Granular phosphorus fertilisers prepn. from aluminium phosphate - superficially attacked by a base and combined with a swellable water-absorbing clay and mineral charge

Phosphorus granular fertiliser contains (a) calcined and ground natural aluminium phosphate, which has been subjected to superficial attack by a strong base, as the essential constituent; (b) swellable clay having a strong water-absorption ability, and (c) a finely divided mineral charge and has a water content such that when heated for 4 hrs at 100 deg.C, the wt. loss is less than 2%, pref. less than 1%. Granular phosphorus fertiliser which has a high P205 content, disintegrates into granules readily, even after prolonged storage, does not take-up moisture on storage and has good resistance to abrasion. The fertiliser may be produced economically in good yields. GRANULE D'ENGRAIS DE PHOSPHATE D'ALUMINE NATUREL.IL CONTIENT UN PHOSPHATE D'ALUMINE NATUREL CALCINE ET BROYE QUI A SUBI UNE ATTAQUE SUPERFICIELLE AU MOYEN D'UNE BASE FORTE, UNE CHARGE MINERALE FINEMENT DIVISEE ET UNE ARGILE GONFLANTE NON TRAITEE A FORT POUVOIR D'ABSORPTION D'EAU. LE GRANULE NE CONTIENT PAS PLUS DE 2 EN POIDS D'EAU DE PREFERENCE PAS PLUS DE 1.OBTENTION D'UN GRANULE D'ENGRAIS 0-30-0 A PARTIR DE PHOSPHATE ALUMINO-CALCIQUE DU GISEMENT DE THIES.