Precision of the Estimates of the Ore Reserves in the Fully Developed Ore-Blocks
1959 Volume 9 Issue 38 Pages 319-333
Details
1959 Volume 9 Issue 38 Pages 319-333
The writer has intended to clarify the sources of error in ore reserve estimation, because the subject has been of considerable interest to mining geologists as well as to miners, and only a little analytical work has been done on the it in Japan.
As the first step, the precision of the estimates of the amount and grade of ore which had been mined in certain blocks of several mines in Japan, was examined from the standpoint of sampling methods, as these estimates had been based on the results of underground stope sampling. Then the precision of the estimates of the ore reserves was roughly evaluated on the assumption that the sampling method corresponds approximately to the case of two-stage sampling where the sample size of the first stage is only two.
The average, variance, etc. are calculated in the dimensions of t/m 2 for ore reserves and kg/m 2 for metal content. The values of standard error/average of metal content are approximately 0.1 to 0.2.
The precision of measurement and calculation required in comparison with the "sampling error"is such that all values (amount of ore reserves, metal content, and assay) may be rounded off to two or three significant figures.
Preliminary study on the size of each increment was also given.
This study gives only approximate results insofar as specific numerical values are concerned.
