Fertilizer granulation method
AssigneeAirborne Industrial Minerals Inc.
InventorRobin Phinney
Life of this patent
Estimating the term…
Abstract
Fertilizer granulation method for incorporating urea directly into the matrix of fertilizer pellets. The process involves introducing the urea in a liquid form into the matrix and then progressively cooling the mixture of pellet and urea to recrystallize the urea within the matrix of the pellet. The result is a substantially harder particle relative to pretreatment hardness, reduced solubility for longer lasting pellets and substantially reduced dust and other handling problems of the formed pellets.
Claims7
A method of forming a composite fertilizer, comprising the steps of:
- providing a compound containing urea;
- providing a source of pre-formed ammonium sulfate granules having interstitial space and in a size distribution of 3 mesh to about 10 mesh, said granules devoid of any compound containing urea;
- introducing said compound containing urea and said granules of ammonium sulfate into a mixing drum;
- maintaining said granules of ammonium sulfate in a solid state in the form of discrete granules to provide individual solid ammonium sulfate matrices into which said compound containing urea may flow;
- maintaining said compound containing urea in a liquid state;
- impregnating liquid urea into said interstitial space of said granules of ammonium sulfate;
- cooling granules having urea impregnated therein with a cooling gas without accretion of said urea about said granules;
- crystallizing said compound containing urea within said interstitial space in said mixing drum;
- and
- forming a composite fertilizer having discrete ammonium sulfate granules containing urea within said interstitial space of each of said granules of ammonium sulfate while retaining a size distribution of 3 mesh to about 10 mesh for said granules.
A method of forming a composite fertilizer, comprising the steps of:
- providing a compound containing urea;
- providing a source of fertilizer granules having interstitial space in a size distribution of 3 mesh to about 10 mesh, said granules devoid of any compound containing urea;
- introducing said compound containing urea and said fertilizer granules into a mixing drum;
- maintaining said granules in a solid state in the form of discrete granules to provide individual solid matrices into which said compound containing urea may flow;
- maintaining said compound containing urea in a liquid state;
- impregnating liquid urea into said interstitial space of said granules;
- cooling granules having urea impregnated therein with a cooling gas without accretion of said urea about said granules;
- crystallizing said compound containing urea in said interstitial space in said mixing drum;
- and
- forming granules containing urea within said interstitial space of each of said fertilizer granules while retaining a size distribution of 3 mesh to about 10 mesh for said granules.
Dependencies are inferred from the claim text.