Q. Show the chemical properties of Uranium?

Uranium is mainly extracted from pitchblende. The concentrated ore (pitchblende, U₃O₈) is washed and then fused with sodium nitrate and sodium carbonate. The fused pass in treated with sulphuric acid, which extracts uranyl sulphate, U0₂S0₄. Addition of sodium carbonate solution in excess to the above solution, removes all the heavy metals as carbonates. Uranium goes in solution as sodium uranyl carbonate Na₄ [U0₂(C0₃)₃]. Addition of dilute toH2SO₄ the dradyl carbonate solution precipitates uranium as sodium diuranate, Na₂U₂0₇which on treatment with concentrated solution of (NH₄)₂C0₃ passes into solution as ammonium uranyl carbonate, (NH₄)₄[U0₂ (C0₃)₃]. Concentration of this solution gives pure U₃Os. Reduction of U₃0₈ with aluminium powder produces uranium metal. All these steps - involved in extraction of uranium from pitchblende are summarised in a flow sheet.