Polissage du granit : qualité, émission et dispersion des poussières et moyens de contrôle à la source

Abstract

This thesis is a part of a large collaborative project between the IRSST, ÉTS and École Polytechnique de Montréal. This project aims to understand the mechanisms of particles generation and dispersion emitted during manual granite polishing in order to better control them, by acting on the industrial polishing process itself and/or by the ventilation. This thesis concerns the 1-characterization of the emission and 2-the control at the source of dust particles (fine (FP) and ultrafine (UFP)) emitted by dry polishing granite, which presents a major importance for health and safety of workers. The first part allows the study of experimental polishing on a machine tool. Its objective is to understand the phenomena of dust emission and dispersion during polishing to optimize polishing parameters and reduce emissions by acting on the polishing process. The second part is an experimental simulation of the dust emission issued from the rotational movement of a disc simulating the polishing of the materials. Its objective to understand the behavior of dust particles in the rotary wake and to evaluate the control devices at the source of the emissions. Results shows that choosing a spindle speed of approximately 1500 tr/min and an average feed rate of 17 mm/s is a good compromise, which leads to minimize emissions while achieving a good surface finish during the polishing process. It is also shown that the dust emitted contaminates in the same way the vicinity and near the polishing tool. Increasing the diameter of the abrasive tool enhances the dust emission. The peak concentration of dust generated during polishing is detected for particle diameters belong to PM2.5 (FP less than 2.5 μm in diameter). The analysis of respirable dust during granite polishing shows that the quartz rate far exceeds standard of 0.1 mg/cm3 (8h/day - 5d/week). Three devices for reducing dust at the source by local ventilation are studied: push-pull, dust shroud and integrated suction slots. These devices provide good control efficiency (> 90%) of the dust emission. The combination of optimized parameters of the polishing process and reduction devices at the source maximizes the efficiency of dust reduction during granite polishing. The originality of this work lies in the study of polishing, emissions and dispersion of particles, as well as the proposal of reduction solutions at the source. To achieve this, we chose a multidisciplinary approach from tooling design, polishing, capture at the source and simulation.

Date	30 Aug 2018
Original language	French
Awarding Institution	École de technologie supérieure
Supervisor	Victor Songmene (Supervisor) & Ali Bahloul (Co-supervisor)