Process of precipitating hydrous vanadium pentoxide

Claim 1

THE PROCESS OF PRECIPITATING HYDROUS VANADIUM PENTOXIDE FROM SOLUTIONS CONTAINING PENTAVALENT VANADIUM, WHICH COMPRISES MIXING SAID SOLUTION WITH SULPHURIC ACID IN AMOUNT TO COMPLETELY CONVERT ALL ALAKLI, FREE AND COMBINED, TO ALKALI SULPHATE AND GIVE A FINAL FREE ACIDITY FOLLOWING COMPLETION OF PRECIPITATION OF ABOUT 0.10 TO 10 GRAMS SULPHURIC ACID PER LITER, AND CARRYING OUT THE REACTION IN TWO PERIODS, THE FIRST PERIOD BEING AN INCUBATION PERIOD OF AT LEAST 20 MINUTES EXTENDING FROM THE BEGINNING OF ADDITION OF SULPHURIC ACID TO THE FORMATION OF A VISIBLE PRECIPITATE, DURING WHICH INCUBATION PERIOD THE NEUTRALIZATION IS COMPLETED AND THE VANADIUM IS HYDROLYZED TO SOLUBLE HEXAVANADIC ACID, THE SECOND PERIOD BEING A PRECIPITATION PERIOD DURING WHICH THE VANADIUM IS PARTIALLY DEHYDRATED AND IS PRECIPITATED, AGITATING THE MIXTURE OF VANADIUM SOLUTION AND SULPHURIC ACID DURING THE INCUBATION PERIOD AND MAINTAINING IT AT A TEMPERATURE LOW ENOUGH TO PREVENT THE FORMATION OF A VISIBLE PRECIPITATE AND TO CAUSE SUBSTANTIALLY COMPLETE NEUTRALIZATION OF THE FREE AND COMBINED ALKALI AND TO HYDROLYZE THE VANADIUM TO SOLUBLE HEXAVANADIC ACID, AND THEREAFTER AGITATING THE MIXTURE AND HEATING IT DURING THE PRECIPITATION PERIOD TO A TEMPERATURE HIGHER THAN THE TEMPERATURE DURING THE INCUBATION PERIOD AND SUFFICIENTLY HIGH TO PARTIALLY DEHYDRATE THE HEXAVANADIC ACID AND TO PRECIPITATE HYDROUS VANADIUM PENTOXIDE.