Patent ID: 7691171
Filing Date: 2010-04-06
Classification: C05B,C05D

Abstract:
1. A process for the preparation of water insoluble, bio-release iron-manganese polyphosphate fertilizer, the process consisting of a) heating phosphoric acid at a temperature of at least 160° C. with a mixture consisting essentially of (i) a source of iron oxide including one or more substance selected from the group consisting of goethite and hematite, (ii) pyrolusite and (iii) one or more basic compound selected from the group consisting of magnesium oxide(s), magnesium carbonate, calcium oxide, sodium oxide, potassium oxide, calcium carbonate, sodium carbonate, and potassium carbonate for a time period ranging from 20 minutes to 2 hours to produce a liquid polyphosphate; b) neutralizing the liquid polyphosphate at a pH of 5 to 7.5, wherein the neutralized liquid polyphosphate is characterized by solubility in 0.33M citric acid and 0.005M DTPA; c) drying the neutralized liquid polyphosphate to obtain a solid; and d) pulverizing the solid.