Characterization, Dissolution, and Solubility of Lead Hydroxypyromorphite [Pb₅(PO₄)₃OH] at 25–45°C

Table 1

Analytical data and solubility determination of lead hydroxypyromorphite [Pb₅(PO₄)₃OH].

Temp	Initial pH	Reaction time (hours)	Analytical data				[kJ/mol]
			pH	Pb (mmol/L)	P (mmol/L)
25°C	2.00	5040	2.63	3.76	0.0489	−80.96	−3797.78
		5760	2.67	3.64	0.0458	−80.79	−3796.79
		7200	2.68	3.70	0.0495	−80.57	−3795.55
35°C	2.00	5040	2.55	4.24	0.0422	−80.99
		5760	2.58	4.17	0.0569	−80.38
		7200	2.59	4.09	0.0475	−80.57
45°C	2.00	5040	2.64	4.73	0.0172	−80.71
		5760	2.76	4.77	0.0229	−79.38
		7200	2.73	4.76	0.0201	−79.78
25°C	5.60	5040	0.58	0.00175	0.00720	−77.42	−3777.57
		5760	0.34	0.00160	0.00726	−77.60	−3778.61
		7200	0.17	0.00173	0.00723	−77.51	−3778.06
25°C	9.00	5040	6.30	0.000191	0.00649	−78.17	−3781.84
		5760	6.36	0.000180	0.00636	−77.94	−3780.54
		7200	6.30	0.000175	0.00642	−78.37	−3782.97