Papers by Author: Wei Yang

Abstract: Based on the characters of expanding and layer adsorbing of vermiculite，industrial vermiculite samples from Weili Mine of Xinjiang Province were expanded by both chemical and microwave chemical methods. The influences to the exfoliation ratio of different parameters such as concentration of hydrogen peroxide, power of the microwave, heating time, ratio of solid-liquid, immersion time were discussed. And the expanded mechanism of vermiculite was also analyzed. The results indicate that the expanded times increase with the increasing of concentration of hydrogen peroxide, and the best expanding point appears when the concentration of hydrogen peroxide is 30%. The solid-liquid ratio of vermiculite and hydrogen peroxide has little effect on the expanding of vermiculite. The vermiculite samples could be expanded 8.5 times by heated 2 min under 800W microwave power after immersion for 12 h when the concentration of hydrogen peroxide is 30%. As a result, the vermiculite could be expanded because of the oxygen pressure produced by the decomposition of hydrogen peroxide into the vermiculite interlayer. When using the microwave chemical method, the pressure of both oxygen and interlayer water lead to the increases of the expanded times. And exfoliation vermiculite plays an important part in energy-saving and environmental treatment.

Abstract: Based on good cation exchange property of vermiculite，the adsorption of vermiculite for simulated radionuclide Sr was studied by the static adsorption method. The adsorption behaviors and the effect of the experimental conditions were investigated. The results show that the saturated adsorption capacity of vermiculite sample for the simulated radionuclide Sr was 8.246×10-2 mmol/g. The suitable pH value ranged from 4 to 11, the balanceable adsorption time was 3d, and the suitable temperature was 30°C. The main adsorption type was cation exchange. The adsorption mechanism can be described by Langmuir and Freundlich models. It acts better in accord with Langmuir model, and the correlation coefficient is 0.99974. This experimental study has important significance on low concentration of Sr radioactive waste liquid treatment.