Mg?Al?LDH was synthesized by the constant pH co?precipitation method,and the micro?structure and composition of the layered bimetallic hydroxides were characterized by X?ray diffraction (XRD),scanning electron microscopy (SEM),energy dispersive spectroscopy (EDS) and BET.The results show that LDHs were successfully prepared with a layered structure,a high degree of order,and mesopores.The toluene?n?heptane method was used to separate the asphaltenes in Tahe into heavy component A₁ and light component A₂.The elemental analysis indicates that A₁ had the highest polarity,followed by the Tahe asphaltenes and A₂.This paper further investigated the adsorption properties of Mg?Al?LDH for asphaltenes and their sub?components A₁ and A₂ in Tahe and found that the adsorption equilibrium can be reached within 2~3 h.The experimental data fitted well with the pseudo?second?order kinetics,and the adsorption isotherms followed the Langmuir model. The adsorption capacity of Mg?Al?LDH was 71.38,140.65 and 39.31 mg/g for asphaltenes in Tahe and their sub?components A₁ and A₂,respectively.

Tahe asphaltene (T_A) was separated into heavy component(T_A1) and light component (T_A2). The surface morphology, crystal structure and functional group structure of T_A, T_A1 and T_A2 were characterized by Scanning Electron Microscope (SEM), X?ray diffraction (XRD), Fourier Transform Infrared Spectroscopy (FT?IR) and ¹H?Nuclear Magnetic Resonance Spectrum (¹H?NMR). The results show that TA has less long?chain structure, more branched chains in side chains, and is mainly composed of short branched alkyl structure such as methyl, ethyl and propyl. Sub?components T_A1 and T_A2 show obviously different microstructure after separated from T_A. TA1 has the highest degree of graphitization, the longest branched chain, more side?chains of aromatic ring, less branched chains of alkyl side?chains and relatively strong aromaticity, while T_A2 has lower degree of graphitization, more branched chains of alkyl side?chains, less side?chains of aromatic ring and relatively weak aromaticity.