Ternary Systems. XXIV. Calcium Sulfate, Sodium Sulfate and Water

A chemical equilibrium model of solution behavior and solubility in the H-Na-K-Ca-OH-Cl-HSO4-SO4-H2O system to high concentration and temperature

“…At 80°C, the model is in good agreement (within 9%) with the 75°C data of Hill and Wills (1938) and the 80°C data in Zdanovskii et al (1973) for stable and metastable invariant equilibria in the CaSO 4 -Na 2 SO 4 -H 2 O system except for the calcium concentration for metastable thenardite ϩ labile salt invariant equilibrium. It is in good agreement with the Na and SO 4 concentrations of Bittrich and Leibnitz (1962) for stable univariant portlandite ϩ anhydrite equilibria in Na-Ca-OH-SO 4 -H 2 O solutions but is in poor agreement with their Ca and OH concentrations (Table 9).…”

“…Table 9). The model is in excellent agreement with the 35°C two-salt invariant data of Hill and Wills (1938). The 3-salt invariant data (stable portlandite ϩ thenardite ϩ glauberite (pt.…”

Gypsum, disodium pentacalcium sulfate, and anhydrite solubilities in concentrated sodium chloride solutions

“…5CaS04.3H20, which was shown to be petro~l t h~~~h many phase equilibrium studies have graphically identical with that found by Hill and been made of the geologically important CaS04-Wills (9) in the CaS04-Na2S04-H20 system. NaC1-H2O system, the relative solubilities of Without X-ray analysis Marshall and Slusher (1) gypsum, hemihydrate, and anhydrite in concen-Were unaware that the solid disodium pentatrated sodium chloride brines are uncertain at calcium sulfate was isomor~hous with the 65 OC.…”

“…Anhydrite was also prepared ions replaced calcium isomorphously within the from the gypsum by heating at 400 OC for 24 h. hemihydrate lattice. In similar gypsum solubility Disodium pentacalcium sulfate was formed with continuous stirring (i) at 65 "C by heating gypsum for less than one day with 6.412 NaCl solutions and for increasing periods of up to 11 days for 5.5 ti1 NaCI, (ii) at 75 "C by reaction of gypsum with glauberite in the presence of aqueous 12 wt % NaZSOL (9). Freshly prepared samples contained excess adsorbed water which was removed by evacuation at 2 Torr for 24 h. N o further water was removed by evacuation for 63 h.…”

Marine evaporites

“…In addition to those so far mentioned, the following references are included in "Literature Cited": Berdesinski, 1952b;Bodaleva and Lepeshkov, 1956;Bundy and Conley, 1956;Bye and Kiehl, 1948;Campbell, Downes, and Samis, 1934;Conley, Gabriel, and Partridge, 1938;Conley and Partridge, 1944;D'Ans, 1915D'Ans, , 1933D'Ans, , 1935D'Ans, , 1944D'Ans, , 1947aD'Ans, , b, 1949D'Ans, , 1950D'Ans, , 1952D'Ans, Bredtscheider, Eick, and Freund, 1955;D'Ans, Busse, and Preund, 1955;Faiziev, 1952a, b;Feakes, 1952;Fulda, 1925a, b;Hi'11, 1937;Hill and Wills, 1938;Ide, 1935;Igelsrud and Thompson, 1936a, b;Hinskii and Danyushevskaya, 1956a, b;Janecke, 1913Janecke, , 1916Janecke, , 1917Janecke, , 1923Janecke, , 1929Janecke, , 1935Janecke, , 1950Kuhn, 1952aKuhn, , b, 1953Leonhardt, 1951;Leonhardt andBerdesinski, 1949-50, 1951;Bodaleva, 1949, 1952;Lightfoot and Prutton, 1946Lightfoot, Prutton, and Meyer, 1949;Lukyanova and others, 1956;Madgin and Swales, 1956a, b;…”