IC 6978 Mining Methods And Costs At The Mount Isa Mines, Ltd., Mount Isa, Queensland, Australia ? Introduction

This paper, describing the mining operations at Mount Isa Mines, is one of a series covering mining methods and costs being published by the United States Bureau of Mines. The Mount Isa property has been in operation since June 1931; during this period operations have changed from the production and treatment of carbonate ores to the mining, milling, and smelting of sulphide ores. This change involved revision of ore-extraction methods. Stoping methods have been designed to apply to parallel lodes ranging from 10 to over 100 feet in width and dipping at 50° to 60°. The hardness and strength of the ore and enclosing wall rocks, together with the strength and thickness of the country rock between lodes, have permitted the selection of a sublevel stoping method for mining the sulphide ores.