Ca-Mg-Al-Fe quaternary layered double hydroxide (LDHs) was successfully synthesized using the abundant and cheap steel slag as raw material via a convenient chemical process: acetic acid-leaching and coprecipitation. The influences of pH value

crystallization temperature and time on the synthesis of Ca-Mg-Al-Fe quaternary LDHs were investigated. The samples were characterized by XRD

XRF

SEM

FT-IR

TEM

DTA/TG and BET. The results showed that pH was the dominant factor for the synthesis of LDHs

and pure LDHs could be synthesized when pH value was controlled in the range of 10.5-11.8 during coprecipitation process. Crystallization temperature and time were important factors influencing the crystal cell parameters and layer spacing. As the crystallization temperature and time increased

lattice parameters a

c and the spacing of layer first reduced and then increased. Crystal grain size of LDHs along the axis of a was larger than that along the axis of c. When LDHs was synthesized at the conditions of pH of 11.8

crystallization temperature of 150℃ and crystallization time of 16 h

it presented well-defined structure and crystal shape

clear layered structure

large aperture and well thermal stability.