• Title/Summary/Keyword: Fining

Search Result 32, Processing Time 0.025 seconds

The Effect of Temperature, Cooling and Surface Tension on the Fining in Alkali-Alkaline Earth-Silica Glassmelts Containing ZnO

  • Kim, Ki-Dong
    • The Korean Journal of Ceramics
    • /
    • v.4 no.3
    • /
    • pp.176-182
    • /
    • 1998
  • The effects of temperature, cooling surface tension on the fining were studied in alkali-alkaline earth-silica TV screen glassmelts containing ZnO. Sodium antimonate $(Na_2OSb_2O_5)$ was used as a fining agent. Viscosity and surface tension of the melts were determined. On the basis of these properties, fining tests for several batches were performed by "MF" (Melting and Fining) and "PMF" (Profiled melting and Fining) methods. The results of these tests showed an opposite behavior each other with increase in ZnO content. This hehavior has been discussed in terms of two fining processes-growth of bubbles and shrinkage of seeds. shrinkage of seeds.

  • PDF

Fining of Flint Glass Melts Containing Blast Furnace Slag

  • Kim, Ki-Dong
    • Journal of the Korean Ceramic Society
    • /
    • v.44 no.11
    • /
    • pp.618-621
    • /
    • 2007
  • In this study, flint glass batches with blast furnace slag (BFS) were prepared and the contribution of the BFS to the fining of melts was studied through investigations of the melting and fining characteristics. Additionally, a sulfur redox reaction for BFS-doped melts was examined by square wave voltammetry (SWV). The results of the melting & fining test showed that BFS improved the fining of the melts. In a voltammogram of BFS-doped melts, two reduction peaks were shown at high frequencies while only one peak appeared at low frequencies. The peaks were located at a potential that was similar to those of melts fined by sulfate. From those results it was concluded that sulfide ($S^{2-}$) in BFS has effects in glass melts that are identical to those of sulfate ($SO_4^{2-}$).

Behavior of Oxygen Equilibrium Pressure in CRT Glass Melts doped with Sb and Ce ions from the Viewpoint of Fining

  • Kim, Ki-Dong;Kim, Hyo-Kwang;Kim, Jun-Hong
    • Journal of the Korean Ceramic Society
    • /
    • v.44 no.8
    • /
    • pp.419-423
    • /
    • 2007
  • The behavior of oxygen gas participating in fining was observed in CRT (Cathode Ray Tube) glass melts doped with $Sb_2O_5\;or\;CeO_2$ by means of a yttria-stabilized zirconia (YSZ) electrode. The temperature dependence of the oxygen equilibrium pressure ($P_{o2}$) or the activity in both melts showed typical behavior corresponding to a theoretical redox reaction. In other words, the $P_{o2}$ value of melts with $CeO_2$ was lower than that of melts with $Sb_2O_5$ above $1250^{\circ}C$. The result implies that $Sb_2O_5$, is more efficient as a fining agent compared to $CeO_2$. On the other hand, melts from a batch containing $Sb_2O_5\;and\;KNO_3$ showed much higher $P_{o2}$ values compared to melts without $KNO_3$ above $1350^{\circ}C$. It is suggested that the addition of $KNO_3$ to CRT glass batch contributes partly to the first fining of the melts.

Effects of Fining Treatments on Color and Clearness of Apple Wine (청징방법에 따른 사과와인의 색과 투명도에 미치는 영향)

  • Bang, Byung-Ho;Jeong, Eun-Ja;Kang, Hyeran;Rhee, Moon-Soo;Yi, Dong-Heui;Paik, Jean Kyung
    • Journal of the Korean Society of Food Science and Nutrition
    • /
    • v.46 no.3
    • /
    • pp.368-373
    • /
    • 2017
  • Comparative fining trials were conducted in a laboratory to study the effects of fining treatments including polyvinylpolypyrrolidone (PVPP) and bentonite on the color and clearness of apple wine. The wines were subjected to three different fining treatments: PVPP, PVPP+bentonite (applied at the same time), and PVPP+bentonite (24 h later). Based on the results, all treatments induced noticeable decreases in wine color (APHA value) and turbidity. The treatment including PVPP and bentonite at the same time provided the best results in relation to wine color and clearness. PVPP was the most effective in the reduction of phenolic compounds, which means it helped wine obtain a paler color. Organic acids and aromatic profile were not altered by the fining treatments.

Electrochemical Approach in Plasma Display Panel Glass Melts doped with Sulfate and Sulfide I. Oxygen Equilibrium Pressure

  • Kim, Ki-Dong;Kim, Hyo-Kwang
    • Journal of the Korean Ceramic Society
    • /
    • v.45 no.2
    • /
    • pp.90-93
    • /
    • 2008
  • The oxygen gas behavior in PDP (plasma Display Panel) glass melts doped with sulfate ($SO_4^{-2}$) or blast furnace slag (BFS, $S^{2-}$) or both by means of yttria-stabilized zirconia (YSZ) electrodes was observed after the first fining. The temperature dependence of oxygen equilibrium pressure ($P_{O2}$) in each melt showed typical behavior, namely $P_{O2}$ decreased as temperature decreased. This suggests that an oxidation of $S^{4+}$ to $S^{6+}$ took place. However, the $P_{O2}$-value at constant temperature increased in the following order: BFS$P_{O2}$ of the melt doped with sulfate+BFS was much lower than that of the melt with only sulfate, although only 10% of sulfur was added by the BFS. This behavior can be explained by the redox reaction between sulfide ions in the BFS and dissolved oxygen ions in the melt during the first fining.

Redox Equilibrium of Antimony by Square Wave Voltammetry Method in CRT Display Glass Melts

  • Jung, Hyun-Su;Kim, Ki-Dong;Kim, Hyo-Kwang;Kim, Young-Ho
    • Journal of the Korean Ceramic Society
    • /
    • v.44 no.1 s.296
    • /
    • pp.1-5
    • /
    • 2007
  • Fining and homogenization of melts during batch melting is closely related to the redox reaction of polyvalent element M (M: Sb, As etc), $M^{(x+n)+}+n/2O^{2-}{\rightarrow}M^{x+}+n/4O_2$. In this study, square wave voltammetry (SWV) measurements were performed to examine the redox behavior of an antimony ion in cathode ray tube (CRT) glass melts. According to results, well-separated two peaks are shown at low temperature while only one peak is shown at high temperature in voltammograms, which reveals that redox reaction of antimony consist of two steps: $Sb^{5+}/Sb^{3+}\;and\;Sb^{3+}/Sb^0$, depending on the temperature. Based on the peak potential shown in the voltammogram, the thermodynamic data and the redox ratio for two redox couple were determined.

Sedimentary Environments and Geochemical Characters of the Core Sediments Near Naju-Yeongam Area in the Lower Part of the Yeongsan River, Cheonnam, Korea (전남 나주-영암지역의 영산강 하류 시추퇴적물의 퇴적환경과 지구화학적 특성)

  • Eun, Go-Yeo-Na;Koh, Yeong-Koo;Youn, Seok-Tai;Oh, Kang-Ho;Kim, Dong-Ju;Kim, Joo-Yong
    • Journal of the Korean earth science society
    • /
    • v.22 no.4
    • /
    • pp.301-316
    • /
    • 2001
  • To consider the vertical variations of sedimentary environments and geochemical characters in the core sediments in Naju-Yeongam area od the lower part of Yeongsan River, grain-size and metal components of the sediments were analyzed. The sediments are pebble to mud and show fining upward. The core sediments are poorly to very poorly sorted and positively skewed. On the basis of grain size distributions, the sediments of the study areas were thought to have been deposited in a meandering stream. The metallic contents of sediments were presumably controlled by carbonate contents of sediments and weakly controlled by fining upward grain size distribution pattern. Enrichment factors indicating metal concentration in the sediments did not suggest any meaningful concentrations for metallic elements.

  • PDF

Preparation of Minimally Processed Mulberry (Morus spp.) Juices (최소가공기술을 이용한 오디 과실주스의 제조)

  • Kim, In-Sook;Lee, Jun-Young;Rhee, Soon-Jae;Youn, Kwang-Sup;Choi, Sang-Won
    • Korean Journal of Food Science and Technology
    • /
    • v.36 no.2
    • /
    • pp.321-328
    • /
    • 2004
  • Raw mulberry (Morus spp.) juice was prepared by minimal processing using several filter aids, fining agents, and clarifying enzymes, followed by filtration, centrifugation, and membrane filtration. Control of browning in minimally processed mulberry juices by anti-browning agents, sodium hydrosulfite, L-ascorbic acid, citric acid, and NaCl, was investigated using quantitative measurements of color changes during storage. Clarification of mulberry juice was improved by adding several filter aids, fining agents, and enzymes, followed by filtration and centrifugation. Several fining agents, including chitosan, chitin, PVPP, gelatin, and casein at a concentration of 1%, and combination of ultrafiltration and centrifugation at 8,000 rpm were not suitable for clarification of juice owing to strong adsorption of anthocyanin pigment. Combination of $0.01\;{\mu}m$ membrane filtration and centrifugation at 8,000 rpm was effective for clarification of mulberry juice. Browning of minimally processed mulberry juice was inhibited significantly by adding 200 ppm sodium hydrosulfite, and 0.1% L-ascorbic acid (L-AsA) and 0,1% citric acid (CA) also showed considerable browning inhibition. Combination of L-AsA and CA, which was moderately effective for browning inhibition of juice, may be useful as a sulfite alternative for mulberry juice. Optimum sugar ($^{\circ}Brix$)/acid ratio and commercial sterilization of minimally processed mulberry juice were approximately 40 and 10 min at $85-90^{\circ}C$, respectively.

A Study on the Regulation Plan for Over-weight Vehicles -in Pusan city- (과적차량의 운행규제 방안에 관한 연구 -항만배후도시 부산을 중심으로-)

  • 정창식;소병곤;이수호;이종식
    • Journal of Korean Society of Transportation
    • /
    • v.10 no.2
    • /
    • pp.55-68
    • /
    • 1992
  • Over-weight vehicles give the structure of the road an impact overly and shorten the life of the pavements. But unfortuntely so far there has been no clear regulation to implement over weight vehicles. So I suggest that the fining should be evaluated differently according to the size of axle loads. In addition I adapt our study to Pusan city and propose an adequate regulation against over weigtht vehicles.

  • PDF