The aqueous dissolution kinetics of the barium/lead sulfate solid solution series at 25 and 60C

Journal Article · Sun Dec 01 00:00:00 EST 1991 · Geochimica et Cosmochimica Acta; (United States)

DOI:https://doi.org/10.1016/0016-7037(91)90053-8· OSTI ID:5115963

Kornicker, W A; Presta, P A; Paige, C R; Johnson, D M; Hileman, Jr, O E; Snodgrass, W J ^[1]

---

1. McMaster Univ., Hamilton, Ontario (Canada)

The dissolution behavior of the Ba{sub x}Pb({sub 1-x})SO{sub 4} solid solution series and pure endmembers was investigated. The solids were participated from sulfuric acid solutions, then dissolved in slightly acidified water at 25 and 60C for 24 h. Endmembers equilibrated within several h at 25C and several min at 60C. At 25C the solid solutions dissolved congruently up to 30 min, then the Ba{sup 2+} concentration decreased and Pb{sup 2+} concentration increased for duration of the experiments. At 60C the results were similar except the region of congruent dissolution was over before the first samples were taken at 3 min. Solid solution-aqueous solution (SSAS) reaction paths were followed on Lippmann diagrams. During congruent dissolution the reaction paths dissolved toward stoichiometric saturation. During incongruent dissolution the systems moved toward two-component thermodynamic equilibrium at lower aqueous mole fractions of Ba{sup 2+}, while maintaining steady states of undersaturation with respect to the stoichiometric saturation. The {sup 25}C results were fit to the two parameter kinetic model of Denis and Michard (1983) with an additional parameter to account for the precipitation rate dependence of the distribution coefficient. The 60C results could not be modeled due to a complete lack of data in the congruent dissolution region. The model was able to generate close fits to the authors Ba{sup 2+} data, but not their Pb{sup 2+} data. The model was unable to generate steady states significantly below the stoichiometric saturation given the observed rates of congruent dissolution. This indicates a process occurs which acts to decrease the congruent dissolution rate after the formation of a secondary phase.

• OSTI ID: 5115963
• Journal Information: Geochimica et Cosmochimica Acta; (United States), Vol. 55:12; ISSN 0016-7037
• Country of Publication: United States
• Language: English

Related Subjects

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE WASTES FROM NUCLEAR FACILITIES
BARIUM SULFATES
DISSOLUTION
LEAD SULFATES
EQUILIBRIUM
LEACHING
MILL TAILINGS
PH VALUE
RADIOACTIVE WASTES
RADIUM
REACTION KINETICS
SATURATION
SOLID SOLUTIONS
SOLUBILITY
STEADY-STATE CONDITIONS
STOICHIOMETRY
SULFURIC ACID
THERMODYNAMIC ACTIVITY
URANIUM ORES
ALKALINE EARTH METAL COMPOUNDS
ALKALINE EARTH METALS
BARIUM COMPOUNDS
DISPERSIONS
ELEMENTS
HYDROGEN COMPOUNDS
INORGANIC ACIDS
KINETICS
LEAD COMPOUNDS
MATERIALS
METALS
MIXTURES
ORES
OXYGEN COMPOUNDS
RADIOACTIVE MATERIALS
SEPARATION PROCESSES
SOLID WASTES
SOLUTIONS
SULFATES
SULFUR COMPOUNDS
TAILINGS
WASTES
052002* - Nuclear Fuels- Waste Disposal & Storage