This presentation looks at the processes used to transform phosphate rock into Monoammonium Phosphate (MAP) and Diammonium Phosphate (DAP) fertilizers.

1. Fertilizers
Experts in process design and material
processing for over 65 years.
Phosphates
Processing
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2. Phosphorus is essential to all life on Earth. Its
life-giving properties are key to a variety of
cellular and biological processes that allow
plants, animals, and even humans to grow
strong and healthy.

3. As such, phosphorus, in the form of
phosphates, is a key ingredient in fertilizer
products, aiding in the creation of strong
roots, resistance to disease, and overall
productivity.

4. As such, phosphorus, in the form of
phosphates, is a key ingredient in fertilizer
products, aiding in the creation of strong
roots, resistance to disease, and overall
productivity.
Before phosphorus can be utilized in fertilizer
products, however, it must first be
processed…

5. Processing
Phosphate Rock

6. Phosphorus is mined all over the world in the
form of phosphate rock. While ground
phosphate rock can be applied directly to
soil, it is more beneficial to first process it, so
the phosphorus can be more readily
absorbed by plants.

7. Phosphate rock deposits vary greatly from
one deposit to the next, and even within the
same deposit.

8. Phosphate rock deposits vary greatly from
one deposit to the next, and even within the
same deposit.
For this reason, the beneficiation process
can differ greatly, with common methods
including crushing, screening, flotation,
filtration, classification, or often, a
combination of methods.

9. Once processed, the resulting phosphate
ore must be dried, a practice commonly
carried out in a rotary dryer. This dried ore is
then most often processed into phosphoric
acid by reacting the ore with sulfuric acid.

10. Once processed, the resulting phosphate
ore must be dried, a practice commonly
carried out in a rotary dryer. This dried ore is
then most often processed into phosphoric
acid by reacting the ore with sulfuric acid.
Phosphoric acid is the base of many
products, both fertilizer and animal feed.

11. A variety of fertilizer products can be made
from phosphate rock, with the two most
common being:

12. A variety of fertilizer products can be made
from phosphate rock, with the two most
common being:
• Monoammonium Phosphate (MAP)

13. A variety of fertilizer products can be made
from phosphate rock, with the two most
common being:
• Monoammonium Phosphate (MAP)
• Diammonium Phosphate (DAP)

14. MAP & DAP
Fertilizer Production

15. MAP and DAP fertilizers are produced
by reacting phosphoric acid with
ammonia, and then granulating the
resulting material.

16. MAP and DAP fertilizers are produced
by reacting phosphoric acid with
ammonia, and then granulating the
resulting material.
First, phosphoric acid and ammonia are
pre-neutralized (reacted) in tanks to
form a slurry. The slurry is fed to a rotary
granulator, where granules are formed
as the material tumbles through the
drum and solidifies.

17. The granules are then carried by a
conveyor or bucket elevator to a rotary
dryer, where they are dried into their
final form.

18. The granules are then carried by a
conveyor or bucket elevator to a rotary
dryer, where they are dried into their
final form.
The tumbling action of the dryer further
rounds and polishes the granules.

19. Upon exiting the dryer, the granules go
through a screening process where over-
and under-size granules are screened
out, while on-size product moves on
to cooling.

20. Upon exiting the dryer, the granules go
through a screening process where over-
and under-size granules are screened
out, while on-size product moves on
to cooling.
Over-size granules are broken down
in a hammer mill and combined with
under-size granules to go back into
the process as recycle.

21. Upon exiting the dryer, the granules go
through a screening process where over-
and under-size granules are screened
out, while on-size product moves on
to cooling.
Over-size granules are broken down
in a hammer mill and combined with
under-size granules to go back into
the process as recycle.
This process is illustrated on the next page.

23. An Alternate Approach to
MAP Fertilizer Production

24. While the aforementioned process is the
primary method for processing MAP
fertilizer, an alternative approach
utilizing the addition of a pipe reactor is
also sometimes used for the energy
savings it can offer.

25. While the aforementioned process is the
primary method for processing MAP
fertilizer, an alternative approach
utilizing the addition of a pipe reactor is
also sometimes used for the energy
savings it can offer.
The process is similar, but instead of
being reacted in tanks, the phosphoric
acid and ammonia are reacted in the
cross pipe reactor.

26. The reaction forms a hot melt, which is
then sparged into the rotary granulator.
The heat from the reaction flashes off
moisture from the granules.

27. The reaction forms a hot melt, which is
then sparged into the rotary granulator.
The heat from the reaction flashes off
moisture from the granules.
A rotary dryer is still needed to further
dry the granules, but the energy
requirements are significantly reduced,
because the captured heat from the
reaction is being used.

29. The addition of a pipe reactor is a
popular option for retrofits, because it is
easily installed and the tanks that were
once used for pre-neutralizing can
serve as feeding tanks to the operation.

30. Additional
Phosphatic Fertilizers

31. In addition to MAP and DAP, a variety of
other phosphatic fertilizers are available as
well. This includes:

32. In addition to MAP and DAP, a variety of
other phosphatic fertilizers are available as
well. This includes:
• Single Super Phosphate (SSP)

33. In addition to MAP and DAP, a variety of
other phosphatic fertilizers are available as
well. This includes:
• Single Super Phosphate (SSP)
• Triple Super Phosphate (TSP)

34. In addition to MAP and DAP, a variety of
other phosphatic fertilizers are available as
well. This includes:
• Single Super Phosphate (SSP)
• Triple Super Phosphate (TSP)
• NPK – While phosphate is not the base of this
product, it is an important ingredient combined
with Nitrogen and Potassium to form various NPK
blends.

35. has been working with phosphates for over 65
years, providing testing services, process
design and development, and custom
phosphate processing equipment.

36. Want to learn more?
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