BALL MILLING
1. Title:
Experiment 1: Ball Milling
2. Objectives:
• To grind the coarse salt into small pieces by using ball milling method.
• Use the sieve method to determine the size of distribution of the small pieces of salt.
3. Introduction:
A ball mill, a type of grinder, is a cylindrical device used in grinding (or mixing) materials like ores, chemicals, ceramic raw materials and paints. Ball mills rotate around a horizontal axis, partially filled with the material to be ground plus the grinding medium. Different materials are used as media, including ceramic balls, flint pebbles and stainless steel balls. An internal cascading effect reduces the material to a fine powder. In the experiment, ball milling method is used to grind 300g coarse salt to produce salt with smaller size. The size of distribution of the grinded salt was determined by the sieving method.
4. Methods:
• Apparatus and Materials:
Ball mill, 10 metal balls with various size, sieve, electronic balance, weighing boat, spatula, 300g coarse salt
• Procedures:
1. 300g of coarse salt was measured by using weighing balance.
2. Metal balls with various size were putted into the mill.
3. 300g coarse was poured into the mill.
4. The process of milling was started with duration of 20 minutes with speed 3.
5. Once the milling process was done, the product was measured.
6. Sieve the product by using sieve nest method.
7. Histogram was plotted by using the data from the ball milling and sieving.
5. Results and Calculation :
Group 5 and 6: (Set 3)
6. Discussion:
First, when comparing the result from set1 (10min, speed 5) and set 2 ( 20 min, speed 5), the amount of grinded salt collected by sieving that are in range of 150um-300um from set 2 is more (23.3451g) compared to set 1 ( 20.7206g). This is because set 2 has longer duration for ball milling, therefore more smaller size salt can be produced.
Next, comparison is done between set 3(10min, speed 3) and set 4(20min, speed 3). The amount of grinded salt collected by sieving that are in range of 150um-300um from set 4 is less (12.4977g) compared to set 3 (13.7336g). There is a little deviation since during the ball milling process both set use the same speed with the duration of set 4 is longer (20min) compared to set 3(10min), thus set 4 should produce more salt that is in the range of 150um-300um), however, in this experiment, the salt in the stated range produced by set 3 is more than set 4. This error may due to different people with different strength was used while using the sieving method.
Besides, comparison can also be done between sets with same duration during the ball milling but different speed. Weight of salt produced in the stated range from Set 1(10min, speed 5) is more (20.7206g) compared to set 3(10min, speed 3) which is 13.7336g. Furthermore, weight of salt produced in the stated range from Set 2(20min, speed 5) is more (23.3451g) compared to set 4(20min, speed 3) which is 12.4977g. This show ball milling process with faster speed can produce more product which is in the desired range. Moreover, from the experimental data it also indicate the speed influence more compared to the duration in the ball milling process.
7. Questions:
1. What are the factors that affect the milling process?
Speed and duration.
2. What are the equipments that can be used in milling?
Cutter mill, mortar and pestle, roller mills, hammer mill, fluid energy milling and others.
3. What are the factor that influence the selection of equipments that used in milling?
The desired size range of product and physical properties such as hardness of product will influence the selection of equipments that used in milling
8. Conclusion:
During ball milling process, set with longer duration and higher speed will produce more products that is in the desired size range. Variation in speed show greater effect compared to duration in ball milling process.
9. References:
• Aulton, M.E. 2002. Pharmaceutics: The Science of Dosage form Design. Edinburgh Churchill Livingstone.
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