• Resources Recycling
• /
• v.27 no.6
• /
• pp.38-43
• /
• 2018

In this study, using electro-refining process and methane gas reduction, we performed studying the recovery of tin with high purity from waste tin oxide had used as a electrode rod of ceramic furnace which occurred during glass production process. We recovered the crude tin of 99% purity from a methane gas reduction process and controlled a little amount of impurities. When the electrolytic refining condition was a current density of $60A/dm^2$ and the sulfuric acid concentration of 0.75 mol, 96.8% of recovered tin (99.979% of purity) were recovered during the electrolytic refining. We confirmed that toxic impurities such as Pb, Sb included in electrode rod. could be controlled.

• Journal of the Korean Society of Manufacturing Process Engineers
• /
• v.11 no.3
• /
• pp.13-18
• /
• 2012

We investigated the cell activity of controlled titanium surface using various grinding methods including ELID (Electrolytic In-Process Dressing) grinding method. The influence of titanium surface condition by each grinding process on the cell activity was evaluated by ALP activity of MSC(Mesenchymal Stem Cells). The ALP activity of controlled surface by ELID grinding process using # 2000 wheel was higher than that of other titanium surface. The morphological, chemical properties of machined surface by grinding method was observed using various analytical method.

• Laser Solutions
• /
• v.16 no.4
• /
• pp.7-11
• /
• 2013

The surface oxidation of magnesium was performed by Plasma electrolytic oxidation treatment method. And the optical reflectance spectra of the oxidation layers are studied. In the PEO process, the growth of the oxide layer take place at room temperature. Surface roughness of the obtained result, the average surface roughness is $0.08{\mu}m$ difference. The reason seems to the influence of the $Na^+$.

• Proceedings of the Korean Radioactive Waste Society Conference
• /
• 2003.11a
• /
• pp.689-695
• /
• 2003

Electrochemical decontamination process has been applied for recycle or self disposal with authorization of large amount of metallic wastes contaminated with uranium compounds such as $UO_2$, ammonium uranyl carbonate (AUC), ammonium di-uranate (ADU), and uranyl nitrate(UN) with tributylphosphate(TBP) and dodecane, which are generated by dismantling the contaminated system components and equipment of a retired uranium conversion plant in Korea Atomic Energy Research Institute (KAERI). Electrochemical decontamination for metallic wastes contaminated with uranium compounds was evaluated through the experiments on the electrolytic dissolution of stainless steel as the material of the system components in neutral salt electrolytes. The effects of type of neutral salt as the electrolyte, current density, and concentration of electrolyte on the dissolution of the materials were evaluated. Decontamination performance tests using the specimens taken from a uranium conversion plant were quite successful with the application electrochemical decontamination conditions obtained through the basic studies on the electrolytic dissolution of structural material of the system components.

• Journal of the Korean Professional Engineers Association
• /
• v.33 no.6
• /
• pp.16-23
• /
• 2000

Anodizing processes is the conversion of the aluminum surface to aluminum oxide while the part is the anode in an electrolytic cell. The object of the anodizing was increased corrosion resistant, paint adhesion and was provided unique, decorative colors. Many electrolytes, under different conditions, have been used for the anodic oxidation of alumminum and its alloys. This paper deals with the procedures used in the anodic oxidation of aluminum and its alloys, the nature and properties of the oxide films, their uses and anodizing equipment and process control.

• Korean Journal of Materials Research
• /
• v.22 no.12
• /
• pp.717-721
• /
• 2012

Manganese dioxide ($MnO_2$) is one of the most important cathode materials used in both aqueous and non-aqueous batteries. The $MnO_2$ polymorph that is used for lithium primary batteries is synthesized either by electrolytic (EMD-$MnO_2$) or chemical methods (CMD-$MnO_2$). Commonly, electrolytic manganese dioxide (EMD) is used as a cathode mixture material for dry-cell batteries, such as a alkaline batteries, zinc-carbon batteries, rechargeable alkaline batteries, etc. The characteristics of lithium/manganese-dioxide primary cells fabricated with EMD-$MnO_2$ powders as cathode were compared as a function of the parameters of a manufacturing process. The flexible primary cells were prepared with EMD-$MnO_2$, active carbon, and poly vinylidene fluoride (PVDF) binder (10 wt.%) coated on an Al foil substrate. A cathode sheet with micro-porous showed a higher discharge capacity than a cathode sheet compacted by a press process. As the amount of EMD-$MnO_2$ increased, the electrical conductivity decreased and the electrical capacity increased. The cell subjected to heat-treatment at $200^{\circ}C$ for 1 hr showed a high discharge capacity. The flexible primary cell made using the optimum conditions showed a capacity and an average voltage of 220 mAh/g and 2.8 V, respectively, at $437.5{\mu}A$.

• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.31 no.2B
• /
• pp.187-192
• /
• 2011

Nitrate nitrogen is common contaminant in groundwater aquifers, its concentration is regulated many countries below 10 mg/L as N (As per WHO standards) in drinking water. An attempt was made to get optimal results for the treatment of nitrate nitrogen in groundwater by conducting various experiments by changing the experimental conditions for ZVI bipolar packed bed electrolytic cell. From the experimental results it is evident that the nitrate nitrogen removal is more effective when the reactor conditions are maintained in acidic range but when the acidic environment changes to alkaline due to the hydroxide formed during the process of ammonia nitrogen there by increasing the pH reducing the hydrogen ions required for reduction which leads to low effectiveness of the system. In the ZVI bipolar packed bed electrolytic cell, the packing ratio of 0.5~1:1 was found to be most effective for the treatment of nitrate nitrogen because ZVI particles are isolated and individual particle act like small electrode with low packing ratio. It is seen that formation of precipitate and acceleration of clogging incrementally for packing ratio more than 2:1, decreasing the nitrate nitrogen removal rate. When the voltage is increased it is seen that kinetics and current also increases but at the same time more electric power is consumed. In this experiment, the optimum voltage was determined to be 50V. At that time, nitrate nitrogen was removed by 94.9%.

• Journal of Surface Science and Engineering
• /
• v.22 no.3
• /
• pp.135-144
• /
• 1989

Aluminium Oxide was deposited with a C.V.D.-technique on various substrates. The effects of various treating condition such as temperature, time, heat resistance and composition of substrates were investigated in order to understand the relationship of structure, property and process. Grain size depends upon the activity of adsorption siite and coarsened with increasing temperature and time. Deposition rate decreases in order of electrolytic iron, carbon steel STS430 and STS304, since the active site for adsorption of reactant was more decreased for Cr and Ni than Fe. Oxidation resistance of alumina coated specimens improved markedely and that of stainless steel was prominent.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
• /
• v.20 no.9
• /
• pp.749-755
• /
• 2007

Recently, novel MEMS probe cards can support reliable wafer level chip test with high density probing capacity. However, manufacturing cost and process complexity are crucial weak points for low cost mass production. To overcome these limitations, we have developed micro spring structured MEMS probe card. For fabrication of micro spring module, a wire bonder and electrolytic polished gold wires are used. In this case, stringent tension force control is essential to guarantee the low level contact resistance of micro spring for reliable probing performance. For this, relation between tension force of fabricated probe card and contact resistance is characterized. Compare to conventional probe cards, developed MEMS probe card requires fewer fabrication steps and it can be manufactured with lower cost than other MEMS probe cards. Also, due to the small contact scratch patterns, we expect that it can be applied to bumping types chip test which require higher probing density.

• Resources Recycling
• /
• v.16 no.1 s.75
• /
• pp.68-72
• /
• 2007

The influences of reduction time, potential difference and ionic concentration flow rate have been investigated on the electrolytic recovery of silver from artificial photographic wastewater in continuous flow reactor system. As the initial concentration of silver ion and applied potential were increased, the amount of silver recovered was observed to be raised. Also, the electrolytically recovered material from artificial wastewater was proved to be pure silver based on the qualitative analyses by EPMA and XRD.