Continuous Liquid-Liquid Extraction of Nickel from Simulated Electroless Nickel Plating Liquid Wastes by Using a Counter Current Emulsion Flow Extractor

Abstract

Simulated electroless nickel plating liquid wastes have been processed by using an emulsion flow extractor of a counter current type with a special focus on the influence of dilution of the liquid wastes on the extraction performance. The emulsion flow extractor provides efficient liquid-liquid extraction without the need for additional stirring or shaking. The solvent used in the present study was a Shellsol D70 solution containing LIX84-I as the extractant for nickel and PC88A as an accelerating agent. As a result, it was found that increasing the degree of dilution with water resulted in an improvement in nickel extractability obtained from the emulsion flow experiments with a maximum value of 96% as well as those obtained from batch experiments. Droplet sizes at the lower and the upper parts of the emulsion phases, estimated by using high-speed microscope, were 214 ± 36 µm and 415 ± 110 µm, respectively.

2-Mercaptobenzimidazole, 2-Mercaptobenzothiazole, and Thioglycolic Acid in an Electroless Nickel-Plating Bath

“…Penetration of the nickel layer is perfect on several substrates [18]. Microscopic particles on the substrate were cleaned using a bath solution, creating a metallic bond between the nickel layer and the substrate surface.…”

“…The recovery of nickel is an important aspect of nickelplating processes, and there are many studies regarding this. Nickel recovery using a Counter Current Emulsion Flow Extractor is an interesting example in this regard [18].…”

Axial Mixing in Emulsion-flow Column under Iodine Extraction

“…A novel operation mode of extraction, "emulsion-flow" allows for both stable counter-current operation and a high extraction ratio [1][2][3][4][5]. The method is characterized by supplying aqueous and organic phases in the form of droplets with uniformly controlled sizes.…”

Size Distribution of Droplets in a Two Liquid-phase Mixture Compared between Liquid Spraying and Mechanical Stirring

“…Recently, a new liquid-liquid extraction method, called the "emulsion flow" method, was developed at Japan Atomic Energy Agency (JAEA). [1][2][3][4][5][6][7][8][9][10] The emulsion flow method, due to the lowest cost, the easiest handling, the highest level in efficiency, compactness and safety, compared with conventional methods, mixer-settler, pulse column, spray column, centrifugal extractor, etc., and eco-friendliness, has attracted attention in industries, and has been expected to bring innovation to liquidliquid extraction technologies. 11 An apparatus based on the emulsion flow method can realize ideal liquid-liquid extraction with its high ability for two-liquidphase mixing to reach an emulsion by spraying micrometersized droplets of an organic phase into the counter-current flow of an aqueous phase by only feeding solutions.…”