Water vapour partial pressures and water activities in potassium and sodium hydroxide solutions over wide concentration and temperature ranges

1985 ◽  
Vol 10 (4) ◽  
pp. 233-243 ◽  
Author(s):  
J BALEJ
Keyword(s):  
Sodium Hydroxide ◽  
Water Vapour ◽  
Partial Pressures ◽  
Temperature Ranges

Synthesis and study of diaboleïte

1968 ◽  
Vol 36 (283) ◽  
pp. 933-939 ◽  
Author(s):  
R. E. Winchell ◽  
H. E. Wenden
Keyword(s):  
Water Vapour ◽  
Atmospheric Pressure ◽  
Stable Phase ◽  
Line Position ◽  
Natural Mineral ◽  
X Ray ◽  
Partial Pressures ◽  
Cell Dimensions ◽  
Natural And Synthetic

SummaryDiaboleïte has been synthesized between 25 and 100° C at atmospheric pressure and approximate water vapour partial pressures of 14·7 lb/in2. Under similar conditions at 170° C cumengéite appears to be the stable phase produced from a diaboleïte composition. Synthetic diaboleïte is much simpler morphologically than the natural mineral but the hemimorphic symmetry is more clearly demonstrated morphologically in the artificial specimens. A comparison of X-ray powder data for natural and synthetic diaboleïte shows almost exact detailed correspondence in line position and intensity between 0 and 180° 2θ. The cell dimensions obtained from X-ray powder data are a 5·869 ± 0·002 Å and c 5·495 ± 0·003 Å.

Kinetics of the Reaction of Solid Anhydrous Potassium Carbonate with Gaseous Sulfur Dioxide

1994 ◽  
Vol 59 (11) ◽  
pp. 2357-2374 ◽  
Author(s):  
Erich Lippert ◽  
Karel Mocek ◽  
Emerich Erdös
Keyword(s):  
Sulfur Dioxide ◽  
Water Vapour ◽  
Potassium Carbonate ◽  
Anhydrous Potassium Carbonate ◽  
Heterogeneous Reaction ◽  
Fixed Bed ◽  
Partial Pressures ◽  
Flow Apparatus ◽  
Gaseous Sulfur ◽  
Kinetics Of

Results are presented of an experimental kinetic study of the heterogeneous reaction between gaseous sulfur dioxide and solid anhydrous potassium carbonate. The measurements were carried out in an all glass kinetic flow apparatus with nitrogen as the carrier gas and a fixed bed of the solid working in the differential regime at atmospheric pressure and a temperature of 423 K (150 °C). The reaction course was studied in dependence on the partial pressures of sulfur dioxide (pSO2) and water vapour (pH2O) in concentration ranges pSO2 = 13 - 430 Pa and pH2O = 0 - 2 100 Pa. In the reaction, water vapour acts as a gaseous catalyst. Based on the experimental data, the corresponding kinetic equation was found together with the numerical values of the relevant rate and equilibrium adsorption constants.

Mass Spectrometric Investigations of the Evaporation of Crystalline Compounds of the System Cs2O-Al2O3-SiO2 Part II: The Compounds CsAlSiO4 and CsAlSi5O12

1980 ◽  
Vol 35 (1) ◽  
pp. 9-13 ◽  
Author(s):  
R. Odoj ◽  
K. Hilpert
Keyword(s):  
Mass Spectrometry ◽  
Mass Spectrometric ◽  
Log P ◽  
Vapor Pressures ◽  
Equilibrium Conditions ◽  
Synthetic Compounds ◽  
High Temperature Mass Spectrometry ◽  
Partial Pressures ◽  
Temperature Ranges ◽  
High Level

Abstract The evaporation of the synthetic compounds CsAlSiO4 and CsAlSi5O12 was studied by high temperature mass spectrometry. The measurements were carried out under equilibrium conditions with Knudsen cells in the temperature ranges 1242 to 1567 K (CsAlSiO4) and 1542 to 1803 K (CsAlSi5O12). The obtained Cs partial pressures are given by the equationslog p (Pa)=-18497/T(K)+11.85(CsAlSiO4)andlog p (Pa)=-26 974/T(K)+14.6(CsAlSi5012).The probable uncertainty of the vapor pressures is ± 43%. The following enthalpies of sub­limation of Cs (g) were computed:⊿Sub H°1405 (CsAlSiO4) =353.6 ± 9.8 kJ mol-1 and⊿Sub H°1673 (CsAlSi5O12) =516.3 ± 18 kJ mol-1.The Cs partial pressures over CsAlSiO4, CsAlSi5O12 and CsAlSi2O6 (see part I of this work [1]) are discussed with respect to their consequences for the final storage of high level radioactive waste.

Effects of Water Vapour on the Oxidation of Chromia Formers

2008 ◽  
Vol 595-598 ◽  
pp. 1189-1197 ◽  
Author(s):  
David J. Young
Keyword(s):  
Grain Boundary ◽  
Water Vapour ◽  
Grain Structure ◽  
Partial Pressures ◽  
Cr2o3 Scales ◽  
Hydrogen Doping ◽  
Chromia Scales

Water vapour interacts with growing chromia scales in several different ways. Formation and volatilisation of Cr2O2(OH)2 is shown to account quantitatively for chromium loss from thin alloy foils reacted with air-steam mixtures over periods of 103 h. In the shorter term, water vapour is shown to refine the grain structure of Cr2O3 scales grown on Ni-25Cr. Scaling kinetics are at the same time accelerated by an additional, larger contribution to diffusion by a grain boundary species, either OH- or H2O. A slight increase in scaling rate observed at low water vapour partial pressures in H2/H2O gases is thought to be due to hydrogen doping.

Metamorphism of the pelitic rocks of the Snyder Group in the contact aureole of the Kiglapait layered intrusion, Labrador: effects of buffering partial pressures of water

1982 ◽  
Vol 19 (10) ◽  
pp. 1888-1909 ◽  
Author(s):  
J. Alexander Speer
Keyword(s):  
Layered Intrusion ◽  
Granulite Facies ◽  
Metamorphic Grade ◽  
Contact Metamorphism ◽  
Contact Aureole ◽  
Partial Pressures ◽  
Dehydration Reactions ◽  
Mineral Assemblages ◽  
Temperature Ranges ◽  
Pelitic Rocks

The petrography and mineral chemistries of the Aphebian Snyder Group pelitic rocks in the contact aureole of the Kiglapait layered intrusion, Labrador reveal a rapid increase in metamorphic grade over 1.7 km from the greenschist facies to the granulite facies. Three zones of metamorphic grade are defined by the aluminum silicates: I, andalusite; II, andalusite + sillimanite; and III, sillimanite. In addition to the succession in the aluminum silicates, progressive metamorphic mineral assemblages, with quartz, K-feldspar, and plagioclase, evolve from chlorite + biotite + muscovite through cordierite + biotite ± muscovite and garnet + cordierite + biotite to orthopyroxene + garnet + cordierite + biotite and eventually either orthopyroxene + cordierite ± biotite or orthopyroxene + garnet + cordierite. Anatectites, believed to be derived from pelitic rocks, intrude as small stocks in zone III. They comprise biotite + cordierite ± garnet ± orthopyroxene monzogranites or granodiorites with accessory ilmenite, rutile, monazite, and dumortierite.The contact metamorphism is isobaric with pressure just above the intersection of the muscovite + quartz decomposition with the andalusite–sillimanite transition. Most published geobarometers place the estimated pressure of metamorphism at 4 ± 1 kbar (400 ± 100 MPa), but use of the lower Holdaway triple point would put it at 2.25 kbar (225 MPa). The temperature ranges from 450 °C in zone I to 900 °C or more adjacent to the Kiglapait intrusion. The range of values of [Formula: see text] is estimated to be 0.1–0.9Ptotal. Because most reactions are dehydration reactions, conditions of [Formula: see text] less than Ptotal allow the metamorphic reactions to buffer the partial pressure of water. This results in the common occurrence of low-variance assemblages and leads to an apparent overlapping of mineral assemblages and mineral chemistries with increasing metamorphic grade.

scholarly journals Precipitation of solid phase calcium carbonates and their effect on application of seawater <i>S<sub>A</sub></i>–<i>T</i>–<i>P</i> models

Ocean Science ◽  
2009 ◽  
Vol 5 (3) ◽  
pp. 285-291 ◽  
Author(s):  
G. M. Marion ◽  
F. J. Millero ◽  
R. Feistel
Keyword(s):  
Solid Phase ◽  
Theoretical Explanation ◽  
Atmospheric Co2 ◽  
Natural Environments ◽  
Geochemical Model ◽  
Calcium Carbonates ◽  
Seawater Ph ◽  
Partial Pressures ◽  
Temperature Boundary ◽  
Temperature Ranges

Abstract. At the present time, little is known about how broad salinity and temperature ranges are for seawater thermodynamic models that are functions of absolute salinity (SA), temperature (T) and pressure (P). Such models rely on fixed compositional ratios of the major components (e.g., Na/Cl, Mg/Cl, Ca/Cl, SO4/Cl, etc.). As seawater evaporates or freezes, solid phases [e.g., CaCO3(s) or CaSO42H2O(s)] will eventually precipitate. This will change the compositional ratios, and these salinity models will no longer be applicable. A future complicating factor is the lowering of seawater pH as the atmospheric partial pressures of CO2 increase. A geochemical model (FREZCHEM) was used to quantify the SA−T boundaries at P=0.1 MPa and the range of these boundaries for future atmospheric CO2 increases. An omega supersaturation model for CaCO3 minerals based on pseudo-homogeneous nucleation was extended from 25–40°C to 3°C. CaCO3 minerals were the boundary defining minerals (first to precipitate) between 3°C (at SA=104 g kg−) and 40°C (at SA=66 g kg−). At 2.82°C, calcite(CaCO3) transitioned to ikaite(CaCO36H2O) as the dominant boundary defining mineral for colder temperatures, which culminated in a low temperature boundary of −4.93°C. Increasing atmospheric CO2 from 385 μatm (390 MPa) (in Year 2008) to 550 μatm (557 MPa) (in Year 2100) would increase the SA and t boundaries as much as 11 g kg−1 and 0.66°C, respectively. The model-calculated calcite-ikaite transition temperature of 2.82°C is in excellent agreement with ikaite formation in natural environments that occurs at temperatures of 3°C or lower. Furthermore, these results provide a quantitative theoretical explanation (FREZCHEM model calculation) for why ikaite is the solid phase CaCO3 mineral that precipitates during seawater freezing.

Upward movement of granitic magma

1970 ◽  
Vol 107 (4) ◽  
pp. 335-340 ◽  
Author(s):  
J. R. Cann
Keyword(s):  
Water Vapour ◽  
Melting Curve ◽  
Granitic Magma ◽  
Upward Movement ◽  
Granite Magma ◽  
Partial Pressures ◽  
Orogenic Belts

SummaryThe negative P-T slope of the wet melting curve of granite sets limits on the degree of upward movement of granitic magma formed at particular partial pressures of water vapour. Wet granite magma cannot rise very far from its place of formation, and only dry granite magma can be erupted as a liquid. This observation leads to a better understanding of the granitic structure of orogenic belts, and explains some of the apparently paradoxical aspects of granites. Other wet magmas would also not be expected to be erupted as liquids.

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