made by Rafi ullah student of Chemical engineering in PU lahore

2. PRESENTATION:
PREPARED BY:
RAFI ULLAH
M13-CE54

3. BALL MILL

4. TABLE OF CONTENT:
 INTRODUCTION
 DEFINITION
 BASIC PRINCIPLE
 CONSTRUCTION
 WORKING
 ADVANTAGES AND DISADVANTAGES
 APPLICATIONS
 EQUATIONS

5. BALL MILL
INTRODUCTION:
• It is efficient tool for grinding many
materials into fine powder.
• There are two types of grinding, the
dry process and wet process.

6. DEFINITON:
• A ball mill is a type of grinder used to grind
and blend materials for use in mineral
dressing processes, paints, pyrotechnics,
ceramics and selective laser sintering etc.

7. PRINCIPLE:
 A ball mill works on the principle of impact
and attrition.
 size reduction is done by impact as the
balls drop from near the top of the shell.

8. CONSTRUCTION:
 Wet or dry ball mill grinding machine
consists of following parts:
1. Feeding part
2. Discharging part
3. Turning and driving part( gear, motor etc)
4. Rotating balls

9. CONSTRUCTION (CONT):
 Consist of a hollow cylindrical shell rotating about its
axis.
 The axis of the shell may be horizontal or at some
angle.
 It is partially filled with balls.
 These balls are grinding materials, made up of
chrome steel, stainless steel or rubber.
 The inner surface of the hollow cylinder is lined with
a resistant material such as manganese steel or
rubber.

10. CONSTRUCTION (CONTD)
The length of mill is approximately equal to
its diameter.
Ball occupy about 30-50% of the volume.
The dia of ball is 12mm to 125mm.
The dia of shell is 3m and its length is about
4.25m.
The shell is rotated through a drive gear
with speed 60-100 rpm.

11. WORKING:
 The material to be grind is fed at angle of 60
degree into the crushing zone and the product
is discharged at 30 degree.
 As the shell rotates the balls are lifted up on
the rising side of the shell and they cascade
down from near the top of the shell.
 The solid particles in between balls are ground
and reduced in size by impact.

12.  If the rate of feed increased, coarser
product will be obtained and if speed of
rotation is increased the fineness for a
given capacity is increases.
 During grinding, the balls themselves wear
and are continuously replaced by new ones
so that mill contains balls of various ages.
 Ball mill produces 1 to 50 ton/hr of powder
and energy requirement of the ball mill is
about 16 kwh/ton.

14. ADVANTAGES OF BALL MILL
 The cost of installation is low.
 The cost of production is low.
 It is suitable for materials of all degree of
hardness.
 The grinding medium is cheap.
 Suitable for both batch and continuous
operations.

15. DISADVANTAGES:
 Rotational ball loading difficulty
 Mill efficiency is low
 The mill feed size range is wide
 Not easy to get thinner end product

16. APPLICATIONS:
 Metallic powders
 Carbon and coal
 Phosphate rock
 Gypsum grinding
 Limestone milling
 Cement processing
 Fertilizers
 Silicate products
 Dressing production
 Granite