(中南大學 資源加工與生物工程學院，長沙 410083)
摘 要: 利用一套自行設(shè)計的，運用水力空化原理產(chǎn)生微納米氣泡的發(fā)生裝置，通過激光粒度儀，納米粒徑電位分析儀以及表面張力儀等手段研究水力空化過程產(chǎn)生的微納米氣泡性質(zhì)，并考察了在浮選藥劑溶液中預先引入微納米氣泡對細粒一水硬鋁石礦物浮選行為的影響。結(jié)果表明：水力空化預處理油酸鈉溶液能夠產(chǎn)生微納米級氣泡；隨油酸鈉濃度、溶液pH值和空化強度的增大，溶液中微納米氣泡的平均尺寸分布不斷減小；空化時間較短時，油酸鈉溶液中能夠形成較多的亞微米及納米級氣泡，隨空化時間延長，溶液體系微納米氣泡的平均尺寸分布增大。外加充氣為空化體系提供了大量氣核，促使空化過程產(chǎn)生大量微納米氣泡，氣泡兼并現(xiàn)象顯著導致測定的微納米氣泡尺寸分布逐漸增大；微納米氣泡具有較好的穩(wěn)定性，尤其是亞微米及納米級氣泡，其能在溶液體系穩(wěn)定存在1 h以上；預先在浮選藥劑溶液中引入微納米氣泡能夠顯著強化細粒一水硬鋁石礦物浮選，尤其是在低藥劑濃度條件下。
關(guān)鍵字: 微納米氣泡；水力空化；尺寸分布；浮選
（School of Minerals Processing and Bioengineering, Central South University, Changsha 410083, China）
Abstract:By using a homemade micro-nano bubbles generator based on hydrodynamic cavitation principle, the properties of micro-nano bubbles generated and their effects on the flotation behaviors of fine diaspore minerals were studied through laser particle size analyzer, Zetasizer and surface tension meter, etc. The results show that hydrodynamic cavitation pretreatment of sodium oleate solution(NaOl) can produce micro-nano bubbles in the bulk solution. With the increase of NaOl concentration, the pH values of solution and cavitation intensity, the average size distribution of micro-nano bubbles in the solution continuously decreases. When the cavitation time is short, submicron and nanoscale bubbles can be formed in NaOl solution, while as cavitation time raises, the average size distribution of bubbles in the solution system increases. The additional aeration provides a large number of gas nuclei for the cavitation system, which promotes the generation of a large number of micro-nano bubbles in the cavitation process, and the bubble merger results in a significant increase in the size distribution of the micro-nano bubbles. Micro-nano bubbles have good stability, especially submicron and nanoscale bubbles, which can stably exist in the solution system for more than one hour. Lastly, the introduction of micro-nano bubbles in the flotation agent solution before flotation can significantly enhance the fine diaspore flotation, especially at low agent concentration.
Key words: micro-nano bubble; hydrodynamic cavitation; size distribution; flotation
