Effect of diluent on interfacial emulsion in copper solvent extraction

The organic phase extracted from interfacial crud of copper solvent extraction at Dexing Copper Mine was analyzed for its different components by combined gas chromatography mass spectroscopy. It was found that the main impurities in organic phase were methylnaphthalenes and di methylnaphthalenes which originated from commercial 260# kerosene used as diluent. It was found that the impurities containing diluent was unfavorable to phase disengagement. Methods were suggested to improve diluent properties to prevent stable interfacial emulsion.

Effect of Lix984N content on phase disengagement dynamics in copper-SX

Lix984N is intimately related to the dynamic characteristics of phase disengagement in copper solvent extraction because of its interfacial activity. With increasing Lix984N content, the phase disengagement time is prolonged and the mechanism dominating phase disengagement process transfers from sedimentation to coalescence. The rate of droplet coalescence is faster than that of droplet sedimentation in the dense dispersion band when the volume fraction of Lix984N is less than 3.0%. The former almost equaled to the latter at Lix984N content of 3.0% and finally becomes lower than the latter when the volume fraction of Lix984N is more than 3.0%. The relationship between the adhesion force of two equal droplets and physical properties of fluids is deduced, which explains that the change of physical properties of organic phase with Lix984N content can make droplet coalescence more difficult and phase disengagement slower.

稀释剂对铜萃取剂动力学及相分离性能的影响

将自选的石油馏份用作稀释剂与目前国际上常用的铜萃取剂Ｍ５６４０及Ｌｉｘ９８４配成萃铜有机相，考察不同种类的自选稀释剂对铜萃取剂的萃取及反萃动力学、萃取及反萃相分离性能的影响。测定了各体系萃取及反萃平衡分数与反应时间的关系，并用作图法求出了萃取及反萃的分相时间。实验结果表明，自选稀释剂中ＤＳＲ３与Ｍ５６４０及Ｌｉｘ９８４配制的萃铜有机相的动力学及相分离性能均很好。

Lix984N对萃取分相和界面乳化的影响

研究了铜萃取过程中Lix984N对萃取分相性能和界面乳化行为的影响。当Lix984N体积分数从 0 .5 %增加到 5 .0 %,由于有机相密度和粘度增加、表面张力降低 ,使相分离速度降低。用基团法算出Lix984N的亲水亲油平衡值 (HLB)为 1.2 9,根据Bancroft法则 ,Lix984N有利于W O型乳化液的稳定。试验结果表明 ,Lix984N在萃取界面乳化过程中不起主导作用 ,固体微粒是界面乳化的决定性诱因 ;随Lix984N体积分数增加 ,有机相与固体微粒间的亲合力加大 ,Lix984N与固体微粒有协同乳化作用。

有机相循环对萃铜性能和萃余液夹带的影响

研究了有机相循环对铜萃取性能和萃余液夹带行为的影响。结果表明,当有机相循环次数从1次增加到10次,萃取分相速率从0.45 mm/s近乎线性地升高到0.61 mm/s,铜萃取率从99.8%线性微降至99.2%。前3次循环中,萃余液表面张力从52.9mN/m降低至41.3 mN/m,萃余液中有机相夹带比例由60%升高到80%,溶解比例相应由40%降低到20%,之后的循环中萃余液表面张力从41.3 mN/m升高到67.9 mN/m,夹带比例降低,溶解比例升高,最终比例接近1∶1。萃余液有机相含量在第3次循环时达到最高,COD值为604 mg/L。萃余液夹带是有机相流失规律的主导因素,对其控制是减少有机相流失的关键。