Fusion process using an alkali metal metalate

A reactor structure comprising a flow-through reactor for forming a purified sodium tungstate salt, the reactor structure comprising:

• (a) an induction coil and a substantially right cylindrical reactor vessel, the reactor vessel free of electrical heating and positioned in an interior of the induction coil, the reactor vessel having a fluid stand pipe used to control flow-through reaction time by accumulating and then permitting a flow of the purified sodium tungstate by generating a back pressure, the stand pipe having a circular diameter of about 1 to about 10 centimeters;
• (b) a heating component consisting of a conductive graphite reactor core positioned within the reactor vessel, the conductive graphite reactor core comprising a top portion and extending downward from the top portion, a downwardly extending cylindrical outer wall defining an interior space, the conductive graphite reactor core structure having a height of about 20 to about 200 centimeters;
• (c) the reactor structure comprises a reactor-flow space positioned between the conductive graphite reactor core and an interior surface of the reactor vessel, the reactor-flow space having an annular thickness of about 2 to about 10 centimeters and is less than 10% of the outside diameter of the vessel, the reactor structure is sized and configured to operate at a power of 10 to 300 kilowatts at about 500 to 10,000 hertz with a flow through rate of about 10 to about 400 kilograms per hour at a reaction temperature of greater than 700° C.;
• and
• (d) a charge of reagents comprising a source of tungsten comprising an ore having a particle size of about 10 to 300 microns and an alkali metal metallate in particulate form at the top of the reactor vessel;
• and
• wherein the charge of reagents and the reactor vessel are inductively heated by the conductive graphite reactor core with power from the induction coil to a temperature greater than about 700° C. sufficient to produce an alkaline micro-corrosion of the source of tungsten resulting in a liquid flux phase separate from a product phase comprising greater than 90% of a purified liquid of the sodium tungstate salt that flows through the conductive graphite reactor core and exits the vessel.