A DEM numerical modelling approach to simulating size segregation of media in a stirred mill and effects on grind characteristics
| dc.contributor.advisor | Mainza, Aubrey | |
| dc.contributor.author | Sievers, Wilco | |
| dc.date.accessioned | 2026-01-26T07:21:53Z | |
| dc.date.available | 2026-01-26T07:21:53Z | |
| dc.date.issued | 2025 | |
| dc.date.updated | 2026-01-26T07:14:30Z | |
| dc.description.abstract | Comminution is an important operation in the minerals processing industry. In both traditional and stirred mills, single-sized grinding beads are used, along with multiple passes through the mills, to achieve a sufficient size-reduction ratio. It is plausible to expand the size reduction capabilities of a mill using multiple-sized grinding beads in the mill. For this study, the discrete element method (DEM) was used to simulate dry size-segregated systems in a vertical stirred mill. These size-segregated systems were evaluated at different impeller speeds and weight distributions. The dry systems were susceptible to the Brazilian nut effect. Furthermore, it was found that excessive impeller speeds did not subsequently increase the overall collision modulus. The overall modal collision intensity for particle collisions was maximised between 350 rpm and 500 rpm where sufficient mixing and impeller speed were facilitated. At excessive speeds past 700 rpm the collision modulus plateaued. Excessive addition of smaller particles reduced the total energy applied to particle-particle collisions which also reduced the overall systems collision modulus. The results presented in this study could be considered as an introduction to dry size-segregated media in a vertical stirred mill. | |
| dc.identifier.apacitation | Sievers, W. (2025). <i>A DEM numerical modelling approach to simulating size segregation of media in a stirred mill and effects on grind characteristics</i>. (). University of Cape Town ,Faculty of Engineering and the Built Environment ,Department of Chemical Engineering. Retrieved from http://hdl.handle.net/11427/42677 | en_ZA |
| dc.identifier.chicagocitation | Sievers, Wilco. <i>"A DEM numerical modelling approach to simulating size segregation of media in a stirred mill and effects on grind characteristics."</i> ., University of Cape Town ,Faculty of Engineering and the Built Environment ,Department of Chemical Engineering, 2025. http://hdl.handle.net/11427/42677 | en_ZA |
| dc.identifier.citation | Sievers, W. 2025. A DEM numerical modelling approach to simulating size segregation of media in a stirred mill and effects on grind characteristics. . University of Cape Town ,Faculty of Engineering and the Built Environment ,Department of Chemical Engineering. http://hdl.handle.net/11427/42677 | en_ZA |
| dc.identifier.ris | TY - Thesis / Dissertation AU - Sievers, Wilco AB - Comminution is an important operation in the minerals processing industry. In both traditional and stirred mills, single-sized grinding beads are used, along with multiple passes through the mills, to achieve a sufficient size-reduction ratio. It is plausible to expand the size reduction capabilities of a mill using multiple-sized grinding beads in the mill. For this study, the discrete element method (DEM) was used to simulate dry size-segregated systems in a vertical stirred mill. These size-segregated systems were evaluated at different impeller speeds and weight distributions. The dry systems were susceptible to the Brazilian nut effect. Furthermore, it was found that excessive impeller speeds did not subsequently increase the overall collision modulus. The overall modal collision intensity for particle collisions was maximised between 350 rpm and 500 rpm where sufficient mixing and impeller speed were facilitated. At excessive speeds past 700 rpm the collision modulus plateaued. Excessive addition of smaller particles reduced the total energy applied to particle-particle collisions which also reduced the overall systems collision modulus. The results presented in this study could be considered as an introduction to dry size-segregated media in a vertical stirred mill. DA - 2025 DB - OpenUCT DP - University of Cape Town KW - DEM KW - vertical stirred mill KW - size-segregated KW - impeller speeds KW - weight distribution KW - grind characteristics LK - https://open.uct.ac.za PB - University of Cape Town PY - 2025 T1 - A DEM numerical modelling approach to simulating size segregation of media in a stirred mill and effects on grind characteristics TI - A DEM numerical modelling approach to simulating size segregation of media in a stirred mill and effects on grind characteristics UR - http://hdl.handle.net/11427/42677 ER - | en_ZA |
| dc.identifier.uri | http://hdl.handle.net/11427/42677 | |
| dc.identifier.vancouvercitation | Sievers W. A DEM numerical modelling approach to simulating size segregation of media in a stirred mill and effects on grind characteristics. []. University of Cape Town ,Faculty of Engineering and the Built Environment ,Department of Chemical Engineering, 2025 [cited yyyy month dd]. Available from: http://hdl.handle.net/11427/42677 | en_ZA |
| dc.language.iso | en | |
| dc.language.rfc3066 | eng | |
| dc.publisher.department | Department of Chemical Engineering | |
| dc.publisher.faculty | Faculty of Engineering and the Built Environment | |
| dc.publisher.institution | University of Cape Town | |
| dc.subject | DEM | |
| dc.subject | vertical stirred mill | |
| dc.subject | size-segregated | |
| dc.subject | impeller speeds | |
| dc.subject | weight distribution | |
| dc.subject | grind characteristics | |
| dc.title | A DEM numerical modelling approach to simulating size segregation of media in a stirred mill and effects on grind characteristics | |
| dc.type | Thesis / Dissertation | |
| dc.type.qualificationlevel | Masters | |
| dc.type.qualificationlevel | MSc |