Thermal decomposition of Leightonite, K₂Ca₂Cu(SO₄)₄·2H₂O

Abstract

The thermal decomposition of Leightonite, K₂Ca₂Cu (SO₄)₄·2H₂O, was studied by thermal gravimetric analysis(TGA), differential thermal analysis(DTA), X-ray diffraction(XRD), etc. The results show that the Leightonite is dehydrated around 170 °C to 390 °C and transformed to be new intermediate (K-Cu-SO₄) sulphate salt with bright-green color. Moreover, the chemical structure changes during the thernal decomposition process was describled in detail. And the as-resulting phases are demonstrated to be K₂Ca₂(SO₄)₃, K₂SO₄, CaSO₄, and Cu₂O.

Keywords

differential thermal analysis / sulphate double salt / leightonite / thermal decomposition

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