The Study Of The Preparation Of Inorganic Ion Adsorbent Using Natural Clay From Potash Ores Of A Salt Lake

Zeolites are widely used in petrochemical, biomedical, functional materials and high-tech, as its uniform pore structure, high specific surface area and good thermal stability. It is significant to achieve diversification of raw material prepared zeolites, reduce the cost of zeolite and synthesize zeolite using tailings of potassium containing clay from salt lake. Simultaneously, it is beneficial to make full use of the salt lake resources and extend the chain of salt chemical industry.A series of microporous zeolites, mesoporous zeolites and composite materials with ammonium phosphomolybdate(AMP) were were prepared by technology of ‘liquid-phase transport’ and hydrothermal synthesis method using tailings of potassium containing clay from salt lake, Mahai area, as raw materials after pretreatments such as crushing, washing, and alkali fusion activation et al, and optimizing the experimental conditions. The products were determined by X-ray powder diffraction(XRD), X-ray fluorescence spectrometer(XRF), scanning electron microscopy(SEM), transmission electron microscopy(TEM), Infrared spectrum analyzer(IR), Nitrogen gas adsorption-desorption, thermogravimetric differential thermal analysis(TG-DSC) and magic angle spinning solid-state NMR(27Al, 31 P MAS NMR). The adsorption properties of octadecylamine(ODA), Pb2+, Cs+ by aboved materials were also studied in this paper. The main results are as follows:(1) The chemical composition and composition analysis of tailings were determined. The best activation treatment was alkali fusion according to the characteristics of components and experimental results.(2) A series of microporous zeolites(ZSM-5, Y, 4A, 13X) were prepared by hydrothermal method using alkali fused clay as material. The adsorption results show The maximum adsorption capacity of zeolite Y for Cs+ in aqueous solution is 303.1mg/g, the equilibrium adsorption time is 3h, the kinetics of adsorption process can be modeled with the quasi-second kinetic model, the sorption data at 25°C can be successfully modeled with the Freundlich isotherm model and Langmuir isotherm model; The equilibrium adsorption amount of Pb(II) was 33.52mg/g. The adsorption processes can be well described by the pseudo-second-order rate equation and classical Langmuir model; The adsorption amount of ODA by 4A, 13 X was 2.68 and 2.60mg/g respectively.(3) Two kinds of mesoporous zeolites(Al-MCM-41, SBA-15) were prepared by hydrothermal method using alkali fused clay as material. The adsorption results show that adsorption capacity of Al-MCM-41, SBA-15 for ODA was 5.87 and 2.29mg/g respectively.(4) A series of composite materials(AMP/Al-MCM-41, AMP/SBA-15, AMP/Y) were prepared by hydrothermal method using alkali fused clay and AMP as materials. The maximum adsorption capacity of AMP/Al-MCM-41 for Cs+ in synthetic salt lake brine is 73.9mg/g, the equilibrium adsorption time is 12 h, the sorption data at 25°C can be successfully modeled with the Freundlich isotherm model; The maximum adsorption capacity of AMP/SBA-15 for Cs+ in synthetic salt lake brine is 90mg/g, the equilibrium adsorption time is 6h, the sorption data at 25°C can be successfully modeled with the Freundlich isotherm model; The maximum adsorption capacity of AMP/Y for Cs+ in synthetic salt lake brine is 97mg/g, the equilibrium adsorption time is 3h, the sorption data at 25°C can be successfully modeled with the Langmuir isotherm model.