Using isothermal titration method and isothermal method of sections, phase equilibria in the ammonium sulfate–oxyethylated nonylphenol (neonol AF 9-10)–water at 25°C system were studied. Optimal extraction parameters (ratio neonol AF 9–10 : ammonium sulfate = 1 : 3, mass fraction of water 75.0 wt.%) were determined and the patterns of distribution of iron(III), copper(II), aluminum and indium ions in the system ammonium sulfate–oxyethylated nonylphenol (neonol AF 9-10)–water in the presence of acetylacetone and 1,2,3-benzotriazole were established . Conditions for the quantitative extraction of aluminum and copper(II) from ammonia media have been found. The conditions for the separation of copper(II) and iron(III) from zinc, cobalt(II) and indium in a neutral environment, as well as copper(II) from zinc and cobalt(II) at a content of 0.05–0.06 mol/l ammonia in the presence of acetylacetone were determined ; nickel from cobalt(II) and iron(III) at a content of 0.1–0.5 mol/l sulfuric acid in the presence of 1,2,3-benzotriazole.