Distingush between 'Roasting' and 'Calcination'.Give equations to illustrate

Asked by  | 3rd Sep, 2008, 08:02: PM

Expert Answer:

 

Roasting is a metallurgical process involving gas-solids reactions at elevated temperatures. A common example is the process in which sulfide ores are converted to oxides, prior to smelting.

CuS + 1.5O2 → CuO + SO2

Calcination  is a thermal treatment process applied to ores and other solid materials in order to bring about a thermal decomposition, phase transition, or removal of a volatile fraction. The calcination process normally takes place at temperatures below the melting point of the product materials. Calcination is to be distinguished from roasting, in which more complex gas-solid reactions take place between the furnace atmosphere and the solids; however, calcination takes place in the absence of air.

CaCO3 = CaO + CO2; 848°C

Answered by  | 4th Sep, 2008, 11:01: PM

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