A 3-dimensional Direct Numerical Simulations (DNS) of an isolated aluminum (Al) particle combustion in air is presented. The focus is placed on three elements: 1) developing an accurate and robust numerical scheme for understanding the physiochemical processes involved in the Al combustion, 2) quantifying the impact of sub-oxides condensation onto the burning droplet and subsequent heterogeneous surface reactions on the Al vaporization processes, and finally, 3) evaluating existing vaporization laws (burn rate) which are applicable to macroscopic combustion models.