• Journal of Powder Materials
• /
• v.28 no.6
• /
• pp.462-469
• /
• 2021

Tin/graphite composites are prepared as anode materials for Li-ion batteries using a dry ball-milling process. The main experimental variables in this work are the ball milling time (0-8 h) and composition ratio (tin:graphite=5:95, 15:85, and 30:70 w/w) of graphite and tin powder. For comparison, a tin/graphite composite is prepared using wet ball milling. The morphology and structure of the different tin/graphite composites are investigated using X-ray diffraction, Raman spectroscopy, energy-dispersive X-ray spectroscopy, and scanning and transmission electron microscopy. The electrochemical properties of the samples are also examined. The optimal dry ball milling time for the uniform mixing of graphite and tin is 6 h in a graphite-30wt.%Sn sample. The electrode prepared from the composite that is dry-ball-milled for 6 h exhibits the best cycle performance (discharge capacity after 50^th cycle: 308 mAh/g and capacity retention: 46%). The discharge capacity after the 50^th cycle is approximately 112 mAh/g, higher than that when the electrode is composed of only graphite (196 mAh/g after 50^th cycle). This result indicates that it is possible to manufacture a tin/graphite composite anode material that can effectively buffer the volume change that occurs during cycling, even using a simple dry ball-milling process.

• Journal of the Korean Ceramic Society
• /
• v.51 no.2
• /
• pp.121-126
• /
• 2014

The influence of a liquid medium duringa wet-milling process in the grinding and oxidation of silicon powder was investigated. Distilled water, dehydrated ethanol and diethylene glycol were used as the liquid media. The applied grinding times were 0.5, 3, and 12 h. Ground silicon powder samples were characterized by means of aparticle size analysis, scanning electron microscopy(SEM), x-ray powder diffraction (XRD), FT-IR spectroscopy and by a chemical composition analysis. From the results of the characterization process, we found that diethylene glycol is the most efficient liquid medium when silicon powder is ground using a wet-milling process. The FT-IR results show that the Si-O band intensity in an unground silicon powder is quite strongbecause oxygen becomes incorporated with silicon to form $SiO_2$ in air. By applying deionized water as a liquid medium for the grinding of silicon, the $SiO_2$ content increased from 4.12% to 31.7%. However, in the cases of dehydrated ethanol and diethylene glycol, it was found that the $SiO_2$ contents after grinding only changed insignificantly, from 4.12% to 5.91% and 5.28%, respectively.

• Korean Journal of Materials Research
• /
• v.14 no.5
• /
• pp.338-342
• /
• 2004

Ni-Zn ferrite powder was obtained by wet method that was to be coprecipitated the metal nitrates, Fe($NO_3$)$_3$ㆍ$9H_2$O, Ni($NO_3$)$_2$ㆍ$6H_2$O, Zn($NO_3$)$_2$ㆍ$6H_2$O to make a high permeability material. The composition of the ferrite powder was $Fe_2$$O_3$ 52 mol%, NiO 14.4 mol%, ZnO 33.6 mol%. Ni-Zn ferrite powder was compounded by precipitating metal nitrates with NaOH in vessel at the synthetic temperature of $90^{\circ}C$ for 8 hours. Calcination temperature and sintering temperature were $700^{\circ}C$ and $1150^{\circ}C$～$1250^{\circ}C$, respectively, for 2 hours. And the other ferrite powder was also prepared by the wet ball milling that was to be mixed the metal oxides as same as the above chemical composition. We studied the properties of the powder and the electromagnetic characteristics of the sintered cores obtained from there two different processes. Wet direct process produced smaller particle size with narrower distribution of the size and more purified ferrite whose sintered cores had high permeability and high magnetization.

• Korean Journal of Food Science and Technology
• /
• v.27 no.6
• /
• pp.834-838
• /
• 1995

The relative retrogradation of Jeungpyun investigated with different milling methods of rice flour. The relative retrogradation of Jeungpyun was reduced in order that of W-C, W-P, D-M, D-J in DSC(Differential Scanning Calorimetry) method while W-C, D-M, D-J, W-P in Diastase method. In wet milling method, the relative retrogradation of Jeungpyun by pin mill (W-P) was lower than Jeungpyun by colloid mill (W-C). In dry milling method, the relative retrogration of Jeungpyun by jet mill (D-J) was lower than Jeungpyun by micro mill(D-M). The relative retrogradation of Jeungpyun by DSC method was similar to the diastase method. The relative retrogradation of Jeungpyun was decreased with decreasing particle size and setback value for amylogram and increasing damaged starch.

• Korean Journal of Human Ecology
• /
• v.3 no.2
• /
• pp.68-76
• /
• 2000

The quality of Injulmi, waxy rice cake is affected by milling methods. varieties. additives, steeping condition before milling and the texture properties during storage. Sinsunchalbyeo and Hwasunchalbyeo flours were made using pin-dry milling(PDM) and roller-wet milling( RWM) methods. Injulmi was made from those flours with different sugars, sucrose, maltose. oligosaccharide, and were measured textural properties of Injulmi stored at 2 $0^{\circ}C$ for 0, 12, 36 and 60 hrs, respectively. The hardness of sucrose added to injulmi made from PDM flour was the highest among any other sugars, but Injulmi from RWM flour was increased in the following order sucrose>maltose>oligosaccharide>non - added Injulmi. Adhesiveness of none added Injulmi were the lowest among sugar added Injulmi including, oligosaccharide, maltose and sucrose added Injulmi.

• Proceedings of the Korean Society of Crop Science Conference
• /
• 2022.10a
• /
• pp.314-314
• /
• 2022

In the production of rice flour, wet milling is a method of milling rice after soaking it in water, and it takes a lot of time and cost from milling to drying. To overcome this problem, the floury type rice was developed for dry milling and it is known to have round starch granules, low content of damaged starch after milling, and a starch structure similar to wheat. Because of its unique properties different from normal rice, it is necessary to research on processing and characteristics of floury-type rice to expand its utility in the food industry. Therefore, this study aimed to prepare the pregelatinized floury type rice (Baromi2) by autoclave and investigate their physicochemical properties. As the heat treatment time increased, the brightness decreased from 83.8 to 76.8, however, both redness and yellowness increased from 0.57 to 4.5 and from 14.58 to 21.13, respectively. Despite of same treatment time, soaking in water (10 min) before autoclaving increased the solubility and swelling power of Baromi2 over 2 times. The peak viscosity of native Baromi2 was over 2000 RVU, on the other hand, there was a significantly decrease to less than 1000 RVU of pregelatinized Baromi2. Heat treatment without immersion caused partial gelatinization of starch, resulting that some starch granules maintaining their integrity. Whereas there were no starch granules in heat treatment with soaking in water due to complete gelatinization. This study would be helpful to the suggestion of using heat-treated floury-type rice as an intermediate material in the food industry in the future.

• Journal of the Korean Ceramic Society
• /
• v.22 no.5
• /
• pp.47-53
• /
• 1985

In view of innovated utilization of Korean clay resources conventional techniques for pulverization are reviewed in comparison with fluid energy milling processes of fluidized-bed type. Throughout experiment indigenous halloysite ores (white grade) after usual pretreatment are employed as typical sample. It is evidenced that grinding by means of porcelain ball mills has limitation in reducing clay particles to less than 10${\mu}{\textrm}{m}$ in diameter regardless of whether it is processed in dry or wet. Upon use of tungsten carbide bull mill particulation to submicron sizes could be effected with relative ease but severe coloration in grey is attended indicating metallic contamination possibly from friction of the grinding apparatus itself. In contrast the modified fluid en ergy milling enables particulation to $\leq$10${\mu}{\textrm}{m}$ in diameter with simultaneous classification int olimited ranges of particle size distributions. Since this technique is in principle based on the interparticle collisions rather than on the frictions between particles and mill surfaces minimum impurity attendance would be an additional advantage. Evidence leads to the conclusion that the fluidized-bed type milling is regarded as highly effective in puverization as well as fractionation of the clay minerals under examination. This is especially so in contemplating high-value and/or high-purity clay products.

• Korean Journal of Materials Research
• /
• v.26 no.2
• /
• pp.95-99
• /
• 2016

In this study, 5 um sized $ZrSiO_4$ was ground to 1.9 um, 0.3 um, and 0.1 um sized powders by wet high energy milling process, and the sintering characteristics were observed. Pure $ZrSiO_4$ itself can-not be sintered to these levels of theoretical density, but it was possible to sinter $ZrSiO_4$ powder of nano-scale size of, -0.1 um to the theoretical density and to lower the sintering temperature for full density. Also, the decomposition of $ZrSiO_4$ with a size in the micron range resulted in the formation of monoclinic $ZrO_2$; however, in the nano sized range, the decomposition resulted in the tetragonal phase of $ZrO_2$. So, it was possible to improve the sintering characteristics of nano-sized $ZrSiO_4$ powders.

• Proceedings of the Korean Society of Postharvest Science and Technology of Agricultural Products Conference
• /
• 2003.10a
• /
• pp.221.2-222
• /
• 2003

The relative retrogradation of Jeungpyun investigated with different millimg methods of rice flour. The relative retrogradation of Jeungpyun was reduced in order that of W-C, W-P, D-M, D-J in DSC(Differential Scanning Calorimetry) method while W-C, D-M, D-J, W-P in Diastase method. In wet milling method, the relative retrogradation of Jeungpyun by Pin mill(W-P) was lower than Jeungpyun by colloid mill(W-C). In dry milling method, the relative retrogration of Jeungpyun by jet mill(D-J) was lower than Jeungpyun by micro mill(D-M). The relative retrogradation of Jeungpyun by DSC method was similar to the Diastase method. The relative retrogradation of Jeungpyun was decreased with decreasing particle size and setback value for amylogram and increasing damaged starch.

• 한국초전도학회:학술대회논문집
• /
• v.15
• /
• pp.56-56
• /
• 2005