Generation of sulphur dioxide in blasting at Fox Mine

CIM Bulletin, Vol. 74, No. 832, 1981

E.N. DuRUSSEL, Fox Mine Superintendent, Sherritt Gordon Mines Limited, Lynn Lake, Manitoba

The Fox Mine has been producing copper/zinc ore since 1970 at a rate of approximately one million tons per year, and until 1978 all production was derived from longhole open stapes. In June 1978, a trial slope using bighole mining methods was started to eliminate the development of two sublevels between 400 level and surface. The trial proved to be successful, and bighole mining is now an accepted mining method for both slopes and pillars at Fox Mine.When production blasting was started in the first slope, the biggest problem encountered was the production of large amounts of sulphur dioxide gas as a result of secondary sulphide dust explosions. This gas generation resulted in lost production time and caused minor damage to underground installations to the blast level, and to the headframe. Sulphur dioxide generation has been noted in secondary drawpoint blasts and, on rare occasions, in drift rounds.This paper discusses the occurrence of the sulphur blasts and the practices and precautions used to prevent their reoccurrence at Fox Mine.
Keywords: Underground mining, Sulphur dioxide, Blasting, Fox Mine, Bighole mining, Sloping, Development.