Performance Evaluation of Nickel Separation and Extraction Process from Simulated Spent Cr/Ni Electroplating Bath Solutions by ELM Process Using LIX63 and PC88A

Abstract

The study was conducted to investigate synergistic extraction of nickel from simulated spent Cr-Ni electroplating bath solutions by emulsion liquid membrane (ELM) process using 5,8-diethyl-7-hydroxydodecan-6-one oxime (LIX 63) and 2-ethylhexylphosphonic acid mono-2-ethylhexyl ester (PC88A) as carriers. The importance of ELM composition and the properties of simulated spent electroplating bath solution have been optimized to synergistically extract nickel. The important parameters affecting the nickel extraction efficiency and ELM stability, such as acid concentration, stripping solution type and concentration, extractant concentration, surfactant concentration, and phase ratio, were experimentally studied. Along with obtained 1309 Downloaded by [New York University] at 18:44 15 May 2015 results, higher than 99% of nickel was selectively extracted within 30 minutes from simulated electroplating bath solutions that their metal concentrations was in the range of 100-500 mg/L. in the optimum conditions. The higher separation factor value of nickel over chromium (b Ni/Cr ) was obtained as 898. As a result, the nickel extraction kinetic was found to depend on PC88A, since extraction mechanism of PC88A is slower than that of LIX63. So, the combined use of LIX63 and PC88A improved the selective extraction of nickel in that process.

The extraction of nickel by emulsion liquid membranes using Cyanex 301 as extractant

“…In addition, the sign of the t‐values (Table ) reveal that H 2 SO 4 concentration and NiSO 4 solution/emulsion volume ratio play negative roles, while the extractant concentration plays a positive role in the response; the NiSO 4 solution pH plays a slightly positive role in the response. This is in agreement with others' work . The reasons are as follows: For the NiSO 4 solution pH, the change in the value was not extremely important to the system, since a drastic pH decrease can be seen during the first several minutes of the extraction process; generally, it changes from an initial pH of 2–6 to an equilibrium pH of 1.7–2.0, and Cyanex 301 is a good extractant in this pH range.…”

“…Nickel is a silvery‐white metal that is very important in modern industries, for example, nickel and its alloys are used to produce coins, batteries, and stainless steel due to its high corrosion resistance properties . Despite its extensive usage, nickel can be toxic and hazardous; excessive exposure to nickel may cause nausea, skin allergies, and lung fibrosis in humans; and the wastewater containing nickel ions discharged from the mining and metal plating industries may also pollute waterbodies and soil, thus damaging the local flora and fauna …”