Abstract:

A kind of highly purified illite was successfully prepared via the wet purification. The purification process was optimized by investigating grinding concentration, inlet flow rate, primary settling time and secondary settling time. The safety of illite was confirmed by heavy metal detection. Scanning electron microscopy, Fourier transform infrared spectroscopy, X-ray diffraction and particle size analysis were used to observe the structure and properties of purified illite. A mud mask was prepared with the purified illite, and the skin sensation and efficacy of the mud mask were investigated. The content of purified illite was increased from 41% to 94% when the grinding concentration （mass ratio of ore to water） was 80%, the inlet flow rate was 15 m³/h, the primary settling time was 24 hours and the secondary settling time was 72 hours. The results of heavy metal detection indicated that the content of heavy metals in the illite obtained was obviously below the limit value, indicative of excellent safety. The SEM and FT-IR results showed that the purified illite had a typical scaly structure and the impurities were effectively removed. The XRD results confirmed that the content of purified illite was 94%. The skin sensation and efficacy results illustrated that, the purified illite had the potential and prospect in preparing mud masks.

Key words: illite, purification process, microstructure, cosmetic application