• Proceedings of the IEEK Conference
• /
• 2001.10a
• /
• pp.398-403
• /
• 2001

There is a potential usability of electric arc furnace(EAF) dust produced during the iron manufacturing process as a recycled resource, because valuable materials such as Zn, Pb and Fe are contained in it. In this study, metallic Zn was recycled from the fine electric arc furnace dust by a solid state reduction method using carbon at relatively low temperature. It was possible to recover metallic zinc by using of high vapour pressure of zinc with this reduction method. The feasibility of recycled zinc for cold bonded pellet(CBP) was investigated. The main composition of EAF dust were franklinite(ZnFe$_2$O$_4$), magnetite(Fe$_3$O$_4$) and zincite(ZnO), and Pb and Cl were completely removed by a heat treatment in oxidation environment. The reduction ratio increased as the solid carbon content increased, and it increased with decreasing of dust particle size and increasing of compaction pressure due to a increase of contact area.

• Proceedings of the Korean Society of Agricultural Engineers Conference
• /
• 2005.10a
• /
• pp.26-31
• /
• 2005

In national prospective, the needs to develop water resources has been increased due to water shortage from diverse use of water resources in agricultural areas. Existing agricultural water demand, which has mainly been limited to the use of farming, are now expanding to diverse water uses such as supporting daily lives, diluting environmental pollution as well as industrial use for agricultural complex currently under construction in agricultural region. In this situation, for the sake of effective procurement of water resources and supply method, it is definitely required to enhance the effectiveness of budget investment and project proceedings through integrated re-development which links projects to strengthen existing dams, reservoirs and hydraulic facilities. The major scopes of this research includes developing different types of system such as selecting potential sites to re-construct reservoirs including generating base maps and thematic maps, data collection regarding water demands and reservoir status; analyzing reservoir data; estimating developable capacity and index calculation; and forecasting inundated areas. In addition, this study provides other products such as developing output generation system which can support wide use of data built and analyzed; database generation for better data management; data analysis including selection, extraction, indexation, and calculation of base items through standardization; data security system prohibiting exterior proliferation and malicious manufacturing of data.

• Resources Recycling
• /
• v.32 no.1
• /
• pp.33-41
• /
• 2023

Herein, we selectively recovered Zn and produced ZnSO₄ from electric arc furnace dust using a hydrometallurgical process. The analysis of the properties of the electric arc furnace dust revealed that the Fe content (9.9%) was relatively low while the Mn content (19%) was high as compared to the composition of general dust. Therefore, an appropriate hydrometallurgical process was designed based on the properties of the raw materials. In the leaching process involving the use of 1.6 M sulfuric acid and 20% solid-liquid ratio at 60℃ for 1 h, 85% of the Zn and Mn got dissolved while the Fe was not leached. To selectively recover Zn, a solvent extraction process using D2EHPA as the extractant was chosen, and 99% of the Zn was extracted using 0.8 M D2EHPA with 32% saponification and an O/A ratio of 2 using counter-current 3-stage extraction. Mn was entirely scrubbed with an aqueous sulfuric acid solution of pH 1.5. Finally, Zn was concentrated and stripped using 1.5 M sulfuric acid at an O/A ratio of 4 using counter-current 4-stage stripping. The stripping solution contained 40 g/L of Zn, and 99.9% of ZnSO₄∙H₂O was obtained by vacuum distillation.

• Journal of the Korean Recycled Construction Resources Institute
• /
• v.2 no.4
• /
• pp.314-320
• /
• 2014

Although the cement industry serves as the cornerstone of the construction industry by supplying one of its fundamental materials, it confronts new environmental challenges due to the problem of the $CO_2$ generated from raw materials and fuel used in the cement manufacturing process. Also, concrete structures can be decomposed and reused as construction materials. Simply in terms of the cyclic processing of $CO_2$, recycling waste concrete to manufacture recycled aggregate or recycling waste concrete powder, which is the material for cement can be considered optimally environment-friendly practices. This study contributes to the aim of manufacturing high value added materials that exploits the chemical properties of the waste concrete powder. From the research results, waste concrete powder is feasible to use to produce low carbon type recycled cement.

• Resources Recycling
• /
• v.16 no.1 s.75
• /
• pp.59-67
• /
• 2007

Recovery of acids from the waste etching solution of containing acetic, nitric and hydrofluoric acid discharged from silicon wafer manufacturing process has been attempted by using solvent extraction method. EHA(2-Ethylhexlalcohol) for acetic acid and TBP(Tri-butly Phosphate) for nitric and hydrofluoric acid as a extraction agent was used to the experiment to obtain the process design data in separation procedure. From the experimental data and McCabe-Thiele diagram analysis, we obtained the optimum conditions of phase ratio(O/A) and stages to separate each acid sequently from the mixed acids. The recovery yield was obtained above 90% for acetic acid from the acid mixtures, 90% for nitric acid from acetic acid extraction raffinate and then above 67% for hydrofluoric acid from final extraction raffinate.

• The Korean Journal of Food And Nutrition
• /
• v.22 no.2
• /
• pp.199-204
• /
• 2009

For the purpose of developing a safe & hygienic manufacturing method to acquire low levels of benzo(a)pyrene in black and red ginseng products, this study investigated the effects of steam- and dry-processing temperatures on benzo(a)pyrene production in ginseng. By the red ginseng with a fix dry-process temperature of $50^{\circ}C$ and setting the steam-process temperature between $80{\sim}120^{\circ}C$, an extremely small amount(0.1 ppb) of benzo(a)pyrene was produced, indicating there was no relationship between the steam-temperature and benzo(a)pyrene production. On the other hand, when the red and black ginseng were steamed at the fixed temperature of $100^{\circ}C$ and dried at various temperatures between $50{\sim}120^{\circ}C$, the amount of benzo(a)pyrene produced was closely connected with the dry-temperature, and increased with higher drying temperatures. Upon repeating the steam and dry process nine times, in which the steam-temperature was set at $100^{\circ}C$ and the dry-temperature at $50^{\circ}C$, higher amount of benzo(a)pyrene were produced in red and black ginseng, respectively, with increasing steam- and dry-processing time. However, the level of benzo(a)pyrene still remained extremely small(below 0.12 ppb), showing a maximum amount in the black ginseng that was steamed and dried nine times. This suggests that the fine root of ginseng may be carbonized by increasing the number of times it is steam- and dry-processed. From the above results, this study determined that the optimum temperatures for manufacturing red and black ginseng products with safe levels of benzo(a)pyrene would be a temperature between 80 and $120^{\circ}C$ for steaming and a temperature less than $50^{\circ}C$ for drying.

• Journal of Fisheries and Marine Sciences Education
• /
• v.25 no.2
• /
• pp.433-447
• /
• 2013

In around of Guryongpo Pohang Port, a Guamegi production special zone is being established as modernized processing plants, cold storages, Guamegi research centers, or publicity centers are being built in a row with forming the tourism and culture streets as a start. Regarding the special Guamegi production zone, the local autonomous entities are promoting various projects as investing approximately 40 billion won as its budget; however, it is still very rare to elevate the level of Guamegi, the special product, and make investment plans to create a brand for it. To make a special product brand cannot be realized just by building the Guamegi industrialization processing complex, and mere publicity also does not guarantee sustainable development. It can be realized only when the product's taste or hygiene satisfies the people's needs. Therefore, this study examines the changes of Guamegi-related business and the strategies to develop Guamegi industry in order to find ways to manufacture Guamegi and cultivate specialized manpower for processing to make a special brand with Guamegi. Regarding the Guamegi business and the cultivation of specialized manpower for Guamegi, this study conducted a survey to 377 persons including the business owners, employees, or civil servants related with Guamegi. It is needed to install educational institutions to cultivate specialized manpower for Guamegi and also operate various programs so as to conduct education to cultivate specialized manpower for Guamegi. And it is necessary to elevate the quality and sanitation of Guamegi and create a brand by inducing a specialized license system that can help those involved in Guamegi business have pride.

• Resources Recycling
• /
• v.23 no.5
• /
• pp.3-11
• /
• 2014

Calcium ferrite is more effective binder for making sintered ore and flux for steel making because of it's low melting temperature. In this Study, calcium ferrite was made by calcinating method in the cement manufacturing process in order to reduce manufacturing costs and increase productivity. Limestone and calcination sludge were used as CaO source, steelmaking sludge, blast furnace dust and iron ore were used as Fe-bearing raw materials. The sintering temperature of specimens is in the range of $950{\sim}1170^{\circ}C$. For Calcium ferrite can be used 'binder for making sintered ore' or 'flux for converter/electric furnace' with a low melting point properties, the raw material characteristics and sintering properties were investigated.

• Journal of Korean Society of Forest Science
• /
• v.90 no.3
• /
• pp.355-362
• /
• 2001

This study was conducted to propose the way to develop and strengthen competitiveness of the Korean paper industry by analysing current competitiveness and the factors which determine and influence it. Delphi method was employed to identify determining factors of international competitiveness of Korean paper industry and evaluate the level of competitiveness. The competitiveness both in the domestic and foreign markets was evaluated by analysing each product market faced by the Korean paper industry in light of each of the determining factors. Based on the Delphi survey results, in order of importance, product quality, manufacturing cost, transportation and storage, timely delivery, supply of raw materials, and marketing were identified as the factors determining international competitiveness. Among them, it was revealed that Korean paper industry has a certain level of competitiveness in the factors such as product quality and timely delivery service while supply of raw materials and manufacturing costs were found to be inferior to overseas manufacturers in both domestic and foreign markets.

• Journal of the Korean Recycled Construction Resources Institute
• /
• v.6 no.3
• /
• pp.190-198
• /
• 2018

The Epoxy-coated Reinforcing bars have been proved to be able to extend a durability life because of its excellent corrosion resistance in bridges and structures under marine and severe environments. The usage of epoxy-coated reinforcement is continuously increasing in developed countries such as the US and Japan. However, domestic use is extremely limited due to lack of research and development, poor production facilities, low quality, increase of initial costs, and difficulty of field management. This study suggests the improvement of construction quality management such as manufacturing, transportation and construction for the field application through the test construction of the proven product in the related test results of the epoxy coated steel bars produced in the recently improved manufacturing facility.