An Eulerian-Lagrangian simulation of the thermobaric explosion and the propagating detonation waves with aluminum particle combustion in a closed chamber is carried out and validated very favorably with the pressure histories measured experimentally. A novel numerical framework based on the space-time conservation-element and solution-element method (CE/SE) was employed to simulate the complex detonating flow with detailed chemistry. A discrete particle technique was adopted with either a mono-dispersed or poly-dispersed particle distribution. The results between the experiment and simulation on pressure histories and corresponding impulse forces are compared and showed good agreement. In addition, the effects of metal combustion on afterburning were discussed in detail in terms of the reaction mechanisms and particle dynamics.