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Sampling gold ore by diamond-drilling in the Homestake Mine, Lead, South Dakota.

Authors
Koch-GS Jr.; Link-RF
Source
NTIS: PB 200 046 :1-35
Link
NIOSHTIC No.
10008747
Abstract
Several methods of calculating ore grades by diamond-drill sampling in the Homestake mine, Lead, S. Dak., Have been evaluated by statistical analyses of assay data. The natural distribution of gold particles, partly masked through sampling and assaying procedures, is probably lognormal. As a consequence of the gold particles being clustered rather than randomly distributed within the ore bodies, (1) more mine samples are needed to obtain a specified precision of mean grade than the number predicted by the standard-error-of-the-mean law; (2) the variance of gold values is not inversely proportional to sample volume, and, therefore, small- diameter drill core yields samples nearly as good as larger diameter core; and (3) sampling at 5-foot intervals provides nearly as good results as sampling at shorter intervals.
Publication Date
19710101
Document Type
IH; Report of Investigation;
Fiscal Year
1971
NTIS Accession No.
PB-200046
NTIS Price
A04
Identifying No.
RI 7508
NIOSH Division
DRC;
Source Name
NTIS: PB 200 046
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