Abstract:
The changing and stricter regulatory environment has
caused the mining industries in South Africa to re-look at their
individual mine health and safety departments. In 1997, after
the report of the Leon Commission of Inquiry (1995), the South
African Department of Minerals and Energy (DME) sent out a
directive to reduce the dust concentration level to below 5
mg/m3 at the operator’s position for the sampling period. The
reasons for the high levels of dust concentrations of dust are:
long headings up to 35 m, inherently high dust generation
rates of coal, and the increased use of highly mechanized
equipment. To aid in developing systems to reduce high dust
levels, a project was formulated under SIMRAC auspices with
the title of “Underground Mechanical Miner Environmental
Control” to address the dust problem.
The project was executed in two phases. The first phase
involved laboratory tests on a continuous miner model for
different ventilation and spray systems at ventilation simulation
tunnel at the Kloppersbos Research Center. In the second
phase of the project, tests were carried out underground, based on the findings and recommendations from the simulated
tests. This paper focuses on the results and findings of
the hood systems, viz., retrofitted hood system and integrated
hood system. The average dust concentration for the
sampling period at the operator’s position for the retrofitted
hood, integrated hood system-smaller scrubber and integrated
hood system-larger scrubbers were 2.33 mg/m3, 6.08
mg/m3 and 5.98 mg/m3 respectively. On the other hand, the
equivalent average dust concentration (TWA-CONC) for an 8-
h period for the retrofitted hood, integrated hood systemsmaller
scrubber and integrated hood system-larger scrubbers
were 1.53 mg/m3, 5.51 mg/m3 and 4.83 mg/m3 respectively.
Finally, the paper highlights the use of auxiliary ventilation
systems during the tests underground.
