An Experimental Study of the Formation of Talc through CaMg(CO₃)₂–SiO₂–H₂O Interaction at 100–200°C and Vapor-Saturation Pressures

Table 3

The Gibbs free energies of the reaction 3CaMg(CO₃)₂ + 4SiO₂(aq) + H₂O = Mg₃(Si₄O₁₀)(OH)₂ + 3CaCO₃ + 3CO₂ at the temperatures of interest and their corresponding saturation pressures.

Temperature (°C)	(kJ/mol)	(bar)	Temperature (°C)	ΔG (kJ/mol)	(bar)
25	7.709	0.032	100	–7.083	1.014
50	4.663	0.124	110	–9.951	1.434
60	2.771	0.199	120	–12.938	1.987
70	0.609	0.312	130	–16.032	2.703
80	–1.778	0.474	140	–19.223	3.615
90	–4.351	0.702	150	–22.502	4.761

refers to the Gibbs free energy of the reaction; represents the corresponding saturation pressures, which are calculated based on the thermodynamic model proposed by Zhang and Duan [45].