Particle Internal Fracture Energy Measurement by Ultrafast Load Cell

Year 2016, , 428 - 433, 04.10.2016

E. Tuğcan Tuzcu

https://doi.org/10.19113/sdufbed.65312

Abstract

Ultrafast Load Cell (UFLC) device is used in micro-scale modeling of particle fracture. Electro-mechanical device measures the internal fracture energy of the particles during the fracture event under impact. The sphere and/or cylinder weight is dropped onto particle staying on a plane cylinder surface. The point where the particle is divided into two pieces without secondary, tertiary breakages is called the fracture point. UFLC is equipped with two Wheatstone bridges. These bridges convert compressive strain signals produced during the impact event to a voltage signal. This signal can be expressed as force, energy, and displacement. All the information gained during the fracture is then used to estimate breakage rates of the particles. In this study, two parameter Weibull distribution is used in modeling the internal fracture energy distributions of the particles those ranges between 7mm and 45mm. It is concluded from the study that the median internal specific fracture energy of the particles of the size 45mm and 7mm are 2.2 Joule /kg and 25.4 Joule /kg, respectively. This study quantitatively shows the relationship between the particle specific fracture energy and the size.

Keywords

Ultrafast Load Cell (UFLC), Fracture; Impact energy; Modeling; Grinding

References

• [1] Weichert, R., Herbst, J. 1986. An Ultra-Fast Load Cell Device for Measuring Particle Breakage. 1. World Congress Particle Technology, 2, 3-14.
• [2] King, R. P., Bourgeois, F., 1991. A New Conceptual Model for Ball Milling. XVII International Mineral Processing Congress, 23-28 September, Dresden, 81 -86.
• [3] Bourgeois, F.S. 1993. Single-Particle Fracture as a Basis for Microscale Modeling of Comminution Process. University of Utah, Department of Metallurgical Engineering, Ph.D. Thesis, Salt Lake City, Utah, USA.
• [4] Kawatra , S. K. 1992. Low-impact single particle fracture. 99-108. Bourgeois, F., King, R. P., Herbst, J.A.., ed. 1992. Comminution – Theory and Practice, Society for Mining, Metallurgy and Exploration Publishing, Littleton, Colorado, USA.
• [5] Cho, K. 1987. Breakage Mechanisms in Size Reduction. University of Utah, Department of Metallurgical Engineering, Ph.D. Thesis, Salt Lake City, Utah, USA.
• [6] Höfler, A. 1990. Fundamental Breakage Studies of Mineral Particles with an Ultra-fast Load Cell Device. University of Utah, Department of Metallurgical Engineering, Ph.D. Thesis, Salt Lake City, Utah, USA.
• [7] Tavares, L.M. 1997. Microscale Investigation of Particle Breakage Applied to the Study of Thermal and Mechanical Predamage. University of Utah, Department of Metallurgical Engineering, Ph.D. Thesis, Salt Lake City, Utah, USA.
• [8] Tuzcu, E.T., 2010. An approach for the modeling of batch grinding with single particle fracture studies and impact energy spectra. University of Utah, Department of Metallurgical Engineering, Ph.D. Thesis, Salt Lake City, Utah, USA.
• [9] Tuzcu, E.T., Rajamani, R.K., 2011. Modeling breakage rates in mills with impact energy spectra and ultra-fast load cell data. Minerals Engineering, 24, 252–260.
• [10] Tuzcu, E.T., Dhawan, N., Rajamani, R., 2011. A Study of Coarse Particle Fracture with the Ultra-Fast Load cell. Mineral and Metallurgical Processing Journal, 28-4, 176-186.
• [11] Hertz, H., 1881. Ueber die Beruehrung fester elastischer Koerper . J.Reine Angew. Math. (Crelle), 92.
• [12] Goldsmith, W. 1990. Impact. The Theory and Physical Behaviour of Colliding Solid. Edward Arnold, London.
• [13] Weibull, W. 1939. A Statistical Theory of the Strength of Materials. Royal Swedih Academy of Eng. Sci., , 151, 1-45.
• [14] Costin, L. 1987. Time-dependent Deformation and Failure. Academic Press Inc., London.