Solubility of carbonates

J. Sandvik and J. Kr. Tuset, The Solubility of Carbon in Ferrosilicomanganese at 1330—1630°C, The Engineering Research Eoundation, Trondheim, Norway, 1970. 

The solubility of carbon dioxide in water is given in Figure 1 (11). Over the temperature range 273—393 K, the solubiUties at pressures below 20 MPa (200 atm) decrease with increasing temperature. From 30 to 70 MPa (300—700 atm) a solubiUty minimum is observed between 343 and 353 K, with solubihties increasing as temperature increases to 393 K. Information on the solubiUty of carbon dioxide in pure water and synthetic seawater over the range 268 to 298 K and 101—4,500 kPa pressure (1—44 atm) is available (12,13). 

The higher solubility of carbon in y-iron than in a-iroii is because the face-ceiiued lattice can accommodate carbon atoms in slightly expanded octahedral holes, but the body-centred lattice can only accommodate a much smaller carbon concentration in specially located, distorted tetrahedral holes. It follows that the formation of fenite together with cementite by eutectoid composition of austenite, leads to an increase in volume of the metal with accompanying compressive stresses at die interface between these two phases. 

Carbon The solubility of carbon in sodium has been measured it is considered lower than the corresponding value for oxygen (2 p.p.m. of carbon at 520°C) but is sufficiently high to give rise to undesirable effects. Carburisation of refractory metals and of austenitic stainless steels has been observed in sodium contaminated with carbon e.g. oil, grease or a low alloy ferritic steel the source of which can be either decomposed organic material, e.g. oil, or a ferritic steel of low or zero alloy content. The latter is an example of... 

The second stage in the carburisation process, that of carbon ingress through the protective oxide layer, is suppressed by the development of alumina or silica layers as already discussed and in some cases protective chromia scales can also form. Diffusion and solubility of carbon in the matrix has been shown by Schnaas et to be a minimum for binary Fe-Ni alloys with a nickel content of about 80<7o, and Hall has shown that increasing the nickel content for the nickel-iron-2S<7o-chromium system resulted in lower rates of carburisation (Fig. 7.54). 

The solubility of carbon dioxide in water depends on the pressure and temperature. The relationship between temperature and pressure for 3.5 and 5 volumes is shown in Figure 17.4. It will also be affected by the amount of air already dissolved in the water. The raw water is therefore carefully filtered and de-oxygenated under vacuum before the sugars and flavourings are added. 

The similarities among the hydroxides are obvious. Let s compare sodium carbonate and ammonia. Sodium carbonate, Na2C03, dissolves in water to give a solution with the properties that identify a base. Quantitative studies of the solubilities of carbonates show that carbonate ion, C03-2, can react with water. The reactions are... 

Both of these facts are employed in the carbonation process of sodas and beer and some sparkling wines. Low-temperature conditions and CO2 pressures of 3 to 4 atm are used to enhance the dissolution of carbon dioxide gas in water. The graph in Fig. 3.1.1 presents the solubility of carbon dioxide in water at various temperatures and pressures. The parameter used to express CO2 solubility is... 

Solubility of Carbon Dioxide in Water at Various Temperatures and Pressures, in Handbook of Chemistry and Physics, 74th ed., ed. David R. Lide (Boca Raton, FL, CRC Press 1993), 6-7. 

Most primary and secondary minerals found in soil systems are barely soluble in the soil solution. The amount of mass from the bulk phase to hydrated ions in soil solution is negligible compared to the total mass of the solid phase. In arid and semi-arid soils, concentrations of most trace metals in soil solution may be controlled by their carbonates and to some extent by their hydroxides. Other than carbonates, trace elements in arid and semi-arid soils may also occur as sulfate, phosphate or siliceous compounds, or as a minor component adsorbed on the surface of various solid phase components. The solubility of carbonates, sulfates and other common minerals of trace elements in arid and semi-arid soils will be discussed in Chapter 5. Badawy et al. (2002) reported that in near neutral and alkaline soils representative of alluvial, desertic and calcareous soils of Egypt, the measured Pb2+ activities were undersaturated with regard to the solubility of... 

This sort of process works because the solubility of carbon dioxide in liquids increases with increasing pressure. This is true for all gases but carbon dioxide is much more soluble in liquids than the permanent gases because it is nearer its critical point. 

In condensing appliances there is a chance that, due the water solubility of carbon dioxide, small C02 fractions are assimilated by the condensate and cannot be measured in the flue gas. However, compared to the deviations from the maximum C02 fraction caused by variations in fuel gas composition, this is a negligible measurement corruption. 

Table 8. Data and Results of Fit on Solubility of Carbon Dioxide in Aqueous Solutions at 298.15°K...

Figure 3. Henry s constant for solubility of carbon dioxide in water (O) int l. crit. table (A) calc, from Takenouchi and Kennedy, and Malinin (Q) calc, from Wiebe and Gaddy, Houghton et al. (V) Malinin, low pressure see Ref. 8...

Markham, A.E. Kobe, K.A. "Solubility of Carbon Dioxide and Nitrous Oxide in Salt Solutions," J. Amer. Chem. Soc.,... 

Yasunishi, A. Yoshida, F. "Solubility of Carbon Dioxide in Aqueous Electrolyte Solutions," J. Chem. Eng. Data, 1979,... 

Ellis, A.J. Golding, R.M. "The Solubility of Carbon Dioxide Above 100 C in Water and in Sodium Chloride Solutions,"... 

Malinin, S.D. Savelyeva, N.I. "Solubility of Carbon Dioxide in Sodium Chloride and Calcium Chloride Solutions at Temperatures of 25, 50, and 75 C and Elevated Carbon Dioxide Pressures," Geochem. Intern., 1972, 9, (3), 410-18. 

Browning, G J. and Weiland, R.H. Physical solubility of carbon dioxide in aqueous alkanolamines via nitrous oxide analogy, J. Chem. Eng. Data, 39(4) 817-822. 1994. 

Elliott, S. The solubility of carbon disulfide vapor in natural aqueous systems, Atmos. Environ., 23(9) 1977-1980, 1989. 

Ellis A. I and Golding R. M. (1963). The solubility of carbon dioxide above 100°C in water and sodium chloride solutions. Amer. Jour. Scl, 261 47-60. 

Stolper E., Eine G., Johnson T., and Newmann S. (1987). Solubility of carbon dioxide in albitic melt. Amer. Mineral, 72 1071-1085. 

Experimental investigations have shown that the solubility of carbonate increases with decreasing temperature. Thus, carbonate cannot be precipitated from... 

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