(1. 中國科學院 過程工程研究所 綠色過程與工程院重點實驗室，北京 100190；
2. 中國科學院 研究生院，北京 100049)
摘 要: 研究了初始pH值、萃取劑濃度、萃取劑類型、稀釋劑類型、平衡時間和料液預(yù)處理方式等因素對界面乳化物形成行為的影響，采用掃描電鏡、X射線能譜儀及X射線衍射等手段分析了界面乳化物中固體微粒的組成。結(jié)果表明：能夠最大程度避免界面乳化物生成的工藝條件為初始pH值4~6，以萃取劑為LK-N21且萃取劑濃度15%(體積分數(shù))，稀釋劑為正己烷，萃取時間5 min；采用0.22 μm的濾膜對料液過濾兩次再萃取，不出現(xiàn)界面乳化物；界面乳化物的形成機制可能為在震蕩混合萃取過程中，料液中的二氧化硅膠體等不溶性物質(zhì)，在乳化液滴表面形成致密的固體膜，穩(wěn)定了乳化液；可溶性無機鹽在乳化液界面結(jié)晶出來，進一步穩(wěn)定了乳化液，形成比較穩(wěn)定的界面乳化物。
關(guān)鍵字: 釩；鉻；萃取；界面乳化物
vanadium and chromium
（1. Key Laboratory of Green Process and Engineering, Institute of Process Engineering,
Chinese Academy of Sciences, Beijing 100190, China;
2. Graduate University of Chinese Academy of Sciences, Beijing 100049, China）
Abstract: The effects of initial pH, extractant concentration, extractant, diluent and equilibrium time on the formation behavior of the interfacial crud produced in extraction separation of V and Cr by primary amine was investigated. Both scanning electron microscopy with X-ray energy spectrum and X-ray diffractometry were used to characterize the solids in crud and elucidate the formation mechanism of crud. The initial pH value of 4−6, 15% (volume fraction) LK-N21, n-hexane as diluent and extraction time of 5 min are optimal conditions, which can eliminate the crud as much as possible. Moreover, no crud appears after filtering feed solution twice by 0.22 μm fiber membrane. The insoluble particles in feed solution, such as SiO2, form a surface film by providing sterichindrance to drop-drop coalescence and stabilize the interfacial emulsion, which attribute to the crystallization of sodium sulfate. The crystal from insoluble particles increases the stabilization of emulsion again, and then the interfacial crud forms.
Key words: V; Cr; extraction; interfacial crud
