Ball mill Grinding
TITLE: Ball mill grinding. INTRODUCTION Indeed the ball milling means, the reduction of particles to smaller sizes with the help of a ball mill. It can be done in two ways. They are,\
Dry milling
Wet milling
Generally, this has porcelain or steel ball as the grinding media. Commiution is occurred by several methods in the ball mill grinding. They are compression, impact and shear between the moving grinding media and the particles. The rate of this depends on some factors. These are mainly three categories.
1. Mill parameters (Diameter, speed and amount of media)
2. Properties of the grinding media (Shape, size and hardness)
3. Properties of the particles
MATERIALS AND APPARATES
Sand
Ball mill and pebbles
Set of sieves
Electronic balance
PROCEDURE
First of all, the ball mill was charge with pebbles to approximately 50% of the mill volume and with sand approximately 25% also. Then the ball mill was switch on and operation was done for one hour. Simultaneously the size distribution of the given sand was noted by using the set of sieves. After one hour later the size distribution was noted for the ground sample. Then ball mill was charged again with pebbles to approximately 25% of the mill volume and with sand approximately 25%. After that this sample was grounded for a one hour. After one hour later the size distribution was noted for this ground sample also. All readings were recorded.
CALCULATION
For sieve analysis of the first sample (without grindings) Cumulative retain (sieve size 500) = 15.01+10.48 = 25.49
%Cumulative retain (sieve size 500) = 25.49/49.07x100% = 15.67
Similarly other calculations can be evaluated. They can be tabulated as follows.
Sieve size
Before grinding
After grinding
Cumulative
Retain
%Cumulative
Retain
With 50% media
With 25% media
Cumulative
Retain
%Cumulative
Retain
Cumulative
Retain
%Cumulative
Retain
1000
7.69
Dry milling
Wet milling
Generally, this has porcelain or steel ball as the grinding media. Commiution is occurred by several methods in the ball mill grinding. They are compression, impact and shear between the moving grinding media and the particles. The rate of this depends on some factors. These are mainly three categories.
1. Mill parameters (Diameter, speed and amount of media)
2. Properties of the grinding media (Shape, size and hardness)
3. Properties of the particles
MATERIALS AND APPARATES
Sand
Ball mill and pebbles
Set of sieves
Electronic balance
PROCEDURE
First of all, the ball mill was charge with pebbles to approximately 50% of the mill volume and with sand approximately 25% also. Then the ball mill was switch on and operation was done for one hour. Simultaneously the size distribution of the given sand was noted by using the set of sieves. After one hour later the size distribution was noted for the ground sample. Then ball mill was charged again with pebbles to approximately 25% of the mill volume and with sand approximately 25%. After that this sample was grounded for a one hour. After one hour later the size distribution was noted for this ground sample also. All readings were recorded.
CALCULATION
For sieve analysis of the first sample (without grindings) Cumulative retain (sieve size 500) = 15.01+10.48 = 25.49
%Cumulative retain (sieve size 500) = 25.49/49.07x100% = 15.67
Similarly other calculations can be evaluated. They can be tabulated as follows.
Sieve size
Before grinding
After grinding
Cumulative
Retain
%Cumulative
Retain
With 50% media
With 25% media
Cumulative
Retain
%Cumulative
Retain
Cumulative
Retain
%Cumulative
Retain
1000
7.69