Patent ID: 8092776
Filing Date: 2012-01-10
Classification: C01B,C22B,Y02P

Abstract:
1. A method for separating elemental selenium (Se) from a material containing tellurium and selenium, the method comprising: leaching an aqueous slurry of the material with a first alkaline solution causing selenium to migrate into the first alkaline solution, while tellurium remains in a leaching residue; oxidizing the tellurium and the selenium by heating a charge including the first alkaline solution and the leaching residue to a predetermined first temperature for a predetermined time to obtain oxidized tellurium and a selenium salt; separating the leaching residue containing the oxidized tellurium from the first alkaline solution containing the selenium salt; adjusting a concentration of the first alkaline solution containing the selenium salt by adding an alkali metal hydroxide to obtain a second alkaline solution, the second alkaline solution having a concentration of about 100-400 g/L; reducing the selenium using a reducing agent before heating the second alkaline solution to a predetermined second temperature; precipitating elemental selenium after cooling the second alkaline solution; and recovering the elemental selenium from the second alkaline solution.