Crystallization of SiO₂–CaO–Na₂O Glass Using Sugarcane Bagasse Ash as Silica Source

Abstract

This work reports the feasibility results of recycling sugar cane bagasse ash (SCBA) to produce glass-ceramic. The major component of this solid residue is SiO 2 (>89%). A 100 g batch composition containing ash, CaO and Na 2 O was melted and afterward, poured into water to produce a glass frit. The crystallization kinetic study by nonisothermal method was performed on powder samples (<63 μm) at five different heating rates. Wollastonite is the major phase in crystallization at T>970°C, and below this temperature there is a predominance of rankinite. The crystallization activation energies calculated by the Kissinger and Ligero methods are equivalent: 374±10 and 378±13 kJ/mol. The growth morphology parameters have equal values n=m=1.5 indicating that bulk nucleation is the dominant mechanism in this crystallization process, where there is a three-dimensional growth of crystals with polyhedronlike morphology controlled by diffusion from a constant number of nuclei. However, differential thermal analysis (DTA) curves on both monolithic and powder glass samples suggest that crystallization of the powder glass sample occurs through a surface mechanism.The divergence in both results suggests that the early stage of surface crystallization occurs through a three-dimensional growth of crystals, which will then transform to one-dimensional growth.

Determination of crystallization kinetics parameters of a Li1.5Al0.5Ge1.5(PO4)3 (LAGP) glass by differential scanning calorimetry

“…Taking into account the mathematical errors, and comparing the activation energy calculated by the models of Ligero and Kissinger, one can observe that these values are very close. This fact indicates that Ligero's model can provide reliable values of activation energy for overall crystallization, as was also suggested by Silva et al 11 and Teixeira et al 12 . On the other hand, both values are higher than the activation energy (E = 300 kJ/mol) obtained by Kun et al 6 , using Kissinger's method.…”

“…While Kissinger's method is widely employed, Ligero's method has been little applied to study the crystallization kinetics of glass systems that present internal nucleation, such as the LAGP composition. In fact, as far as we know, this model has only been applied to metallic 9 and silicate systems 11,12 that nucleate heterogeneously.…”

Crystallisation and microstructure of nepheline–forsterite glass-ceramics

“…This process usually involves milling a glass frit into fine particles, which are then shaped by conventional forming techniques and subsequently heat treated to provide sintering and crystallisation of the glass particles. A sintering process is normally used when the parent glass exhibits a strong tendency for surface crystallisation or when complex shapes are required [8]. Because the most important forming systems are based on silicate compositions, the key crystalline phases of glass-ceramics are principally silicates [1].…”

“…They can also be prepared from cheaper raw materials such as wastes because the glass-ceramic process has been established as a suitable way to valorise mining and industrial wastes [29,30], including fly ash from incineration [31,32] and thermal power plants [4,33], wastes from hydrometallurgical processing plants [30], residual glass fibres from polyester matrix composites [34] and bagasse ashes [8], among others wastes. One residue that has experienced a significant increase in production in recent years is biomass ash, which originates from the combustion of biological material for energy purposes.…”

Valorization of sugarcane bagasse ash: Producing glass-ceramic materials

“…This ash (SCBA) contains high amounts of organic material (∼35% charcoal and bagasse debris by weight). We have shown (Teixeira et al, 2008, Teixeira et al, 2010a, Teixeira et al, 2010band Teixeira et al, 2011a that it is possible to concentrate both fractions (inorganic and organic) and to use the first one to produce materials for the construction industry (glass-ceramic, ceramic plates and frits). The major inorganic component of the ash is SiO 2 , and among the minor components there are some mineralizing or fluxing agents.…”