A New Method for Sampling Diamond-Drill Core: Fillet-Cutting

CIM Bulletin, 1968

E. BONSALL; A. R. GRAHAM and J. J. BRUMMER, Falconbridge Nickel Mines Limited, Toronto, Ont.

A method and device are described for sampling diamond- drill core by cutting a continuous fillet of constant cross section from the cylindrical surface of the core throughout appropriate sample lengths. The apparatus employs a tapered, abrasive-set, cutting wheel, the conical cutting surface of which projects slightly into a rectangular core-guiding trough set parallel to the axis of rotation. The depth of fillet and thus the amount of sample per unit length can be regulated by adjusting the core guides. The freshly cut fillet itself, by engaging in a guide beyond the cutting wheel, acts to prevent rotation of the core during operation of the device. The cuttings which form the sample are normally collected in a tray below the cutting-wheel and appear at about 80 per cent -100 mesh. They require little or no further treatment or comminution before analysis. Speed, economy and convenience of sampling are thus greatly increased as compared with conventional sampling by impact breaking or sawing, followed by crushing, grinding and subdivision for assay. Assays from fillets (about 1/20 the cross-sectional area of the core) and from 180-degree segments, from the same ninety-three core-samples, representing 431 feet of nickel-copper mineralization, gave the following results: Nickel (wt. o/o) Copper (wt. o/o ) 1800 Segment Fillet 180° Segment Fillet Grade Estimate 0.92 ± 0.24 0.98 ± 0.25 0.71 ± 0.16 0.78 ± 0.21
Keywords: Assays, comminution, copper, Fillet-cutting, nickel, samples, copper, CORE, Cost, Costs, mineral, minerals, Sampling