Krotite, CaAl2O4, occurs as the dominant phase in an unusual Ca-,Al-rich refractory inclusion from the NWA 1934 CV3 carbonaceous chondrite. Krotite occupies the central and mantle portions of the inclusion along with minor perovskite, gehlenite, hercynite, and Cl-bearing mayenite, and trace hexamolybdenum. A layered rim surrounds the krotite-bearing regions, consisting from inside to outside of...

Through powder techniques and in situ solid state reactions, a refractory cement CaAl2O4-based was fabricated, using CaCO3 extracted from chicken eggshells Al as precursor materials. To reduce the particle size achieve homogeneous mixture, powders were subjected to high-energy milling planetary mill. The resulting grinding compacted form cylindrical tablets. These samples pressureless sintered ...

The effect of using Na2HPO4 solution as mixing liquid in the physicochemical and mechanical properties of calcium aluminate cement (CAC), with a view to a possible reinforcement additive of conventional α-TCP-based CPC was studied. The results showed that the degree of the hydration reaction of CaAl2O4 (CA) increased when Na2HPO4 solution was used as mixing liquid. The porosity of cement was al...

Nanomineralogy is the study of Earth and planetary materials at nano-scales, focused on characterizing nanofeatures (like inclusions, exsolution, zonation, coatings, pores) in minerals and revealing nanominerals and nanoparticles [1,2]. With advanced high-resolution analytical scanning electron microscopy, we are now capable to characterize solid materials in situ easier and faster down to nano...

The article presents the results of studying effect modifying additives CaAl2O4 (CA) and CaAl4O7 (CA2), as well boric acid on processes phase formation clinker minerals. calculation content raw materials in charge is carried out taking into account production high-alumina with participation Al2O3 71–72 wt.% CaO 27–28 wt.%. In accordance state diagram CaO–Al2O3 system, mass amount accumulates tw...

The results of experimental studies on the phase formation CaAl2O4 (CA) and CaAl4O7 (CA2) from CaCO3-Al2O3 powder mixtures in temperature range 1250 - 1450 ° C ate presented. In order to calculate content raw materials charge, criterion obtaining high-alumina clinker with Al2O3 71 72 wt. % CaO 27 28 wt.% is proceeded. This mass ratio system state diagram suggests presence two calcium-aluminate ...

Partially deuterated Ca3Al2(SiO4)y(OH)12 4y–Al(OH)3 mixtures, prepared by hydration of Ca3Al2O6 (C3A), Ca12Al14O33 (C12A7) and CaAl2O4 (CA) phases in the presence of silica fume, have been characterized by Si and Al magic-angle spinning–nuclear magnetic resonance (MAS–NMR) spectroscopies. NMR spectroscopy was used to characterize anhydrous and fully hydrated samples. In hydrated compounds, Ca3A...

The hydration behaviour of Ca3Al2O6, Ca12Al14O33 and CaAl2O4 with added amorphous silica at 40, 65 and 90 1C has been studied for periods ranging from 1 to 31 days. In hydrated samples crystalline phases like katoite (Ca3Al2(SiO4)3 x(OH)4x) and gibbsite, Al(OH)3, were identified, likewise amorphous phases like Al(OH)x, calcium silicate hydrates, C–S–H, and calcium aluminosilicate hydrates, C–S–...