Dry bead mills are believed to contribute significantly to the shortening of drying processes and reduction of required production space, as well as the energy costs reductions that result from these improvements. In this study, we used a dry bead mill to perform grinding test on silica sand, alumina, and activated carbon. We investigated the impact various dry bead mill conditions had on grinding, and explored the dry grinding potential of bead mills. We found a regular relationship between the median diameter and the power, and that this tended to match previous reports. We also demonstrated that within the scope of this experiment, tip speed, bead filling, and the feed rate were not factors that affected the energy efficiency.

The control of powder flowability with fine particles is important for tablets prepared by direct compaction. In the present study, the addition ratio of two types of fine particles of silicic acid compounds that can be used as glidants was examined to improve powder flowability. The powder sample, lactose, with a count median diameter (D_P50) of 103 μm, was used as an excipient, while magnesium aluminometasilicate (MA; D_P50 = 1.2 μm) and magnesium silicate (MS; D_P50 = 0.6 μm) were used as glidants. MA or MS was added to the excipient at different ratios in a range from 0.2 to 3.0 mass%. Powder flowability was evaluated by a vibrating tube method, which can characterize both the static and dynamic friction properties, and by conventional methods, i.e., measuring the angle of repose and compressibility. From a series of experiments, it was found that MA is more effective than MS in improving powder flowability, but with a strong dependence of addition ratio.

The transport of particles in disordered systems does not follow the classic laws that describe transport in ordered media, which leads to many anomalous physical properties. This review represents the first experimental study on the pattern formation of precipitation waves in a disordered gel formed using the quenching method. We elucidate the quantitative relationship between the gel microstructures and dynamics of pattern formation based on an analysis of the anomalous diffusion dynamics. This analysis revealed that permeability fluctuations of the gel increase the complexity of precipitation patterns. This study is expected to inspire fundamental studies of the formation mechanisms of organized patterns in disordered media in nature and enable the development of new methods for the control of pattern formations in reaction-diffusion systems without the use of external forces.

To achieve high comminution energy efficiency is one of the most important factors in comminution machine development. We have proposed a new concept comminution machine, CAHM (Conjugate Anvil-Hammer Mill), as a US Patent. In this report, we evaluate the energy efficiency of CAHM and compare it with a conventional comminution machine by using a computer simulation method. We use the general purpose non-sphere particle DEM software “ROCKY” for the investigation and demonstrate higher comminution energy efficiency of CAHM than that of the conventional machine. We also introduce a particle breakage model incorporated in ROCKY and an actual calibration procedure of parameters to reproduce a particle size distribution after the breakage.