Study On The Explosion Characteristics And Simulation Of Dust Of Sulfide Ores

The mining process of the mines contain sulfide will produce a large amount of dust and it will produce explosion hazards in certain conditions,which threat the safety of personnel and equipment and bring great security risks to the mine.In this paper,A(sulfur accounts for30%~40%),B(sulfur accounts for 20~30%),and C(sulfur accounts for 10~20%)sulfide ore dust as the research object,and the mine dust explosion characteristics as the main line.The influence of dust mass concentration,particle size,sulfur content,ignition extension time and ignition energy on the explosion characteristic parameters of sulfide ore dust was discussed by means of 20L explosive ball testing device,and the related laws were summarized.By using the logistic regression model in statistical analysis,the calculation of the lower limit of the explosion of sulfide ore dust cloud was carried out by probability method,and the result was compared with the experimental results.When the particle size of sulfide ore was changed,the explosion strength was calculated theoretically.By using fluent software,the simulation of the diffusion and explosion process of sulfide ore dust was carried out,which provided a theoretical basis for preventing and controlling the dust explosion of sulfide ore.The specific research contents were as follows:(1)The variation regularity of the explosion strength of sulfide ore dust with mass concentration was obtained.Through the 20L explosion ball test device,all types of sulfide dust explosion index were lower than 8Mpa m/s,which was regarded as St1 class according to the explosion intensity,and it means weak explosive.(2)The influence of different ignition energy on the explosion behavior of sulfide mine dust was analyzed.When the ignition energy changed from 2KJ to 10KJ,the explosion pressure of the Class A,B and C sulfide dust were increased,and A mine dust was the most affected by the ignition energy,the second Class B and the C class were the least.It shows that the higher sulfur content of sulfide ore dust,the more significant the explosive pressure was affected by ignition energy.(3)The lower explosive concentration of B sulfide ore dust cloud was obtained.The lower explosive concentrations of the B500,B300 and B200 sulfide ore dust clouds were200g/m~3,150g/m~3,230 g/m~3.By using the logistic regression model in statistical analysis,the probability method was used to calculate the lower explosion limit concentration of B-type sulfide ore dust cloud,and when the probability of ignition success was 10%,the lower limit concentration of sulfide ore dust cloud of particle size<25?m(B500)was 209.17g/m~3,When the dust particle size increases to 25~48?m(B300)and 48~75?m(B200),the corresponding explosion lower bound concentrations were 154.54g/m~3 and 239.24g/m~3 respectively.(4)The relationship between the explosion lower limit of the dust cloud and the particle diameter of the mine dust was obtained by calculation.In this paper,the lower limit of the explosion of sulfide ore dust cloud was analyzed theoretically,from the calculation results,it was found that the lower explosion limit of sulfide ore dust cloud be positively correlated with the mean particle size.(5)The empirical expression between the particle radius of sulfide ore dust and the explosion pressure was calculated.When the dust particle size of sulfide ore was changed and the dust explosion was fully exploded,the explosion strength of Class B sulfide dust(high sulfur-containing group)was calculated qualitatively,and finally the empirical expression between the particle radius and the explosion pressure of sulfide ore dust was obtained.(6)The diffusion process and explosion process of sulfide ore dust were simulated.By using fluent software,the dust of B-type sulfide ore was simulated,and the diffusion of sulfide dust was relatively uniform during 60~80ms,which means 60ms was considered as the best time of ignition.After the ignition of the mine dust in the 20L explosive ball device,the temperature of the B300 was about 1800K,the temperature of the explosion was about2100K,and the temperature peak was about 2500K.The area of the B500 was about 1400K,the temperature was about 2000K when it exploded,and the peak temperature was about2600K after a period of time.Which means the smaller the particle size of sulfide,ore dust was more easily ignited and the explosion temperature was higher.