Nitrogen fertilizer compositions based on polyphosphate caged structure
AssigneeAgtec Innovations, Inc.
InventorChandrika Varadachari
Life of this patent
Estimating the term…
Abstract
Urea based nitrogenous fertilizers are described which have reduced water solubility. The fertilizers are intended to provide environmental benefits and economic advantages over urea. The fertilizers are a product of reaction of urea with polyphosphates whereby the urea is trapped within the polyphosphate crystal cage. The fertilizers contain nitrogen, phosphorus and one or more of calcium, magnesium and iron. The fertilizers optionally contain other nitrogen compounds and optionally other micronutrients. The fertilizers are granular.
Claims20
A urea-polyphosphate composition comprising urea, a polyphosphate, inorganic cations, and a water-insoluble fraction, the water-insoluble fraction having
- (a) a urea content of at least 5 wt %,
- (b) a phosphorus content in the range of 1 wt % to 20 wt. %,
- (c) primary inorganic cations in the range of 1 wt % to 20 wt % wherein the primary inorganic cations are selected from the group consisting of ammonium, calcium, iron, magnesium, and potassium cations and combinations thereof,
- (d) a molar ratio of nitrogen to the combined total of the primary inorganic cations in the range of 2:1 to 40:1,
- (e) a number average chain length of polyphosphate groups of 1.1 to 20 when orthophosphates are included in the number average chain length calculation,
- (f) a molar ratio of nitrogen to phosphorous in the range of 3:1 to 60:1, and
- (g) a solubility in citric acid such that (i) at least 70 wt. % of each of the total nitrogen and total phosphorous in the water-insoluble fraction is soluble in 2 wt. % citric acid, and (ii) at least 50 wt. % of each of the total nitrogen and the total phosphorous in the water-insoluble fraction is soluble in 0.2 wt. % citric acid.
Dependencies are inferred from the claim text.