The present paper summarizes the results of phosphoric acid production from Youssoufia Washed Floated phosphate with addition of minerals aiming at increasing the filtration rate and better understand the effects of silica and alumina on filtration rates and phosphogypsum crystal size distribution.
It is shown that the addition of reactive silica for complexation of the F element, which is unfavorable to a good crystallization, is seen to be insufficient in the absence of alumina; the crystals are developed, but in a single direction and become like thin bars. Furthermore, the presence of alumina improves the crystal morphology advantage with regular development along the three axes and achievement of large and uniform crystal shape.