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 an acid other
than 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.