• Journal of the Korean Ceramic Society
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• v.40 no.8
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• pp.720-724
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• 2003

Aluminum nitride (AlN) powders were synthesized by using a mixture of an aluminum nitrate or sulfate salt and carbon (mole ratio of $Al^{3+}$ to carbon=L : 30). The AlN was obtained by calcining the mixture under a flow of nitrogen in the temperature range 1100-1$600^{\circ}C$ and then burning out the residual carbon. The process of conversion of the salt to AlN was monitored by XRD and $^{27}$ Al magic-angle spinning (MAS) NMR spectroscopy. The salt decomposed to ${\gamma}$-alumina and then converted to AlN without phase transition from ${\gamma}$-to-$\alpha$-alumina. $^{27}$ Al MAS NMR spectroscopy shows that the formation of AlN commenced at 110$0^{\circ}C$. AlN powders obtained from the sulfate salt were superior to those from the nitrate salt in terms of homogeneity and crystallinity. A very small amount of AlN whiskers was obtained by calcining a mixture of an aluminum sulfate salt and carbon at 115$0^{\circ}C$ for 40 h, and the growth of the whiskers is well explained by the particle-to-particle self-assembly mechanism.

• Journal of Korean Society of Water and Wastewater
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• v.33 no.6
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• pp.413-420
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• 2019

Pretreatment system of desalination process using seawater reverse osmosis(SWRO) membrane is the most critical step in order to prevent membrane fouling. One of the methods is coagulation-UF membrane process. Coagulation-UF membrane systems have been shown to be very efficient in removing turbidity and non-soluble and colloidal organics contained in the source water for SWRO pretreatment. Ferric salt coagulants are commonly applied in coagulation-UF process for pretreatment of SWRO process. But aluminum salts have not been applied in coagulation-UF pretreatment of SWRO process due to the SWRO membrane fouling by residual aluminum. This study was carried out to see the effect of residual matal salt on SWRO membrane followed by coagulation-UF pretreatment process. Experimental results showed that increased residual aluminum salts by coagulation-UF pretreatment process by using alum lead to the decreased SWRO membrane salt rejection and flux. As the salt rejection and flux of SWRO membrane decreased, the concentration of silica and residual aluminum decreased. However, when adjusting coagulation pH for coagulation-UF pretreatment process, the residual aluminum salt concentration was decreased and SWRO membrane flux was increased.

• Journal of Korea Foundry Society
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• v.20 no.1
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• pp.38-45
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• 2000

The remelting for recycling or thin aluminum scrap, such as aluminum chip generally involves melting of these pieces submerged in molten salt flux. In this study, the effects of salt flux compositions and alloying elements on the aluminum dropletscoalescence and oxide film removal were studied in 99.8%Al, Al-1.01%Cu, Al-1.03%Si, and Al-1.38%Mg alloys as a function of holding time at $740^{\circ}C$ Salt fluxes based on NaCl-KCl(1:1) with addition of 5wt.% fluorides(NaF, $Na_3AlF_6$, $CaF_2$) or 5 wt.% chloride($MgCl_2$, $AlCl_3$) were used. The experimental results show that NaCl-KCl(1:1) with addition of 5 wt.% fluorides exhibits better coalescence ability than that with chlorides. The oxide film is not removed by NaCl-KCl(1:1) with addition of 5 wt.%chlorides, while it is removed by NaCl-KCl(1:1) with addition of 5 wt.% fluorides. The aluminum droplets coalescence and oxide film removal by salt fluxes are related to interfacial tension tension between metal and salt flux.

• Journal of the Korean Ceramic Society
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• v.27 no.7
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• pp.851-860
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• 1990

The hydrolysis-precipitation reaction of mixed aluminum salt solutions of aluminum sulfate, aluminum nitrate, and urea has been investigated to obtain narrow-sized and unagglomerated fine spherical precipitates of aluminum hydroxide required for coating core particles. The hydrolysis-precipitatin reaction could be controlled to be appropriate to coating processes by usign urea as a pH control-agent. As the concetration of total Al3+ ion and the molar ratio of SO42-/Al3+ in starting solutions became smaller and also as the vol. ratio of water/solution for hydrolyzing mixed aluminum salt solution became larger, the morphology of precipitates tended to be more unagglomerated and spherical, while their size(0.5longrightarrow0.05${\mu}{\textrm}{m}$) to be smaller. The optimum hydrolysis condition for coating processes was to hydrolyze the mixed aluminum salt solution, in which the molar ratio of SO42-/Al3+ was 0.75, while the amount of water corresponding to the vol. ratio of water/solution of 15. The precipitate was the aluminum hydroxide which sulfate ions were strongly adsorbed on and the maximum yield in the hydrolysis-precipitation reaction was about 20%.

• Resources Recycling
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• v.6 no.1
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• pp.5-10
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• 1997

The aluminum was recovered from the middle size (Q1.0-12.0 mm) aluminum drosses using NaCl and KC1 mixuture as a basic salt flux. The maximum aluminum recovery was about 76.9% when 40% basic salt flux was added to aluminum dross at 850$^{\circ}$C for two hours. Also, aluminum remvery increased with increasing fluoride (1%-5%) addition to basic salt flux. But, there was no considerable effect due ta the increasing of viscosity when the fluorides were added over 5%, respectively. E s p d y , the most aluminum recovery was about 83.5% when 5% cryolite was added to 40% basic salt flux.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.58 no.9
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• pp.1764-1768
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• 2009

As the demand of electric power is increasing rapidly, the need of the compact and light electric power device is also increased. Copper clad aluminum (CCA) is newly proposed electrical conductor, because of its light-weight and low-cost characteristics, to replace the existing conductor made of copper. This paper presents the salt-proof characteristics of the copper clad aluminum (CCA) to certificate long time safe operation of the newly proposed electrical conductor. The two types of the CCA conductor were tested in the neutral salt spray tester. The experimental results of two types of the CCA with salt spray were presented in this paper. The results comprise resistance measured data, micro picture of the selected surface, and component measured data according to the elapsed time. The period of the experiment was 1,000 hours. There was no evidence to show the corrosion of CCA during the whole period of the experiments.

• Journal of Advanced Marine Engineering and Technology
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• v.33 no.6
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• pp.860-866
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• 2009

It is very important to choose optimal material having good corrosion resistance and capabilities for the part materials such as the automotive exhaust system under a hot salt corrosion atmosphere. Generally, two types of corrosion come into the automotive exhaust system. One is 'Condensate Corrosion', which is occurred by exhaust gas condensate formed at the inner surface of exhaust system heated up during driving, which results in the acid condensate pitting. The other is 'High Temperature Salt Corrosion' occurring from the interaction between the chloride ion coming from salt at the seaside district or snow salt and the outer surface of exhaust system. By the corrosion attack, the main muffler is firstly damaged and the life cycle of an automobile is significantly decreased. It has been investigated that the hot salt corrosion properties of a STS 409L and 436L ferritic stainless steels which are well-known for the materials of the automotive exhaust system. In addition, the corrosion properties of hot dip aluminum coated STS 409L have been compared with uncoated steels. Aluminum coated STS 409L showed a superior corrosion resistance than uncoated STS 409L, and futhermore showed a better corrosion resistance than a STS 436L, which is an expensive ferritic stainless steel having a excellent corrosion resistance caused from more chromium content of an alloying element.

• Resources Recycling
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• v.27 no.5
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• pp.61-68
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• 2018

The aluminum dross is oxide generated on the surface of the molten metal during the aluminum melting process and it is divided into white dross and black dross according to presence of the Salt flux. White dross has high metal content and is recycled via the melting process. Black dross is largely berried, because the it has a low metal content and difficulty in separating the components. Black dross contains a salt components such as NaCl and KCl, and inorganic materials such as $Al_2O_3$ and MgO, and it is necessary to study the technology to recover and recycle such valuable resources. In this study, a process for recycling aluminum black dross was proposed. The inorganic and soluble substances present in the black dross were separated through crushing-dissolution-solid/liquid separation-decompression evaporating. By controlling the ratio of water and black dross, the recovery condition of the separated product was optimized and we confirmed the highest Salt flux recovery efficiency 91 wt.% at black dross:water ratio 1:9. Finally, Through the synthesis of zeolite using recovered ceramic material, the materialization possibility of black dross was confirmed.

• Journal of the East Asian Society of Dietary Life
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• v.7 no.4
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• pp.512-518
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• 1997

This study was performed to determine the amount of aluminum, which is one of the factors of Alzheimer's disease, In some fishes caught from some areas of the west coast in Korea. The 46 aquatic products were composed of fishes, molluscs, and salt-fermented products (jeot-gal). The 24 fishes were Hickory shad, Gobies, Pomfref, Atkafish, Flounder, Jambeng-ie Monk fish, Yellow hair tail, Mackerel, Bartailed flathead, Alaska pollack, Brown croaker, Eel, Fine-spotted flounder, Black spotted grouper, Sea-eel, Pacific saury, Areliscus honaleus, Small boil-dried anchovy, Croaker, Hair tail, Sea bream genuine, Motleystrip rainbowfish, and Bastard halibut. The 15 Molluscs were Whip-arm octopus, Sea arrow, Common squid, Han chi, Cuttle fish, Turban shell, Pond snail, Orient calm, Surf calm, Butter calm, Crib shell, Oyster, Egg cockle, Little neck calm, and Arkshell. The 7 salt-fermented products were salt-fermented Shrimp, Little neck, Oyster, Shad, Gonjeng-ie, Hqangsegi, and Squid. All of them were ashed with 5$m\ell$ HNO$_3$ and then with 10$m\ell$ ternary solution (HNO$_3$ : H$_2$SO$_4$ : HClO$_4$= 10 : 1 : 4). After ashing of the samples, the aluminum amount were measured by ICP. The aluminum amount of molluscs was significantly higher than that of fishes and salt-fermented products(p＜0.01). The aluminum amount of Orient calm and Healak in molluscs were 827.70, 812.55ppm, respectively, which were the most amounts compared nth that of the other samples. But the aluminum amounts of Bartailed flathead and Sea bream, genuine In fishes were 0.98, 0.97ppm, respectively, which were the least amounts compared with that of other samples. This study was limited within 46 aquatic samples, therefore I hope there will be wider efforts to determine about auminum amount in broade range of aquatic foods for the prevention of Alzheimer's disease.

• Journal of the Korean institute of surface engineering
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• v.32 no.3
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• pp.452-455
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• 1999

ORV which vaporizes LNG to NG is consisted of tube and header whose substrate is aluminum alloy. The corrosion of the tube is very severe because of sea water being used as the heating source. In this research to protect ORV substrate material, the corrosion behavior of aluminum alloys was investigated for the sacrificial role of Al-Zn alloy for ORV tubes. The electrochemical behavior of aluminum alloys in sea water was investigated. The corrosion behavior of thermally-sprayed and cladded samples were compared through salt spray tests. Al-Zn alloy can act as a sacrificial anode and cladded Al-Zn alloy has a better corrosion resistance than that of thermally sprayed one. The galvanic effect of Al-Zn to substrate material was conformed from scratched sample tests.