Tellurium

The anode slime calcination product containing tellurium obtained from the copper electrolysis process is treated with alkali to prepare a crude tellurite alkali solution (PH > 10.8), and then sulfide alkali is added to turn lead, copper, silver, iron, etc. into sulfides and precipitate for separation. When the filtrate is neutralized with hydrochloric acid, tellurium dioxide precipitates. Filtering. Dissolve tellurium dioxide in 6mol/L hydrochloric acid (with a tellurium concentration of 200g/L) and heat to 90℃. Add 13g of hydroxylamine hydrochloride per liter of the solution to precipitate and filter out the impurity selenium. Introduce sulfur dioxide gas washed with water and dilute sulfuric acid into the above filtrate to precipitate tellurium. After filtration, water washing and drying, tellurium is obtained. Tellurium products are then purified by the sodium polysulfide extraction method.