| This paper aims to obtain the two parameters of the explosive strength and the minimum explosible concentration of dust cloud of sufide ore.Ignition energy is set as 10 k J according to GB/T 16425-1996,GB/T 16426-1996.Six concentration have been set,including 60 g/m3,250 g/m3,500 g/m3,750 g/m3,1000 g/m3,1500 g/m3.As the main influencing factors,the sulfur content of less than 10 %,10 % 20 %,20 % 30 % has been divided into three levels of D,C,B and the particle size has been divided into three levels according to 200 mesh sieve,300 mesh sieve and 500 mesh sieve.Two factors and three levels of complete test has been established by using the 20 L explosion test chamber.Firstly,the maximum explosion pressure,the maximum rate of explosion pressure rise and the deflagration index have been obtained by the explosive strength test.Secondly,the minimum explosibe concentration has been obtained by the explosive limits test.Finally,the GRNN prediction model has been established.The main work is as follows:?1?The explosion severity and explosion sensitivity of the dust of sufide ore have been evaluated.According to the the maximum rate of explosion pressure rise < 33 MPa·s-1,the deflagration index < 9 MPa·m·s-1 and the minimum explosible concentration < 100 g/m3 of every tests,the dust of sulfide ore is weak explosible dust that belongs to St1 degree of explosion class,and the explosion sensitivity of it is weak.?2?The influence of concentration on the maximum explosion pressure of the dust of sulfide ore.The maximum explosion pressure was first increased and then decreased with the increase of concentration.Predicted by the maximum explosion pressure curve fitting,the maximum explosion pressures of B200,B300,B500,C200 are as follows: 0.271 MPa,0.281 MPa,0.209 MPa,0.157 MPa,and the concentration of it are as follows: 1220 g/m3,1272 g/m3,1000 g/m3,843 g/m3.?3?Summarizes the influence of sulfur content of the dust of sufide ore.The sulfur content plays the most crucial role in the explosion of the dust of sulfide ore.The sulfur content of less than 15.96 %,the tests were not explosion.Sulfur content is higher than 17.12 %,the dust have explosive capacity.The critical sulfur content is 16 %17 %,which exceeds the critical sulfur content for explosive dust,sulfur content is lower than the critical performance of inert dust.The sulfur content is greater,the greater the explosion pressure of sulfide dust.?4?Summarizes the size and content of sulfur on the influence of the duration of the explosion.The same level sulfur concentration in the 250 g/m3,the duration of the explosionby particle impact,the larger the particle,the longer the duration of the explosion.More than250 g/m3,the duration of sulfide ore dust explosion jointly governed by the two sulfur content and particle size.?5?The minimum explosible concentration have been obtained.The minimum explosibile concentration of B200,B300,B500,C200 are as follows: 230 g/m3,150 g/m3,200 g/m3,640 g/m3.The higher the sulfur content,the lower the minimum explosible concentration.The diameter of less than 10 ?m,high sulfur group optimal particle size?about 6.185 ?m?to form the most stable turbulence dust.The mininmum explosible concentration of the lowest concentration is about 150 g/m3.?6?The explosive products of the dust of sufide ore have been analyzed.Test release of SO2 is more than 940 ppm,and the explosive products performance for the features that Fe2+ is oxidized to Fe3+.Therefore,mainly involved in the explosion should be Fe containing sulfide.?7?The GRNN predicting model has been established.The sulfur content,particle size,concentration,mineral water content,Fe content as the network input,to predict the maximum explosion pressure,the average prediction error is less than 7 % and forecast has good effect. |
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