• Proceedings of the IEEK Conference
• /
• 2001.10a
• /
• pp.315-324
• /
• 2001

Mechanochemical effects that occurred in the fine grinding process of quartz particles using planetary ball mill was investigated. Quartz particles have been frequently utilized for optical materials, semiconductor molding materials. We determined that grinding for a long time can be create amorphous structures from the crystalline quartz by Mechanochemical effects. But, to be produced nano-composite particles that the critical grinding time reached for composite materials in a short time. Henceforth, a qualitative estimation must be conducted on the filler for EMC(Epoxy molding compound) materials. It can be produced mechanochemically treated composite materials and also an integrated grinding efficiency considering of the nano-composite amorphous structured particles. The mechanochemical characteristics were evaluated based on particle morphology, size distribution, specific surface area, density and the amount of amorphous phase materials into the particle surface. The grinding operation in the planetary ball mill can be classified into three stages. During the first stage, initial particle size was reduced for the increase of specific surface area. In the second stage, the specific surface areas increased in spite of the increase in particle size. The final stage as a critical grinding stage, the ground quartz was considered mechanochemically treated particles as a nano- composite amorphous structured particles. The development of amorphous phase on the particle surface was evaluated by X-ray diffractometry, thermal gravity analysis and IR spectrometer. The amount of amorphous phase of particles ground for 2048 minutes was 85.3% and 88.2% by X-ray analysis and thermal gravity analysis, respectively.

• Korean Journal of Food Science and Technology
• /
• v.28 no.6
• /
• pp.1078-1083
• /
• 1996

During the pearling process of hull-less barley, protein, lipid, ash and insoluble dietary fiber (IDF) contents decreased, while soluble dietary fiber (SDF) and ${\beta}-glucan$ contents slightly increased. Depending on milling methods and types of grinding mills used, there were differences in particle size distribution of barley flour. Flour particle size was smaller in the following order of Fitz mill, Ball mill, Pin mill, Cyclotec sample mill and Jet mill. Color (brightness) was closely related to the particle size of barley flour. Damaged starch (%) in pearled barley flour was the highest in Jet mill among different mills. Flours prepared with Cyclone mill and Pin mill had a reasonable amount of damaged starch. Flour produced by Fitz mill showed the lowest amount of damaged starch. Scanning electron microscopy (SEM) of the flour samples demonstrated different sizes and shapes of particles consisting of starch granules and cell wall materials. Damaged starch tended to increase water absorption index (WAI), water solubility index (WSI), and water retention capacity (WRC). Pasting viscosity determined by amylograph was relatively high in Pin-milled and Cyclone-milled flours. Viscosity was the lowest in coarsely ground flour by Fits mill.

• Journal of Life Science
• /
• v.9 no.2
• /
• pp.194-200
• /
• 1999

Grinding aid is a necessary unit operation when the raw materials are handled in solid form, and the purpose is to improve the bioavailability by reducing the particle size. For the particle design of pefloxacin, the dry planetary ball-mill was used. With the drying process, 330 g of zirconia ball with its size of 2 mm in diameter and 10 g of pefloxacin were transferred to the pot and mixed well. The mixture was ground at 112 rpm (60 Hz) for 15, 30, and 60 min, respectively. The most satisfactory grinding products were generated at 15 min of grinding time for their particle size. The volume mean diameter $\X_50$ of the grinding products was 2.97 $\mu$m. X-ray diffraction (XRD), differential scanning calorimeter (DSC), and infrared spectroscopy (IR) patterns were relatively unchanged before pulverizing pefloxacin and in the progress of grinding. Thus, these results suggest that this pulverizing method can be used for grinding products without evident effect on stability of the drug pefloxacin. Dissolution test was carried out to set up the optimal detective condition against residual antibacteria of fish by HPLC. The grinding pefloxacin for 15 min is most effective in dissolution test.

• Journal of Advanced Marine Engineering and Technology
• /
• v.31 no.6
• /
• pp.753-760
• /
• 2007

For protection of the cylinder wall of the ball mill for grinding raw ore. the inner side of the cylinder is covered with rubber liner. The rubber is easily worn down because the rubber relatively soft compared with raw ore. So the rubber liner in the ball mill cylinder must be replaced almost every year and the cost for replacing rubber liner formidable. In this paper, for reducing or excluding the cost of replacing rubber liner the basalt liner is designed. The basalt materials are generally harder than raw ore and the basalt liner in the ball mill does not wear down and so it can be used almost permanently. The concave surfaces are made on the liner of the ball mill and the liner in the cylinder wall plays also the role of raising the steel balls mixed in the raw ore. The section profiles of the concave surface have an important effect on the performance of the ball mill. The deep concave grooves raise the steel balls to high levels and give the large potential energy to the steel balls impacting to the raw ore. But if the concave grooves are too deep. the steel balls raised too high by the concave grooves fly along the parabolic path and reach to the other side of cylinder wall and so the steel balls do not play the roles of grinding the raw ore. The forces acting to a steel ball in a concave groove of the cylinder liner are also analyzed in this paper. The formulas calculating the height and the impact point of the steel ball are introduced and presented. Based to these formulas, the optimum section profiles of the basalt liner are presented.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.32 no.3
• /
• pp.363-369
• /
• 2003

In this study, cell cracker method as a non-collision method was evaluated for the possibility of new red ginseng grinding technique. The moisture contents were 3.16% for the powder pulverized by hammer mill (group A) and 6.30% for the powder produced by cell cracker (group B), and the difference between both groups was significant, The contents of other component such as ash, crude lipid, reducing sugar, total sugar, acidic polysaccharide, crude fiber and crude protein between both groups were not significant. There were no significant differences in phenolic compound, fatty acid, amino acid, free sugar, crude saponin and ginsenosid contents between both groups. And also the contents of mineral components were evaluated to determine the incorporation of red ginseng powder during grinding, and also the differences of those between both groups were not significant.

• Journal of Power System Engineering
• /
• v.17 no.1
• /
• pp.91-96
• /
• 2013

The present paper focuses on the fabrication of materials with higher thermal conductivity. Nanofluid is a novel transfer prepared by dispersing nanometer-sized solid particles in traditional heat transfer fluid to increase thermal conductivity and heat transfer performance. The purpose of this study is making the nano-size particle. The experiment of MWCNT and $Al_2O_3$ was carried out using a planetary ball mill at several rotation speeds: 200 ~ 400 rpm. The results were examined using scanning electron microscope(SEM). In the case of the MWCNT, it could be more grinding into the small particle in the dry condition and it confirm in the case of the $Al_2O_3$ to be more grinding into the small particle contrary to the MWCNT in the wet condition. In the mixture grinding result of MWCNT and $Al_2O_3$, the dry condition showed the good result in low rotation speed than the wet condition.

• Proceedings of the Korean Society for Agricultural Machinery Conference
• /
• 1998.12a
• /
• pp.250-258
• /
• 1998

• The Korean Journal of Ceramics
• /
• v.2 no.4
• /
• pp.251-256
• /
• 1996

Effect of mixed grinding with a planetary ball mill of starting materials before heat treatment on the crystal structure and superconduction properties in the YBaCu composite oxide was studied. The size reduction of powders too place in the early stage of grinding, followed by aggregation of the resultant fine particles. The uniformity of the composition in the mixture was improved with grinding, which later decreased in the crystal grain size and well distribution of twin phase in the sintered bodies. The critical current density of the sintered bodies obtained from the mixture ground for 60 minutes showed the maximum value about 150 A/$\textrm{cm}^2$, while critical temperatures were around 90K and were independent of the grinding time.

• Korean Chemical Engineering Research
• /
• v.51 no.6
• /
• pp.685-691
• /
• 2013

Ibuprofen, non-steroidal anti-inflammatory drugs; NSAIDs, is a highly crystalline substance with the pharmaceutical properties of poor solubility and low bioavailability. The size reduction of ibuprofen is needed to improve the solubility. The objective of this study is to optimize the grinding condition of ibuprofen. Grinding of ibuprofen was carried out using a planetary mill. Grinding parameters were optimized using Box-Behnken experimental design method. The physical characteristics of ground ibuprofen were investigated for the particle size by particle size analyzer, for the crystal size by X-ray diffraction (XRD), and for the tensile strength by tensile/compression tester. The optimum conditions for the milling of ibuprofen were 290 rpm of the revolution number of mill, 24.6 g of the weight of sample, and 10 minutes of grinding time. The measured value of the particle size of ground ibuprofen at these optimum conditions was $13.5{\mu}m$. The results showed that the crystal size of ibuprofen was reduced by the planetary milling process. In case the relative density of the tablets formulated of ground ibuprofen was range of 0.85~0.90, the tensile strength of them was range of 1$2{\sim}14Kg_f/cm^2$.

• Journal of Korean Society of Environmental Engineers
• /
• v.22 no.6
• /
• pp.1139-1148
• /
• 2000

To treat and recycle a large quantity of converter slag. the milling properties of -14/ +24 mesh-sized slag has been considered. The optimal conditions in milling process were investigated for producing powder-type slag and the required consumption was derived for the economical grinding. The characteristics of milling processes were studied in the variation of the rotational speed, milling time, filling ratio of ball, and size and amount of feed. The grinding efficiency was also examined. The optimal rotational speed in this experimental condition was observed to be the value of 79% of critical speed. The extent of grinding was increased with increasing the grinding time. but the efficiency of milling was decreased with the time. 50% ball filling was shown to have the optimal grinding effect, and less amount and small-sized feed made the milling efficiency high. As the result, using Bond's equation, power required for efficient milling was considered and the highest value was observed in the condition of high grinding time and optimal rotational speed.