Author:
Janne Torvela
February 2020
Thesis submitted for the Master's Degree Program of Mechanical Engineering.
Supervisors:
Dr. Marcos de Paiva Bueno and Prof. Simon Michaux
Abstract:
Double Wheel Crusher prototype
Janne Torvela
University of Oulu, Degree Programof Mechanical Engineering
Master’s thesis2020, 70pp. + 2Appendixes
Supervisor(s) at the university: Dr. Toni Liedes, Dr. Marcos de Paiva Bueno
This thesis presents a proof of concept for a new testingdevice. The prototype device was commissioned as a part of a project to develop a fast, low-cost, and reliable breakage characterization test for geo-metallurgical modelling. One of the key processes involved in minerals extraction is comminution: mineral ores are broken down with crushing and grinding machinery.Comminution testing can be used for the purposes of optimizing these processes. Various testing methods used in the industry subject rock particles to varying levels of crushing impacttomeasure the amount of fine materials liberated relative tothe input energy. The role of mechatronic engineering in this context is to design and develop intelligent machines that ease the work of the researchers and techniciansperforming these tests. The structure of the new device was proposed as a variation of an instrumented roll crusher with an adjustable gap. The trial operation of the prototype was doneusing rocks from different mine sites around Finland. The test set resulted in data with a clearly identifiable correspondence of energy to the amount of breakage, proving the plausibility of the device. Some issues were found with the accuracy of energy measurements. The programming error behind the fault was corrected and the improved device was found to produce a standard deviation of measurement of 1.07 Joules. Means to further improve the accuracy of the energy and force measurements arediscussed, with recommendations and suggestions for other improvements to the device in the future.
Key words: Geometallurgy, comminution, ore breakage characterization, variability.