Difference between Calcination and Roasting.
Calcination
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Roasting
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1)Process of heating the ore strongly in absence of air below its M.P
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1)Process of heating the ore strongly in presence of air below its M.P.
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2)This process is used to convert carbonate & hydroxide into their oxides
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2) This process is used to convert sulphide into oxide & sulphate.
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3)Purpose is to remove the moisture & volatile impurities from the ore
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3)Purpose is to remove moisture & oxidation of ore & the impurities like S,P,As etc.
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4)In calcination, the mass becomes highly porous.
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4) In roasting, the mass becomes less porous.
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5) Process done in hearth of a reverberatory furnace when the doors are kept closed.
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5) Process done in hearth of a reverberatory furnace when the doors are kept opened.
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6. Decomposition reaction takes place
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6.Oxidation reaction takes place
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