Hao Zhang,Haiqiang Yang,Zhengjun Chen,Fang Yuan,Qiang Yang,Bo Liu
The presence of dissolved salts in water inhibits bubble coalescence, facilitating the generation of microbubbles, while also maintaining a tangentially mobile air-water surface. In this study, we investigated the variation of bubble size and gas holdup with gas velocity in NaCl solutions using a rectangular bubble column and interpreted the experimental data using the one-dimensional drift-flux model. For the generated bubbles at the size between 0.4 mm and 1 mm, we found that the Moore model assumes mobile air-water surfaces, rather than the Schiller and Naumann model, should be used to describe the bubble terminal velocity. The latter model, which assumes an immobile air-water surface, has been used successfully to predict two-phase flow in surfactant solutions but would overestimate the gas holdup by almost 100 % for NaCl solutions. This finding emphasizes the crucial role of surface mobility in determining gas holdup. Thus, we propose the use of a one-dimensional drift-flux model, incorporating the Moore model to describe bubble terminal velocity, for microbubble systems with a mobile air-water interface.
Zhanqin Wang,Yongzhong Jia,Bing Liu,Yan Jing,Ying Yao
Flotation complexation extraction can effectively extract and separate lithium isotopes. The effects of nitrogen flow rate, bubble size, gas holdup, reaction flow pattern, aeration time, and temperature on the separation process were studied. In addition, the complex relationship and separation mechanism of lithium with 10-hydroxybenzoquinoline were discussed. Results show that nitrogen flow rate and bubble size significantly affected the flotation complexation extraction process. With an appropriate flow rate, we obtained a homogeneous regime pattern containing small and evenly distributed bubbles to achieve better separation efficiency and ensure a smooth extraction process. According to the slope method, lithium and 10-hydroxybenzoquinoline were complexed and extracted at a ratio of 1: 2. Compared with the traditional oscillating extraction, the bubble mass transfer mode in the flotation complexation extraction strengthened the complex extraction process and achieved higher extraction rate and separation efficiency.
危险品化学品经营许可证（带存储）