Investigation of blasting dust emission depending on bench geometries and blasting parameters

The aim of this thesis is to investigate dust resulted from open pit mining blasting depending on slope geometry and blasting parameters. To achieve research objectives, measuring the amount of dust and measuring the height of dust cloud are among the basic field research activities. Based on field investigation and statistical analysis element of novelties of this study are as follow: First: to propose a practical method for measuring the amount of dust in a small number of blast holes, close distance and short time of measurement. Second, dust cloud is separated and defined into two parts according to timing after blast initiation. Third, to propose the method of evaluating blast geometries and parameters based on blasting dust cloud height. Two different of dust cloud sections: the dust cloud that appears up to 5 seconds after the blast initiation is defined as first stage dust. After the first stage, vertically and horizontally spreading dust which affected by weather parameters is defined as second stage dust. From 33 of total blast event, 20 of dust measurement result was recorded. Three different approach to determining dust amount was compared: measured result (actual), box model based and improved box model based. It was observed that there is significant differences amount of dust between actual result and model based result. In this study, multivariate regression analysis was performed to investigate the influence of slope geometry and blasting parameters on dust cloud height. The dust Cloud height increased as the number of blast holes and the maximum amount of explosive per delay increased, the dust cloud decreased as the slope height and stemming length increased. From this result, new preliminary approach of evaluating blast geometry and blast parameters based on dust cloud height is proposed