Method of extracting metal ions

Abstract

Provided is a method of extracting metal ions in which a water phase including metal ions and an oil phase including an acidic extractant are combined to be mixed while flowing, subsequently the mixture is phase-separated into a water phase and an oil phase to extract the metal ions to the oil phase, and a content of the acidic extractant in the oil phase that is caused to flow is 35% to 100% by volume, the method including: a step of reducing a flow diameter of each of the water phase and the oil phase that are flowing, combining the water phase and the oil phase, and continuously causing a two-liquid combined solution to flow; a step of combining the water phase, the oil phase, and a pH adjusting agent aqueous solution and additionally causing a three-liquid combined solution to flow; and a step of phase-separating the three-liquid combined solution after extraction of metal ions to be extracted reaches an extraction equilibrium.

Dependencies are inferred from the claim text.