Seperation and concentration of nickel from ammoniac solutions by liquid membranes

Key Words: Nickel, emulsion type liquid membrane, seperation and concentration of nickel, extraction, stripping, 8-hydroxquinoline( 8-HQx ), demulsification. Nickel ranks 24th among elements with respect to abundancy with an average amount of 75 ppm in earth crust. Nickel is one of the most widely used metals in metal industry due to the superior properties it posseses. It is widely used in the form of metal and its alloys or in the form of stainless steel. Recovery of precious metals found in little concentration in waste solutions is important. Since requirements for nickel and other precious metals are continually increasing and also ores with high concentrations of precious metals are in decrease, recovery of precious metals in low concentrations in solid or liquid waste is becoming significant. Therefore new methods that contribute to the recovery and seperation of precious metals from dilute aqueous solutions have recieved much attention in recent years. Liquid membrane is a significant seperation process which has a potential application for selective recovery of such precious metals. In this study, a selective and enriched seperation capability of nickel from ammoniac solutions by means of an emulsion type liquid membrane process was investigated. Also, the parameters affecting liquid membrane process were examined and optimum conditions were determined. In conclusion, it was shown that nickel from ammoniac solutions can be recovered selectively by liquid membrane process using 8-HQx extractant.