore should be easily stripped from the melt at high temperatures, it actually has a marginally higher boiling point than magnesium chloride. 
     Development of a low cost, high speed, continuous or near-continuous process for producing high-grade titanium metal which is essentially pure, represents a great improvement in the field of metallurgy, and satisfies a long felt need for a commercial process with a high potential capacity, but which is less labor intensive. Further, any component which will make the process even more cost effective and efficient is beneficial. 
     Referring to the drawings which illustrate a preferred embodiment of this invention, the general flow diagram of FIG. 1 shows the general sequence of steps. The first step  10  includes the formation of essentially pure titanium tetrachloride (TiCl 4 ) from a starting titanium bearing ore such as rutile or ilmenite or mixtures of ores. Rutile is an ore containing titanium and oxygen (TiO 2 ) while ilmenite is an ore containing iron, titanium and oxygen (TiO 2 Fe 2 O 3 ). For the purposes of this invention, any titanium containing ore or mixtures of ores preferably with oxygen, with or without other metals, may be used as the starting ore. The titanium ore is dressed in a conventional manner to produce an ore concentrate. In effect, the first general step  10  includes conversion of the starting ore to titanium tetrachloride preferably having less than 4 parts per billion of metallic impurities since the latter are difficult to remove in later processing. Generally, this step includes reacting chlorine with the ore to form titanium tetrachloride. 
     The next general step  12  involves conversion of the essentially pure titanium tetrachloride to titanium metal by plasma arc treatment in a chemical reduction process resulting in the reduction of the TiCl 4  to titanium and 2(XCl 2 ), where X is a divalent reductant such as beryllium, magnesium, calcium, strontium, barium or, radium, or 4(YCl), where Y is a monovalent reductant such as lithium, sodium, potassium, rubidium, cesium or francium. In this second general step  12 , a plasma reactor  40  (FIG. 3, to be described below) is used in which magnesium, sodium, lithium, potassium, rubidium, cesium, francium, beryllium, calcium, strontium, barium or radium is melted if necessary, and is injected continuously into a reaction chamber with heated titanium tetrachloride resulting in the formation of titanium metal and 2(XCl 2 ), or 4(YC1), depending on the choice of reductant. 
     The third general step  15  involves processing the titanium from the second step under a controlled environment in which the titanium is heated and kept molten by plasma guns  130  (FIG. 5) and at controlled environment conditions resulting in a very pure titanium metal which can be cast into ingots  125  or converted to an aluminum-vanadium alloy while the titanium metal is in liquid form. In this third general step  15 , dissolved gases such as hydrogen and chlorine are removed by out gassing. Since out gassing generally cannot remove oxygen, nitrogen and carbon, the entire process takes place at atmospheric pressures in an inert gas environment to flush out these impurities. 
     FIG. 2 illustrates the details of the process involved in the first general step  10  shown in FIG. 1 for the production of titanium tetrachloride from a suitable ore. As shown, a titanium and oxygen bearing ore  17  such as rutile or ilmenite or mixtures, is dressed  16  with petroleum coke  18  and chlorine gas  19  and processed in a chlorination step  20  at an elevated temperature. After chlorination  20 , the mixture contains titanium tetrachloride and iron chloride and other impurities which are separated out in a separation and condensation step  22 . The impurities are separated at  24  resulting in the formation of a crude titanium tetrachloride as shown at  25 . 
     The crude titanium tetrachloride  25  is then processed at  28  to remove vanadium, as shown at  29 , followed by distillation at  30 , again at an elevated temperature, to remove silicon chloride as shown at  32 . After removal of vanadium  29  and silicon chloride  32 , the concentration of impurities is preferably below about 4 parts per billion. The result is essentially pure titanium tetrachloride (TiCl 4 ). 
     Thus, the first detail step within the first general step  10  involves ore dressing  16  to produce an ore concentrate. The second detail step involves chlorination  20  of the ore concentrate to form crude metal  25 . This second detail step involves two separate sub-steps: 
     (a) Conversion of the ore concentrate to crude TiCl 4    25 . This is done in the chlorination process  20  and is represented by the reaction (where “s” indicates solid and “g” indicates gas): 
     
       
         TiO 2 ( s )+2Cl 2 ( g )+2C( s )→TiCl 4 ( g )+2CO( g ) 
       
     
     The chlorination process  20  is carried out in a chlorinator. With rutile ores, in the case of ilmenite, iron chloride is also formed and has to be removed as a separate step  22 . 
     (b) The crude TiCl 4    25  is further purified  28 ,  30  to remove vanadium  29  and silicon  32  impurities. The final product is pure TiCl 4 . All the metallic impurities have to be removed, in this step since they cannot be removed subsequently. 
     The next general step  12  is the plasma arc reduction of titanium tetrachloride in the presence of gaseous hydrogen for the plasma and molten metallic magnesium, sodium, lithium, potassium, rubidium, cesium, francium, beryllium, calcium, strontium, barium or radium reductant to produce titanium and 2(XCl 2 ), where X is divalent reductant such as beryllium, magnesium, calcium, strontium, barium or, radium, or 4(YCl), where Y is a monovalent reductant such as lithium, sodium, potassium, rubidium, cesium or francium according to the equation: 
     
       
         TiCl 4 +2X→Ti+2(XCl 2 ) 
       
     
     where X is beryllium, magnesium, calcium, strontium, barium or, radium, or 
      TiCl 4 +4Y→Ti+4(YCl) 
     where Y is lithium, sodium, potassium, rubidium, cesium or francium. 
     The plasma reduction step  12  may be carried out in an apparatus  40  illustrated in FIG.  3  and referred to as a plasma reactor utilizing an inert atmosphere of argon or helium. The reactor  40  includes basically two zones both of which contain inert gas at atmospheric pressures. The upper zone  41  contains the plasma arc in which the reduction occurs, and the lower zone  43  is the input side of the refining and alloying apparatus (step  15  of FIG. 1; illustrated in FIG. 5) also at a controlled pressure of about 760 Torr, as are later stages. The two zones  41 ,  43  are separated by a flange  45 , from which is suspended a collar  107  holding collector crucible  110  (to be described). 
     The top portion  50  of the reactor  40  includes an injection port  51  through which the reductant metallic magnesium, sodium, lithium, potassium, rubidium, cesium, francium, beryllium, calcium, strontium, barium or radium (herein after, metallic reductant) is introduced into the reactor  40 . Surrounding the top portion  50  is a graphite block  54  for high temperature resistance. 
     The metallic reductant is heated and melted (if necessary) by a plurality of plasma torches  52  arranged at a tilted down 60 degree angle and disposed circumferentially at 120 degrees from each other, two being shown at  52 , and located vertically below the metallic reductant injection port  51 . The metallic reductant is introduced at the focal point of the torches  52 , as illustrated diagrammatically as “*”. Located vertically below the torches  52  is a titanium tetrachloride injection port  55  such that the molten metallic reductant comes into intimate contact with the injected titanium tetrachloride and is intermixed therewith for reaction. A constant stream of inert gas (such as argon or helium) and hydrogen for the plasma is introduced into zone  41  through ports such as ports  53  that can be coaxial with the torches  52 . Located vertically below the titanium tetrachloride injection port  55  is a dual reactor section  57 ,  58 , including a graphite liner  54   a , for reaction between the molten metallic reductant and the heated titanium tetrachloride. Graphite rings  56  are used for temperature resistance, and within the reactor sections  57 ,  58  are temperature resistant graphite columns  56   a . Vertically below the reactor sections  57 ,  58  is a separator section  59  through which the 2(XCl 2 ) or 4(YCl) is withdrawn through an exhaust system (not shown). Titanium metal in the form of molten titanium droplets passes from the separator  59  into region  43  and the crucible  110  which links the reactor  40  to the refining apparatus  100 . 
     A titanium tetrachloride supply system  60  for titanium tetrachloride injection into the plasma reactor  40  is illustrated diagrammatically in FIG.  4 . The supply system  60  includes a sealed titanium tetrachloride reservoir tank  62  which receives relatively pure titanium tetrachloride from the distillation step  30  of FIG.  2 . The tank  62  includes an inert gas supply system  63  for argon or helium gas, for example, supplied from a pressurized gas source such as an argon or helium gas tanks (not shown) through a two-stage pressure regulator. The tank  62  also includes an in-line pressure relief valve  66  which may vent to a hood and a pressure gage  64  to monitor the internal pressure of the tank  62 . The tank  62  also includes an outlet system  65  whose output is connected to a titanium tetrachloride-boiler vessel  70 . 
     The outlet system  65  includes a series of manually operated valves  71 ,  72  and Swagelok® unions  74  for disconnecting the reservoir tank  62  from the remainder of the system  60 . Down stream of the valves  71 ,  72  is a flowmeter  75  controlled by a manually operated valve  77 . The outlet  78  of the flowmeter is connected as the inlet at the bottom of the boiler vessel  70 . The boiler vessel  70  itself includes an inner heater section  80  and an outer titanium tetrachloride heater chamber  82 . The heater chamber  82  surrounds the heater section  80  and is sealed relative thereto. The titanium tetrachloride is fed into the heater chamber  82  under a blanket of argon or helium gas. 
     The heater section  80  includes an immersion heater assembly  85  which includes an immersion heater device  86  which extends into the heater section  80  and which is supported at the top of the tank  70  by means well known in the art. The immersion heater  86  may be any one of the immersion heaters well known in the art. As shown, the immersion heater  86  is spaced from the wall forming the heater chamber  82  and is preferably filled with a heat transfer fluid for effective transmission of heat from the immersion heater  86  to the wall of the chamber  82 . 
     Surrounding the outer wall of the tank  70  is a heater tape unit  90  connected to a source of electrical power through a junction  91 . Mounted at the top of the tank  70  and communicating with the heater chamber  82  is an in-line pressure relief valve  92  which vents to a hood. The tank  70  and the heater chamber  82  include an outlet  93 . The exit side  95  of the outlet forms the inlet injection nozzle for the injector  55  of the plasma reactor  40  of FIG.  3 . The outlet system  93  from tank  70  includes heating tapes  96  supplied with power from a junction  97 . Downstream of the tapes  96  is an argon or helium purge valve  98  controlled by a three way electrically operated solenoid valve  99 . 
     The apparatus  100  for refining and/or alloying the titanium metal output from the device of FIG.3 is shown in FIG.  5 . The apparatus  100  includes multiple chambers  102 ,  104  separated into two general zones by a gate valve  105  (as shown). The zone  102  on the left contains an input through the collar  107  from the titanium reduction plasma apparatus  43  (FIG.  3 ), and additional plasma gun  108  for heating the titanium carrying ceramic vessel or crucible  110  and the molten titanium as it is produced. Zone  102  is at atmospheric pressure, e.g. 760 Torr, and receives molten titanium, in the form of titanium droplets, from the section  43  of the reactor  40 . The liquid titanium droplets entering section  102  through the collar  107  are heated by the plasma gun  108  and the gun output impinges on a molten titanium pool in the ceramic vessel or crucible  110  provided with a water cooled copper insert (FIG. 3) on which titanium has previously solidified on the crucible walls to form a skull or solidified titanium coating  114  of essentially pure titanium metal. The titanium skull  114  prevents the molten titanium from contacting the bare walls of the crucible  110  which would result in reaction with resultant contamination of the titanium. Thus, incoming molten titanium contacts the solid titanium coating  114  of the crucible  110 , the coating  114  being maintained solid by the water cooled insert in the ceramic crucible  110 . 
     The zone  104  on the right of zone  102  is also at 760 Torr (atmospheric pressure) and contains a hearth  116  on which a titanium skull  118  has been previously formed. The copper hearth  1   16  may be cooled by interior water cooling pipes, not shown. There are multiple sections in this zone: the first section  120  at atmospheric pressure; the next and successive section  122  is at the same pressure as the first section, e.g., 760 Torr, the final section  122  including the cold hearth  116  having a lip  123  over which the molten metal flows to be cast into a retractable ingot mold  125 . Plasma guns  130  keep the titanium molten in each of these sections. Alloying elements can be introduced into the second section  122  operating at 760 Torr so that an alloy, as previously described, may be formed. To form the alloy mentioned, powdered aluminum in an amount of 6% by weight and powdered vanadium in an amount of 4% by weight are introduced into the chamber  122 . The flow rate through the sections  120 ,  122  has to be a constant if the proper amount of alloys are to be introduced to meet alloy specifications. 
     There may be one to three ceramic vessels or crucibles  110 ,  110   a  with titanium skulls  114 ,  114   a , formed as described. The ceramic crucibles  110 ,  110   a  are positioned and supported on a table  135  which can be rotated 180 degrees so that the crucible  110 ,  110   a  full of molten titanium can be swung from zone  102  into the left part of zone  104  (of section  120 ). There is also a tilt mechanism  138  in the left position of zone  104  (of section  120 ) which permits the molten titanium to be gradually poured over the sloping hearth  116  and flow from left to right and be cast into an ingot in mold  125 . As shown, each of sections  120  and  122  includes exit ports  140  for degassing control. These zones are constantly purged by inert gas (such as argon or helium ) entering through input ports  142 . 
     With this design, the reduced titanium metal collection rate in zone  102  is independent of the flow rate on the hearth  116  in zone  104 . Since two vastly different technologies are operating in the zones  102  and  104 , it is almost impossible to match the reduction rate in the right zone  102  to the flow rate on the hearth  116  in the left zone  104 . 
     In operation, the first step is to turn on the plasma guns  108  and melt the surface of the skull  114  in zone  102 . In the next step, the plasma reduction reactor is brought into operation, and the newly reduced titanium falls onto the molten surface of the skull  114  to fill it up. 
     Once the skull  1   14  is filled, the succeeding step is to open the gate valve  105  between zones  102  and  104  and swing the crucible  110  full of molten titanium to zone  104  while an empty skull  114  swings to position in zone  102 . Alternate arrangements as may be apparent to those skilled in the art may also be used for this operation. The next step is to close the gate valve  105  isolating the two zones  102  and  104 . 
     Following the closure of the gate valve  105 , the plasma guns  130  in zone  104  are turned on to melt the surface of the skull  118  in the sloping hearth  116 . The crucible  110   a  full of molten titanium is tilted and poured at a steady rate onto the hearth  116  so that the gaseous contaminants, chlorine and hydrogen, are removed by outgassing and the titanium is cast into the ingot mold  125 . The rate at which the metal is poured over the hearth  116  depends on the quantity of gases present in the titanium from the reduction step. The larger this quantity, the slower the rate so as to give enough time for degassing to occur. A constant flow of inert gas entering ports  142  carries the contaminants away through exit ports  140 . 
     While the preceding step is occurring in zone  104 , the first step is operational in zone  102 . The virtue of this arrangement is that the processing rates in the left  102  and right  104  zones can be controlled independently of each other to achieve an overall steady production rate. 
     This process produces reduced titanium free from dissolved impurities, i.e., chlorine, oxygen, nitrogen, carbon, and hydrogen. Chlorine and hydrogen can be readily removed by exposing the molten titanium surface to high velocity argon or helium plasma, while keeping the titanium sufficiently hot so that it can be cast as an ingot after the degassing operation. As noted, oxygen, nitrogen and carbon cannot be removed in this late stage and hence must be kept out of the titanium by carrying out all processing in an environment where the partial pressures of these gases is very low, i.e., in an inert atmosphere, taking great care that there are no leaks to or from the atmosphere in any of the processing vessels by overflow of argon or helium gas. 
     Thus, one of the advantages of this invention is that the plasma reactor  40  and the refining station  104  are basically one integrated apparatus  100 . In this way the reduced titanium tetrachloride in the form of molten titanium droplets exits the reactor  40  directly to the second processing stage. The transition zone  43  from the reactor  40  is between the reactor  40  and the reducing refining zones  102 ,  104  and thus the molten drops of titanium are not exposed to fresh ambient environment or at least the exposure to fresh ambient environment is minimized. The purity of the plasma gas, argon or helium, were chosen to maximize the purity of the titanium. 
     In effect, from the time of the formation of the molten titanium, the metal is under controlled conditions and inert gas so that the partial pressures of the gases which are difficult to remove by outgassing are kept at. a minimum. This is achieved by a single integrated apparatus  100  so that the molten titanium metal can be handled and transferred within a controlled environment provided by a single contained apparatus  100  which is effective not only to maintain environmental conditions surrounding the molten titanium under control, but also to exclude contaminant gases. 
     An additional and valuable option is the ability to alloy the titanium while it is still molten and make a much more valuable titanium alloy, e.g., 4Ti-6Al-4V. This may be accomplished in the right hand section  104  of the device. 
     Another advantage of this invention is the formation of essentially pure titanium tetrachloride which is then processed to provide essentially pure titanium metal which can be alloyed, as desired. Moreover, while the starting material is a titanium containing ore  17 , this is preferred as opposed to the use of titanium dioxide powders since the latter are relatively expensive and may contain impurities which may be difficult to remove and which may adversely impact the overall purity of the final titanium product. Another advantage of the present invention is that the final refining and alloying operation is carried out in a single device  100 , under controlled atmosphere pressure conditions, i.e., inert gas environment. These atmospheric conditions are relatively benign in the sense that the atmosphere with which the molten titanium is in contact does not include contaminating gas or gases. Because there is a constant out flow of inert gas the purity of the final product is not compromised by exposure to ambient air and the contaminants in air. 
     The present invention has been described herein with reference to a particular embodiment for a particular application. Those having ordinary skill in the art and access to the present teachings will recognize additional modifications, applications and embodiments within the scope thereof. 
     It is therefore intended by the appended claims to cover any and all such applications, modifications and embodiments within the scope of the present invention.