• Journal of the Korean Society for Nondestructive Testing
• /
• v.31 no.1
• /
• pp.53-61
• /
• 2011

Edge notched A16061-T6 aluminum was repaired with a GFRP composite patch as a function of the number of stacking, Damage progress of specimen for tension load has been monitored by acoustic emission(AE), AE energy rate, hit rate, amplitude, waveform and 1st peak frequency distribution were analyzed. Fracture processes were classified into Al cracking, Fiber breakage, Resin cracking and Delamination. Displacement of a specimen can be divided into Region I, II and ill according to acoustic emission characteristics. Region II where the patch itself was actually fractured was focused on to clarify the AE characteristics difference for the number of stacking.

• Journal of Korean Society of Environmental Engineers
• /
• v.33 no.7
• /
• pp.530-535
• /
• 2011

In this work, the adsorption characteristic of the composites by adding loess with aluminum ("Al-loess") and Loess with lanthanum ("La-loess") which have been developed to effectively remove phosphorus, the substance which causes the eutrophic lake has been evaluated. According to the result of the work, as the amount of aluminum or lanthanum put in 1g of loess increases, the combined amount also increases accordingly. When the loess with no aluminum or lanthanum attached was used, the rate of removing phosphorus was different in comparison with the case of using the composites of 0.5, 1 and 2 mg of aluminum and 0.5, 1 and 3 mg of lanthanum in each gram of loess. It was observed the amount required to remove 1 mg $PO_4^{3-}$-P/L of phosphorus completely is approximately 2 to 10 times less for the composite of Al-loess than loess alone. Also, in case of the composite of La-loess, the amount was decreased by about 1.5 to 10 times. In order to observe the rate of adsorption phosphorus with Al-loess and La-loess, the composites were used for the observation up to three times by water washing. As a result, the water washing of the composite did not affect phosphorus removal. According to the effect of pH, there is a high rate of removing phosphorus in the pH range of 5~8. It seems that the developed composite will effectively remove phosphorus when it is spread in the natural water system. Also, since Al-loess and La-loess composites are rapidly precipitated within 30 minutes, it is stabilized quickly at the bottom of the eutrophic lake and becomes responsible for the removal of phosphorus in water and eluted from the water and the sedimentary layer.

• Resources Recycling
• /
• v.30 no.2
• /
• pp.39-45
• /
• 2021

Spent photovoltaic module is one of the important resource of silver, while related research concerning silver recovery remains limited. In our previous research, HNO3 was utilized to dissolve Ag(I) and Al(III) from the spent silicon solar cells. In order to recover Ag(I) from the leachate of a silicon solar cell, the present study made use of a nitrate solution containing Ag(I) and Al(III), which was subjected to a solvent extraction process with 5,8-diethyl-7-hydroxydodecan-6-oxime (LIX63). Ag(I) was selectively extracted with LIX63 over Al(III) from the nitrate leach solution. Subsequently, quantitative stripping of Ag(I) from the loaded LIX63 was performed by using 20% ammonia water. The McCabe-Thiele plots for the extraction and stripping isotherms of Ag(I) were also constructed. Extraction and stripping simulation tests confirmed an Ag(I) extraction and stripping efficiency of >99.99% and 98.9%, respectively with high purity Ag (99.998%) and Al (99.99%) solution. A process flow sheet for Ag(I) recovery from the nitrate leach solution was proposed.

• Journal of Korean Society of Environmental Engineers
• /
• v.37 no.6
• /
• pp.325-331
• /
• 2015

The experimental results of the characteristics of aluminum based and ferric based coagulants for the Nakdong River water showed that the main hydrolysis species contained in alum and $FeCl_3$ are monomeric species of 98% and 93.3%, respectively. The PACl of r=1.2 produced by the addition of base contained 31.2% of polymeric Al species and the PACl of r=2.2 contained 85.0% of polymeric Al species, as showing more polymeric Al species with increasing r value. Coagulation tests using Al(III) and Fe(III) salts coagulants for the Nakdong River water showed that the coagulation effectiveness of turbidity and organic matter was high in the order of $FeCl_3$ > PACl (r=2.2) > PACl (r=1.2) > alum. $FeCl_3$ has showed better flocculation efficiency than Al(III) salts coagulants. In addition, in case of Al(III) coagulants, the Al(III) coagulants of higher basicity, which contained more polymeric Al species, resulted in better coagulation efficiency for both turbidity and organic matter removed. The optimum pH range for all of the coagulants investigated was around pH 7.0 under the experimental pH range of 4.0~9.5. Especially, the highest basicity PACl (r=2.2) and $FeCl_3$ were considered as more appropriate coagulants for the removal of turbidity in the case of raw water exhibiting higher pH.

• Resources Recycling
• /
• v.33 no.4
• /
• pp.36-46
• /
• 2024

We investigated a hydrometallurgical process of nickel recovery from Inconel 713C scrap. The process proceeded with a series of i) comminution of pyrometallurgical treated scrap, ii) sulfuric acid leaching, iii) solvent extraction of unreacted acid, molybdenum, aluminum, and precipitation of chromium, iv) crystallization of nickel sulfate by vacuum evaporation, and v) nickel electrowinning. The nickel-aluminum intermetallic compound, Ni₂Al₃, was formed by the pyrometallurgical pretreatment readily grounded under 75 ㎛. Sulfuric acid leaching was done for 2 hours in 2 mol/L, 20 g/L solid/liquid ratio, and 80 ℃. It revealed that over 98 % of nickel and aluminum was dissolved, whereas 28 % of molybdenum was. A nickel sulfate solution with 2.34 g/L for the crystallization of nickel sulfate hydrate was prepared via solvent extraction and precipitation. Over 99 % of molybdenum and aluminum and 93 % of chromium was removed. Nickel metal with 99.9 % purity was obtained by electrowinning with the nickel sulfate monohydrate in the cell equipped with anion exchange membranes for catholyte pH control. The membrane did not work well, resulting in a low current efficiency of 73.3 %.

• Aerospace Engineering and Technology
• /
• v.2 no.2
• /
• pp.124-132
• /
• 2003

This paper described the structural design and the fabrication procedure of KSR-III composite pressure tank. The type of the composite pressure tank was COPV(Composite Overwrapped Pressure Vessel). A non-load sharing liner was made of aluminum 6061-0 and the liner provided a helium gas seal. The composite pressure tank was winded using T700 carbon/epoxy on the liner. Because the aluminum liner was thin, multiple cure cycles were applied to the filament winding technique. The multiple cure cycles prevented the liner-cylinder from losing a circular shape. A fitting force at the metallic boss was spread to the carbon fiber by a boss ring. The boss ring also prevented a local deformation at the boss part.

• Korean Journal of Metals and Materials
• /
• v.48 no.2
• /
• pp.148-153
• /
• 2010

The effects of Cu(II) and Al(III) on the extraction and separation of Pt(IV) and Pd(II) have been investigated in a mixed chloride solution using Alamine336 as the extractant. In the HCl concentration range of 1 to 5 M, more than 99% of Pt and Pd could be extracted by Alamine336 from all of the mixed chloride solutions investigated in this study. Lower HCl concentration led to a higher separation factor between Pd and Pt when Alamine336 concentration was constant. Extraction percentage of Cu increased with the increase of HCl concentration, while that of Al was nearly constant at 33% in our experimental range. The optimum conditions to extract Pt and Pd from Cu or Al and the separation factor under these conditions were obtained.

• Clean Technology
• /
• v.19 no.3
• /
• pp.249-256
• /
• 2013

The experiments have been performed to obtain zinc complex compound with smaller particle sizes, which is used as a charge control agent in manufacturing toner. Metallic salts and polyhydric alcohols have been studied to investigate their effects on the formation and the triboelectric charge of zinc complex-compound particle with different sizes. Reactants such as zinc chloride and 3,5-di-tert.-butyl salicylic acid have been used to form the complex compound. Polyethylene glycol (PEG-300), glycerin and ethylene glycol have been added into the zinc chloride solution beforehand to lower the reaction rate in the formation of zinc complex-compound. Aluminium(III) chloride has been mixed in the zinc chloride solution beforehand to restrain the particle size from growing. When PEG-300 and aluminium(III) chloride are used to lower the reaction rate and to restrain the particle size from growing, the average particle size of zinc complex compound decreases from $5.28{\mu}m$ to $2.33{\mu}m$, which was 44.1% of $5.28{\mu}m$.

• Journal of the Korean Society of Marine Environment & Safety
• /
• v.20 no.4
• /
• pp.451-460
• /
• 2014

In this paper, we examined the problem of the structural stability according to the patch load of a rectangular plate that reflects the material properties of A6082-T6 is used primarily for marine plant structure. it applied to the four patch loading shapes, the effect of aspect ratio, a boundary condition and calculated the critical elastic buckling load. Calculating the critical elastic buckling load, During the eigenvalue buckling analysis it is applied to the shell181 as 4 node shell element. when the plate subjected to patch loading compare to the plate under a uniform axial compression load, it is possible observed to occur the different elastic buckling behaviour and it could be confirmed that it is affected significantly on a variable position and type of loadings, such as the effect of the aspect ratio. Also, Critical elastic buckling load according to th patch loading type in simply supported rectangular plate a/b=1.0, ${\gamma}b$=200mm are calculated 67%(Loading type I), 119 %(Loading type II), 76 %(Loading type III), 160 %(Loading type IV), respectively. Loading type I and III could be determined with the strong elastic buckling behavior much more than Loading type II and IV.

• Journal of the Korean Applied Science and Technology
• /
• v.33 no.3
• /
• pp.441-448
• /
• 2016

Heavy metal removal study is conducted from synthetic waste water by reduction and oxidation(redox) reaction of Cu-Zn metal alloy and adsorption reaction of aluminium silicate. Heavy metal whose ionization tendency is smaller than zinc are reducted in an aqueous solution, and the concentration of ionized zinc is reduced by adsorption reaction. The average diameter of metal alloy micro fiber is about $200{\mu}m$, and the surface area is wide enough to get equilibrium in a single cycle treatment. A single cycle treatment of redox reaction of Cu-Zn metal alloy, could remove 100.0 % of Cr(III), 98.0 % of Hg, 92.0 % of Sn and 91.4 % of Cu respectively. An ionization tendency of chromium is very close to zinc, but removal efficiency of chromium by redox reaction is significant. This result shows that trivalent chromium ion is expected to generate hydroxide precipitation with $OH^-$ ion generated by redox reaction. Zinc ion generated by redox reaction is readily removed by adsorption reaction of aluminium silicate in a single cycle treatment. Other heavy metal components which are not perfectly removed by redox reaction also showed very high removal efficiency of 98.0 % or more by adsorption reaction. Aluminium ion is not increased by adsorption reaction of aluminium silicate. That means heavy metal ion removal mechanism by adsorption reaction is turned out to be not an ion exchange reaction, but an adsorption reaction.