| abstract |
A process for recovery of vanadium dissolved in acid solutions or liquors by precipitating it out as vanadium pentoxide. Separation is carried out by adding calcium hydroxide, quicklime or calcium carbonate to the acid solution or liquor, producing a precipitate of vanadium pentoxide, which is separated from the liquid by physical methods such as filtration or centrifugation. If the acid is other than sulfuric acid, the calcium which remains dissolved in the solution or liquor by the addition of calcium hydroxide, quicklime or calcium carbonate, is removed by adding sulfuric acid, to produce solid calcium sulfate and water. The calcium sulfate is extracted from the solution or liquor or liquor by filtration or centrifugation. With sulfuric acid solution or liquors, after addition of the neutralizing agent, a solid precipitate of vanadium pentoxide and calcium sulfate is formed, which is then separated from the solution or liquor. The solid vanadium pentoxide is dissolved by adding sulfuric acid to the vanadium pentoxide and calcium sulfate precipitate and the solid calcium sulfate is separated from the resultant solution or liquor. Solid sodium hydroxide is added to the resultant solution or liquor and vanadium pentoxide is precipitated. |