Sodium Incorporation Behavior in Mineral Phases of Solid Waste Based Portland Cement Clinker
GAO Yifan
HAN Ruikai
LI Zhaofeng
ZHANG Jian
Abstract：The solid waste based Portland cement clinker(SWCC)prepared by industrial solid wastes such as carbide slag,red mud,and silica fume,were utilized to investigate the doping mechanism of sodium ions in the major clinker phases.The results show that the main mineral phases of SWCC consist of 68.3%belite(β-C₂S),21.0%brownmillerite(C₄AF),6.6%tricalcium aluminate(C₃A),and a small amount of alite(C₃S).When 8%desulfurized gypsum is added to this clinker,the 28 d compressive strength reaches 16.7 MPa.Na⁺ is easily incorporated into the iron-containing mineral phases of the clinker,preferentially substituting for Ca²⁺,but exhibites limited solid solubility in C₂S,particularly in replacing Si⁴⁺ in C₂S.Except for Si atoms,Na atoms form the same coordination number as the host atoms(Al,Fe,Ca),inducing only localized structural distortions.These distortions are manifested in the local bonding environment rather than in the overall crystal deformation.
Keywords：cement clinkercrystal structureion substitutiondensity functional theorydifferential charge density
Publication Date：2025-06-30
Online Publishing Date：2025-08-15(First online date of this platform, not the publication date of the document)
Pages：10( 508-517 )