PROCESS FOR PRODUCING PHOSPHATE FERTILIZER WITH MICRONIZED SULFUR
Embodiments herein generally relate to a process for producing a solid phosphate fertilizer comprising micronized elemental sulfur. The process of producing a solid fertilizer comprises the steps of: (a) combining micronized sulfur with one or both of phosphate rock and phosphoric acid; (b) reacting the phosphate rock and phosphoric acid to produce TSP mixed with micronized sulfur particles; and (c) granulating the TSP and micronized sulfur into fertilizer granules.
1 . A process of producing a solid fertilizer comprising the steps of:
(a) combining micronized sulfur with one or both of phosphate rock and phosphoric acid;
(b) reacting the phosphate rock and phosphoric acid to produce triple superphosphate (TSP) mixed with micronized sulfur particles; and
(c) granulating the TSP and micronized sulfur into fertilizer granules.
2 . The process of claim 1 , wherein the micronized sulfur is mixed with ground phosphate rock having a particle size of 80%<200 mesh (75 micron).
3 . The process of claim 1 , wherein the micronized sulfur is mixed with phosphoric acid, the acid having a concentration in a range of about 35% to about 54%.
4 . The process of claim 1 , wherein the micronized sulfur has a mean particle size of less than about 30 microns, 10 microns, or 5 microns.
5 . The process of claim 1 , wherein the micronized sulfur is added as a dispersion in an aqueous dispersant solution.
6 . The process of claim 5 , wherein the dispersant comprises a surfactant, such as an anionic surfactant.
7 . The process of claim 1 , further comprising adding calcium carbonate to step (b).
8 . The process of claim 7 , wherein the calcium carbonate is added in a range of approximately 2 to 3% wt.
9 . The process of claim 1 , wherein step (b) involves adding an excess of phosphoric acid relative to phosphate rock.
10 . The process of claim 9 , wherein the acid to rock ratio is in a range of between about 2.2 to 3.2.
11 . The process of claim 10 , wherein the acid to rock ratio is in a range of about 2.5 to 2.8.
12 . The process of claim 1 , after step (b), further mixing one or a combination of micronutrients and secondary nutrients.
13 . The process of claim 12 , wherein the one or a combination of micronutrients and secondary nutrients comprises one or a combination of zinc, calcium, magnesium, boron, iron, copper, manganese, molybdenum, sodium, cobalt, chlorine, or selenium.
14 . A fertilizer product comprising granules of: (i) solid triple superphosphate (TSP), and (ii) micronized sulfur in a range of between 1 to 50% by weight of the fertilizer product.
15 . The product of claim 14 , where the amount of micronized sulfur is in a range of approximately 5% and 25% by weight of the fertilizer product.
16 . The product of claims 14 , wherein the amount of micronized sulfur is in a range of approximately 5% and 15% by weight of the fertilizer product.
17 . The product of claim 16 , wherein the product further comprises one or a combination of micronutrients or secondary nutrients.
18 . The product of claim 17 , wherein the one or a combination of micronutrients or secondary nutrients comprises one or more of zinc, calcium, magnesium, boron, iron, copper, manganese, molybdenum, sodium, cobalt, chlorine, or selenium.