Thermal Analysis Curves of Sulfide Minerals

Sulfide minerals show oxidation and decomposition by releasing SO2 accompanied by a mass loss during heating. The decomposition and oxidation reactions take place at temperatures from 300 to 800 °C. Sulfide of many elements is transformed into complex oxides, some of which are volatilized at low temperature whereas others melt at high temperature. Some Sulfide is poly-morphically transformed before oxidation and decomposition. 

Pyrite—311 °C exotherm, polymorphic transformation 498 °C exotherm, oxidation and decomposition FejOS is obtained by liberation of SO 2 accompanied by a mass loss 637 °C 

Hauerite—261 °C endotherm, partial decomposition of hauerite 428 and 485 C exotherms, hauerite decomposes and oxidizes. MnS is obtained by liberation of SO2 accompanied by a mass loss 615 C exotherm, MnS oxidizes and is transformed to MnS04 accompanied by mass increase 904 °C endotherm, MnS04 decomposes and is transformed to Mn304 by liberation of SO, accompanied by a mass loss. 

Tungstenite—575 °C exotherm, tungstenite oxidizes and decomposes WO, is formed with loss of SOj. 

Molybdenite—596 °C exotherm, molybdenite starts oxidation and decomposition 706 C exotherm, molybdenite oxidizes to MoO, and SO 2 is released 800 °C MoO, melts and evaporates. 

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