Analysis of Calcined Red Mud Properties and Related Mortar Performances
Zhengfan Lyu1,3, Yulin Li2,3, Mengmeng Fan1,3,*, Yan Huang1, Chenguang Li2
1
Technical Center Office, Guangxi Jiaojian Engineering Inspection Consulting Co., Ltd., Nanning, 530001, China
2
Technical Center Office, Guangxi Road Construction Engineering Group Co., Ltd., Nanning, 530001, China
3
Nanning Road Construction Technology and Road Construction Materials Engineering Technology Research Centre, Guangxi
Road Construction Engineering Group Co., Ltd., Nanning, 530001, China
*
Corresponding Author: Mengmeng Fan. Email: fanmengmeng1712@163.com
Fluid Dynamics & Materials Processing https://doi.org/10.32604/fdmp.2023.043512
Received 04 July 2023; Accepted 26 October 2023; Published online 07 December 2023
Abstract
Red mud (RM) is a low-activity industrial solid waste, and its utilization as a resource is currently a hot topic. In
this study, the micro characteristics of red mud at different calcination temperatures were analyzed using X-ray
diffraction and scanning electron microscopy. The performance of calcined red mud was determined through
mortar strength tests. Results indicate that high-temperature calcination can change the mineral composition
and microstructure of red mud, and increase the surface roughness and specific surface area. At the optimal temperature of 700°C, the addition of calcined red mud still leads to a decrease in mortar strength, but its activity
index and flexural coefficient increase by 16.2% and 11.9% with respect to uncalcined red mud, reaching values
of 0.826 and 0.974, respectively. Compared with the control group, the synergistic activation of calcined red mud
with slag can increase the compressive and flexural strength of the mortar by 12.9% and 1.5%, reaching 8.7 and
62.4 MPa, respectively. Correspondingly, the activity index and flexural coefficient of the calcined RM and GGBS
(Ground Granulated Blast furnace Slag) mixtures also increase to 1.015 and 1.130, respectively.
Graphical Abstract
Keywords
Red mud; slag; thermal activation; synergistic activation; mortar test; microscopic properties