Analysis of Engineering Characteristics and Microscopic Mechanism of Red Mud–Bauxite Tailings Mud Foam Light Soil

Abstract

In order to effectively utilize aluminum industrial waste—red mud and bauxite tailings mud—and reduce the adverse impact of waste on the environment and occupation of land resources, a red mud–bauxite tailings mud foam lightweight soil was developed based on the existing research results. Experiments were conducted to investigate the mechanical properties and microscopic characteristics of the developed materials with different proportions of red mud and bauxite tailings mud. Results show that with the increase in red mud content, the wet density and fluidity of the synthetic sample was increased. With 16% red mud content, the water stability coefficient of the synthetic sample reached its maximum of 0.826, as well as the unconfined compressive strength (UCS) of the sample cured for 28 d (1.056 MPa). SEM images reveal that some wastes of the sample without red mud were agglomerated, the peripheral hydration products were less wrapped, and when the amount of red mud was 16%, the hydration products tightly wrapped the waste particles and increased the structural compactness. The final concentration of alkali leaching of samples increased with the addition of red mud. The maximum concentration of alkali leaching was 384 mg/L for the group with the addition of red mud of 16%. Based on the obtained mechanical strength and alkali release analysis, the sample B24R16 was selected as the optimum among all tested groups. This study explored a way to reuse aluminum industrial waste, and the results are expected to be applied to roadbed and mining filling.

Special Issue: Advancement of Functionalized Mineral Materials and Rock

“…The physical and mechanical behaviour, fracture, damage, and evolution processes of geomaterials under various environmental and mechanical conditions, such as thermal, mechanical, chemical, and electrical environments [6][7][8][9][10][11][12][13][14][15][16][17]20,21].…”

“…This Special Issue covers numerous aspects of functional mineral research. These topics focus on various themes, including the analysis of mineralogical composition and its effects on the physico-mechanical properties of geomaterials, the investigation of the impact of triaxial stress on the damage creep behaviour of geomaterials, and the evaluation of the thermophysical and mechanical characteristics of rocks under high-temperature circumstances [6][7][8][9][10][11][12][13][14]. The research conducted on these topics also involves various experimental and numerical techniques, such as digital image processing, Discrete Element Method (DEM), and analytical solution and simulation [13,[15][16][17][18].…”

“…The study conducted by Ou et al [9] investigates the engineering characteristics and microscopic mechanism of foam light soil that incorporates red mud and bauxite tailings, with the aim of exploring its potential use in geotechnical engineering applications. According to the research, the incorporation of red mud and bauxite tailings into foam lightweight soil resulted in enhancements in its mechanical characteristics, including, but not limited to, strength and stability.…”

Surface Properties of Eggshell Powder and Its Influence on Cement Hydration

“…Eggshells have such great potential in the application of cement-based materials that their use has attracted the attention of many researchers [ 23 , 24 , 25 , 26 , 27 , 28 , 29 ]. Jhatial et al [ 30 ] reported that the eggshell can be used as auxiliary cementitious material after being ground into powder.…”

Research on Flocculant Selection for Classified Fine Tailings Based on Micro-Characterization of Floc Structure Characteristics

“…These particles can easily affect the stability and impermeability of tailings in a dam, which may lead to the formation of hazardous dams [ 1 ]. With the progress of solid waste utilization technology, coarse-grained tailings can be considered as a mineral in different applications [ 2 ], such as building materials and roadbed construction [ 3 ]. This development is a key measure to build tailless mines, reuse the resources of coarse-grained tailings after grading, fill underground empty areas with classified fine tailings, and achieve 100% comprehensive utilization of tailing resources [ 4 , 5 , 6 , 7 ].…”