Planetary ball mill is proposed as an intensive high-energy mixer to obtain flowability improvement of industrially exploited, cohesive and finely comminuted powders via dry coating. Response surface methodology (RSM) coupled with central composite rotatable design (CCRD) is applied as an effective method to prediction of high-energy mixing conditions. The use of this procedure allows to identify relatively narrow ranges of high-energy mixing parameters (rotating speed of planetary ball mill and mixing time) and the amount of additives used (nanosilica and isopropyl alcohol) providing substantial improvement of flowability of Aluminium hydroxide (Apyral) and Calcium carbonate powders. To find the optimal values of the process parameters, allowing to obtain the lowest values of flowability indices (angle of repose, compressibility index), desirability function approach was applied. The obtained results may be a basis for developing a general routine allowing mixing parameters to be successfully predicted regarding some physical properties of powders only with no experiments needed.