Abstract: A process for the preparation of granular fertilizer grade DAP (a product composed of ammonium phosphates, principally diammonium phosphate, resulting from the ammoniation of phosphoric acid, as defined in Official Publication No. 52 of the Association of American Plant Food Officials, dated 1999) comprising partially preneutralizing orthophosphoric acid with ammonia, completing the ammoniation of the orthophosphoric acid with ammonia in a rotary ammoniator-granulator to provide granular DAP, sizing the granular DAP to provide the granular DAP product, reducing the particle size of the oversized granular DAP, and recycling the undersized granular DAP and the sized-reduced oversized granular DAP to the ammoniator-granulator.

Abstract: The present invention features a filtration plate for use in a filter pan comprising a corrugated sheet having a series of alternately upwardly and downwardly opening channels and a reinforcing material bonded to surfaces of the downwardly opening channels. The reinforcing material is effective for strengthening the sheet and retaining heat in a manner effective to slow cooling of the filtration plate during washing and to reduce heat losses from the filtration plate during filtering. According to a preferred aspect of the invention, the corrugated sheet is a monolithic sheet of structural metal having a smooth upper filtration surface. The invention also provides a filter pan configured for use in filtration of a filtrate from solid particles. The filter pan comprises a filtration plate including a corrugated, monolithic sheet of structural metal having a series of alternately upwardly and downwardly opening channels.

Abstract: Improved solvent systems for the formulation of N-alkyl thiophosphoric triamide urease inhibitors. These formulations enable the preparation of stable concentrated solutions of N-alkyl thiophosphoric triamides for storage, transportation, and eventual impregnation onto solid urea containing fertilizers and incorporation into liquid urea containing fertilizer compositions. These formulations are comprised primarily of a solvent selected from the group consisting of glycols and glycol derivatives. Optionally, in addition to the glycol base solvent, the formulations can contain a co-solvent selected from the group consisting of liquid amides, 2-pyrrolidone and N-alkyl 2-pyrrolidones, and/or a nonionic surfactant selected from the group consisting of alkylaryl polyether alcohols. The presence of the co-solvent and/or surfactant has been found to impart desirable properties to the formulations under certain conditions.