Showing papers on "Calcium aluminates published in 1986"
TL;DR: In this article, the chemical shift and quadrupolecoupling data of polycrystalline calcium aluminates with varying CaO/Al 2 O 3 ratios were derived from static and magic-angle spinning NMR spectra recorded at different magnetic field strengths up to 11.7 T.
71 citations
Patent•
30 Jun 1986
TL;DR: In this paper, a method of separating sulphate ions from industrial waste water by precipitating difficulty-soluble calcium aluminate sulphates by adding reactive aluminium oxide and/or calcium aluminates to the waste water, with mechanical mixing and adjustment of the pH with Ca(OH)2 to a value in the range from 11.2 to 11.1.
Abstract: 1. A method of separating sulphate ions from industrial waste water by (A) precipitating difficulty-soluble calcium aluminate sulphates by adding reactive aluminium oxide and/or calcium aluminates to the waste water, with mechanical mixing and adjustment of the pH with Ca(OH)2 to a value in the range from 11.2 to 11.8 and (B) separation of the calcium aluminate sulphates formed, characterised in that in step (A) (A1) the reactive aluminium oxide and/or the calcium aluminate or aluminates are added simultaneously with or after adjustment of the pH, (A2) the pH of the resulting precipitation system is kept constant at 11.2 to 11.8 during the entire precipitation reaction by adding Ca(OH)2 in solid form or in the form of milk of lime, and (A3) the precipitation reaction is brought about at a temperature of 25 to 35 degrees C.
19 citations
Patent•
04 Dec 1986
TL;DR: The binder mix for use with water and, if appropriate, aggregates and additives consists of: a. Portland cement clinker in a quantity of 75 to 95 % by mass, b. reactive calcium aluminates in the form of CA, C12A7 and/or alumina cement, and additionally the following components, relative to components a and b forming 100 % bymass, c. reactive calcined calcium sulphate, which inhibits the nucleation and growth of calcium aluminate sulphate and e.
Abstract: The binder mix for use with water and, if appropriate, aggregates and additives consists of: a. Portland cement clinker in a quantity of 75 to 95 % by mass, b. reactive calcium aluminates in the form of CA, C12A7 and/or alumina cement in a quantity of 5 to 25 % by mass, and additionally the following components, relative to components a and b forming 100 % by mass, c. reactive calcium sulphate in a quantity of 2.5 to 4 % by mass, d. an organic setting retarder, which inhibits the nucleation and growth of calcium aluminate sulphate, in a quantity of 0.1 to 1 % by mass and e. an alkali metal carbonate in a quantity of 0.2 to 0.8 % by mass of Na2O equivalent, the total CaO content being adjusted at least in such a way that no metastable or low-lime hydrated calcium aluminates or ferrites can be formed.
11 citations
TL;DR: In this paper, eight commercial grade calcium aluminate cements were prepared macro-defect free by high shear mixing, lowering the water/cement ratio and using polyvinyl alcohol as a plasticizer.
10 citations
TL;DR: In this paper, l'influence d'additifs sur les reactions entre D 2 O and les composants du clinkes de ciment Ca 3 Al 2 O 6, Ca 12 Al 14 O 33 and CaAl 2 O 4, au moyen de la diffraction de neutrons a temperatures jusqu'a 120°C.
Abstract: Etude de l'influence d'additifs sur les reactions entre D 2 O et les composants du clinkes de ciment Ca 3 Al 2 O 6 , Ca 12 Al 14 O 33 et CaAl 2 O 4 , au moyen de la diffraction de neutrons a temperatures jusqu'a 120°C. Les additifs etudies sont CaSO 4 •1/2D 2 O, CaSO 4 •2D 2 O, CaCO 3 , Ca(OD) 2 , CaCl 2 et SiO 2
7 citations
TL;DR: In this article, the compositions of impregnants inside B-type dispenser cathodes containing barium calcium aluminates were examined by means of quantitative microprobe analysis.
3 citations