• Journal of the Korean Society for Precision Engineering
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• v.20 no.5
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• pp.225-231
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• 2003

The injection molding is a traditional manufacturing method that can make plastic parts by just one time in mold. Therefore, the injection molding has become one of a manufacturing method, which is widely applied in a producing of plastic products. Nowadays, to use of plastic parts has increased and plastic product-model using term has been shorten. By these reasons, using term of a injection mold has fast been reduced. These produced molds will be disused and leaved in a storage after a regular term to use it. These leaved molds are sometime sold as scrap iron. But, these molds have lots parts for recycling except special parts for example, cavities, cores and eject pins, etc. In this research, we investigated when the cavity and core of in injection mold would be changed, the injection mold could be recycled. We suggested the structures and standardizations for recycling of a moldbase. We also developed a program in which can be used when the recycling moldbase design in the Auto-CAD with the recycling standards. We called this program as the Recy-Mold. For the availability of the program and moldbase structure fur the recycling standards, we experimented a used mold for automobile lens, which was remanufactured by the recycling standard. The results of this test showed feasibility for the recycling mold.

• Proceedings of the IEEK Conference
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• 2001.10a
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• pp.140-143
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• 2001

A study has been made on the recovery of nitric acid and valuable metals such as Cu, Sn, Pb from the spent nitric etching solutions. The nitric acid was extracted effectively by TBP but the heavy metals such as Fe, Cu, Sn, Pb were not extracted by TBP from the spent nitric etching solutions. From the experimental results, 95% of nitric acid in spent etching solution was extracted at O:A ratio of 3:1 with five stage by 60% TBP and 98% of nitric acid was stripped from the loaded organic phase at O:A ratio of 1:1 with four stages by distilled water. After extracting nitric acid, Cu was recovered as a metal by electrowinning effectively and Sn was successfully removed by precipitation method by adjusting the pH of raffinate solution. Finally, Pb was recovered by cementation with iron scrap at $65^{\circ}C$. Parameters controlling the cementation process, such as temperature, pH and the effect of the additives were investigated.

• Journal of Korea Foundry Society
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• v.42 no.6
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• pp.358-368
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• 2022

In this study, visual simulations were performed on the packing behaviors of various press scraps. The packing states after the initial charging step were quantitatively compared. The comparison targets were 300mm cubic press scraps, customized cubic press scraps, customized octagonal prism press scraps and customized cylinder press scraps. The customized press scraps were designed in customized sizes for furnaces with melting capacities of 1, 1.5, 2, 3, 4, 5 and 6t/h. The packing states such as the initial charging number, the additional charging weight percentage, the packing density and the gap volume percentage were comparatively evaluated.

• Journal of Environmental Impact Assessment
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• v.6 no.1
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• pp.105-110
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• 1997

Sanitary landfill is a general method as a final disposal of municipal solid waste(MSW), therefore leachate characteristics are very various as lime goes by because of highly concentrated organic acids are contained non biodegradable COD. So it is hard to abide by the mandatory standards of discharge eventhough applying the physicochemical and biological processes to treat the leachate. The process of treating leachate are determined by the degree of removal and components, but they are highly contained organic materials. It is a removal method to use jointly with the physicochemical process if the hard and fast rule is needed. The critical components of material are COD, ammonia, salts and heavy metals in the case of treating biologically. Biological process is to use metabolism of microorganism, therefore it is a desirable condition which heavy metals are not contained, because they acting as an inhibitor of enzyme. Of these are contained, organic decomposition and synthetic function of microorganisms decrease significantly. Consequently, this research paper lays emphasis on the concentration of heavy metals in leachate and for the purpose of forecasting the factors which are affecting the leaching of metalic waste in some degree, experimented the various reacting conditions. 1. When the concentration of heavy metals in leachate is in comparison with the level eluted after reaction, at pH 7.9 the result of reaction for PCB to CCL scrap showed that Zn, Mn, Cu was more eluted 11.6 times, 340.3 times, and 2,705.5 times respectively than the leachate undiluted solution. 2. At the condition of strong acid pH 4.7, the concentration of heavy metals in EM undiluted solution showed that Zn, Mn, Cu was more eluted 26.5 times, 147.3 times, and 3,656.3 times respectively than leachate undiluted solution. 3. When the ratio leachate to EM was 50 vs 50(V/V%), Mn was more eluted 198.7 times than leachate undiluted solution, but Zn and Cu do not show the meaningful results. 4. The color of landfill leachate was black-brown. And fulvic acid that is main ingredient of NBD COD contained, oxygen of 44~50%. For that reason, I estimated that the level of Zn, Mn, Cu was higher than the case of leachate. 5. COD of leachate from general landfill is difficult to remove. Because the solution of heavy metals is improved by the character of leachate(pH & ingredient of oxygen etc.) hence the Mn, Cu, Zn act as disturbing factor, the biochemical treatment is hard. Therefore the type of PCB & CCL scrap, iron, aluminum contained metals need to previously separate from general wastes as much as possible.

• Resources Recycling
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• v.21 no.5
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• pp.58-64
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• 2012

Ti button type ingots were prepared by recycling of Ti turning scraps using vacuum arc melting process for production of consumable arc electrode. The behavior of impurities such as Fe, W, O, and N in the Ti button ingots was investigated and the properties of the Ti button ingots were also evaluated. In the case of oxygen gaseous impurity, the oxygen layers on the surface of the Ti turning scraps were easily removed by the first vacuum arc melting. On the other hand, the solute oxygen in the Ti turning scraps was not removed by the next melting. In the case of Fe, major impurity in the Ti turning scraps, the removal degree in the final Ti button ingot refined by vacuum arc melting for 20 minutes was approximately 43 %, which is due to the vapor pressure difference between Ti and Fe. As a result, the Ti button ingots with ASTM grade 3 could be obtained by multiple vacuum arc melting from the Ti turning scraps. Therefore, it was confirmed that the preparation of consumable electrode for vacuum arc remelting could be possible by recycling of Ti turning scraps.

• Journal of the Korean Ceramic Society
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• v.51 no.3
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• pp.184-189
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• 2014

Electric arc furnace dust (EAFD) is a solid waste generated by the steel-scrap recycling process. It mainly consists of zinc oxides (ZnO), alumina ($Al_2O_3$), iron oxides ($Fe_2O_3$), and silica ($SiO_2$). Here we report the preparation and characterization of blue ceramic pigments using EAFD powder as a starting material. $(Zn(EAFD),Co)Al_2O_4$ blue ceramic pigment was prepared by the solid-state reaction method. The color characteristics of the pigment obtained were compared with those of pure $CoAl_2O_4$. The new pigment was characterized using XRD, CIE-$L^*a^*b^*$ color-measurements, SEM, and EDX. The XRD analysis revealed that the $(Zn(EAFD),Co)Al_2O_4$ pigment was composed of mainly the spinel phase of $(Zn,Co)Al_2O_4$. The $Zn(EAFD)_{0.25}Co_{0.75}Al_2O_4$ pigments showed a vivid blue color with a $b^*$ value of -28.64 and a good glaze stability with a transparent glaze.

• Resources Recycling
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• v.11 no.4
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• pp.11-16
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• 2002

Analysis and separation of constituent materials of old car have been performed by using the industrial shredding line. For this aim, three old cars made by domestic automobile manufacturers, Sonata II, Sephia and Prince were chosen and delivered in pressed form without engine, tires and doors, etc. Shredding line was substantially composed of pre- and main-shredder. cyclone, magnetic separation, eddy current separation and man-power separation. From the separation of shredder products, iron scrap was observed to be the major material of old car accounting for 60.1 ％ of total weight and non-ferrous metals involving Al, Cu and Zn, etc. were about 2％. Light fluff, about 90％ of total fluff product, was comprised with plastic, fiber and sponge, etc. and the fraction of 5 cm undersize in light fluff was 70.5%. In case of heavy fluff, however. rubber and plastic were found to be the major constituent materials of it. Among the constituent materials of fluff, plastic showed the highest calorific value, more than 10,000 cal/gr and leather and rubber showed relatively high chlorine content, 10.3 and 2.55 wt%, respectively.

• Proceedings of the Korean Institute of Resources Recycling Conference
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• 2005.05a
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• pp.57-61
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• 2005

In this study, the machine vision system for inspection using color recognition method have been designed and developed to automatically sort out a specified material such as Cu scraps or other non-ferrous metal scraps mixed in Fe scraps. The system consists of a CCD camera, light sources, a frame grabber, conveying devices and an air nozzled ejector, and is program-controlled by a image processing algorithm. The ejector is designed to be operated by an I/O interface communication with a hardware controller. The sorting examination results show that the efficiency of separating Cu scraps from the Fe scraps mixed with Cu scraps is around 90 % at the conveying speed of 15 m/min. and the system is proven to be excellent in terms of its efficiency. Therefore, it is expected that the system can be commercialized in shredder firms, if the high-speed automated sorting system will be realized.

• Resources Recycling
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• v.19 no.6
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• pp.11-26
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• 2010

In order to review the recycling status of urban mine resources in Japan, metal consumption, metal recycling rate and metal recycling industry such as iron scrap, end of life vehiclcs(ELV), waste home appliances and spent IT equipments were surveyed. Japan took rank of top class in the world on the metal consumption and urban mine stock reserve. Metal recycling industries in Japan have been developed through excellent technologies for mineral processing and non-ferrous smelting. On the other hand, the technologies for recycling of rare metals are being developed now. Recycling rate of EL V, waste home appliances and personal computer are higher than the guidelines of the legislative standard.

• Proceedings of the Korea Port Economic Association Conference
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• 2006.08a
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• pp.159-179
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• 2006

As the current trend to the main index of the port competitiveness evaluation, the competitiveness index of the port service comes to more important than the part of expense, location and facility. To reform the bottleneck of port has an effect on improving port service competitiveness. Therefore, this study shows the importance of analyzing bottlenecks on logistics to improve port competitiveness. It collected recent questionnaire data which are the subject as the Custom Service, the Chamber of Commerce and Industry, the Trade Association about bottlenecks of port logistics for working out bottlenecks of domestic port logistics and it produced the order of priorities of bottlenecks by multiplying each output priorities and weights of each process in user of Incheon inner-outer port which is focused on container freight by analysis of priority and Analytic Hierarchy Process(AHP). Unlike existing studies, this study has important values. It presents the priority evaluation only focused on the container freight was produced by port users who are categorized into shipping company, terminal operation company and forwarder, car-ferry in Incheon inner-outer port and making a application of logistics process. It means internal and external competitiveness improvement plan can be presented more concretely and detailed than past competitiveness attributes such as location, facility, service and expense. If the analysis of port logistics bottlenecks which was focused on container freight is extended to the part of general cargo and sundries such as haul grain, car, scrap iron, those studies will be able to provide Incheon port users with useful information and a model of analyzing overall bottleneck of logistics in Incheon port.