Integrated methods for increasing p-solubility of phosphate rock

Abstract EN

Laboratory experiments were carried out to study the effect of some integrated factors on solubility of phosphate rock (PR) obtained from two locations which were Abou Tartour and El-Sibaia Gharb as well as tricalcium phosphate.

PRs were crushed to pass through a ١.١٨-mm sieve and separated into ٧ particle diameters of ٥٠٠, ٢٥٠, ٢١٢, ١٢٥,٧٥ and ٤٥ μm.

Scanning Electron Microscope “SEM” and X-ray diffraction were done.

P-solubility was assessed using water and ٥ acids of formic (FR), Acetic (AC), tartaric (TR) oxalic (OX) and citric (CT) (each of ٢%).

P in Abou Tartour samples was mainly as calcium phosphate hydroxide “Ca٥(PO٤)٦ OH.

Other crystalline were silicon oxide SiO٢, calcium carbonate CaCO٣ and calcium di-hydrogen phosphate hydrate Ca H٢PO٤.

P in El-Sibaia samples was mainly in form of Brushite.

P contents (g kg-١) were ٠.٢ to ٠.٦ water-soluble, and ١٠ – ١٧ for Olsen extract.

Ranges for the acid-extractants from the two PRs were ٣٩-٤٤ for CT, ٢٥-٤١ for AC, ٢٧-٤٩ for TR, ١٤-٢٨ for OX and ٣٢-٥٢ for FA.

A tendency to increase with decreased particle size occurred.

Practical aspects could be inferred regarding the use of PR for fertilization.