Dolomite surface speciation and reactivity in aquatic systems

Pokrovsky, Oleg S.; Schott, Jacques; Thomas, Fabien

doi:10.1016/s0016-7037(99)00240-9

Cited by 204 publications

(118 citation statements)

References 26 publications

Supporting

Mentioning

102

Contrasting

Order By: Relevance

“…Hence, the effect of calcium ions on the zeta potential of minerals was studied. Previous studies were focused separately on the zeta potential measurements of apatite [26,27], dolomite [24,28], and quartz [29] in the presence of calcium ions. In fact, the zeta potentials varied due to different ionic strength, experimental apparatus, sample preparation process, etc.…”

Section: Zeta Potentials Of Pure Minerals In the Presence Of Calcium mentioning

confidence: 99%

Effects of Metal Ions on the Flotation of Apatite, Dolomite and Quartz

et al. 2018

View full text Add to dashboard Cite

Abstract:The effects of Ca 2+ , Mg 2+ , Al 3+ , and Fe 3+ on the flotation behaviors of apatite, dolomite and quartz were investigated through a micro-flotation test, and the influence of calcium ions on the flotation of these minerals was further elucidated by solution chemistry study, zeta potential measurement, and X-ray photoelectron spectroscopy (XPS) analyses. The results indicate that an appropriate amount of Ca 2+ and Mg 2+ can improve the floatability of apatite but had a negligible effect on the flotation performance of dolomite, whereas Al 3+ , Fe 3+ , and excessive amounts of Ca 2+ decreased the recovery of apatite and dolomite. The studied metal cations can activate quartz at a particular pH. It can be inferred from solution chemistry and zeta potential measurement that the influence of metal ions on the flotation of different minerals should be attributed to the adsorption of various hydrolysis species on the mineral surfaces. XPS analyses reveal that calcium ions can enhance the adsorption of anionic collector on apatite and quartz surfaces, and there are no apparent changes to be observed on the surface of dolomite in the absence and presence of calcium ions at a concentration of 2.5 × 10 −3 M, which was in good agreement with the micro-flotation results.

show abstract

Section: Zeta Potentials Of Pure Minerals In the Presence Of Calcium mentioning

confidence: 99%

Effects of Metal Ions on the Flotation of Apatite, Dolomite and Quartz

et al. 2018

View full text Add to dashboard Cite

show abstract

“…A total of 65 time limited, biotite-bearing batch experiments were performed at 25 °C which, when taken together, represent a potentiometric titration series, as previously described by Pokrovsky et al (1999) and Oelkers et al (2009). In brief, 20g/L of biotite was equilibrated while stirred in a polypropylene reactor with a NaCl electrolyte of known ionic strength (I) for at least 12 hours under a N 2 atmosphere (5.0 grade).…”

Section: Batch Potentiometric Titrationsmentioning

confidence: 99%

“…Pokrovsky et al, 1999;Sverjensky, 2004). Among the most significant minerals in the subsurface, in terms of controlling the chemical composition and evolution of surface waters, are the phyllosilicates (including clays).…”

Section: Introductionmentioning

confidence: 99%

Biotite surface chemistry as a function of aqueous fluid composition

Bray

Benning

Bonneville

et al. 2014

Geochimica et Cosmochimica Acta

View full text Add to dashboard Cite

“…The adsorption of Ca 2+ and Mg 2+ to dolomite surfaces may favor one ion over the other via thermochemical controls, however, potentiometric and electrokinetic studies of dolomite powder suspensions by Pokrovsky et al (1999) led to the modeling of this interface in which the affinities of Mg 2+ and Ca 2+ for surface carbonate sites were statistically similar when comparing the following ion exchange equilibria:…”

Section: Introductionmentioning

confidence: 99%

X-ray photoelectron spectroscopic studies of dolomite surfaces exposed to undersaturated and supersaturated aqueous solutions

Joshi

Mukhopadhyay

et al. 2006

Geochimica et Cosmochimica Acta

View full text Add to dashboard Cite

Cleaved surfaces of dolomite were studied using ex-situ X-ray photoelectron spectroscopy (XPS) following exposure of the surfaces to various experimental conditions. Dolomite samples exposed to air, to a highly undersaturated solution (0.1 M NaCl, pH = 9), and to solution with a supersaturation (ÀDl/kT) of 5.5 (pH = 9) were investigated with semiquantitative methods of analysis to ascertain the degree of non-stoichiometry resulting at the dolomite surface from reactive conditions. It was found that the dolomite cleavage surface in undersaturated solution was not altered significantly from the stoichiometric surface termination. The composition of the cleaved surface after exposure to supersaturated solution, a surface known to have self-limiting growth characteristics under similar conditions, was found to be Ca 2+ rich (Ca x Mg 2 À x (CO 3 ) 2 , 1.7 > x > 1.3). The observations, while underscoring differences in hydration/dehydration kinetics of the two alkaline earth cations, suggest that achievement of equilibrium at dolomite-water interfaces may be subject to significant barriers from both undersaturated and supersaturated solutions.

show abstract

Dolomite surface speciation and reactivity in aquatic systems

Cited by 204 publications

References 26 publications

Effects of Metal Ions on the Flotation of Apatite, Dolomite and Quartz

Effects of Metal Ions on the Flotation of Apatite, Dolomite and Quartz

Biotite surface chemistry as a function of aqueous fluid composition

X-ray photoelectron spectroscopic studies of dolomite surfaces exposed to undersaturated and supersaturated aqueous solutions

Contact Info

Product

Resources

About