Treatment of ferrophosphorus

Claim 1

A PROCESS FOR OBTAINING ALKALI METAL PHOSPHATES FROM FERROPHOSPHORUS WHICH COMPRISES HEATING FERROPHOSPHORUS AND AN ALKALINE MATERIAL SELECTED FROM THE GROUP CONSISTING OF ALKALI METAL OXIDES, ALKALIE META HYDROXIDES, AND ALKALI METAL CARBONATES, UNDER OXIDIZING CONDITIONS AT A TEMPERATURE AND FOR A PERIOD OF TIME SUFFICIENT TO EFFECT OXIDATION OF SUBSTANTIALLY ALL OF THE PHOSPHORUS VALUES IN THE FERROPHOSPHORUS AND FORM A TRIALKALI META PHOSPHATE, THE ALKALINE MATERIAL BEING PRESENT IN AT LEAST THE THEORETICAL AMOUNT REQUIRED TO EFFECT FORMATION OF THE TRIALKALI METAL PHOSPHATE, LEACHING THE RESULTING MATERIAL WITH WATER TO EXTRACT THE TRIALKALI METAL PHOSPHATE THEREFROM, AND PRODUCE AN AQUEOUS PHASE CONTAINING THE TRIALKALI METAL PHOSPHATE, SILICON VALUES AND VANADIUM VALUES, AND A SOLID PHASE CONTAINING SUBSTANTIALLY ALL OF THE IRON VALUES IN THE FERROPHOSPHORUS, SEPARATING THE SAID AQUEOUS PHASE FROM THE SOLID PHASE, ADJUSTING THE PH OF THE THUS-SEPARATED AQUEOUS PHASE WITH PHOSPHORIC ACID TO WITHIN THE RANGE OF ABOUT 8.0 TO 9.0, ADJUSTING THE PHOSPHOURS CONCENTRATION OF THE AQUEOUS PHAS TO WITHIN THE RANGE OF ABOUT 7.0 TO 9.5 PERCENT BY WEIGHT PHOSPHORUS, MAINTAINING THE TEMPERATURE OF THE AQUEOUS PAHSE NOT SUBSTANTIALLY BELOW ABOUT 80 DEGREES CENTRIGRADE, AT LEAST AT THE TME IMMEDIATELY FOLLOWING THE SAID ADJUSTMENT OF THE PH, THEREBY EFFECTING FORMATION OF A PRECIPITATE OF HYDROUS SILICA IN THE SAID AQUEOUS PHASE, ADDING FERROUS SULFATE TO THE AQUEOUS PHASE, WHILE MAINTAINING THE TEMPERATURE OF THE AQUEOUS PHASE AT SUBSTANTIALLY THE BOILING POINT AND WHILE MAINTAINING THE PHOSPHORUS CONCENTRATION OF THE AQUEOUS PHASE WITHIN THE RANGE OF ABOUT 7.0 TO 9.5% BY WEIGHT PHOSPHORUS, THEREBY FORMING A PRECIPITATE CONTAINING THE MAJOR AMOUNT OF VANADIUM FROM THE AQUEOUS PHASE, WHICH PERCIPITATE IS AN INSOLUBLE IRON-VANADIUM-PHOSPHATE COMPOUND, THE AMOUNT OF ERROUS SULFATE ADDED TO THE AQUEOUS PHASE BEING WITHIN THE RANGE OF ABOUT 10 TO 15 MOLES OF FERROUS SULFATE FOR EACH MOLE OF VANADIUM IN THE AQUEOUS PHASE, AND, THEREAFTER, SEPARATING THE THUS-FORMED PRECIPIATE FROM THE AQUEOUS PAHSE TO PRODUCE A SOLUTION AND ONLY MINOR AMOUNTS OF VANADIUM.