Development of a wear index and its methodology related to mineral processing - Part I

Abstract: This Master Thesis was performed for Sandvik SRP in collaboration with the Institution for Industrial Production Faculty of Engineering at Lund University. Tool wear is one of the main cost drivers in the mining industry. By being able to characterize what kind of rock involved, you can choose a more beneficial tool material to minimize the wear and thereby reduce the maintenance costs. The purpose of this thesis is to see if there is a correlation between the surface and the wear. The work had to be divided into Part I and Part II due to the size of the project. In Part I nanoindentation was used to get data to models that describes the variation in hardness, different hardness phases and the quantity of each phase for the rock being examined. Nanoindentation examines the rock at nano-scale by forcing a diamond Berkovich indenter into the rock hundreds of times. A part of this thesis was also to find a standard methodology to prepare the samples for the nanoindentation, which requires a good surface roughness. The work started with a theory study to know the basics about the method and a literature study to see what have been done before. During the work new experiences were given by using a trial and error method when preparing the samples. The methodology has been described carefully to be able to repeat the process regardless of the rock being examined. However, the grinding and polishing processes can be different depending on the rock, meaning that the time for each process can vary. The results from the nanoindentation have been put into a table with expected wear based on internal order of the rocks involved. The table is supposed to be a basis used to find a correlation between the surface hardness and the wear after performing Part II. In the end of this thesis different suggestion of how to perform Part II are given.