High-Energy Ball Mills: Parameters for Optimizing Milling Efficiency

High-energy ball milling is a method used to reduce solid particles to a micron-size level. Operations can also use milling for mixing, blending and mechanical synthesis. A planetary ball mill is the most commonly used equipment for milling. However, reducing particle size to nano size with a planetary ball mill is challenging. Since various factors can affect milling performance, the process requires careful optimization. A high-energy ball mill machine provides a solution to these challenges. The machine collides rotating ceramic or steel balls with the material, breaking it into smaller pieces.

High-energy ball milling can be done with dry or wet grinding. During wet grinding, a liquid is added to the process, lubricating the particles and grinding media. This technique results in a more even mixture and limited dust. Dry grinding uses less energy, but it has a lower throughput. The more effective technique depends on several factors, including:

1. Milling jars and media material
2. Milling media size
3. Milling time
4. Grinding speed
5. Ball-to-powder ratio

MSE Supplies offers various high-energy ball mills, milling jars and media. Additionally, we can provide customized products designed to meet your specific needs. The proper milling tool set depends on your sample characteristics. Use the following guidelines to choose the most effective option for your needs.

High-Energy Ball Milling Applications

High-energy ball milling is a highly versatile technique. Industries can use these tools to produce alloys, nanocomposites, ceramics and more. High-energy ball milling is also valuable for its ability to create materials with unique properties. Ball mills repeatedly grind and collide particles at high speeds. This process can force different materials' atoms to mix at the atomic level, forming new structures.

High-energy ball milling delivers superior performance characteristics to materials. In particular, the aerospace, energy storage and electronics industries use this process to produce specialized materials.

Your milling application influences the products you select. Each application requires different end properties, features and production scales. Choose equipment that can handle the scale of production without compromising quality.

High-Energy Ball Milling Materials

Your ball mill or milling jar selection will depend on the sample materials. In general, the milling jar material must be harder than the sample for effective milling. Common milling jars and media materials include:

• Stainless steel
• Zirconia
• Alumina
• Tungsten carbide
• Agate

Milling Media Size Selection

The milling balls' diameter is critical for optimizing and improving milling efficiency. The milling balls' size is related to the size of the initial sample. Small balls are used for feed material with small sizes while larger balls are used for larger-sized feed material. The effective mixing and high-stress frequency is crucial for chemical synthesis, which can be achieved by using small balls¹¹.

Every application can have a very different optimal milling media size. It highly depends on the sample particle size and properties. It is also very common to use mixed sizes.

MSE Supplies offers various milling media sizes and different media sets. If you do not know which size of milling media to choose, using our milling media set is a good start. You can then further optimize the size further to meet your specifications.

Grinding Speed

Grinding speed affects the milling process' outcome. Higher grinding speeds increase the balls' kinetic energy, creating more intense collisions. The result is increased particle size reduction rates and faster, more uniform mixing. In comparison, lower speeds create weaker impacts. Weaker particle impacts can lead to less effective particle reduction and mixing.

Finding the right grinding speed ensures the desired result and prevents material degradation. If the milling speed is too high, it can lead to high wear, increasing milling jar or media contamination. High speeds can also result in higher jar temperatures and pinning the ball to the inner wall. Balancing milling speed control is essential for efficient milling processes and protecting your equipment.

Ball-to-Powder Ratio

High-energy mechanical milling is one of the primary methods for producing nano-crystalline materials via mechano-chemical synthesis. Ball size distribution and ball-to-powder ratio (BPR) can affect milling efficiency. There are no standard rules for choosing optimal BPR. Several parameters can influence each other. Many researchers use simulation models and statistical analysis of variance (ANOVA) to determine the effects of the ball-to-powder ratio on milling efficiency and identify the statistically significant parameters.

(Kim et al., 2022)¹²

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Our team of PhD-level scientists and engineers offers unmatched technical support. We'll ensure you receive tailored solutions for your research and production needs. With expertise across multiple industries, we have the resources to help you with confidence. Trust MSE Supplies to support your success.

Explore Milling Tools From MSE Supplies

MSE Supplies is a major global supplier of high-energy milling tools. We offer both standard and customized products to ensure operations find the right fit for their needs. If you need something not listed on our website, please email us at sales@msesupplies.com, and we will prepare a quote for the customized products for you. If you have any questions, reach out to us through our contact form or at tech@msesupplies.com.

Reference

1. Zhu, H.; Cao, Y.; Zhang, J.; Zhang, W.; Xu, Y.; Guo, J.; Yang, W.; Liu, J., One-step preparation of graphene nanosheets via ball milling of graphite and the application in lithium-ion batteries. Journal of Materials Science 2016, 51, 3675-3683.
2. Kubota, K.; Seo, T.; Ito, H., Solid-state cross-coupling reactions of insoluble aryl halides under polymer-assisted grinding conditions. Faraday Discuss 2022.
3. Sawama, Y.; Niikawa, M.; Sajiki, H., Stainless Steel Ball Milling for Hydrogen Generation and its Application for Reduction. J. Synth. Org. Chem., Jpn 2019, 77 (11).
4. Saghir, M.; Umer, M. A.; Ahme, A.; Monir, N. B.; Manzoor, U.; Razzaq, A.; Xian, L.; Mohammad, K.; Shahid, M.; Park, Y.-K., Effect of high energy ball milling and low temperature densification of plate-like alumina powder. Powder Technology 2021, 383, 84-92.
5. Peterson, S. C.; A.Jackson, M.; Kima, S.; E.Palmquist, D., Increasing biochar surface area: Optimization of ball milling parameters. Powder Technology 2012, 228, 115-120.
6. Wood, M.; Gao, X.; Shi, R.; Heo, T. W.; Espitia, J. A.; Duoss, E. B.; C.Wood, B.; JianchaoYe, Exploring the relationship between solvent-assisted ball milling, particle size, and sintering temperature in garnet-type solid electrolytes. Journal of Power Sources 2021, 484, 229252.
7. Castrillo, P. D.; D.Olmos; D.R.Amador; J.González-Benito, Real dispersion of isolated fumed silica nanoparticles in highly filled PMMA prepared by high energy ball milling. Journal of Colloid and Interface Science 2007, 308 (2), 318-324.
8. Jung, H. J.; Sohn, Y.; Sung, H. G.; Hyun, H. S.; Shin, W. G., Physicochemical properties of ball milled boron particles: Dry vs. wet ball milling process. Powder Technology 2015, 269, 548-553.
9. T.Rojac; M.Kosec; B.Malič; J.Holc, The application of a milling map in the mechanochemical synthesis of ceramic oxides. Journal of the European Ceramic Society 2006, 26 (16), 3711-3716.
10. Pierard, N.; Fonseca, A.; Konya, Z.; Willems, I.; Tendeloo, G. V.; B.Nagy, J., Production of short carbon nanotubes with open tips by ball milling. Chemical Physics Letters 2001, 335 (1-2), 1-8.
11. Burmeister, C. F.; Kwade, A., Process engineering with planetary ball mills. Chem. Soc. Rev 2013, 42, 7660-7667.
12. Kim, K.-C.; Jiang, T.; Kim, N.-I.; Kwon, C., Effects of ball-to-powder diameter ratio and powder particle shape on EDEM simulation in a planetary ball mill. Journal of the Indian Chemical Society 2022, 99 (1), 100300.