The process of recovering vanadium oxide from metal or carbon into vanadium metal is an important part of vanadium metallurgical process. The first four methods are calcium thermal recovery, vacuum carbon thermal recovery, chloride magnesium thermal recovery and aluminum thermal recovery. Calcium thermal recovery an approach to industrial planning for the production of vanadium metal. Take V2O5 or V2O3 as material, chip as the restorer. The amount of calcium is 60% of the theoretical amount. Fragmental and V2O5 or mixes V2O3, clean with inert gas to put in a steel reaction tank of magnesia crucible (PiaoChangLin), add iodine compound (sulfur), generation of iodine in quantity by 1 mol, vanadium increases 0.2 mol, iodine measurement, after argon filling sealing, heat with high frequency sensor, the temperature of 973 k when it start response: V2O5 + 5 + 5 ca material 2 v cao + 1620.07 kJ V2O3 + 3 ca material 2 v + 3 cao + 683.24 kJ because of exothermic reaction, response to start then stop after heating. When you stop heating, the temperature will go up to 2173 degrees kelvin. The produced plastic vanadium metal block or vanadium particles were washed with water to remove the attachment, and the yield of vanadium was about 74%. If aluminum is added to the charge, the vanadium yield can be increased to 82% ~ 97.5%. Vacuum carbon heat recovery mix V2O5 powder with high purity carbon powder, add 10% camphor solution or alcohol, press the block into the vacuum carbon resistance furnace or induction furnace. After the vacuum pressure in the furnace reaches 6.66× 10-1Pa, the temperature rises to 1573K and the insulation lasts for 2h. After cooling will echo product broken. According to the components of the first recovery product and add an appropriate amount of vanadium carbide or vanadium oxide for the second recovery. The vacuum pressure in the secondary recovery furnace is 2.66× 10-2Pa, the temperature is controlled between 1973 and 2023K, and the temperature is kept for a period of time. The components (mass fraction m/%) of vanadium metal obtained by vacuum carbon recovery method are: vanadium 99.5, oxygen 0.05, nitrogen 0.01 and carbon 0.1.
The yield of vanadium can reach 98% ~ 99%. Magnesium heat recovery metal magnesium high purity, quote is lower than calcium, the reaction generated by magnesium chloride than calcium chloride volatile, so magnesium recovery is more reasonable than calcium recovery. The recovery process is as follows :(1) the crude was prepared by chlorination of vanadium with 80% ferric vanadium; (2) remove crude vanadium tetroxide by distillation; (3) convert to VCl3 in cylindrical magnesium reflux; (4) VOC13 in VCl3 was removed by distillation; (5) the cooled and broken parts were placed in the recovery tank, and VCl3 was restored to vanadium metal by participating in magnesium under argon maintenance; (6) remove magnesium and magnesium chloride from vanadium metal by vacuum distillation; (7) the residual magnesium chloride in vanadium metal was washed with water, and the product vanadium powder was obtained after drying. The recovery operation is carried out in a mild steel crucible. The mild steel crucible is placed in a mild steel tank and heated with gas. The magnesium ingots after pickling were first added to the crucible and then added to the three times the quantity of magnesium ingots. The recovery temperature is controlled at 1023 ~ 1073K.
