Drilling Methods Used For Sampling Soft Iron Ore Deposits

CIM Bulletin, Vol. 70, No. 783, 1977

Raju S. Sagi, Exploration and Development, Iron Ore Company of Canada, Schefferville, Quebec

This paper deals primarily with the different types of drilling methods used by the Iron Ore Company of Canada for sampling the soft and friable hematite-limonite (secondary) iron ore deposits found in the Schefferville area. The problems associated with drilling, sampling, sample handling and sample preparation for chemical analysis of these ores are discussed. Systematic evaluation of the various drilling methods led to the selection of an integrated drilling system. This system consists of a rotary -dual-tube - reverse-circulation drill, with tricone bit, polymer mud and mechanical sample splitter. The historical development of this drilling system is described in detail, as are the equipment, sample flow and quality control checks carried out to obtain representative samples. This integrated drilling and sampling system has been used satisfactorily on a routine basis for determining the grade and tonnage of ore for the various deposits for the last five years (1972-76) in the Schefferville area.
Keywords: Drilling, Development drilling, Sampling, Iron Ore Company of Canada, Iron deposits, Diamond drilling, Chop-and-drive drilling, Eotary drilling, Mud drilling, Wireline coring, Tricones, Sample splitters, Dewatering.