(1. 中南大學(xué) 礦物工程系，長(zhǎng)沙 410083;
2.上海應(yīng)用技術(shù)學(xué)院 材料系，上海 200233)
摘 要: 為解決德興銅礦生物浸出-溶劑萃取-電積銅生產(chǎn)的萃取界面乳化問題，研究了界面乳化物的穩(wěn)定性。實(shí)驗(yàn)結(jié)果表明：界面乳化物陳化時(shí)產(chǎn)生極限聚結(jié)現(xiàn)象，液滴平均粒徑增加到極限值13～14μm時(shí)不再變化，聚結(jié)過程停止而使乳化物長(zhǎng)期穩(wěn)定性很高；雙電層作用使液滴界面區(qū)介質(zhì)的介電常數(shù)遠(yuǎn)低于體相溶液的介電常數(shù)，促使硫酸鹽沉淀自乳化物連續(xù)相中析出，并不斷在液滴表面沉積使界面膜逐漸變厚，同時(shí)界面效應(yīng)也使連續(xù)相中Fe(OH)3和SiO2膠體結(jié)構(gòu)不斷聚合，使乳化物膠凝化，液滴的聚結(jié)變得越來越難，最終出現(xiàn)極限聚結(jié)現(xiàn)象。計(jì)算結(jié)果表明，一些硫酸鹽的界面溶解度比體相中的溶解度低近10倍。
關(guān)鍵字: 生物浸出；銅溶劑萃取；界面乳化物；穩(wěn)定性；極限聚結(jié)；沉淀機(jī)制
of interfacial emulsion in copper
solvent extraction
（1.Department of Mineral Engineering，Central South University，
Changsha 410083，China；
2.Department of Material Engineering, Shanghai Institute of Technology,
Shanghai 200233, China）
Abstract:The serious interface emulsion created in the copper solvent extraction operation of Dexing Copper Mine influences adversely the whole bioleaching-solvent extraction-electrowinning process. To solve this problem the stability of interfacial emulsion was researched. It is discovered that limited coalescence of emulsion droplets takes place during the emulsion storage, which results in the stabilization of average diameter of droplets at 13～14μm. Droplets can not coalesce and the emulsion can keep along-term. Sulfate precipitation is promoted in interfacial region where the medium dielectric constant is relatively lower due to the effect of electrical double layer. The sedimentation of precipitates on droplet interface makes the interfacial skins become more and more thick and the coalescence become more and more difficult. Interfacial effects make the colloids of Fe(OH)3 and SiO2 in aqueous phase polymerize continuously, so that the emulsion gelates gradually. As a result limited coalescence of droplets takes place. Calculated interfacial solubility of some sulfates is lower by about 10 times than that in continuous body phase.
Key words: bioleaching; copper solvent extraction; interfacial emulsion; stability; limited coalescence; precipitation mechanism
