Using a horizontal batch dry bead mill newly developed by our company, talc raw material was ground in air, and its grinding performance and mechanochemical effect on the sample were evaluated from various perspectives. First, the average diameter of the ground product as a grinding performance decreases with the increase in grinding time or power source unit, reaching the submicron size. In addition, when mill operation is continued, talc changes fine particle aggregation and crystal structure change due to mechanochemical effects, and the phenomenon of detachment of the (OH) group around Mg in the crystals becomes remarkable. The flowability of the ground product is inhibited by the withdrawal of (OH) from the talc crystal, but this flowability is restored when it is dried. When the power source unit in the grinding approaches 3 kWh/kg, it asymptotes to the maximum value of 9% in the weight reduction percentage.

Wet granules are used in various areas, owing to their higher compressibility. In this study, finite element method (FEM) simulations of wet granule compression are performed to discuss the influence of binder on the compressibility of wet granules. The Drucker-Prager Cap model was applied to wet granules with parameters obtained from compression and powder shear tests, and the FEM simulation was performed using these parameters. The results showed that the axial stress at the bottom surface and the radial stress of the wall obtained from the FEM simulation were consistent with the experimental values for the bottom and radial (wall) stress of the compression cell in large strain regions. Furthermore, the FEM results for wet granules with different amounts of binder suggested that particles in wet granules with higher amounts of binder adhered each other more strongly, thereby increasing the axial and radial stresses.

Continuous wet granulation using a twin-screw granulator has attracted much interest in the pharmaceutical industry. The physical properties of granules prepared through the twin-screw granulation process depend on the several factors, such as screw and barrel geometries, operating conditions, and formulations of raw materials. In particular, it is known that the fill level in a twin-screw granulator and the binder additive ratio have an impact on the twin-screw granulation process. In this study, mutual effects of the two major factors on the granulation process was investigated experimentally and numerically. By combining the experimental and numerical analyses, a prediction model of the granule growth rate was proposed. The proposed model demonstrated that the granule growth rate was determined by the total energies (compressive and shear directions) and the index of granulation.

In this study, we focused on the low-temperature preparation of the typical Garnet-type cubic solid electrolyte powders of lithium lanthanum zirconate (LLZO) with new dopants. We chose the new dopants of Mg and Sr to stabilize the cubic phase by different preparation methods. One is the solid state reaction with a wet chemical coating of Li source, and the other is the all wet chemical processing of so called modified sol-gel method. As a result, we successfully prepared cubic LLZO powders with Mg and Sr dopants by the modified sol-gel method at lower temperature. In addition, new dopants affected the stability of the cubic phase if compared with the other dopants such as Al and Ta. The modified sol-gel method was the powerful tool to stabilize the cubic phase because of the high homogeneity of a precursor at the molecular level by the suitable molecular-design of the precursor solution.

Suspensions of monodisperse spherical particles under shear flow were simulated using a solid-liquid two-phase model based on coupled lattice Boltzmann method (LBM) and discrete element method (DEM). Evaluating the shear stresses due to the viscous behavior of the bulk fluid, the hydrodynamic interaction between particles and fluid, and the physical contact between particles, the contribution of each factor to the suspension viscosity was investigated. The results showed that in the range of low to moderate particle volume fractions, the viscosity of suspensions is mainly determined by the action of the fluid, and that the contribution of particle contact increases with increasing particle volume fraction. In particular, the flow behavior of dense suspensions should be viewed not as a fluid motion but as the motion of a group of particles. From these results, in order to predict and control the rheological properties of particle suspensions, it is important to understand that the main factors increasing viscosity vary with the concentration range of interest.