Abstract:
After initial studies by the CSIR indicating that a discrepancy
exists in the dust concentration results between gravimetric dust
samplers, alternative instruments or methods were sought. In
the study that followed; it was recommended by the HSL in the
UK that a cowl arrangement, together with a sampling rate
equivalent to the CEN / ISO standard, be used to minimize over
sampling. As such CEN/ISO recommended sampling rate of 2.2
l/min was used for the first time in South African mines. A BGIstainless
steel cyclone sampler and a Higgins Dewell type
sampler with a cowl arrangement were used in the study.
Implementation of the recommended changes to samplers and
the flow rate will interrupt the continuity of monitoring data built
up over the years, but they will raise South African dust measurements
to international standards. Although extensive work has
been carried out on the use of cyclones, most of the previous
studies were carried out in the laboratory, which have an advantage
over the extremely difficult conditions in underground coal
mines. This paper describes the field results from the two gravimetric
samplers tested underground.
