A process for precipitating iron as a jarosite from a sulphate solution containing ferric iron, free acid and valuable non-ferrous metals, characterized by cooling the solution; partially neutralizing the free acidity, and then clarifying the solution; heating the clarified solution to a temperature not exceeding the boiling point at atmospheric pressure, in the presence of at least one ion selected from the group consisting of sodium, potassium and ammonium ions, and in the presence of recycled jarosite, and without the addition of any further neutralizing agent, so that substantially all of the ferric iron is precipitated as a jarosite; and separating precipitated jarosite from the solution; thereby producing a jarosite contaminated with only minor amounts of non-ferrous metals, and a solution which may be further processed by established procedures for the recovery of dissolved valuable non-ferrous metals therefrom. The invention also contemplates a dilution step, and recycle of jarosite.