A process for preparing an ammonium glyphosate paste that can be processed downstream and a process for preparing a dry granular herbicidal composition.

摘要

A process is provided for preparing a downstream processable ammonium glyphosate paste, comprising mixing in a suitable vessel (i) particulate glyphosate acid, (ii) ammonia in an amount of about 0.8 to about 1.25 moles per mole of the glyphosate acid, and (iii) water in an amount of about 10% to about 25% by weight of all materials being mixed in the vessel, thereby causing a reaction of the glyphosate acid and ammonia that generates heat causing partial evaporation of the water, and forms an ammonium glyphosate paste having a moisture content of about 5% to about 20% by weight.A process is also provided for preparing a dry granular herbicidal composition, comprising (a) forming an ammonium glyphosate paste as described above and thereafter, if the moisture content of the paste is greater than about 15% by weight, applying heat and/or vacuum to reduce the moisture content to about 5% to about 15% by weight; (b) thereafter adding to the paste, with mixing, one or more surfactants in a weight ratio of total surfactant to ammonium glyphosate of about 1:9 to about 1:3 to form an extrudable wet mix; (c) extruding the wet mix to form extrudate strands that break to form moist coherent granules; and (d) drying the granules to produce the dry granular composition.