Prospective Application of Response Surface Methodology for Predicting High-Energy Mixing Process Conditions towards Fine Powders Flow Improvement

Abstract

Planetary ball mill was 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) was applied as an effective method for the prediction of high-energy mixing conditions. The use of this procedure allows identifying 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 the flowability of Aluminium hydroxide (Apyral) and Calcium carbonate powders. In order to find the optimal values of the process parameters, enabling to obtain the lowest values of flowability indices (angle of repose, compressibility index), the 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.

Chemical and Process Engineering

“…Disulfiram powder was chosen, as a typical material from this group. The results obtained in this study for coarse particles (Disulfiram and potato starch) were merged with the earlier gained results for finely ground cohesive powders (given in (Leś and Opaliński, 2021)). On the basis of this, some practical guidelines regarding conditions and parameters of mixing in a planetary ball mill towards better flow quality of cohesive powders were formulated.…”

“…6. In the case of coarse powders the degree of surface covering is high and the deposition is regular in contrast to the fine powders (Leś and Opaliński, 2021).…”

“…dissolution improvement) via dry coating of powders (Sonoda et al, 2008). It has also turned out that mixing in a planetary ball mill is an effective method of a cohesive powder flowability improvement (Leś et al, 2015;Leś et al, 2017;Leś and Opaliński, 2021). The possibility of performing experiments in an industrial scale, even in a continuous mode, is the main advantage of this type of a high-energy mixer.…”

Studies on Moisture Effects on Powder Flow and Mechanochemical Improvement of Powder Flowability

“…In the works by the authors a planetary ball mill was used for flowability improvement of cohesive powders, used mainly in chemical, pharmaceutical and food process industries: calcium carbonate [66], Apyral [67], Disulfiram (Esperal) [68] and potato starch [69] powders. The powders were doped with nano-sized silica (Aerosil) and also with propan-2-ol as a process control agent (PCA), needed to avoid caking of fine powders during their mixing.…”

“…Model optimization of multi-parametric process, as is the case with interactive mixing, is difficult to formulate due to several local minima [66,67,69]. For that reason, to perform the process optimization, the authors' suggestion is to convert the model equations to a desirability function.…”