Preparation and characterization of organic red mud and its application in asphalt modification

Xiao, Junwei; Zhang, Jizhe; Zhang, Henglong; Bi, Yi; Yue, Hongya; Xu, Ruidong

doi:10.1016/j.conbuildmat.2022.130269

Cited by 6 publications

(1 citation statement)

References 42 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…As a major producer of alumina, China produced more than 120 million tons of red mud in 2022, with a cumulative stockpile of 1.7 billion tons. Red mud created with the Bayer process is used as an industrial by-product for other applications, such as building materials [1][2][3][4][5][6] and environmental [7][8][9][10], chemical [2,[11][12][13][14][15], agronomic [16][17][18][19], metallurgical [20][21][22] processes, and so on. Currently, building materials consume reused red mud the most.…”

Section: Introductionmentioning

confidence: 99%

Analysis of Alkali in Bayer Red Mud: Content and Occurrence State in Different Structures

Wang,

Jing,

Zhang

et al. 2023

Sustainability

View full text Add to dashboard Cite

The application of large amounts of red mud in the field of building materials is one of the main ways to reuse this material, but the high alkali content of red mud limits its application. In this paper, the washable alkali, removable alkali, and lattice alkali contents of Bayer red mud were studied, and the occurrence states of potassium and sodium in red mud were studied using XRD, IR, XPS, and NMR. On this basis, the removal mechanism for potassium and sodium in red mud was analyzed. The results showed that the Na in the red mud was mainly deposited in the shelf silicon voids of hydroxy sodalite (Na8(AlSiO4)6(OH)2(H2O)2) in the form of Si-O-Na or Al-O-Na. K is deposited in the shelf silico-oxygen void of potassium feldspar (KAlSi3O8) in the form of Si-O-K or Al-O-K. The washable Na and K contents of the mud were 13.7% and 4.47%; the alkali removal agent CaO removed 83.1% and 50.8% of Na and K in the red mud; and the lattice alkali Na and K contents were 3.20% and 44.8%, respectively. In the process of red mud dealkalization, Ca2+ ions can enter the internal voids of the hydroxyl sodalite and potassium feldspar silica skeleton and then replace Al3+ in the Si-O skeleton and Na+ and K+ in the skeleton voids. The replacement reaction changes the silica tetrahedron network structure, resulting in the disintegration of the frame-like silica tetrahedron in the hydroxyl sodalite and potassium feldspar, forming an isolated, island-like silica tetrahedron in hydrated garnet.

show abstract