Abstract A study is reported of the separation of iron(III) and aluminium by solvent extraction from chloride and sulphate leach liquors produced by the acid leaching of aluminosilicate ores as an alternative to the Bayer process for pure alumina manufacture. The use of tributyl phosphate, amines and aliphatic monocarboxylic acids was investigated on both synthetic solutions and actual leach liquors. The effect of pH, chloride, iron and aluminium concentrations and temperature on the separation is reported. Extraction and stripping isotherms were used as a basis for laboratory scale testing of continuous extraction schemes using either mixer-settlers (for the carboxylic acid) or rotating disc contactors (for the other extractants). Iron concentrations in the leach liquors from about 5–10 g l −1 to less than 0.1 g l −1 could be achieved. Some solvent loss figures are given.