The present disclosure provides improved methods for the removal of heavy metals, in particular cadmium, from an aqueous phosphoric acid containing composition, wherein an ionic polymeric flocculating agent is added to a phosphoric acid containing composition subsequent to the addition of an organothiophosphorous heavy metal precipitating agent to said composition, particularly under gentle mixing conditions, such as between 100 and 300 rpm. The flocculating agent promotes the formation of agglomerates of the heavy metal containing precipitate, thus facilitating their removal from the composition. More in particular, the phosphoric acid containing composition is obtained by the acid digestion of phosphate rock, preferably by nitric acid, sulfuric acid, or a combination thereof.