TY - JOUR
T1 - Potential of blended byproduct caps for management of bauxite residues
T2 - How do texture and weathering impact geochemistry?
AU - Taki, Golam
AU - Grierson, Pauline F.
AU - Brand, Helen E.A.
AU - Murphy, Daniel V.
AU - Santini, Talitha C.
N1 - Publisher Copyright:
© 2024 The Author(s)
PY - 2024/12/18
Y1 - 2024/12/18
N2 - This study evaluated how successive leaching of caustic bauxite residues of different textures, coupled with blending with locally available byproducts, might improve geochemical characteristics of capping materials. Three bauxite residue textures (fines, fines plus 10 % residue sand and residue sand) were blended with three byproducts (fly ash, sewage water and eucalypt mulch) individually or in combination. Treatments were subject to leaching of three wetting/drying cycles over 18 weeks to mimic field weathering. The pH, salinity and Na concentration of blended materials decreased after leaching regardless of texture. Alkaline minerals (sodalite and calcite) content also decreased during weathering due to enhanced dissolution. Combined byproducts improved multiple chemical properties simultaneously more than any single byproduct. Further decreases in pH, sodicity and concentration of toxic elements are needed to improve suitability of blended capping materials for meeting closure targets, including vegetation establishment.
AB - This study evaluated how successive leaching of caustic bauxite residues of different textures, coupled with blending with locally available byproducts, might improve geochemical characteristics of capping materials. Three bauxite residue textures (fines, fines plus 10 % residue sand and residue sand) were blended with three byproducts (fly ash, sewage water and eucalypt mulch) individually or in combination. Treatments were subject to leaching of three wetting/drying cycles over 18 weeks to mimic field weathering. The pH, salinity and Na concentration of blended materials decreased after leaching regardless of texture. Alkaline minerals (sodalite and calcite) content also decreased during weathering due to enhanced dissolution. Combined byproducts improved multiple chemical properties simultaneously more than any single byproduct. Further decreases in pH, sodicity and concentration of toxic elements are needed to improve suitability of blended capping materials for meeting closure targets, including vegetation establishment.
KW - Bauxite residue fine
KW - Bauxite residue sand
KW - Capping material
KW - Industrial byproducts
KW - Red mud
KW - Tailings management
UR - http://www.scopus.com/inward/record.url?scp=85212217491&partnerID=8YFLogxK
U2 - 10.1016/j.resconrec.2024.108077
DO - 10.1016/j.resconrec.2024.108077
M3 - Article
AN - SCOPUS:85212217491
SN - 0921-3449
VL - 215
JO - Resources, Conservation and Recycling
JF - Resources, Conservation and Recycling
M1 - 108077
ER -