Refining of ferrophos

Claim 1

IN THE METHOD OF RIFINING A VANADIUM AND CHROMIUM BEARING CRUDE FERROPHOS BY HEATING SAID FERROPHOS TO A TEMPERATURE OF BETWEEN 1300% AND 150%C. IN THE PRESENCE OF AN OXYGEN-CONTAINING GAS IN AMOUNTS SUFFICIENT TO PROVIDE AN OXIDIZING ATMOSPHERE UNTIL A CONCENTRATE HAVING A VANDIUM CONTENT OF FROM ABOUT 10 TO 15% EXPRESSED AS V2O5 AND A CHROMIUM CONTENT OF ABOUT 8-12% EXPRESSED AS CR2O3 IS SEPARATEDFROM A RESIDUAL REFINED FERROPHOS HAVING A PHOSPHORUS CONTENT OF AT LEAST 23%, THE IMPROVEMENT WHICH COMPRISES INITIALLY HEATING SAID CRUDE FERROPHOS IN A REACTOR LINED WITH A REFRACTORY MADE UP OF SILICON CARBIDE PARTICLES BONDED TOGETHER INTO AN ADHERENT MASS, AND THEREAFTER RAPIDLY COOLING THE OUTER SURFACE OF SAID REFRACTORY BY PASSING A COOLING FLUID IN HEAT EXCHANGE RELATIONSHIP THEREWITH TO REMOVE HEAT EVOLVED IN SAID REACTOR IN ORDER TO MAINTAIN THE TEMPERATURE OF SAID FERROPHOS AT ABOUT 1300%-1560%C., WHEREBY SAID FERROPHOS AND SAID REACTOR CAN BE RAPIDLY COOLED WITHOUT CRACKLING OF SAID REFRACTORY, AND RECOVERING SAID CONCENTRATE AND SAID RESIDUAL, REFINED FERROPHOS.