Improvement And Application Research On Evaluation Method Of Coal Mine Dust Hazard Degree

Coal mine dust hazards have always been an important part of Coal Mine Occupational hazards.At present,there is a lack of specific evaluation methods for coal mine dust hazard degree in the industry.The existing evaluation methods have more or less defects in subjective dependence,universal applicability,operability,pertinence and so on.In view of these problems,this paper compares and analyses the occupational hazard assessment methods at home and abroad,synthesizes the advantages and disadvantages of different assessment methods,chooses the evaluation method suitable for coal mine dust,and combines with the field investigation of coal mine in our country to improve it,so as to make it a scientific,practical and effective evaluation method of coal mine dust hazard degree suitable for the actual situation of coal mine in our country.In order to provide a more convenient and effective evaluation method for dust occupational hazard assessment in coal mine industry in the future.This paper comprehensively analyses and compares the suitability of the EPA evaluation model of the United States Environmental Protection Agency,the semi-quantitative risk assessment method of Singapore,the ICMM model of the International Mining and Metals Commission,the Occupational Health and Safety Risk Assessment Method of Australia,the Occupational Accident and Occupational Disease Risk Assessment Method of Romania and the Technical Guidelines for Occupational Health Risk Assessment of Chemical Hazardous Factors in the Wor On the basis of maneuverability,the ICMM model was improved,and the exposure probability PrE was assigned according to the possibility of exceeding the occupational exposure limit.It was revised as follows: according to the concentration values of multiple tests in different working periods of the same post,the occupational exposure limit was exceeded 2 times or less in all test results.Those who exceeded the occupational exposure limit 2 to 4 times were low,those who exceeded the occupational exposure limit 4times or more were high.The classification method of occupational hazards in workplace in "Classification of Occupational Disease Hazards in Workplaces Part 1: Productive Dust" is introduced into the calculation of health consequences grade C of ICMM model,which avoids the interference of subjective factors of evaluators and makes the classification resultmore scientific and credible.The improved method can avoid the interference of human factors and has strong maneuverability.It is suitable for the evaluation of dust hazard degree in coal mines.The research object of this paper is large-scale coal enterprises which mainly focus on coal mining,comprehensive utilization of power generation and coal chemical industry.Investigation sites include fully mechanized mining face,mining face,tunneling face,transporter and other major areas with serious dust pollution.The investigation mainly includes the production process of mining and transportation in coal mines,the overall layout of mining areas and equipment,the exposure of dust-producing jobs(such as dust exposure concentration,exposure number,exposure time,etc.),the setting of Engineering protective facilities,the use of personal protective equipment,occupational health examination,etc.According to the requirements of "Code for Occupational Disease Hazard Assessment of Construction Projects",sampling conditions are carried out according to the designed full-load production conditions.According to the actual situation of production and operation,each dust sampling point is sampled in the period of the highest concentration in a working day.Short-time sampling is used,each sampling time is 15 minutes,continuous sampling for three working days.Individual dust collection is carried out for workers who have the highest concentration of harmful substances and the longest exposure time.Each working day is sampled for working hours,and three workers are sampled continuously.Samples shall be kept in accordance with relevant regulations after collection.The results showed that dust concentration exceeded the standard in several positions.On the basis of comprehensive comparison and analysis of existing occupational hazard assessment methods,the International Mining and Metal Commission Occupational Health Risk Assessment Model(ICMM)was improved.Combining with the field survey of coal mines,the improved ICMM model was used to evaluate the dust hazard degree of typical dust-producing positions in the investigated coal mines,and the occupational hazard risk index method was used to verify the results.Analysis.The evaluation results are basically consistent with the dust detection results and quantitative classification method.Compared with the occupational hazard risk index method,the evaluation results of coal miners’ posts,gangue pickers’ posts in machine roadways and coal bunkers’ dropping posts in fullymechanized mining face are on the high side.After analysis and optimization,the harmfulness degree of the evaluation results of coal bunkers’ dropping posts and boiler inspection posts in surface coal bunkers is higher.There was a decrease.Therefore,it is concluded that the improved ICMM model can be used to evaluate the hazard degree of coal mine dust,which is convenient,fast and easy to operate,and the evaluation results are scientific and reasonable.