Direct synthesis of mesoporous aluminosilicate using natural clay from low-grade potash ores of a salt lake in Qinghai, China, and its use in octadecylamine adsorption

Aluminum-containing hexagonally ordered mesoporous silica , Al-MCM-41, was successfully synthesized for the first time using natural clay from low-grade potash ores of a salt lake in Qinghai, China, through liquid-phase transport. Synthesis involved the use of impure natural clay, the principal components of which are kaolin and quartz, as a starting material to produce Al-MCM-41 directly without sedimentation processing; no additional silica or aluminum reagents were required in this process. The resultant product was characterized by X-ray fluorescence, X-ray diffraction, Fourier-transform infrared spectroscopy, N 2 adsorption/desorption isotherms, transmission electron microscopy , and 27 Al magic-angle spinning NMR. The adsorption capacity of the final product for removing octadecylamine in synthetic salt lake brine was also investigated. Results suggested that salt lake clay is a promising low-cost precursor for the industrial production of mesoporous aluminosilicate .