Abstract: This method is based in the recirculation of an iron free solution or a solution with low iron content in such a manner that the final acidity conditions obtained are ideal for iron to efficiently precipitate as jarosite. In a variation of the invention the zinc concentrate is subjected to the following stages: a. Roasting of at least part of the zinc concentrate. b. Neutral leaching where zinc oxide is dissolved. c. Acid leaching where zinc ferrites are leached. d. Reduction of the Fe+++ contained in the solution to Fe++ by adding zinc concentrate and diluting it with a zinc sulphate solution resulting from stage (f) to lower the concentration of Fe++. e. Neutralizing the acidity in the solution with calcine. h. Iron oxidation and jarosite precipitation, free of contaminating solids, by means of the injection of oxygen or oxygen-enriched air and the addition of an alkali or a Na+ o NH4+ salt.