Determination of Operational Inclusion Criteria (OIC) for Diesel Operated Load Haul Dumpers in Underground Hard Rock Mines Considering DPM Emission as Key Indicator

Abstract

Diesel-powered heavy earth moving machineries are nowadays being deployed widely in Indian underground hard rock mining operations due to its power, reliability and productivity. However, the combustion of diesel fuel releases different exhaust emissions, including Diesel Particulate Matter (DPM), which poses a significant health risk to miners. DPM, by and large consists of very small/micro (less than 1 μm in diameter) particles including carbon compounds, sulphates, and metals etc., which can penetrate deep into the respiratory system and cause various diseases. Monitoring and dipping DPM levels in underground hard rock mines are thus crucial to safeguard the occupational health and well-being of miners. In this study, DPM emission patterns of 10 numbers of LHDs (Load Haul Dumpers) were measured during loading operation and relevant data comprising surface DPM emission, the underground average DPM emission and DPM dose values obtained by operators (08hrs TWA basis) were recorded for each LHD. The experimentation was conducted at 03 number of different mine workplaces having separate ventilation scenarios. Air velocity, Humidity and Temperature etc. were also measured at the mine workplaces specified for the study. Simple linear regression and multivariate regression analyses were carried out to determine the strength and pattern of interrelationship between the variables like Surface DPM emission(SDE), Operator’s DPM dose (ODD), air velocity, temperature and humidity at mine workplace etc. After scrutinizing the relationships and associated empirical equations, the thresholds of surface SDE were quantified for the mine sections with different ventilation scenarios, to restrict the dose values below 100 microgram Ec/m3. Considering these thresholds as yard sticks, the allocation of LHDs can be made or Operational Inclusion Criteria (OIC) for Diesel Operated Load Haul Dumpers can be determined in such a way that the dose values will remain controlled under the statutory limits.