Solid–liquid Reactions: Part Ii. Solid–liquid Reactions Amongst the Calcium Aluminates and Sulphoaluminates

Abstract

When 3CaO.Al2O3.6H2O (i.e. C3AH6) was placed in contact with a solution of Ca(OH)2 labeled with Ca45 and maintained at 25 °C, there was very little change in either the activity or composition of the liquid. These observations, when taken together, indicate that the compound is probably stable in the system used. On the other hand, when either C3AH6 or 3CaO.Al2O3.CaSO4.12H2O (i.e. C3AΣH12) was added to a mixed Ca(OH)2–CaSO4 solution, the composition of the liquid varied in a manner consistent with the formation of 3CaO.Al2O3. 3CaSO4.31H2O (i.e. C3AΣ3H31). The activity also changed markedly, and a detailed consideration of the relations between activity and composition enabled the reaction mechanisms to be determined. In further experiments, the reactions of C3AH6 and C3AΣH12 to form C3AΣ3H31 were shown to proceed also at 70° and 90 °C. The consistently greater ultimate stability of C3AΣ3H31 over C3AΣH12 between 25° and 90 °C is to be contrasted with the fact, observed in the course of preparing the C3AΣH12, that when solutions of A12(SO4)3, CaSO4, and Ca(OH)2 are mixed the immediate precipitate is C3AΣ3H31 at room temperature, but C3AΣH12 at boiling temperature.

eview on the general technical approaches as an effective ways to fabricate inorganic nanomaterials

“…A solid-liquid reaction as known the solid reactant in low soluble with a liquid to form a second soluble less soluble in term of liquid is intended here to include both solvents and randomly dissolved. This process is of particular benefit in cement chemistry, since they are answerable for both the setting and impairment of cementations materials 40 . Undoubtedly, there are innumerable differences in the details of solid and liquid reaction mechanisms.…”

Heat of formation of calcium aluminate monosulfate at 25 °C

“…The conclusions of Lerch, Ashton, and Bogue [1] on the role of alkalinity are thus confirmed.With extremely high CaO/Al 2 O 3 ratios, the mass-action effect of the Ca ++ ion may be stronger than the influence of OH − , and trisulfate may be very readily precipitated at very high Ca ++ concentrations.The experience of other workers, who have been unable to prepare the monosulfate at room temperature, is possibly explained by these concentration-ratio requirements. For example, Kelly [20] attempted to prepare the monosulfate at room temperature from one liter of saturated CaSO 4 solution containing 3.06 g of Al 2 (SO 4 ) 3 ·18H 2 O and two liters of saturated Ca(OH) 2 solution. This mixture represents a CaO/Al 2 O 3 molar ratio of 12, and an OH _ /Al 2 O 3 ratio of 18.…”

“…The experience of other workers, who have been unable to prepare the monosulfate at room temperature, is possibly explained by these concentration-ratio requirements. For example, Kelly [20] attempted to prepare the monosulfate at room temperature from one liter of saturated CaSO 4 solution containing 3.06 g of Al 2 (SO 4 ) 3 ·18H 2 O and two liters of saturated Ca(OH) 2 solution. This mixture represents a CaO/Al 2 O 3 molar ratio of 12, and an OH _ /Al 2 O 3 ratio of 18.…”