Calcination kinetics of limestone and the microstructure of nascent CaO

• The calcination kinetics of limestone was investigated by TGA at 600-1000-degrees-C and from 1 mbar to 1 atm. The temperature, total pressure, CO2 partial pressure and particle size affect the calcination rate. Above 90% of calcination efficiency can be reached in less than 2.5 s at 1000-degrees-C and 1 mbar. Under the conditions of eliminating all diffusion resistances, the instantaneous rate of calcination is proportional to the surface area of undecomposed CaCO3, and this process can be described by a shinking core model. The microstructure of nascent CaO that was prepared in an entrained-flow reactor at 1 atm, was studied using the BET method. The BET surface area of the calcines increases with increasing residence time and temperature in less than 2 s and below 1000-degrees-C. The largest BET surface area and cumulative pore volume of 2 s nascent CaO are obtained at 1000-degrees-C and 700-degrees-C, respectively.

Ämnesord

TEKNIK OCH TEKNOLOGIER  -- Kemiteknik (hsv//swe)

ENGINEERING AND TECHNOLOGY  -- Chemical Engineering (hsv//eng)

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