The addition of a pin mixer to a limestone pelletizing operation as a method of pre-conditioning offers many benefits. This presentation discusses the benefits this pre-conditioning stage can offer, as well as the basics of pin mixer operation.

1. Pin Mixer to a
Experts in process design and material
processing for over 60 years.
Limestone
Pelletizing Operation
The Benefits of Adding A

2. While many limestone pelletizing
operations utilize a pin mixer as a
conditioning method prior to the disc
pelletizer, this step is not required.

3. While many limestone pelletizing
operations utilize a pin mixer as a
conditioning method prior to the disc
pelletizer, this step is not required.
However, as you will see, a pin mixer can
bring an array of benefits to a disc
pelletizing system.

4. How A
Pin Mixer Works

5. Pin mixers use high-speed centrifugal
force to create densification within the
material, forming “micro-pellets.”

6. A pin mixer consists of a central rotor shaft,
housed in a stationary casing. The shaft is
fitted with several rods, or “pins.”
The rotational movement of the shaft and
pins at a constant speed of several
hundred rpms creates a high-velocity
spinning action.

7. This provides a conditioning stage that sets a
precedent for the rest of the process, and
the end product quality.

8. This provides a conditioning stage that sets a
precedent for the rest of the process, and
the end product quality.
In addition to improving end product
quality, the use of a pin mixer also improves
subsequent processing steps.

9. Benefits of
Adding A Pin Mixer

10. Adding a pin mixer to a limestone disc
pelletizing process offers the following
benefits:
- De-Dusting
- Increased Production
- Reduced Binder Costs
- Improved Blending

11. De-Dusting
Because disc pelletizers are an open system,
the material is free to escape into the air,
which can be a problem with a dusty material
such as limestone.

12. De-Dusting
Because disc pelletizers are an open system,
the material is free to escape into the air,
which can be a problem with a dusty material
such as limestone.
Adding a pin mixer prior to the disc pelletizer
allows the material to be de-dusted before it
hits the disc pelletizer. This is done by
thoroughly mixing the feed material with a
binding agent. This creates a near dust-free
material for processing on the disc pelletizer.

13. Increased Production
When a pin mixer is not employed, the
required amount of moisture/binder must be
gradually added during processing on the disc
pelletizer, a process which can be lengthy.

14. Increased Production
When a pin mixer is not employed, the
required amount of moisture/binder must be
gradually added during processing on the disc
pelletizer, a process which can be lengthy.
With the addition of a pin mixer, however, most
of the required moisture can be added during
the pre-conditioning stage, as opposed to on
the disc pelletizer. This means the limestone
can spend significantly less time on the disc
pelletizer, thereby increasing production.

15. Reduced Binder Costs
Densification is naturally achieved due to
the high speed, rotational movement inside
the pin mixer.

16. Reduced Binder Costs
Densification is naturally achieved due to
the high speed, rotational movement inside
the pin mixer.
Because densification is achieved through
motion, and not through added binder, less
binder is required to reach the same result,
translating into reduced binder cost.

17. Improved Blending
Because a disc pelletizer is not intended
for mixing materials, the distribution of
binder throughout the material can be
uneven.

18. Improved Blending
Because a disc pelletizer is not intended
for mixing materials, the distribution of
binder throughout the material can be
uneven.
The addition of a pin mixer mitigates this
problem, because the pin mixer
thoroughly mixes the binder and feed
material, creating a homogenous mix, and
resulting in more uniform pellets.

19. This is especially seen with crush strength;
because the binder and feed are not thoroughly
mixed, varying crush strengths are often observed
in the final product when a pin mixer is not
utilized. When pre-blended in a pin mixer, end
crush strength is considerably more uniform.

20. Conclusion
The addition of a pin mixer to a limestone disc
pelletizing operation can add significant value
through increased production, reduced binder
costs, less dusting issues, and improved product
uniformity. Pin mixers are a valuable part of the
limestone pelletizing process, helping to create
the best end product possible, and
streamlining production.

21. has been working with limestone for over 60
years, providing testing, process design and
development, and manufacturing of custom
limestone processing equipment, including
heavy-duty pin mixers.
FEECO

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