Diesel particulate matter in a South African platinum mine -- a case study

摘要

Since the utilisation of trackless mechanised equipment in the platinum industry is projected to increase extensively over the next few years, a baseline diesei paniculate matter (DPM) study was done to quantify DPM in the underground environment of a production section in a platinum mine. As part of the DPM baseline study, the impact of low-sulphur diesel fuel (<50 ppm) opposed to regular mine diesei (<500ppm), in order to reduce DPM exposure, was also investigated. For the purpose of this study DPM exposures were evaluated against the proposed international occupational exposure limit of 308 mu g/m~3 for EC. The ventilation flow rates for the section assessed were then calculated and new ventilation flow rates were determined in order to reduce the average DPM levels measured, to comply with the proposed international occupational exposure limit of 308 mu g/m~3. The results obtained from the DPM baseline study indicated that 85 percent of the individuals sampled for both the tests were exposed to DPM levels of above the 308 mu g/m~3 EC internationally proposed occupational exposure limit. The impact of flow-sulphur diesei fuel on personal DPM exposure concentrations were performed during the conducting of two similar tests: test one was conducted with diesei fuel containing a sulphur content of below 500 ppm (regular diesei currently used by the mines), and test two was performed with diesei fuel with a sulphur content of below 50 ppm (low-sulphur diesei) compared with the regular diesei currently used by the mines. Based on preliminary results a 15 percent reduction in DPM exposure levels was evident for the low-sulphur fuel (< 50 ppm). In order to reduce the workplace DPM concentrations to comply with the 308 mu g/m~3 proposed exposure limit, it was calculated that currently used ventilation flow rates are required to be roughly doubled for both the regular and low-sulphur diesels.