Calibration of DEM contact parameters for tumbling mills using PEPT

• Autor(a) principal: Chagas, Anderson Silva das
• Data de Publicação: 2015
• Tipo de documento: Trabalho de conclusão de curso
• Idioma: eng
• Título da fonte: Repositório Institucional da UFRJ
• Texto Completo: http://hdl.handle.net/11422/18064
• topic: CNPQ::ENGENHARIAS::ENGENHARIA DE MATERIAIS E METALURGICA; Comminution; energy efficiency; ball milling

Tumbling mills are among the most used equipments in the comminution of minerals, presenting great robustness, and being capable of dealing with large tonnages of material per day and a wide size range for the feed. Although tumbling mills have been developed to a high degree of mechanical efficiency and reliability, they are extremely wasteful in terms of energy expended. The modeling and complete understanding of the charge behavior and mechanisms related to particle breakage in tumbling mills are of extreme importance. However, understanding the mechanical environment inside the mill during operation presents certain challenges since tumbling mills are closed and opaque systems, making the complete quantification of charge distribution and motion extremely difficult or even impossible. The discrete element method (DEM) is highly suitable for the tumbling mill problem and consists of applying Newton's second law to particulate bodies in motion and a force to the bodies in collision. In order for a DEM simulation to describe the particle movement with fidelity to the real equipment, it is necessary to use proper material and contact parameters. Those parameters can be estimated through calibration, by quantitative comparison of experimental and simulation results. In that sense, it is advantageous to use laboratory-scale mills. The Positron Emission Particle Tracking (PEPT) is a technique for measuring the flow trajectory of a radioactive particle tracer in a granular or fluid system such as a ix tumbling mill and presents itself as an ideal technique for calibrating DEM parameters in some cases. The main objective of the present work is to suggest a methodology for the calibration of contact parameters, for DEM simulations, using data acquired from tests in a mill using the PEPT technique. Some options of comparing PEPT and DEM are presented and the validity of the comparison itself is assessed.