Study on Sintering System of Calcium Barium Sulphoaluminate by XRD Quantitative Analysis

Abstract

Calcium barium sulphoaluminate (CBSA), derived from calcium sulphoaluminate (CSA), has excellent cementitious properties. In this study, the sintering system of CBSA with a theoretical stoichiometric Ca3BaAl6SO16 was investigated. Rietveld refinement was performed using TOPAS 4.2 software to quantitatively calculate the content of CBSA and the actual ionic site occupancy of Ba 2+. The results indicate that the content of Ca4−xBaxAl6SO16 increases with increasing sintering temperature in the 1200-1400 °C ranges. When sintered at 1400 °C for 180 min, the content of CBSA reaches 88.4%. However, CBSA begins to decompose at 1440 °C, after which the content decreases. The replacement rate of Ba 2+ was also enlarged by increasing sintering temperature and prolonged sintering time. Sintering at 1400 °C for 180 min is considered as the optimum when replacement rate of Ba 2+ and the content of CBSA were taken into account. Ca3.2Ba0.8Al6SO16 with a content of 88.4% was synthesized.

Effect of Iron Phase on Calcination and Properties of Barium Calcium Sulfoaluminate Cement

“…These particles were C 2.75 B 1.25 A 3 , and the grain size was about 3–5 μm. Because the liquid phase was lower in the sintering process, it was not conducive to the migration of mineral ions during the clinker calcination process, which would affect the formation and development [ 29 , 31 ].…”

“…The weighed raw meal was mixed with water and put into the steel tank of the planetary mill for stirring, then the mixed raw material was put into a blast box for drying. Finally, the raw material was pressed into a 60 mm × 10 mm test cake and put it into a blast drying box to keep it warm for 1 h. The samples were put into a high-temperature furnace for calcination, the temperature was raised to 1350 °C with a heating rate of 5 °C/min and kept warm for 2 h and then the samples were taken out and cooled to room temperature quickly [ 26 , 27 , 28 , 29 , 30 , 31 ].…”

Alite calcium sulfoaluminate cement: chemistry and thermodynamics

“…Another method for the synthesis of a-C$A clinker involves stabilizing ye'elimite to higher temperatures by doping with divalent elements. Studies have been conducted showing partial replacement of calcium in ye'elimite by either strontium or barium, thus stabilising it to temperatures approaching traditional PC clinkering temperature (Xin, Jun et al 2000, Lu, Li et al 2012, Chang, Shang et al 2015).…”