Abstract: Crude wet process phosphoric acid is pretreated, to ensure against impurity precipitation and objectionable coloration during the downstream processing, e.g., liquid-liquid extraction thereof, by first homogeneously admixing same with an impurity adsorbent, next mixing the liquid dispersion which results with a liquid suspension of a flocculating agent, maintaining the resulting admixture under nonshearing agitation until same separates into a flocculated phase and a liquid solution phase, and then separating therefrom the flocculated phase and a purified, product acid liquid solution phase.