Dust Concentration And Diffusion Mechanism Of Open Pit Mine Based On Climate Influence

Air pollution is one of the greatest scourges of our time,not only because of its impact on climate change,but also because of the increased sickness and mortality it causes in the public and individual health.Air pollution is anticipated to surpass unclean water and lack of sanitation as the biggest cause of mortality worldwide by 2050.Most mining operations produce dust when air-borne becomes serious hazard to miner’s health and may cause respiratory diseases for example chronic bronchitis/pneumoconiosis.The WHO/ILO International programme on the global elimination of silicosis puts emphasis on characterisation of dust and its sources which involves determination of quartz content in respirable air borne dust.In this project,an attempt has been made to carry out dust monitoring and dust characterization at Haerwusu opencast coal project and Kalumbila copper mine using real time aerosol monitor and FTIR.Dust dispersion modelling was carried out using AERMOD and FLUENT software to assess the magnitude of the dust concentration at the working and peripheral areas of the study area with reference to the Nation Ambient Air Quality Standards(NAAQS).The following objectives guided the research: i)Determine dust concentration levels in the Open Pit Mine area.ii)Analyze parameters that influence dust dispersion in a mining environment.iii)Study the characteristics of dust content in Kalumbila Copper Mine.iv)Study the law and mechanism of dust diffusion in an Open Pit Mine using FLUENT software.v)Conduct numerical simulation model of dust dispersion using AERMOD software.The geospatial zoning in this research provided simple predictions of probable isopleths and maps of the level of dust concentration in and around a site.The production of dust from mining activities has negative consequences for human health,the environment,and a mine’s safety and productivity.Legislation around the world aims to ensure air quality and for that reason ambient air standards are employed,which the industry has to adopt.Occupational exposure standards are also used to determine safe exposure limits in the workplace for all compounds that are potentially harmful to humans.A thorough understanding of dust concentration in an open pit mine,as well as the relationship between the dust generation process and the mechanisms of various industrial operations,in order to aid in the development and precise determination of potential alternative dust mitigation solutions.Geospatial and geostatistical analysis of mine dust pollution was conducted for Haerwusu Open pit coal mine to Enhance Environmental Sustainability.To comprehensively and more accurately map the changes in concentration of PM2.5 and identify the influencing factors affecting its dispersion and concentration geospatial analysis using Arc GIS 10.2 and geostatistical Principal component analysis(PCA)was used respectively.Since the PM dispersion is influenced by meteorological elements,environmental factors such as temperature,rainfall,and humidity contribute to the unpredictability of emissions,necessitating the use of Principal component Analysis(PCA)statistical analysis,which is more precise than classic statistical methods.In the four seasons of winter,spring,summer,and autumn,the average yearly concentration of PM2.5 in the air pollution monitoring sites in Haerwusu surpass the international standards annual averages of World Health Organization(WHO)=10 μ/m3 and China National Ambient Air Quality Standards(CNAAQS)of 15 μ/m3.Pollution mapping of PM2.5 using geographic information systems displayed polluted and unpolluted areas in Haerwusu using Ordinary Kriging and inverse distance weight(IDW)interpolation approach and a variety of colors to spruce up the map to represent different levels of dust concentration.This helped to investigate which regions are most affected by PM2.5in order to propose solutions to make the mine safe for workers and environmentally sustainable.FLUENT numerical simulation was used to systematically study the dust generating mechanism,distribution,and diffusion law of open-pit mine dust in order to control dust pollution in open-pit mines.Computational fluid dynamics(CFD)models provide detailed information about the airflow pattern and air velocity distribution,temperature,and fugitive dust concentration within the enclosed domain of an open-pit.An actual open-pit domain of Kalumbila open-pit Copper mine is simulated with various simulation parameters to predict fugitive dust retention in the selected open-pit mine.The airflow pattern is observed to change for winter and summer seasonal conditions due to the variability in the amount of sensible heat flux.It is observed that fugitive dust particles predicted by the RANS method clear out of the actual open-pit domain sooner than the LES method.Dust characterisation for Kalumbila Copper mine was achieved by collection of dust samples from various mine locations in order to determine the quartz content of the dust using the Fourier Transform Infrared method.Real-time monitoring of dust levels using Dust Trak II was employed to determine the dust concentration from different mine operations such as drilling,blasting,loading,haul road and dumpsite.Dust exposure to workers was determined.Finally,the prediction of dust concentration at various mine areas and nearby areas using AERMOD view software was achieved.This research analysed the influence of mining activities such as drilling,blasting,loading,transporting,crushing,conveying,haul road,and exposed overburden face on surrounding air quality,by identifying dust emission sources and determining the emission rate of various mine site activities with precision.The determination of silica content and characterisation of the physical and chemical properties of PM allowed the assessment of potential impacts in the surrounding atmosphere and on the health of mine workers in the mines.The geospatial zoning in this research provided simple predictions of probable isopleths and maps of the level of dust concentration in and around a site.This research will help improve environmental,health and safety performance,making a positive impact in the community and improving their relationship by monitoring and analysing scientifically collected data.