Dissolution and Solubility Product of Cd-Fluorapatite [Cd₅(PO₄)₃F] at pH of 2–9 and 25–45°C

Table 1

Analytical data and solubility product of cadmium fluorapatite [Cd₅(PO₄)₃F].

Temperature (°C)	Initial pH	Reaction time (hour)	Analytical data					(kJ/mol)
			pH	Cd (mmol/L)	P (mmol/L)	F (mmol/L)
25	2.00	5040	3.83	7.0385	2.2094	0.0311	−60.46	−4068.23
		5760	3.95	7.0154	2.1788	0.0312	−59.74	−4064.11
		7200	3.92	7.0474	2.2127	0.0319	−59.89	−4064.96
35	2.00	5040	3.78	6.8019	2.4679	0.0276	−60.48	—
		5760	3.80	6.7681	2.4834	0.0275	−60.35	—
		7200	3.80	6.8037	2.5215	0.0278	−60.32	—
45	2.00	5040	3.74	7.3463	1.6982	0.0437	−60.63	—
		5760	3.78	7.2840	1.6924	0.0432	−60.40	—
		7200	3.79	7.3356	1.6821	0.0439	−60.33	—
25	5.60	5040	6.01	0.0426	0.0814	0.0822	−61.20	−4072.43
		5760	6.10	0.0438	0.0698	0.0814	−60.82	−4070.27
		7200	5.98	0.0427	0.0768	0.0853	−61.43	−4073.74
25	9.00	5040	6.35	0.0143	0.1006	0.0869	−61.31	−4073.05
		5760	6.41	0.0139	0.0877	0.0876	−61.21	−4072.48
		7200	6.29	0.0137	0.0904	0.0882	−61.87	−4076.25