Process for precipitating iron as jarosite with a low non-ferrous metal content

A process for precipitating ferric iron as a jarosite from a sulfate solution containing ferric iron, free sulfuric acid, and valuable non-ferrous metals, said sulfate solution having a free sulfuric acid concentration of 30 to 50 grams per liter and a ferric iron concentration of 15 to 50 grams per liter characterized by diluting the said sulfate solution with a diluent solution of low acidity so that the ferric iron concentration of the diluted sulfate solution lies in the range 5 to 35 grams per liter and the free sulfuric acid concentration of the said sulfate solution is reduced by said act of dilution to 5 to 20 grams per liter without prior cooling, heating the diluted solution to a temperature in the range of 80.degree. C. to the boiling point at atmospheric pressure in the presence of at least one ion chosen from the group consisting of sodium, potassium and ammonium ions, in the presence of recycled jarosite, without the addition of any neutralizing agent so that substantially all of the ferric iron is precipitated as a jarosite, followed by separation of the jarosite from the solution, thereby producing a jarosite contaminated with only minor amounts of nonferrous metals.