Showing papers on "Calcium aluminates published in 1960"
TL;DR: In this article, it has been shown that the preparation of barium-calcium tungstates by combined precipitation of substances which form the aluminates on subsequent ignition makes it possible to increase the purity of the product obtained and to decrease the temperature and shorten the duration of the ignition.
Abstract: By making use of x-ray phase analysis it is possible to determine the technological conditions for preparing barium-calcium tungstates and aluminates. It has been shown that the preparation of barium-calcium aluminates by combined precipitation of substances which form the aluminates on subsequent ignition makes it possible to increase the purity of the product obtained and to decrease the temperature and shorten the duration of the ignition. This is probably related to the fact that during the combined precipitation, thorough mixing of the original components takes place, facilitating the course of the reaction in the solid phase. In the preparation of tungstates by the combined precipitation method, however, no significant decrease in the temperature or duration of ignition were obtained.
3 citations
TL;DR: 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 as mentioned in this paper.
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 C3AΣH1...
2 citations