Explosion inhibition of coal dust clouds under coal gasification atmosphere by talc powder

Abstract

During coal gasification, the explosion intensity of coal dust was enhanced and more difficult to inhibit due to the presence of CO and H2. To mitigate the risk of dust explosion under a coal gasification atmosphere, the inhibition performance of talc powder (TP) on coal dust explosion was investigated by using a 20 L spherical explosive vessel. The results showed that the explosion intensity of dust clouds was attenuated with the inhibition of TP. As the particle size of TP decreased, the explosion pressure gradually was reduced and the explosion time was extended. The maximum explosion pressure of dust clouds decreased from 0.845 to 0.270 MPa after the addition of 8000 mesh TP, representing a reduction of 68 %. And the flame propagation velocity was consequently dropped from 1.22 to 0.17 m/s. Moreover, the explosion of higher rank coal dust was more easily inhibited by TP. XPS analysis demonstrated that the C–C and C–O–C in coal dust were effectively protected under the effect of TP. And the inhibition mechanism of TP on coal dust explosion was elaborated thoroughly in combination with the analysis of explosion products.