Compacted muriate of potash fertilizers containing micronutrients and methods of making same

Abstract

A granular cohered MOP fertilizer having one or more micronutrients, and one or more binding ingredients. The fertilizer is prepared by compacting MOP feed material with one or more micronutrients and one or more optional binders to form a cohered MOP composition. The cohered MOP composition is then further processed, such as by crushing and sizing, to form a cohered granular MOP product containing micronutrients. The process yields a fertilizer product containing micronutrients with superior elemental and granule size distribution without comprising handling or storage qualities.

What is claimed is: 
     
         1 . A cohered MOP product containing one or more micronutrients, the MOP product being formed from a compacted MOP composition, the composition comprising:
 potassium chloride in an amount from about 99.999 weight percent to about 0.001 weight percent;   at least one micronutrient component in an amount from about 0.001 weight percent to about 99.999 weight percent, wherein each of the at least one micronutrient component is available as a metal ion in a compound.   
     
     
         2 . The MOP product of  claim 1 , wherein the MOP product comprises a plurality of cohered MOP granules formed from crushing and size classifying the compacted MOP composition. 
     
     
         3 . The MOP product of  claim 2 , wherein the at least one micronutrient component is uniformly distributed throughout each of the cohered MOP granules, thereby being adapted to provide a uniform application of micronutrients to a growing area to facilitate greater access of micronutrients to a root zone of a plant in the growing area compared to uncompacted dry blends. 
     
     
         4 . The MOP product of  claim 2 , wherein the plurality of cohered MOP granules has a substantially uniform size distribution to reduce or eliminate segregation during material handling and transfer otherwise due to size migration of granules. 
     
     
         5 . The MOP product of  claim 1 , wherein a source of the potassium chloride comprises MOP having a chemical profile of either 0-0-60 weight percent K 2 O or a 0-0-62 weight percent K 2 O based on a N—P 2 O 5 —K 2 O convention. 
     
     
         6 . The MOP product of  claim 5 , wherein the source of the potassium chloride comprises MOP having a chemical profile of 0-0-60 weight percent K 2 O based on the N—P 2 O 5 —K 2 O convention. 
     
     
         7 . The MOP product of  claim 5 , wherein the source of the potassium chloride comprises MOP having a chemical profile of 0-0-62 weight percent K 2 O based on the N—P 2 O 5 —K 2 O convention. 
     
     
         8 . The MOP product of  claim 1 , wherein the at least one micronutrient is selected from the group consisting of boron (B), zinc (Zn), manganese (Mn), molybdenum (Mo), nickel (Ni), iron (Fe) copper (Cu), sulfur (S) in its elemental form, sulfur in its oxidized sulfate form (SO 4 ), and combinations thereof. 
     
     
         9 . The MOP product of  claim 1 , wherein the one or more micronutrients are present in the composition in a range from about 0.001 to about 10 weight percent. 
     
     
         10 . The MOP product of  claim 1 , the composition further comprising a binding agent. 
     
     
         11 . The MOP product of  claim 10 , wherein the binding agent is selected from the group consisting of sodium hexametaphosphate (SHMP), tetra-sodium pyrophosphate (TSPP), tetra-potassium pyrophosphate (TKPP), sodium tri-polyphosphate (STPP); di-ammonium phosphate (DAP), mono-ammonium phosphate (MAP), granular mono-ammonium phosphate (GMAP), potassium silicate, sodium silicate, starch, dextran, lignosulfonate, bentonite, montmorillonite, kaolin, or combinations thereof. 
     
     
         12 . A method of producing a cohered MOP product containing micronutrients comprising:
 providing an MOP composition including potassium chloride in an amount from about 99.999 weight percent to about 0.001 weight percent, and at least one micronutrient component in an amount from about 0.001 weight percent to about 99.999 weight percent, wherein each of the at least one micronutrient component is available as a metal ion in a compound;   compacting the MOP composition to form a compacted MOP composition;   crushing the MOP composition into granules to produce the cohered MOP product.   
     
     
         13 . The method of  claim 12 , further comprising:
 classifying the granules of cohered MOP product by size.   
     
     
         14 . The method of  claim 13 , wherein a size distribution of the granules is substantially uniform, and wherein granules that are non-conforming are resized until conformance. 
     
     
         15 . The method of  claim 12 , wherein the at least one micronutrient is selected from the group consisting of boron (B), zinc (Zn), manganese (Mn), molybdenum (Mo), nickel (Ni), copper (Cu), sulfur (S) in its elemental form, sulfur in its oxidized sulfate form (SO 4 ), and combinations thereof. 
     
     
         16 . The method of  claim 12 , wherein providing an MOP composition includes providing a plurality of micronutrients to the potassium chloride, each of the micronutrients being added separately and blended before compaction. 
     
     
         17 . The method of  claim 12 , wherein providing an MOP composition includes providing a plurality of micronutrients to the potassium chloride, the micronutrients being blended in bulk before addition into the potassium chloride. 
     
     
         18 . The method of  claim 12 , further comprising adding a binding agent to the MOP composition before compaction. 
     
     
         19 . The method of  claim 18 , wherein the binding agent is selected from the group consisting of sodium hexametaphosphate (SHMP), tetra-sodium pyrophosphate (TSPP), tetra-potassium pyrophosphate (TKPP), sodium tri-polyphosphate (STPP); di-ammonium phosphate (DAP), mono-ammonium phosphate (MAP), granular mono-ammonium phosphate (GMAP), potassium silicate, sodium silicate, starch, dextran, lignosulfonate, bentonite, montmorillonite, kaolin, or combinations thereof. 
     
     
         20 . The method of  claim 12 , wherein the one or more micronutrients are present in the composition in a range from about 0.001 to about 10 weight percent.