Method for recovering rhenium, method for selectively recovering rhenium from solution including rhenium and other metals, and method for increasing content ratio of rhenium in solution including rhenium and other metals

A method of selectively recovering rhenium from a solution containing rhenium and one or more different metals, comprising:

• adding an electron donor and a ketone compound to a solution containing perrhenate ions and a co-existing metal other than alkali metals and alkaline earth metals, the electron donor being an aliphatic secondary alcohol or an aliphatic secondary thioalcohol;
• adjusting the pH of the solution to 6.3 or higher;
• and
• irradiating the solution with ultraviolet light to precipitate a reduced species of the perrhenate ions contained in the solution,
• wherein the co-existing metal is molybdenum.

A method of enriching rhenium in a solution containing rhenium and one or more different metals, comprising:

• adding an electron donor and a ketone compound to a solution containing perrhenate ions and a co-existing metal other than alkali metals and alkaline earth metals, the electron donor being an aliphatic secondary alcohol or an aliphatic secondary thioalcohol;
• adjusting the pH of the solution to a range of higher than 2.1 and up to 4.7;
• and
• irradiating the solution with ultraviolet light to precipitate a compound of the co-existing metal contained in the solution,
• wherein the co-existing metal is molybdenum.