CA2806475C

Phosphate fertilizers and methods of using the same

Abstract

A water-insoluble phosphate fertilizer, methods of producing, and methods of using the same are provided. The fertilizer may comprise at least one alkaline earth metal selected from calcium and magnesium and optionally at least one nutrient ion selected from the group consisting of potassium, ammonium, zinc, iron, manganese, copper, boron, chlorine, iodine, molybdenum or selenium. The fertilizer compounds are preferably water-insoluble, dilute acid-soluble, and free-flowing powders.

CA2806475C, drawing sheet 1
Sheet 1 of 2

Term

4.9 yearsleft in the term

Expires 8 August 2031.

  1. Priority and filed
  2. Granted
  3. Today
  4. Expires

22 claims: 13 independent, 9 dependent

  1. 1
    CA 02806475 2016-06-09 75975-59 CLAIMS:1. A water-insoluble, dilute acid-soluble inorganic polyphosphate composition in solid form, the inorganic polyphosphate composition containing: at least 15 wt. % calcium, magnesium or a combination thereof;5 5 to 70 wt % orthophosphate: and optionally at least one micronutrient selected from the group consisting of boron, chromium, cobalt, copper, iodine, iron, manganese, molybdenum, selenium and zinc, with the proviso that the inorganic polyphosphate composition contains 10 no more than 3.5 wt % of the at least one micronutrient, based on the total weight of the inorganic polyphosphate composition, wherein: the inorganic polyphosphate composition has a number average chain length of greater than 2 but less than 50 repeat units when the content of the 15 orthophosphate is excluded from the average chain length calculation, the inorganic polyphosphate composition has a number average chain length of at least 1.1 but less than 50 repeat units when the orthophosphate content is included in the average chain length calculation, the repeat units comprise phosphate units, sulfate units, borate units, 20 molybdate units, selenate units, or a combination thereof, with the proviso the ratio of the phosphate units to the combined total of the sulfate units, the borate units, the molybdate units and the selenate units is at least 2:1, and the inorganic polyphosphate composition has: (i) a solubility in roomtemperature (25°C) deionized water wherein the combined amount of calcium, CA 02806475 2016-06-09 75975-59 chromium, cobalt, copper, iodine, iron, magnesium, manganese, and zinc which dissolves from the inorganic polyphosphate composition during a 30 minute period in the room temperature deionized water is less than 20% of the combined amount of calcium, chromium, cobalt, copper, iodine, iron, magnesium, manganese, and zinc which dissolves from the inorganic polyphosphate composition during a 30 minute period in room-temperature 0.1 N HCI, and (ii) a solubility in room-temperature dilute citric acid wherein the combined amount of calcium, chromium, cobalt, copper, iodine, iron, magnesium, manganese, and zinc which dissolves from the inorganic polyphosphate composition during a 20 minute period in room-temperature 0.2 wt. % citric acid is at least 75% of the combined amount of calcium, chromium, cobalt, copper, iodine, iron, magnesium, manganese, and zinc which dissolves from the inorganic polyphosphate composition during a 20 minute period in room-temperature 0.1 N HCI.
  2. 4
    The inorganic polyphosphate composition of any one of claims 1 to 3, which has a number average chain length of 2.1 to 20 repeat units when the orthophosphate content is excluded from the average chain length calculation, and which has a number average chain length of at least 1.2 to 20 repeat units when the orthophosphate content is included in the average chain length calculation.
  3. 6
    The inorganic polyphosphate composition of any one of claims 1 to 5, wherein the repeat units comprise sulfate units, borate units, molybdate units, or selenate units.
  4. 7
    The inorganic polyphosphate composition of any one of claims 1 to 6, which has a ratio, A:Z, of 0.3:1 to 1.25:1, wherein A is the combined number of equivalents of calcium and magnesium and Z is the combined number of equivalents of phosphorous, boron, molybdenum, and selenium incorporated in the sulfate units, the borate units, the molybdate units or the selenate units.
  5. 8
    The inorganic polyphosphate composition of any one of claims 1 to 7, which has a ratio, A:P, of 0.3:1 to 1.25:1, wherein A is the combined number of equivalents of calcium and magnesium and P is the number of equivalents of phosphorous atoms.
  6. 10
    The inorganic polyphosphate composition of any one of claims 1 to 9, which has a solubility in:(i) room-temperature dilute citric acid wherein the combined amount of calcium, chromium, cobalt, copper, iodine, iron, magnesium, manganese, and zinc which dissolves from the inorganic polyphosphate composition during a 20 minute period in room-temperature 0.1 wt. % citric acid is at least 75% ofthe combined amount of calcium, chromium, cobalt, copper, iodine, iron, magnesium, manganese, and zinc which dissolves during a 20 minute period in room-temperature 0.1 N HCI, or (ii) room-temperature dilute ethylenediaminetetraacetic acid (EDTA) wherein the combined amount of calcium, chromium, cobalt, copper, iodine, iron, magnesium, manganese, and zinc which dissolves during a 20 minute period in room-temperature 0.005 M EDTA is at least 75% ofthe combined amount of calcium, chromium, cobalt, copper, iodine, iron, magnesium, manganese, and zinc which dissolves during a 20 minute period in room-temperature 0.1 N HCI. CA 02806475 2016-06-09 75975-59
  7. 11
    The inorganic polyphosphate composition of any one of claims 1 to 10, which is in solid form, and which contains less than 10 wt. % water.
  8. 12
    The inorganic polyphosphate composition of any one of claims 1 to 11, which is in solid form, and which is in the form of free-flowing granules having a 5 particle size which is less than 80 mesh BS.
  9. 13
    The inorganic polyphosphate composition of any one of claims 1 to 12, which contains at least 15 wt. % of calcium.
  10. 14
    The inorganic polyphosphate composition of any one of claims 1 to 13, which contains not more than 35 wt. % of calcium and magnesium, in combination. 10
  11. 15
    The inorganic polyphosphate composition of any one of claims 1 to 12, which is in solid form, and which has an atomic ratio of calcium to magnesium of at least 0.2:1(calcium:magnesium).
  12. 19
    The inorganic polyphosphate composition of any one of claims 1 to 18, 20 which is in solid form, and which has at least 0.01 wt. % of the at least one micronutrient.
  13. 20
    The inorganic polyphosphate composition of any one of claims 1 to 19, which contains less than 2.5 wt. % of the at least one micronutrient. CA 02806475 2016-06-09 75975-59
Independent claims13