Overdrilling of Open-Pit Blast Holes

CIM Bulletin, 1971

J. L. COLLINS, Research Assistant, A. GALIBOIS, Associate Professor, H. MONETTE, Associate Professor, Departement des Mines et de Metallurgie, Universite Laval, Quebec, P.O.

This paper deals with the problem of caving, which occurs in varying degrees in blast holes before loading. It is shown that the distribution of the amount of caving in materials may be described by a gamma density function. A decision model to determine the <>ptimal depth of overdrilling 'in order to minimize the expected additional cost per hole is described. Two different policies are discussed. In addition, charts which permit the mine operator to realize significant savings have been drawn for different actual situations.
Keywords: Blast, Caving, caving, gamma distribution, mining engineering, Quebec City, random variable, Cost, Costs, Materials, mining, Model, Models, Quebec