Method of preparing particulate fertilizer coated with urea-wax adduct

• US 3,331,677 A
• Filed: 02/20/1964
• Issued: 07/18/1967
• Est. Priority Date: 02/20/1964
• Status: Expired due to Term

• Current Assignee: Robert H. Campbell, William L. Huntington
• Original Assignee: Robert H. Campbell, William L. Huntington
• Inventors: Campbell, Robert H., Huntington, William L.
• Application Number:
  US04/346,123
• Time in Patent Office: 1,244 Days
• US Class Current: 71/28
• CPC Class Codes: C05C 9/00 Fertilisers containing urea or urea compounds
• CPC Class Codes: C05G 3/30 Anti-agglomerating additives; Anti-solidifying additives
• CPC Class Codes: C05G 5/38 layered or coated with wax or resins

Claims

1. A METHOD OF REDUCING THE CAKING TENDENCY OF SOLID DISCRETE FERTILIZER PARTICLES COMPRISING A DISPERSION OF SOLID UREA IN SOLID PARAFFIN WAX WHICH COMPRISES (1) IMMERSING SAID PARTICLES IN A LIQUID UREA-PARAFFIN WAX ADDUCT ACCELERATOR OTHER THAN WATER, WHEREBY A REACTION BETWEEN UREA AND PARAFFIN WAX AT THE SURFACE OF SAID PARTICLES TO FORM AND UREA-PARAFFIN WAX ADDUCT IS INITIATED, (2) CONTINUING SAID IMMERSING FOR AT LEAST 12 SECONDS AND UNTIL SAID REACTION IS INITIATED OVER SUBSTANTIALLY THE ENTIRE SURFACE OF SAID PARTICLES, (3) REMOVING THE PARTICLES FROM SAID LIQUID ADDUCT ACCELERATOR IN WHICH THEY WERE IMMERSED, (4) REMOVING RESIDUAL ADDUCT ACCELERATOR FROM THE SURFACE OF THE WET PARTICLES THEREBY OBTAINED, AND (5) RECOVERING DISCRETE PARTICLES EACH OF WHICH CONTAINS (A) A CORE WHICH COMPRISES A DISPERSION OF SOLID UREA IN SOLID PARAFFIN WAX AND (B) A THIN CONTINUOUS FILM, OVERLAYING AND ADJACENT TO SAID CORE, OF A UREA PARAFFIN WAX ADDUCT FORMED IN SITU ON THE SURFACE OF SAID CORE, SAID THIN CONTINUOUS FILM SUBSTANTIALLY COMPLETELY COVERING THE SURFACE OF SAID CORE AND (6) REMOVING RESIDUAL ADDUCT ACCELERATOR FROM THE INTERIOR OF SAID RECOVERED PARTICLES UNTIL THE ADDUCT ACCELERATOR CONTENT OF THE RECOVERED PARTICLES IS REDUCED TO LESS THAN 0,005%.