Formation of Chloropyromorphite from Galena (PbS) in the Presence of Hydroxyapatite
- Sandia National Laboratories
Transformation of unstable lead [Pb(ll)] forms into insoluble pyromorphite, [Pb5(P04)3(OH, Cl, F...)], by addition of phosphate to Pb contaminated soil has been proposed as a remediation technology which reduces the mobility and bioavailability of Pb. Under aerobic condition, oxidation of dissolved sulfide increases dissolution of galena (PbS), causing it to become a source of liable Pb forms in soils, sediments and wastes. Thus, a galena ore was reacted with synthetic hydroxyapatite [Ca5(P04)30H] under various pH condition to determine the formation rate of pyromorphite and the volubility of galena under the ambient conditions. In a 6 day reaction period the dissolution rate of galena increased with pH due to the oxidation of dissolved sulfide. Correspondingly, formation of chloropyrornorphite became apparent in the galena- apatite suspensions with increasing pH. The insignificant effect of mineral P/Pb molar ratio on the formation of chloropyromorphite implied that dissolution of galena was the rate limiting step.
- Research Organization:
- Sandia National Laboratories (SNL-NM), Albuquerque, NM
- Sponsoring Organization:
- USDOE
- DOE Contract Number:
- AC04-94AL85000
- OSTI ID:
- 2985
- Report Number(s):
- SAND98-2304J; ON: DE00002985
- Journal Information:
- Environmental Science and Technology, Journal Name: Environmental Science and Technology
- Country of Publication:
- United States
- Language:
- English
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