Fi. Elhosiny et al., EFFECT OF THERMAL-TREATMENT OF RICE HUSK ASH ON THE SURFACE-PROPERTIES OF HYDRATED LIME-RICE HUSK ASH BINDERS, Journal of thermal analysis, 46(1), 1996, pp. 105-116
Rice husk ash fired at different temperatures, 450, 700 and 1000 degre
es C, was mixed with different concentrations of lime (molar lime/sili
ca ash ratio of 0.2, 0.5 and 1.0). Each dry mixture was first ground a
nd hydrated in the suspension form (water/solid ratio = 10) for variou
s time intervals within the range of 1 to 365 days. The surface proper
ties of the unhydrated and hydrated samples were studied by means of n
itrogen adsorption measurements. The results indicated that the surfac
e areas and total pore volumes of unhydrated solid mixtures and hydrat
ed lime-rice husk ash samples, prepared with lime/silica ash ratio of
1.0, decrease with increasing firing temperature of rice husk ash. The
effect of varying the lime/silica ash ratio of the solid mixture on t
he surface area and pore structure was fully discussed. The results of
surface area and pore volume measurements could also be related to th
e crystal structure of silica produced from rice husk ash.