An evaluation of cave mining in weak hangingwall conditions at Hartbeesfontein Gold Mining Limited
Date
1993
Authors
Arnold, David Anthony
Journal Title
Journal ISSN
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Abstract
A mining area at Hartebeesttentein Gold Mine, designated as the 5.K. North Block, is
traversed" by ageological alteration zone known locally as the "pseudo-breccia". The
rockmass in this zone has been rendered friable, weak and prone to collapse as a result of this
phenomenon. The area is also marginally payable, making stoping width control vitally
important. Any failure of tht:: hangingwall which dilutes the ore can render the mining area
uneconomical.
The stoping method employed-in the SA North Block, and extensively elsewhere on the mine,
is called "cave mining" or "caving". The method, which has been in use on the min~ since
the early 1960's, allows the back area to collapse behind a zone of face support Which
consists of either timber sticks or steel hydraulic props.
Varibus stope support strategies were investigated to deal with severe strata control problems
arising from the prevailing poor hangingwall conditions. Serious consideration was given to
c backfilling as an alternative to caving, but the option was finally rejected for reasons outlined
in this report,
The development of improved prop-based face support strategies and an evaluation of their
effectiveness in combination with cave mining formed the main thrust of the project work.
Some adaptations had to be made to suit the caving method, and these aspects are described
in some detail in this report.
The report thus concentrates on the development and implementation of stope support
strategies designed to cater for weak ground conditions, rather than dealing with the cave
mining method per se. Nevertheless, a Comprehensive review of the history and theory of
cave mining is presented together with a fairly detailed evaluation of the backfill alternative.
Some quantitative assessments of strata behaviour under caving conditions have been made
from time to time in the past. It was therefore deemed worthwhile to measure, quantify and
interpret hangingwall rock movement at a number of stope sites within the pseudo-breccia
alteration zone, for comparative purposes.
Description
Thesis (M.Sc. (Engin))--University of the Witwatersrand, Faculty of Engineering, 1993
Keywords
Caving, Stoping (Mining)