Pub Date : 2020-04-30DOI: 10.7844/KIRR.2020.29.2.48
Sang-hun Lee
Korea, one of the manufacturing-oriented countries, consumes a large amount of metals in various industrial areas, but should depend on import of most of the metals from foreign countries. Also, global metal consumption amounts are increasing in relation to those of the world's reserve and production. Some metals are limitedly produced from only several centuries, which might lead to instability of the future supply of those metals. In addition, when such metals are hazardous, those may result in various environmental troubles with contamination. To resolve those issues, the recovery and the recycling of hazardous but valuable metals in industrial waste are desirable. However, there are overwhelming numbers of the metal types, waste generators, and amounts of wastes containing the metals, so it can be troublesome even to implement a preliminary status analysis to screen proper metals, wastes with the metals, and waste producers. Therefore, this study introduces the valuable metals for Korean industry, announced by public institutions, Also, a flow chart is suggested to facilitate a preliminary status analysis, using the domestic PRTR (Pollutant Release and Transfer Register) database, to screen proper waste producers containing some of hazardous but valuable metals such as nickel, cobalt, and manganese.
{"title":"Preliminary Status Analysis Methodology on Hazardous and Valuable Metal Recovery in Industrial Wastes Using Public Database","authors":"Sang-hun Lee","doi":"10.7844/KIRR.2020.29.2.48","DOIUrl":"https://doi.org/10.7844/KIRR.2020.29.2.48","url":null,"abstract":"Korea, one of the manufacturing-oriented countries, consumes a large amount of metals in various industrial areas, but should depend on import of most of the metals from foreign countries. Also, global metal consumption amounts are increasing in relation to those of the world's reserve and production. Some metals are limitedly produced from only several centuries, which might lead to instability of the future supply of those metals. In addition, when such metals are hazardous, those may result in various environmental troubles with contamination. To resolve those issues, the recovery and the recycling of hazardous but valuable metals in industrial waste are desirable. However, there are overwhelming numbers of the metal types, waste generators, and amounts of wastes containing the metals, so it can be troublesome even to implement a preliminary status analysis to screen proper metals, wastes with the metals, and waste producers. Therefore, this study introduces the valuable metals for Korean industry, announced by public institutions, Also, a flow chart is suggested to facilitate a preliminary status analysis, using the domestic PRTR (Pollutant Release and Transfer Register) database, to screen proper waste producers containing some of hazardous but valuable metals such as nickel, cobalt, and manganese.","PeriodicalId":17385,"journal":{"name":"Journal of the Korean Institute of Resources Recycling","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-04-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90411203","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-04-30DOI: 10.7844/KIRR.2020.29.2.18
C. Baek, Jun-hyung Seo, Young-Jin Kim, Kye-Hong Cho, Kunwoo Kim, Jin-Young Lee
Chemical experiment KS F 2545 and Physical experiment ASTM C 1260 has been accomplished to estimate the potential of alkali aggregate. Used for testing aggregate samples are forest aggregate and recycled aggregate which collected in Gangwon province Samcheok and Pyeongchang, Jeollabuk province Gimje and Kochang, and Gyeongsangnam province Goryeong. As the results of chemical experiment confirmed that if silicate rock and carbonate rock are mixed, reduction in alkalinity is increase. So it has been identified that case makes a disturb at the result of alkali aggregate reaction. In 9 out of the 62 aggregate samples check dissolved silica exceeding 100 mmol/l. and mortar bar length increase rate confirmed that 5 of 9 chemical method aggregates were 0.1~0.2% and 2 aggregates were 0.2%. As a result of the alkaline aggregate reaction test using the chemical method and the mortar bar method, the aggregates showing alkali aggregate reaction are sandstone and tuff aggregates. Therefore, Alkali aggregate reaction tests are required to use clastic sedimentary rocks and volcanic pyroclastic rocks aggregates.
通过化学实验KS F 2545和物理实验ASTM C 1260对碱骨料的潜力进行了评价。用于测试骨料样品的是在江原三陟、平昌、全北金济、高昌、庆尚南道高岭等地采集的森林骨料和再生骨料。化学实验结果证实，硅酸盐岩与碳酸盐岩混合后，碱度的还原性增加。因此，确定了对碱集料反应结果有干扰作用。62个骨料样品中有9个样品的溶解二氧化硅超过100毫摩尔/升。砂浆条长增加率证实了9种化学法骨料中有5种骨料在0.1~0.2%之间，2种骨料在0.2%之间。采用化学法和砂浆棒法进行了碱性骨料反应试验，结果表明，表现出碱性骨料反应的骨料为砂岩和凝灰岩骨料。因此，碱骨料反应试验需要使用碎屑沉积岩和火山火山碎屑岩骨料。
{"title":"A Fundamental Study on the Potential of Alkali-Aggregate Reaction according to KS F 2545 and ASTM C 1260 Test Methods","authors":"C. Baek, Jun-hyung Seo, Young-Jin Kim, Kye-Hong Cho, Kunwoo Kim, Jin-Young Lee","doi":"10.7844/KIRR.2020.29.2.18","DOIUrl":"https://doi.org/10.7844/KIRR.2020.29.2.18","url":null,"abstract":"Chemical experiment KS F 2545 and Physical experiment ASTM C 1260 has been accomplished to estimate the potential of alkali aggregate. Used for testing aggregate samples are forest aggregate and recycled aggregate which collected in Gangwon province Samcheok and Pyeongchang, Jeollabuk province Gimje and Kochang, and Gyeongsangnam province Goryeong. As the results of chemical experiment confirmed that if silicate rock and carbonate rock are mixed, reduction in alkalinity is increase. So it has been identified that case makes a disturb at the result of alkali aggregate reaction. In 9 out of the 62 aggregate samples check dissolved silica exceeding 100 mmol/l. and mortar bar length increase rate confirmed that 5 of 9 chemical method aggregates were 0.1~0.2% and 2 aggregates were 0.2%. As a result of the alkaline aggregate reaction test using the chemical method and the mortar bar method, the aggregates showing alkali aggregate reaction are sandstone and tuff aggregates. Therefore, Alkali aggregate reaction tests are required to use clastic sedimentary rocks and volcanic pyroclastic rocks aggregates.","PeriodicalId":17385,"journal":{"name":"Journal of the Korean Institute of Resources Recycling","volume":"10 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-04-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82018361","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-04-30DOI: 10.7844/KIRR.2020.29.2.3
Sang-hun Lee
Recently, the gold leaching technologies draw much interest to recover gold from low grade ores. Current leaching processes mostly use cyanide as the leaching agent, due to its high leaching efficiencies and cost-effectiveness. However, use of cyanide is severely problematic, because of toxicity and thereby environmental risks, and requires strict regulations and environmental management. Especially, this issue becomes further apparent when cyanide should be applied for dump or heap leaching for low cost gold recovery along with recent trends. To resolve this issue, the alternative leaching processes using thiosulfate or halogen compounds, instead of cyanide, have been studied and developed but there have been lots of difficulties toward commercialization, and therefore further research should be conducted. The commercialization of dump or heap bioleaching technologies should be urgently required for effective direct biogenic gold recovery from low grade ores or tailings without use of cyanide.
{"title":"Current Status of Gold Leaching Technologies from Low Grade Ores or Tailings","authors":"Sang-hun Lee","doi":"10.7844/KIRR.2020.29.2.3","DOIUrl":"https://doi.org/10.7844/KIRR.2020.29.2.3","url":null,"abstract":"Recently, the gold leaching technologies draw much interest to recover gold from low grade ores. Current leaching processes mostly use cyanide as the leaching agent, due to its high leaching efficiencies and cost-effectiveness. However, use of cyanide is severely problematic, because of toxicity and thereby environmental risks, and requires strict regulations and environmental management. Especially, this issue becomes further apparent when cyanide should be applied for dump or heap leaching for low cost gold recovery along with recent trends. To resolve this issue, the alternative leaching processes using thiosulfate or halogen compounds, instead of cyanide, have been studied and developed but there have been lots of difficulties toward commercialization, and therefore further research should be conducted. The commercialization of dump or heap bioleaching technologies should be urgently required for effective direct biogenic gold recovery from low grade ores or tailings without use of cyanide.","PeriodicalId":17385,"journal":{"name":"Journal of the Korean Institute of Resources Recycling","volume":"27 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-04-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91181006","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-04-30DOI: 10.7844/KIRR.2020.29.2.37
Kee-seok Kim, Jaewon Lee, Dongwon Lee, Kyongnam Min
According to Vietnam government establishes additional thermal power plant, processing the coal ash from power plant is urgent issue. This study targeted reducing unburned carbon contents in low quality fly ash to below 6% that according to international standards. As a result, the unburned carbon contents of low quality fly ash was high and irregular as 5.3~23.6%, and it was possible to reduce unburned cabon contents to under 6%, in case of unburned carbon contents below 9.8% ashes using air classification, in case of unburned carbon contents below 23.6% ashes using combined process composed of air classification and electrostatic separation.
{"title":"Study on Reduction Unburned Carbon Contents in Low Quality Fly Ash from Vietnam","authors":"Kee-seok Kim, Jaewon Lee, Dongwon Lee, Kyongnam Min","doi":"10.7844/KIRR.2020.29.2.37","DOIUrl":"https://doi.org/10.7844/KIRR.2020.29.2.37","url":null,"abstract":"According to Vietnam government establishes additional thermal power plant, processing the coal ash from power plant is urgent issue. This study targeted reducing unburned carbon contents in low quality fly ash to below 6% that according to international standards. As a result, the unburned carbon contents of low quality fly ash was high and irregular as 5.3~23.6%, and it was possible to reduce unburned cabon contents to under 6%, in case of unburned carbon contents below 9.8% ashes using air classification, in case of unburned carbon contents below 23.6% ashes using combined process composed of air classification and electrostatic separation.","PeriodicalId":17385,"journal":{"name":"Journal of the Korean Institute of Resources Recycling","volume":"47 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-04-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73815700","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-04-01DOI: 10.7844/KIRR.2020.29.2.55
A. B. Sola, J. Jeon, Jin-Young Lee, P. Parhi, R. Jyothi
선택적 촉매 환원법(SCR)은 여러 산업에서 질소산화물 (NOx)에 의한 대기오염을 줄일 수 있는 매우 유망한 기술이다. SCR 촉매의 소비는 기술이 발전함에 따라 매년 증가하고 있지만, 촉매의 수명은 제한되어 있으며, 일반적으로 수명이 다해 활성이 떨어진 폐촉매는 재활용 되지 않고 매립되어 처리되고 있다. 현재 가장 ...
{"title":"Spent SCR Catalyst Leach Liquor Processed for Valuable Metals Extraction by Solvent Extraction Technique#","authors":"A. B. Sola, J. Jeon, Jin-Young Lee, P. Parhi, R. Jyothi","doi":"10.7844/KIRR.2020.29.2.55","DOIUrl":"https://doi.org/10.7844/KIRR.2020.29.2.55","url":null,"abstract":"선택적 촉매 환원법(SCR)은 여러 산업에서 질소산화물 (NOx)에 의한 대기오염을 줄일 수 있는 매우 유망한 기술이다. SCR 촉매의 소비는 기술이 발전함에 따라 매년 증가하고 있지만, 촉매의 수명은 제한되어 있으며, 일반적으로 수명이 다해 활성이 떨어진 폐촉매는 재활용 되지 않고 매립되어 처리되고 있다. 현재 가장 ...","PeriodicalId":17385,"journal":{"name":"Journal of the Korean Institute of Resources Recycling","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82966906","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-02-01DOI: 10.7844/KIRR.2020.29.1.53
Yang-Yi Woo, Keun-Bae Park, Young Ma, Hun Song
This study aimed to develop a foam concrete material for a ground repair system that has low strength and low fluidity by using an eco-friendly binder, which substitutes industrial by-products for more than 90% of cement. Basic properties were evaluated after substituting a small amount of calcium sulfo aluminate (CSA) for the binder to improve the sinking depth rate and volume change, commonly found when it had a large amount of industrial by-products. The substitution rates of CSA for the eco-friendly binder used for the foam concrete were 2.5, 5, and 10%. Fresh properties, hardened properties, pore structure, and hydrates were analyzed. Experimental results showed that using only 2.5% of CSA could improve the deep sinking depth which occurred when using an eco-friendly binder. As a result, the weight difference between the upper, middle, and lower parts of cast specimens was improved even after being hardened. The addition of CSA also contributed to the formation of small, uniformly sized closed pores and improved initial strength. However, when the proportion of CSA increased, the long-term strength decreased. However, it satisfied the target strength when 5% or less of CSA was used. The results of this study revealed 54 우양이 · 박근배 · 마영 · 송헌영 J. of Korean Inst. Resources Recycling Vol. 29, No. 1, 2020 1. 서 론 2017년 환경부가 발표한 전국 폐기물 발생량은 연간 총 1억5천톤 이상으로 이중 생활계 폐기물이 12.9%, 사업 장 배출 폐기물이 39.8%, 건설폐기물이 47.3%를 점유한 다. 이중 가연성 재료가 82%를 차지하는 생활폐기물과는 상반되게 사업장 폐기물은 불연성 재료가 75%, 건설폐기 물은 99%에 달한다. 이와 같은 불연성 폐기물은 재활용 되지 못하는 경우 대부분 매립되어진다. 우리 인류가 매일 배출하는 폐기물의 양은 일천평의 대 지 위에 17층 규모의 건물 높이와 같으며, 이에 세계는 지 금 급증하는 쓰레기의 처리문제로 고심하고 있다. 급증하 는 폐기물에 대한 해결책은 매립을 최대한 억제하고, 재 활용을 적극적으로 실시하며, 배출량을 최소화하는 길뿐 이다. 생활폐기물 및 건설폐기물의 재활용 용도는 이들 폐기물의 자원화를 위해 다방면의 연구가 진행되고 있지 만, 재자원화 및 유효 활용되지 못하는 부산물들을 수용 할 수 있는 활용처는 수용력 및 스펙트럼이 광범위한 건설 산업이라 할 수 있다. 현재도 부산물의 다량이 토목공사 용 재료 및 건축용 소재로 재활용되고 있다. 한편 건설산업 또한 환경문제에 자유롭지 못하다. 건설 산업의 주요 재료인 시멘트 산업은 무분별한 채광 및 CO2 다배출 산업으로서 환경규제에 강화에 따른 업계의 고민은 깊어지고 있다. 따라서 시멘트 산업에서의 환경적인 문제 해결을 위해 시멘트의 원료 및 혼화재로서 산업부산물을 활 용한 친환경 건설소재 연구 및 실용화가 활발해지고 있다. 최근 건설소재로서 시멘트의 사용량을 최소화하고 산 업부산물의 활용율을 극대화하여 도로보수 및 연약지반 의 보강재로 사용하는 CLSM(Controlled low strength material, 저강도 고유동 충전재)에 대한 연구가 2000년 초반 미국을 시작으로 국내에서도 2010년도 부터 진행되 기 시작하였다. CLSM의 주요 원료는 활용도가 낮은 산업 부산물을 사용하는 것으로 원재료비 절감, 시공비 절감 등의 경제성 면에서 강점이 있으며, 무수축과 높은 충전 성을 갖는 시공이 가능한 것이 특징이다. 본 연구는 이와 같이 친환경 건설소재 및 공법 개발을 위하여 국내 철강 및 전력산업에서 발생되는 부산물을 OPC(Ordinary portland cement, 보통 포틀랜드 시멘트) 에 90% 이상 대체하여 저강도 ·고유동의 선발포 기포 콘 크리트를 제조하고, 이를 시공하기 위한 연구의 일환이다. 선행연구를 통하여 선발포 기포 콘크리트를 통한 저강 도 ·고유동 지반보강재 배합 최적화를 완료하였으나, OPC의 다량을 초기 반응성이 낮은 산업부산물로 대체할 경우 침하에 의한 불안정한 체적안정성을 보인다. 기포콘크리트의 용액상태의 기포는 일반적으로 3단계 로 변화하면서 파괴된다고 알려진다. 기포가 서로 연결된 부분 없이 구 모양을 형성하는 초기단계의 기포에서 기포 표면을 형성하고 있는 페이스트가 비중 차이로 아래 부분 으로 흘러내리며 배수현상이 일어나 기포가 용액의 표면 으로 이동하며, 최종적으로는 배수현상에 의해 표면의 기 포들이 합체되어 다각형 구조의 기포로 변하며 사이즈가 증대된다. 따라서 기포와 혼합된 페이스트가 경화되기 까지 기포는 상하부의 재료분리가 발생하고, 표면 기포의 결합을 통한 침하가 발생하게 된다. 이에 본 논문은 저강도 ·고유동 지반 보수용 배합에 빠 른 경화를 통한 기포의 안정성을 확보하고, 체적 변화를 최 소화
{"title":"The Fundamental Properties of Foamed Concrete as the Eco-friendly Ground Repair System for Cast in Site Using the CSA","authors":"Yang-Yi Woo, Keun-Bae Park, Young Ma, Hun Song","doi":"10.7844/KIRR.2020.29.1.53","DOIUrl":"https://doi.org/10.7844/KIRR.2020.29.1.53","url":null,"abstract":"This study aimed to develop a foam concrete material for a ground repair system that has low strength and low fluidity by using an eco-friendly binder, which substitutes industrial by-products for more than 90% of cement. Basic properties were evaluated after substituting a small amount of calcium sulfo aluminate (CSA) for the binder to improve the sinking depth rate and volume change, commonly found when it had a large amount of industrial by-products. The substitution rates of CSA for the eco-friendly binder used for the foam concrete were 2.5, 5, and 10%. Fresh properties, hardened properties, pore structure, and hydrates were analyzed. Experimental results showed that using only 2.5% of CSA could improve the deep sinking depth which occurred when using an eco-friendly binder. As a result, the weight difference between the upper, middle, and lower parts of cast specimens was improved even after being hardened. The addition of CSA also contributed to the formation of small, uniformly sized closed pores and improved initial strength. However, when the proportion of CSA increased, the long-term strength decreased. However, it satisfied the target strength when 5% or less of CSA was used. The results of this study revealed 54 우양이 · 박근배 · 마영 · 송헌영 J. of Korean Inst. Resources Recycling Vol. 29, No. 1, 2020 1. 서 론 2017년 환경부가 발표한 전국 폐기물 발생량은 연간 총 1억5천톤 이상으로 이중 생활계 폐기물이 12.9%, 사업 장 배출 폐기물이 39.8%, 건설폐기물이 47.3%를 점유한 다. 이중 가연성 재료가 82%를 차지하는 생활폐기물과는 상반되게 사업장 폐기물은 불연성 재료가 75%, 건설폐기 물은 99%에 달한다. 이와 같은 불연성 폐기물은 재활용 되지 못하는 경우 대부분 매립되어진다. 우리 인류가 매일 배출하는 폐기물의 양은 일천평의 대 지 위에 17층 규모의 건물 높이와 같으며, 이에 세계는 지 금 급증하는 쓰레기의 처리문제로 고심하고 있다. 급증하 는 폐기물에 대한 해결책은 매립을 최대한 억제하고, 재 활용을 적극적으로 실시하며, 배출량을 최소화하는 길뿐 이다. 생활폐기물 및 건설폐기물의 재활용 용도는 이들 폐기물의 자원화를 위해 다방면의 연구가 진행되고 있지 만, 재자원화 및 유효 활용되지 못하는 부산물들을 수용 할 수 있는 활용처는 수용력 및 스펙트럼이 광범위한 건설 산업이라 할 수 있다. 현재도 부산물의 다량이 토목공사 용 재료 및 건축용 소재로 재활용되고 있다. 한편 건설산업 또한 환경문제에 자유롭지 못하다. 건설 산업의 주요 재료인 시멘트 산업은 무분별한 채광 및 CO2 다배출 산업으로서 환경규제에 강화에 따른 업계의 고민은 깊어지고 있다. 따라서 시멘트 산업에서의 환경적인 문제 해결을 위해 시멘트의 원료 및 혼화재로서 산업부산물을 활 용한 친환경 건설소재 연구 및 실용화가 활발해지고 있다. 최근 건설소재로서 시멘트의 사용량을 최소화하고 산 업부산물의 활용율을 극대화하여 도로보수 및 연약지반 의 보강재로 사용하는 CLSM(Controlled low strength material, 저강도 고유동 충전재)에 대한 연구가 2000년 초반 미국을 시작으로 국내에서도 2010년도 부터 진행되 기 시작하였다. CLSM의 주요 원료는 활용도가 낮은 산업 부산물을 사용하는 것으로 원재료비 절감, 시공비 절감 등의 경제성 면에서 강점이 있으며, 무수축과 높은 충전 성을 갖는 시공이 가능한 것이 특징이다. 본 연구는 이와 같이 친환경 건설소재 및 공법 개발을 위하여 국내 철강 및 전력산업에서 발생되는 부산물을 OPC(Ordinary portland cement, 보통 포틀랜드 시멘트) 에 90% 이상 대체하여 저강도 ·고유동의 선발포 기포 콘 크리트를 제조하고, 이를 시공하기 위한 연구의 일환이다. 선행연구를 통하여 선발포 기포 콘크리트를 통한 저강 도 ·고유동 지반보강재 배합 최적화를 완료하였으나, OPC의 다량을 초기 반응성이 낮은 산업부산물로 대체할 경우 침하에 의한 불안정한 체적안정성을 보인다. 기포콘크리트의 용액상태의 기포는 일반적으로 3단계 로 변화하면서 파괴된다고 알려진다. 기포가 서로 연결된 부분 없이 구 모양을 형성하는 초기단계의 기포에서 기포 표면을 형성하고 있는 페이스트가 비중 차이로 아래 부분 으로 흘러내리며 배수현상이 일어나 기포가 용액의 표면 으로 이동하며, 최종적으로는 배수현상에 의해 표면의 기 포들이 합체되어 다각형 구조의 기포로 변하며 사이즈가 증대된다. 따라서 기포와 혼합된 페이스트가 경화되기 까지 기포는 상하부의 재료분리가 발생하고, 표면 기포의 결합을 통한 침하가 발생하게 된다. 이에 본 논문은 저강도 ·고유동 지반 보수용 배합에 빠 른 경화를 통한 기포의 안정성을 확보하고, 체적 변화를 최 소화","PeriodicalId":17385,"journal":{"name":"Journal of the Korean Institute of Resources Recycling","volume":"59 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79915578","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-02-01DOI: 10.7844/KIRR.2020.29.1.3
H. Sohn
This work provides an overview of the steel production process, pretreatment and tramp elements of scraps and recycling technology of dust generated from steelmaking process. Steel is the most common metal used by mankind, with the world production of crude steel in 2018 exceeding 1.8 billion tonnes. Recycling of ferrous scraps reduces CO2 emissions by about 42 % and saves about 60 % of energy, compared to production steel from iron ore. Steel scraps are usually recycled to both an electric arc furnace (EAF), scrap-based steelmaking and the basic oxygen furnace (BOF), in ore-based steelmaking. EAF steelmaking, which uses iron scrap as a main raw material, is changing to an energy-saving type with a device for preheating scrap. Dust generated from the steelmaking process is recycled in various ways in the steel mill to recover iron and zinc.
{"title":"Recycling of Ferrous Scraps","authors":"H. Sohn","doi":"10.7844/KIRR.2020.29.1.3","DOIUrl":"https://doi.org/10.7844/KIRR.2020.29.1.3","url":null,"abstract":"This work provides an overview of the steel production process, pretreatment and tramp elements of scraps and recycling technology of dust generated from steelmaking process. Steel is the most common metal used by mankind, with the world production of crude steel in 2018 exceeding 1.8 billion tonnes. Recycling of ferrous scraps reduces CO2 emissions by about 42 % and saves about 60 % of energy, compared to production steel from iron ore. Steel scraps are usually recycled to both an electric arc furnace (EAF), scrap-based steelmaking and the basic oxygen furnace (BOF), in ore-based steelmaking. EAF steelmaking, which uses iron scrap as a main raw material, is changing to an energy-saving type with a device for preheating scrap. Dust generated from the steelmaking process is recycled in various ways in the steel mill to recover iron and zinc.","PeriodicalId":17385,"journal":{"name":"Journal of the Korean Institute of Resources Recycling","volume":"28 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88226762","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-02-01DOI: 10.7844/KIRR.2020.29.1.81
Wei-Sheng Chen, Yi-Fan Chung, Ko-Wei Tien
Recovery of gallium and indium from waste light emitting diodes has been emphasized gradually owing to high content of gallium and indium. This study was established the recovery of gallium (Ga3+) and indium (In3+) from waste gallium nitride was contained in waste light-emitting diodes. The procedure was divided into the following steps; characteristic analysis, alkaline roasting, and leaching. In characteristic analysis part, the results were used as a theoretical basis for the acid leaching part, and the chemical composition of waste light emitting diodes is 70.32% Ga, 5.31% Si, 2.27% Al and 2.07% In. Secondly, with reduction of non-metallic components by alkaline roasting, gallium nitride was reacted into sodium gallium oxide, in this section, the optimal condition of alkaline roasting is that the furnace was soaked at 900°C for 3 hours with mixing Na2CO3. Next, leaching of waste light emitting diodes was extremely important in the process of recovery of gallium and indium. The result of leaching efficiency was investigated on the optimal condition accounting for the acid agent, concentration of acid, the ratio of liquid and solid, and reaction time. The optimal condition of leaching procedures was carried out for 2.0M of HCl liquid-solid mass ratio of 30 ml/g in 32minutes at 25°C and about 96.88% Ga and 96.61% In were leached.
{"title":"Recovery of Gallium and Indium from Waste Light Emitting Diodes†","authors":"Wei-Sheng Chen, Yi-Fan Chung, Ko-Wei Tien","doi":"10.7844/KIRR.2020.29.1.81","DOIUrl":"https://doi.org/10.7844/KIRR.2020.29.1.81","url":null,"abstract":"Recovery of gallium and indium from waste light emitting diodes has been emphasized gradually owing to high content of gallium and indium. This study was established the recovery of gallium (Ga3+) and indium (In3+) from waste gallium nitride was contained in waste light-emitting diodes. The procedure was divided into the following steps; characteristic analysis, alkaline roasting, and leaching. In characteristic analysis part, the results were used as a theoretical basis for the acid leaching part, and the chemical composition of waste light emitting diodes is 70.32% Ga, 5.31% Si, 2.27% Al and 2.07% In. Secondly, with reduction of non-metallic components by alkaline roasting, gallium nitride was reacted into sodium gallium oxide, in this section, the optimal condition of alkaline roasting is that the furnace was soaked at 900°C for 3 hours with mixing Na2CO3. Next, leaching of waste light emitting diodes was extremely important in the process of recovery of gallium and indium. The result of leaching efficiency was investigated on the optimal condition accounting for the acid agent, concentration of acid, the ratio of liquid and solid, and reaction time. The optimal condition of leaching procedures was carried out for 2.0M of HCl liquid-solid mass ratio of 30 ml/g in 32minutes at 25°C and about 96.88% Ga and 96.61% In were leached.","PeriodicalId":17385,"journal":{"name":"Journal of the Korean Institute of Resources Recycling","volume":"1934 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91113675","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-02-01DOI: 10.7844/KIRR.2020.29.1.62
Seokjin Chung, Seok Jung
Manufacturing processes in industrial complexes produce NOx, SOx, VOCs, which cause particulate matter (PM). Therefore, this study analyzed the characteristics of each industrial complex by using scattered public data, matched the existing particulate matter(PM) reduction technology, and proposed an optimized reduction plan. The application of matching technologies and facilities by industrial complexes based on data is able to mitigate NOx, SOx, and VOCs which cause particulate matter in the process in advance. This way can be an effective alternative in order to reduce PM in the manufacturing processes as well as industrial complexes.
{"title":"A Novel Approach for the Particulate Matter(PM) Reduction in the Industrial Complex using Integrated Data Platform","authors":"Seokjin Chung, Seok Jung","doi":"10.7844/KIRR.2020.29.1.62","DOIUrl":"https://doi.org/10.7844/KIRR.2020.29.1.62","url":null,"abstract":"Manufacturing processes in industrial complexes produce NOx, SOx, VOCs, which cause particulate matter (PM). Therefore, this study analyzed the characteristics of each industrial complex by using scattered public data, matched the existing particulate matter(PM) reduction technology, and proposed an optimized reduction plan. The application of matching technologies and facilities by industrial complexes based on data is able to mitigate NOx, SOx, and VOCs which cause particulate matter in the process in advance. This way can be an effective alternative in order to reduce PM in the manufacturing processes as well as industrial complexes.","PeriodicalId":17385,"journal":{"name":"Journal of the Korean Institute of Resources Recycling","volume":"495 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86827040","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-02-01DOI: 10.7844/KIRR.2020.29.1.25
Min-seuk Kim, K. Chung, Jae-chun Lee
Electrochemical Quartz Crystal microbalance is a tool that is capable of measuring nanogram-scale mass change on electrode surface. When applying alternating voltage to the quartz crystal with metal electrode formed on both sides, a resonant frequency by inverse piezoelectric effect depends on its thickness. The resonant frequency changes sensitively by mass change on its electrode surface; frequency increase with metal dissolution and decrease with metal deposition on the electrode surface. The relationship between resonant frequency and mass change is shown by Sauerbrey equation so that the mass change during metal dissolution can be measured in real time. Especially, it is effective in the case of reaction mechanism and rate studies accompanied
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