A rod mill is a tumbling mill that uses steel rods as the grinding medium. It is commonly used as the first stage of grinding in a milling process. Rod mills operate by tumbling the ore along with steel rods inside a rotating drum, which helps reduce the ore particles to sizes between 0.1-2 mm. Feed enters from one end and product discharges from the other or center of the mill. Rod mills are suitable for grinding hard minerals and are often used for initial size reduction in a milling circuit due to their lower cost compared to other mills.

1. Rod
Mill

2. # Size Reduction Equipment
A :- Crushers (coarse & fine)
B :- Grinders (Intermediate & fine)
1.Hammer mills
2.Rolling-compression mill
3.Attrition mill
4.Tumbling mill
a. Rod mill
b. Ball mill
c. Tube mill

3. # Rod mill
• Description
The rod mill is a tumbling mill but
having a large percentage of its
volume (30 - 40%) loaded with steel
rods. The rods are placed axially in
the mill and are loose and free to
move within the mill.

4. # Inside & the Outside of a Rod Mill

5. The internal lining of the drum has a
series of lifters which raise the rods and
drop them at a predetermined point.
The mineral is fed in at one end with a
maximum size of about 25mm. The
rods crush the rock and as the charge
passes through the mill it is reduced in
size to approximately 2mm to 0.1mm.

6. # Feed enters & Product out in mill

7. The mill can be fed from one end with
the product removed from the other end
or, alternatively, the mill can be fed from
both ends with the discharge at the
centre.
The process can be wet or dry but is
more commonly carried out wet.

8. Maximum rod length is about 6 to 7
metres, otherwise there is a risk of the
rods bowing. The drum diameter is
limited to 0.6 or 0.7 times the length of
the mill.
# Working Principle of Rod Mill:-
The rod mill is a horizontal rotating
device transmitted by the outer gear. The
materials are transferred to the grinding
chamber through the quill shaft uniformly.

9. There are ladder liner and ripple liner and
different specifications of ceramic ball in
the chamber. The centrifugal force caused
by rotation of barrel brings the ceramic
ball to a certain height and impact and
grind the materials. The ground materials
are discharged through the discharging
board thus the grinding process is
finished.

10. # Part of a Rod Mill

11. # Technical Parameters of Rod Mill:-
Model
Mill body size
(mm) Rotating
speed
(r/min)
Feeding rod
weight(t)
Feeding
granularity
(mm)
Discharging
granularity
(mm)
Output
(t/h)
Motor
power
(kw)
Diameter length
MB0918 900 1800 29.0-31.3 2.3 <25 0.16-5 1.6-6 22
MB0924 900 2400 29.0-35.4 3.1 <25 0.16-5 2.9-10 30
MB1224 1200 2400 27.0-34.0 6.5 <25 0.16-5 5.0-13 37
MB1530 1500 3000 26.5-29.5 11.5 <25 0.16-5 6.0-25 90
MB1830 1800 3000 21.6-22.8 17.5 <25 0.16-5 4.8-28 155
MB2130 2100 3000 19.0-21.0 23.5 <25 0.16-5 12.6-30 210
MB2136 2100 3600 19.0-21.0 23.2 <25 0.16-5 15.1-45 245
MB2736 2700 3600 17.2-18.5 47.0 <25 0.16-5 25.0-75 400
MB2740 2700 4000 17.2-18.5 51.0 <25 0.16-5 27.7-90 430

12. # Characteristics:-
Rod mills are used for grinding hard
minerals. This type of mill is usually
used as the first stage of a milling
process to provide a reduced size
feedstock for a further milling process.

14. # APPLICATIONS:-
• Coal
• Pigments
• Felspar For Pottery
• Ores
• Chemicals
• Ceramic Raw Materials
• Paints

15. # ADVANTAGES:-
• Cost of installation
• Power
• Grinding medium is low
• Suitable for both batch and
continuous operation
• Materials of all degrees of hardness

16. By:-
Sandeep.(45)
(MSNT) 2nd Year,
4th Sem