Characteristic of the Electric Arc Furnace Slag with Various Sources as Concrete Aggregate 다양한 발생원을 갖는 전기로 산화슬래그의 콘크리트용 골재로서의 특성
김진만 Jin Man Kim , 박헌일 Hun Il Park
29(5) 431-440, 2012
Title
Characteristic of the Electric Arc Furnace Slag with Various Sources as Concrete Aggregate 다양한 발생원을 갖는 전기로 산화슬래그의 콘크리트용 골재로서의 특성
김진만 Jin Man Kim , 박헌일 Hun Il Park
DOI:
Abstract
For utilization of Electric Arc Furnace Slag`s high added value, KS F 4571 was revised, so the institutional environment to use concrete aggregate was prepared. But, it has hardly been reported how much the slag occurring in actual steel-making plants meets KS requirements. Therefore, this study was intended to analyze various engineering features of electric arc furnace slag, which occur in diverse kinds of electric arc furnace process to manufacture reinforcing rebar, hot roll, and shape steel, in accordance with KS and relevant standards. The test results from this study showed that electric arc furnace slag occurring in Korea didn`t meet the standards relating to many physical properties, such as water absorption, grading, unit volume weight, and material passing standard sieve 0.08 mm which are required for concrete aggregate and are prescribed in KS F 4571, and therefore that something is needed to be improved. Regarding chemical properties, heavy metal solubility based on official wastes test method, CaO and FeO were met, but content of MgO related to expansion and basicity exceeded or came close to standards. Therefore, it was found that some measures should be taken to address the issue.
Key Words
Electric arc furnace slag, Concrete aggregate, Slag, Free-CaO, Free-MgO
Effect of Foodwaste Leachate Injection in Stabilized Lysimeters on Degradation of Municipal Solid Waste 모의 안정화 매립조 내 음식물류폐기물 폐수 주입이 폐기물의 분해 특성에 미치는 영향
배성진 Sung Jin Bae , 이동훈 Dong Hoon Lee
29(5) 441-449, 2012
Title
Effect of Foodwaste Leachate Injection in Stabilized Lysimeters on Degradation of Municipal Solid Waste 모의 안정화 매립조 내 음식물류폐기물 폐수 주입이 폐기물의 분해 특성에 미치는 영향
배성진 Sung Jin Bae , 이동훈 Dong Hoon Lee
DOI:
Abstract
With total four lysimeters, having a decreased reaction rate of municipal solid waste (MSW) through the 1st study,the effects of foodwaste leachate (FWL) injection on the degradation of MSW and FWL were estimated for 533days. Average methane potential of FWL injected in lysimeters investigated through the Biochemical Methane Potential (BMP)test was 368.2 mL-CH4/g-VS. The amounts of methane generated in lysimeters injected simultaneously with FWL and leachate were higher than that of FWL injected each lysimeter. The pH levels of leachate generated in each lysimeter maintained a range of 7.2 ~ 8.1. CODCr concentrations were 1,640 ~ 2,275 mg/L initially, and were rising to 4,640 ~ 5,950 mg/L as increasing FWL injection amount. Whereafter those repeated fluctuation in a range of 2,400 ~ 5,600 mg/L as methane productions in each lysimeter increase. BOD5/CODCr ratios were kept below 0.1 during the test period. Settlement analysis results of MSW in each lysimeter indicated that the simultaneous injections with FWL and leachate in each lysimeter promoted the degradation of not only FWL itself, but MSW. This became clear when the methane balance in lysimeter under rich-organic condition is established.
CFRP Laminate Recycle Technique using Near-critical Hydrolysis 아임계 수를 이용한 CFRP 라미네이트 분리 기법
박정홍 Jung Hong Park , 문병영 Byung Yong Moon
29(5) 450-456, 2012
Title
CFRP Laminate Recycle Technique using Near-critical Hydrolysis 아임계 수를 이용한 CFRP 라미네이트 분리 기법
박정홍 Jung Hong Park , 문병영 Byung Yong Moon
DOI:
Abstract
The purpose of this study was to investigate yield rate of carbon fibers reinforced epoxy composites in near-critical water. A CFRP (carbon fiber reinforced plastic) laminate stacked with twenty layers was used and the specimens were cut in 10 × 50 mm (thickness: 4 mm) size. The CFRP sample was placed and heated within the non-stirred bath autoclave with an electric furnace. The yield percentage is calculated by the weight percentage of eliminated resin. To check the surface of carbon fiber, scanning electron microscopy was employed. The results showed that the removal percentages of weight were between 53.9% and 97.1%. The best yield was significantly increased up to 97.1% when operating in 573 K (14 MPa) condition. This research suggests an basic data to design a commercial scale recycling system or a new low cost recycling system for CFRP waste.
Comparison of Contents Characteristics of Heavy Metals in the Co-processing Waste of Cement Kiln in Korea 시멘트 소성로 투입 부원료,보조연료의 중금속 함량 특성 비교
전태완 Tae Wan Jeon , 정미정 Mi Jeong Jeong , 신선경 Sun Kyeong Shin , 오길종 Gil Jong Oh , 황동건 Dong Gun Hwang
29(5) 457-465, 2012
Title
Comparison of Contents Characteristics of Heavy Metals in the Co-processing Waste of Cement Kiln in Korea 시멘트 소성로 투입 부원료,보조연료의 중금속 함량 특성 비교
전태완 Tae Wan Jeon , 정미정 Mi Jeong Jeong , 신선경 Sun Kyeong Shin , 오길종 Gil Jong Oh , 황동건 Dong Gun Hwang
DOI:
Abstract
An issue of environmental pollutions has been aroused according to increases in recycling alternative raw materials and alternative fuels, which are the inputed wastes of cement kilns in Korea. Also, the infections of heavy metals in cement products on healths and environments have been issued by the National Assembly and the press. Thus, in this study, a total of 198 waste samples, 109 alternative raw material samples and 89 alternative fuel samples, which are the coprocessing wastes in eight major cement producers in Korea, are collected for two months. Then, 18 different heavy metals according to types of wastes are analyzed and the concentrations of the alternative raw materials and alternative fuels are investigated for comparing them with the foreign management guidelines. In the case of the alternative raw materials, although arsenic, cadmium, and copper do not exceed the domestic autonomy agreement guideline, lead exceeds the autonomy agreement guideline, 1,000 mg/kg. In the case of mercury, it satisfies the references of domestic guideline (2.0 mg/kg), Switzerland criteria (0.5 mg/kg), and France criteria (10.0 mg/kg). In the case of the alternative fuel, arsenic, cadmium, copper, and lead satisfy the autonomy agreement guideline, and the average content concentration of Hg represents 0.7702 mg/kg and that satisfies the references of autonomy agreement guideline (1.2 mg/kg) and France criteria (10.0 mg/kg). However, it slightly exceeds the references of Germany guideline (0.6 mg/kg) and Switzerland criteria (0.5 mg/kg). In particular, some of dust, WDF, waste synthesis resin, and purified oil show a high detection level in mercury and that leads to increase the average concentration. In addition, by investigating the concentration of heavy metals in various auxiliary wastes loaded to cement kilns in Korea, a management reference for such alternative raw materials and alternative fuels for future cement kilns in stages is proposed.
Key Words
Co-Processing, Alternative raw materials, Contents characteristics
A Study on the C-CO2 Reaction using TGA and MASS Spectrometer 열중량분석법과 질량분석기를 이용한 C-CO2 반응 연구
문승현 Seung Hyun Moon , 유인수 In Soo Ryu , 이승재 Seung Jae Lee
29(5) 466-473, 2012
Title
A Study on the C-CO2 Reaction using TGA and MASS Spectrometer 열중량분석법과 질량분석기를 이용한 C-CO2 반응 연구
문승현 Seung Hyun Moon , 유인수 In Soo Ryu , 이승재 Seung Jae Lee
DOI:
Abstract
In this study, C-CO2 reaction was investigated to achieve a simultaneous effect reducing green house gas and enhancing synthetic gas production. Carbon dioxide and oxygen were used as gasification agents in various concentrations. The Boudouard reaction in which CO2 reacts with carbon was expected for the enhancement of CO production. The reaction CO2 + C 2 CO was confirmed through thermo-gravimetric analysis (TGA) experiment. The weight of activated carbon used as a carbon source did not changed above 750oC in nitrogen condition, while sharply decreased in CO2 condition, illustrating the presence of Boudouard reaction. The weight of activated carbon and concentrations of H, H2, CH2, CH4,H2O, CO, O2, CO2 evolved from gasification reaction were continuously analysed in different gasification agent varying CO2 and O2 ratio. Weight loss rate increased according to the increase of oxygen ratio. The window on which CO peak evolved shifted to higher temperature according to CO2 concentration in gasification agent. It is proposed that varying CO2/O2 mole ratio can control the reaction ratio of combustion and gasification and shift concentration peak temperature.
An Experimental Study on the C-CO2 Reaction in a Downdraft Reactor Downdraft 반응기에서 C-CO2 반응의 실험적 연구
문승재 Seung Jin Moon , 유인수 In Soo Ryu , 이승재 Seung Jae Lee
29(5) 474-481, 2012
Title
An Experimental Study on the C-CO2 Reaction in a Downdraft Reactor Downdraft 반응기에서 C-CO2 반응의 실험적 연구
문승재 Seung Jin Moon , 유인수 In Soo Ryu , 이승재 Seung Jae Lee
DOI:
Abstract
In this study, fixed bed type CO2 gasification reactor was tested to enhance the production of synthetic gas (CO + H2) from low grade carbon source such as sewage sludge, wood chip, municipal waste, and low calofic valued coal. Various parameter effects on the 0.1 ton/day fixed bed gasifier operation were investigated. The parameters are reaction temperature, CO2/Air ratio, and total flow rate. Temperature was measured at the inlet and outlet of the reactor as well as at 18 positions along the reactor height and radius. The CO2 inlet concentration was tested between 0% and 30%. Total flow rate was varied from 40 L/min to 80 L/min at 20% CO2 inlet and 8 kg activated carbon packing. In the fixed bed CO2 gasification, CO2 took more parts in the gasification than combustion. But CO2 concentration higher than 40% made the two reactions unstable and the one between 20% and 40% did not give so much influence on the reaction time. The reaction time was shortened according to the total flow rate increase, and changed its slope gently above 50 L/min,illustarting CO2 gasification reaction is superior to combustion reaction in the low total flow rate condition.
Characteristics of Corrosion Rate of Hazardous Wastes with pH Changes 유해폐기물의 pH 변화에 따른 부식 특성 연구
김우일 Woo Il Kim , 강영렬 Young Yeul Kang , 정성경 Seong Kyeong Jeong , 조윤아 Yoon A Cho , 신선경 Sun Kyoung Shin , 오길종 Gil Jong Oh , 김동운 Dong Un Kim
29(5) 482-489, 2012
Title
Characteristics of Corrosion Rate of Hazardous Wastes with pH Changes 유해폐기물의 pH 변화에 따른 부식 특성 연구
김우일 Woo Il Kim , 강영렬 Young Yeul Kang , 정성경 Seong Kyeong Jeong , 조윤아 Yoon A Cho , 신선경 Sun Kyoung Shin , 오길종 Gil Jong Oh , 김동운 Dong Un Kim
DOI:
Abstract
As the industrial and urban development has been accelerated, the issues on Hazardous wastes (HWs) management have become important. HWs that are not included in the code lists are also managed by hazardous characteristics and determination methods in Korea. This study has been performed to investigate corrosive characteristics of hazardous wastes (HWs) depending on pH variations. We considered the type, discharge process and pH of the 14,000 corrosive waste dischargers, of which we visited 60 sites and collected 68 waste acid and alkali samples. Based on results using corrosive testing methods of the USA (EPA Method 1110A) and the Japanese environmental agency (Appendix 8 of the Japan Standard Methods on Specific HWs), it was found that, of total 54 waste acids with pH 2 or below, 47 samples by the USA EPA Methods, and 37 samples by the Japanese testing method exceeded the limit value of the corrosive rate, while 5 waste alkalic samples with pH 12.5 or above did not exceed the limit value of the corrosion rate. Besides, 9 samples with a pH higher than 2 and less than 12.5 failed to meet the corrosive rate limit. It was determined that 17 samples with a pH less than 2, which did not satisfy the standard corrosion rate, gained more weight, due to the acid deposition from acid gas on their exposed surface. Thus, it is assumed that the USA EPA Method is more strictly applicable than the Japanese Method.
Evaluation of Hazardous Heavy metals in Portland Cement 시멘트제품 중 중금속 유해성평가
전태완 Tae Wan Jeon , 정미정 Mi Jeong Jeong , 신선경 Sun Kyeong Shin , 김나 Na Jin , 박호연 Ho Yeon Park , 정용우 Yong Woo Jeong , 김용준 Yong Jun Kim
29(5) 490-496, 2012
Title
Evaluation of Hazardous Heavy metals in Portland Cement 시멘트제품 중 중금속 유해성평가
전태완 Tae Wan Jeon , 정미정 Mi Jeong Jeong , 신선경 Sun Kyeong Shin , 김나 Na Jin , 박호연 Ho Yeon Park , 정용우 Yong Woo Jeong , 김용준 Yong Jun Kim
DOI:
Abstract
There are some problems of lacking the information on the safety of cement products and for determining harmfulness due to differences in the concentrations of heavy metals according to organizations. Thus, the harmfulness of heavy metals in cement products has been monitored by one time per month since August 2008 and the results have also been noticed for every month. In this study, the concentrations of seven different heavy metals (Cr(Ⅵ), T-Cr, Cd, Cu, Pb, As, and Hg) in cement products collected from 11 factories of 9 manufacturers are verified for every month and changes in the concentrations are also compared with the cement products of Japan, Germany, USA, and China. The company, HO, in domestic companies represents the highest values in four items and AJ shows the next high values. Thus, regarding these two manufacturers, it is necessary to take an effort for reducing the concentrations of five heavy metals through considering the major and alternative raw materials for producing their cement products. the chrome conversion rates in domestic cement products are about 36.4 % and that exhibits higher rates about 16.0 % and 8.3 %, 2.3 and 4.3 times, than that of Japan and USA, respectively.
Key Words
Portland Cement, Heavy metal, Autonomy agreement guideline
Comparison of Disaster Debris Guidelines and Analysis of Flood Debris Recovery 국내외 재해폐기물 관리 지침 비교 및 수해폐기물 처리 현황 분석
정상재 Sang Jae Jeong , 김재영 Jae Young Kim
29(5) 497-503, 2012
Title
Comparison of Disaster Debris Guidelines and Analysis of Flood Debris Recovery 국내외 재해폐기물 관리 지침 비교 및 수해폐기물 처리 현황 분석
정상재 Sang Jae Jeong , 김재영 Jae Young Kim
DOI:
Abstract
Disasters make huge debris in short period of time. In spite of increasing risk of disasters by recent climate change, consideration on disaster debris is still insignificant in Korea. In order to improve management of disaster debris, disaster debris management guidelines have been compared with those of United States and Japan. According to comparison, debris management of Korea showed lack of concreteness for field workers. The unit recovery costs of inland debris and offshore debris were 173 and 318 thousand won per ton, respectively. Inland debris was mainly affected by quantity and location. And offshore debris were affected by finances.