Preparation of refractory calcium aluminate cement using the sonochemical process

Abstract

Calcium aluminate cements (CAC) were prepared using the sonochemical process, followed by heat treatment. A study was made of the action of ultrasonic waves and the influence of thermal treatment conditions on two initial molar compositions of 1:1 and 1:2 of calcia:alumina. The aqueous suspension containing the raw materials (A-50 alumina and CaO) was subjected to an ultrasonic bath, followed by drying and burning at 1000, 1200 and 1300 °C. These cements were characterized by SEM, XRD and the mechanical strength was evaluated by splitting tensile tests, using commercial cement as a reference. Furthermore, the phases were semi-quantified using the Rietveld method. The results show that hydration and sonochemical action increased the reactivity of the raw materials during firing and that phase formation is dependent on the thermal treatment conditions. The CAC cements were obtained at temperatures at least 200 °C lower than those used in conventional methods, indicating the potential of this route of synthesis.

The Effect of Calcination Temperature on the Structure and Performance of Nanocrystalline Mayenite Powders

“…The results of X-ray studies indicate a direct reaction of oxide precursors of the C12A7 phase with the participation of solid state diffusion and the use of the process of nucleating new crystallites on the surfaces of already existing crystalline mayenite particles or growing atom by atom of these surfaces. Often the presence of CA may hasten the set time of the CA2 phase, which is why it appears in aluminous cements as a secondary phase [36].…”

Sorption equilibria of CO2 on synthesized CaO in the presence of water

“…Contrary to raw cockle shell, synthesized CaO agglomerates are larger, rounded and profusely cracked as shown in Fig. 4(b) [32]. Sun et al [33] claimed that the grain shape are almost spherical but with some evidence of initial grain-neck growth due to early stage of sintering.…”

Physical, mechanical properties and antimicrobial analysis of a novel CaO·Al2O3 compound reinforced with Al or Ag particles

“…Also, this material has been studied for biomedical applications (Regina de Oliveira et al, 2015), such as in odontology (Leal Silva et al, 2014;Engqvist et al, 2004;Parreira et al, 2016;Loof et al, 2003;Oliveira et al, 2010;Andrade et al, 2014), bone replacement (Uchida et al, 1984) and bone-graft applications (Kalita et al, 2002;Hulbert et al, 1970). As well, calcium aluminate has been the focus of several studies about of the synthesis processes, such as the sol-gel method (Aitasalo et al, 2002), solid state reaction (Miranda Hernández et al, 2018;Aitasalo et al, 2002;Yongpan et al, 2016), sintering (Miranda Hernández et al, 2018;Iftekhar et al, 2008;, mechanochemical synthesis (Wieczorek-Ciurowa et al, 2010), and the sonochemical process (Lourençoa et al, 2013). Calcium aluminate is synthesized principally from the CaO and Al 2 O 3 (Andrade et al, 2014;Yongpan et al, 2016;Iftekhar et al, 2008;Wieczorek-Ciurowa et al, 2010;Lourençoa et al, 2013;Zawrah and Khalil, 2007), but in some cases, the CaO is obtained through the thermic effect from CaCO 3 (Miranda Hernández et al, 2018;Andrade et al, 2014;Iftekhar et al, 2008;Galan et al, 2013).…”

“…As well, calcium aluminate has been the focus of several studies about of the synthesis processes, such as the sol-gel method (Aitasalo et al, 2002), solid state reaction (Miranda Hernández et al, 2018;Aitasalo et al, 2002;Yongpan et al, 2016), sintering (Miranda Hernández et al, 2018;Iftekhar et al, 2008;, mechanochemical synthesis (Wieczorek-Ciurowa et al, 2010), and the sonochemical process (Lourençoa et al, 2013). Calcium aluminate is synthesized principally from the CaO and Al 2 O 3 (Andrade et al, 2014;Yongpan et al, 2016;Iftekhar et al, 2008;Wieczorek-Ciurowa et al, 2010;Lourençoa et al, 2013;Zawrah and Khalil, 2007), but in some cases, the CaO is obtained through the thermic effect from CaCO 3 (Miranda Hernández et al, 2018;Andrade et al, 2014;Iftekhar et al, 2008;Galan et al, 2013). Also, CaCO 3 can be obtained from natural sources such as snail shells, egg shells or clam shells (Miranda Hernández et al, 2018;Singh and https://doi.org/10.1016/j.jmbbm.2019.05.041 Received 18 January 2019; Accepted 27 May 2019 Purohit, 2010;Viriya et al, 1016;Ligaszewski et al, 2009;White et al, 2007;Marxen et al, 2003;Niju et al, 2016).…”