This article describes research on the use of foam separation processes for removing metal ions from water. Whether the removal process is a foam fractionation, precipitate flotation, or ion flotation depends primarily on the nature of the metal‐collector product, the sublate. Factors affecting the solubility of the sublate, and therefore the mechanism, include the coordination behavior of the metal toward the collector surfactant, the nature of the collector, and the pH of the solution. Other variables that may significantly affect the removal process include the rate of gas flow, the concentrations of metal and collector, and the ionic strength of the solution.