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In this study, synthesis of yttrium aluminum garnet (YAG):Ce3+ phosphor powders for white light emitting diodes was investigated by mechanical method using the attrition‐type mill with no external heating and no flux in dry phase. High mechanical energy input to the starting powder mixture of Y2O3, Al2O3 and CeO2 achieved the synthesis of YAG:Ce3+ without any flux materials. X‐ray diffraction patterns of the processed powders after 5 min processing revealed the peaks of YAG were clearly identified. The maximum temperature of the mill chamber during the processing was 240℃. The YAG phosphor obtained by the mechanical method revealed the internal quantum yield of 65% in the case of the sample mechanically processed under a reducing atmosphere. The synthesized powder showed granule structure consisting of submicron size of YAG particles, which is better handling for the fabrication of light emitting diode devices. [ABSTRACT FROM AUTHOR]

The paper analyzes a solution in green manufacturing of foamed or cellular ceramics. The objective of this study was to determine the technical solution for rice husk ash and "tales" of mixed glass cullet reusing based on the specific properties of these materials for creation of spherical holes inside ceramic using the process of coalescence of cellular glass. The paper reports on experimental results obtained from the production of lightweight cellular glass granules produced using glass cullet and rice husk ash. Lightweight cellular glass granules were mixed with clay, pressed and fired in air at 920°C. Clay sintering and the formation of ceramic were followed with the coalescence of cellular structure of glass granules and with the formation of spherical hollows inside the matrix. Density and strength of the fired ceramic bodies were determined. It is observed that the lightweight ceramics with density 900 ÷ 920 kg/m3 possess a compressive strength of about 5 MPa that is acceptable for bricks or tiles manufacture. The utilization of amorphous silica waste for lightweight ceramics manufacture helps in reducing waste disposal concerns and costs associated, and also transforms the waste into an alternative raw material with added value, moreover making the final product cheap. [ABSTRACT FROM AUTHOR]

The influence of the atomization technique on the suitability of granules for dry pressing is the focus of the presented investigations. Therefore, destabilized alumina, zirconia, and zirconia toughened alumina (ZTA) slurries were spray dried and the obtained granules were used to fabricate green and finally sintered bodies for evaluation. Granules made in a laboratory spray dryer with a two‐fluid nozzle served as a reference. An ultrasonic atomizer was integrated into the same spray dryer and the influence on the granule properties was evaluated. Untapped bulk density, granule size distribution, and flowability are among the evaluated granule‐related properties as well as the granule yield which is used as an indicator of the process efficiency. Yield and flowability as most important granule properties are clearly improved when atomization is realized with ultrasound. The investigated sinter body properties include porosity, sinter body density, and biaxial strength and are as well positively affected by switching the atomization technique to ultrasound. Therefore, the approach to improve the compressibility of granules by ultrasonic atomization, which leads to an improved microstructure, density, and strength of sintered bodies, has proven to be successful for single‐component ceramics (alumina and zirconia) as well as for the multicomponent ceramic ZTA. [ABSTRACT FROM AUTHOR]

Chicken litter (CL) is a waste generated by poultry farming and it that has increased significantly in recent years. Due to chicken litter levels of nitrogen, potassium, phosphorus, and other nutrients, the CL has a potential use as fertilizer, nevertheless, this purpose has been threatened by the pollution of water resources owing to the leaching and disposal of these nutrients. The production of CL granular organomineral fertilizers (OMF) is one way of minimizing these problems and to add value to poultry waste. Thus, this study evaluates the potential of the use of different binder materials on the improvement of the hardness and nutrient release. For this, five ceramic materials were added in four different concentrations to the powder mixture containing Monoammonium Phosphate (MAP) and CL. The fertilizers were granulated and through hardness evaluation, it was possible to observe that the positive effect on the hardness depended on the additive used and its concentration. The most promising additive was magnesium oxide that, was able to improve the strength of by up to four times, when compared to the OMF control. The results shown that the nutrient release is not affected with addition different binder materials. [ABSTRACT FROM AUTHOR]