Effect of magnesium aluminum hydrotalcite on the properties of CAC-bonded castables

Particle grading effect on properties of reactive MgO‐bonded castables

“…In comparison, the volume stability of CAC‐bonded castables with a value of 0.25 was higher because of the shrinkage associated with sintering of fine patricles 34 . However, it could not straightforward analogize the conclusion from CAC‐bonded to RM‐bonded castables because of the differences in volume expansion of in situ products 29 . CaO·2Al 2 O 3 (CA 2 ) and CaO·6Al 2 O 3 (CA 6 ) accompanied with 13.6% and 3.0% volume expansion, respectively, are generated in CAC‐bonded castbales, 14,35 whereas MgAl 2 O 4 (MA) with 8.4% volume expansion formed in RM‐bonded castables 1,33 .…”

“…The flow‐ability and explosion resistance during drying of RM‐bonded castables were also experimentally studied by Pandolfelli and co‐workers 6,13,30 . Zhao et al 29 . reported that RM‐bonded castables possessed better volume stability and corrosion and infiltration resistance to CaO‐Al 2 O 3 ‐Fe 2 O 3 ‐SiO 2 (CAFS)‐based slag than CAC‐bonded one, because of the absence of CaO·6Al 2 O 3 (CA 6 ).…”

“…This is because (1) the slag corrosion and infiltration resistance of castables could be improved due to the in‐situ formed MgAl 2 O 4 spinel, 5 (2) and low energy consumption and CO 2 emission during RM preparation 31,32 . To evaluate the feasibility of RM‐bonded castables in industrial application, numerous researches have been carried out 6,13,27,29,30 . By modifying the hydration behavior of MgO using formic acid and or aluminum lactate, 25 crack‐free RM‐bonded castables were prepared 27 .…”

“…found that Cr(VI) formation can be effectively suppressed in RM‐bonded Cr 2 O 3 ‐bearing castables compared with calcium aluminate cement (CAC)‐bonded samples. In these work, RM‐bonded castables with a q ‐value of 0.26 were prepared and studied 6,13,27,29,30,33 . Zou et al., 34 however, have figured out that properties of CAC‐bonded castables could be affected by the particle gradation.…”

“…CaO·2Al 2 O 3 (CA 2 ) and CaO·6Al 2 O 3 (CA 6 ) accompanied with 13.6% and 3.0% volume expansion, respectively, are generated in CAC‐bonded castbales, 14,35 whereas MgAl 2 O 4 (MA) with 8.4% volume expansion formed in RM‐bonded castables 1,33 . These differences would consequently result in varied thermal‐mechanical properties of CAC‐ and RM‐bonded castables 29 . However, to authors’ knowledge, no experiment has been performed to address the effect of particle gradation on properties of RM‐bonded castables.…”