The effect of calcination conditions on the physical and chemical characteristics of sugar cane bagasse ash

Abstract

The effect of calcination temperature and air flow on the content of organic material, morphology of particles, degree of crystallinity and the reactivity with lime solution of the sugar cane bagasse ash is evaluated. The results show that the long fibers of the bagasse and organic material are retained when calcination occurs without sufficient air flow. Calcining with forced air-flow breaks the fibers, removes organic material and produces fine particles at a temperature of 600ºC. The non-organic material observed in the ash displays a high degree of crystallinity. Experiments show that the crystalline structure observed in the ashes is due to adhered sand which was not previously washed away. The reduction on the conductivity in lime solution and X-rays diffraction pattern suggest that amorphous silica is formed at temperatures lower than 600ºC and cristobalite is formed at higher temperatures.

The influence of untreated sugarcane bagasse ash on the microstructural and mechanical properties of mortars

“…In summary, the high LOI, lower density, greater PSD, larger SSA (in comparison with CPC), simultaneous appearance of amorphous and crystalline phases, and variability of the the UtSCBA's shapes and sizes can be attributed to the variations of temperature and air flow during the bagasse's calcination process in the sugar mill, in accordance with results observed by other authors (24).…”

“…The amorphous phase in the UtSCBA was observed as a diffuse halo in the interval 2θ from 10° to 35°. This halo, which is characteristic of pozzolanic materials, suggests the presence of amorphous substances such as silica (6,8,15,24,(28)(29). The crystalline phases of quartz and cristobalite in the UtSCBA were detected; both phases have been reported by others (6,25,29).…”

“…This type of distribution can be caused by two factors: the presence of particles from the different mineralogical components because a compound cement was used (13), and the result of grinding because fine particles tend to cluster (7). The UtSCBA show grains of varied shapes and sizes in accordance with the calcination conditions ( Figure 3) (12,24). There are agglomerated particles with high porosity, typical for organic materials, and prismatic particles with well-defined edges (9,(25)(26).The EDS microanalysis revealed that the agglomerated particles (A) are rich in Si, Al and C oxides and not so rich in Ca oxides (8).…”

Effect of partial replacement with thermally processed sugar cane bagasse on the properties of mortars

“…Table 5 presents the chemical composition of the SCBA RG in terms of the main oxides identified by XRF. The main oxide present in the ash was SiO 2 , followed by Al 2 O 3 and Fe 2 O 3 , in agreement with previous results [30,31]. The cumulative amount of these three oxides is 80.26%.…”

“…The peaks can be associated with the crystalline phases of silicon dioxide. Previous results have also demonstrated the presence of quartz [30]: for instance, Cordeiro et al [31] found quartz and cristobalite in SCBA. Table 5 presents the chemical composition of the SCBA RG in terms of the main oxides identified by XRF.…”