Papers by Author: Ping Chen

Abstract: Using Octadecyltrimethylammonium cations with long carbon chain to modify calcium montmorillonite samples, the adsorption properties of different dyes on montmorillonite before and after modification were investigated. Results showed that the basic dye of methylene blue was easily adsorbed by natual calcium montmorillonite, while the adsorption ability for acid blue and neutral blue was greatly improved when it was organically modified, and the adsorption amount increased with the increasing of modifier dosage. The adsorption ratio was influnced by reaction time, the temperature and the solution’s pH value. It suggested that the adsorption balance time was about 60min; higher temperature was good for acid blue adsorbed on organic montmorillonite, but neutral blue’s adsorption amount was greater at the room temperature; the optimum pH was 9 for methylene blue adsorption, while low pH was better for acid blue and neutral blue adsorption.

Abstract: Adsorption Characteristics and controlling methods of long-chain alkyl ammonium cations in montmorillonite interlayer space are theoretic evidence of the montmorillonite/alkylammonium complexes in the process of preparation. This paper summarizes the advances in research on adsorption characteristics of alkyl ammonium in montmorillonite inter-layer space.

Abstract: In order to study the phase of Fe and Ti in a beach placer , different methods such as the X-ray diffraction analysis, chemical analysis, scanning electron microscopic , electron probe microanalysis are used to study the characteristics of the beach placer . The research results show the major metallic mineral in the beach placer is titanic magnetite, EDS and energy spectrum map features of which indicate that the vast majority of titanic magnetite contain a certain amount of Ti , the two elements of Fe and Ti take on closely symbiosis and distribute more evenly in titanic magnetite. The Ti exists in the Magnetite lattice in form of isomorphism. The theoretical highest grade of Fe and Ti in the separated Magnetic concentrate are 66.02per cent and 4.86 per cent respectively. In addition, the beach placer contains a small quantity of Ilmenite which is hysterogenic and exists in the form of fine solid solution separation structure in the titanic magnetite

Abstract: Using Octadecyltrimethylammonium (OTA) cations with long carbon chain to intercalate into Na-montmorillonite samples, the change of adsorption amount and adsorption state of OTA with the retention time was investigated. The sdudy on the reaction kinetics for the alkylammonium adsorption in the montmorillonite interlayers showed that the isothermal adsorption behavior fit in with a second order reaction kinetics equation. Reaction rate constants had great differences with application force of adsorption process. OTA in the montmorillonite interlayers through re-arrangement constantly at different time, adsorption state of OTA are analysised by XRD and FTIR. The interlayer spacing and diffraction peak relative intensity of montmorillonite/OTMA complexes shows a dynamic change, the alkyl chain conformations can change from “liquid-like” to “solid-like” with the reaction time. The arrangement of alkylammonium cations are more orderly.

Abstract: A series of montmorillonite/alkylammonium complexes were prepared by the intercalation reaction between montmorillonite and Octadecyltrimethylammonium chloride (OTA). The effects of OTA dosage and intercalation duration on the structure and gelating properties of the complexes were investigated. And, the correlation between the structure of complexes and their gel viscosities were discussed. Results indicate that the OTA dosage and retention time have remarkable influence on the structure and gelating properties of montmorillonite/alkylammonium complexes, and the gelating properties also relates to the arrangement of the alkylammonium molecules in the interlayers of montmorillonite. Along with the increase of the OTA dosage under the same retentation time, both the d001 value of the montmorillonite/alkylammonium complexes and the adsorption amount of OTA increase to some extent, and the layer structure of the complex tends to show an interstratification structure. However, maximum gel viscosity of the complex was obtained at a moderate OTA dosage of 1.1~1.3CEC. Along with the increase of the retentation time, the adsorption amount of the OTA shows little variations, but the interlayer structure of the complex prepared under longer retention time tends to form a stable monolayer structure from an unstable interstratification structure under shorter retention time, and the gel viscosity of the complex increases gradually to the maximum value.