Basicity-Gibbs Free Energy Relationships for Binary Alkali Silicates

Abstract

In present paper there are presented such correlations for the silica-alkali systems (M2O – SiO2) where reliable thermodynamic data exists from the thermal equilibrium diagrams. It was observed that with the saturation of SiO2 tetrahedron with metal ions, the difference in basicity between the reactants is diminished, in the order SiO2 → disilicate → metasilicate → orthosilicate, and that confirms the role of driving force for these reactions of the acid-base interaction between oxides and the intermediate silicates formed. Also, there were proposed some correlations between the standard formation Gibbs free energy, (Gº298), and basicity percentage, pB, for the binary compounds from the same oxide systems. Considering the fact that for a system at equilibrium, reaction constant Kp depends on the reaction free Gibbs energy (rG0 298) and temperature, a correlation between basicity difference through basicity percentage, pB, and rG0 298 is proposed.

Regeneration of anode materials from complex graphite residue in spent lithium-ion battery recycling process

“…The standard reaction free energy of both reactions is less than zero at room temperature and decreases gradually with increasing temperature. 31 It is proved that thermodynamically, the reactions can be carried out at room temperature and the conversion of α-Al 2 O 3 and SiO 2 is more complete with the increase of temperature. Considering that the decomposition temperature of organic matter needs to reach 500 °C, and the graphite is not oxidized at 500 °C (Fig.…”