Journal of the Korean Institute of Resources Recycling最新文献

{"title":"Effect of Flux on Recovery of Aluminum During Molten Metal Treatment of Aluminum Can Scrap","authors":"Chulwoong Han, B. Ahn, D. Kim, Man-Seung Lee, Y. H. Kim","doi":"10.7844/KIRR.2020.29.1.70","DOIUrl":"https://doi.org/10.7844/KIRR.2020.29.1.70","url":null,"abstract":"This study investigates the effect of flux type and mixing ratio on efficiency in aluminum can scrap recycling using induction furnace. The removal of surface coating layer of aluminum can scrap was possible through heat treatment at about 500 °C for about 30 min. The temperature for the melting process was set to be slightly above the melting temperature of the aluminium can scrap. The molten metal treatment was performed with different types of flux and mixing ratio. As a result, The optimum efficiency of Al recovery ratio was revealed when the process was performed with at least 3 wt.% of the flux (Salt and MgCl2 mixture of ratio 70:30) at 750 °C. The mechanical property of the recovered Al alloy showed that the tensile strength is about 249 MPa and elongation is about 14 %. This result was found to be similar to the mechanical property of the virgin Al 5083 alloy.","PeriodicalId":17385,"journal":{"name":"Journal of the Korean Institute of Resources Recycling","volume":"10 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82800074","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}

{"title":"Strategy to Recover Rare Earth Elements from a Low Grade Resource via a Chemical Decomposition Method","authors":"R. Kim, Heechan Cho, Jinan Jeong, Jihye Kim, Sugyeong Lee","doi":"10.7844/KIRR.2020.29.1.17","DOIUrl":"https://doi.org/10.7844/KIRR.2020.29.1.17","url":null,"abstract":"In this study, rare earth elements (REE) leaching from a refractory REE ore containing goethite as a major gangue mineral was conducted, introducing a two-stage method of chemical decomposition-acid leaching. At the chemical decomposition step, using one of alkaline agent, NaOH, the ore was decomposed, changing NaOH concentration from 20 to 50 wt% at 10% (w/w) of pulp density and the maximum temperature achieved without boiling at each NaOH concentration. With increasing NaOH concentration, light REE (Ce, La and Nd) and iron were concentrated in the solid phase which is the decomposed product, while aluminum (Al) and phosphorus (P) were removed to the liquid phase, and their concentrations in the solid phase were down to 18 김리나 · 조희찬 · 정진안 · 김지혜 · 이수경 J. of Korean Inst. Resources Recycling Vol. 29, No. 1, 2020 1. 서 론 희토류는 주기율표 상의 17개 원소들로서, 란타넘족 15개 원소(La~Lu) 를 비롯하여 Sc, Y 등을 포함한다. 희 토류의 특수한 화학적, 광학적, 자기적 특성으로 인해 이 들 원소는 이차 전지, 형광체, 연마제, 영구자석, 각종 센 서 제조 등 현대 첨단 산업의 다양한 분야에서 사용되고 있다. 일반적으로 희토류 원소들은 모나자이트(REEPO4), 제 노타임(YPO4), 바스트나사이트(REECO3F) 등의 광물로 부터 유래된다. 광물을 물리적 선별법으로 농축할 수 있 는 경우, 모나자이트, 제노타임 등의 인산염 광물을 함유 한 광석은 농황산 분해-수침출 또는 알칼리 분해-산 침출 의 방법으로 처리되고, 바스트나사이트 함유 광석의 경우 산화 배소 후 염산 또는 황산 침출 방법이 주로 사용된다. 이온 흡착형 클레이 또한 대표적인 함희토류 자원인데, 황산암모늄 용액을 이용한 이온 교환 메커니즘을 통해 희 토류 원소를 회수할 수 있다. 그러나 위에서 언급된 광물 이외의 희토류 광물이 함유된 경우, 희토류 광물을 농축 할 수 없는 난용성 광석의 경우, 또는 광석이 아닌 2차자 원으로부터 희토류를 회수하는 경우 등에는 해당 자원의 특성(예: 광물학적 조성, 불순물 함량 및 구성) 에 맞는 처 리법이 도입되어야 한다. 특히, 희토류 광물의 농축이 불 가능한 광석 또는 2차자원의 처리 시 각각 맥석광물이 희 토류 농축을 방해하거나 희토류가 매우 안정한 합금 형태 로 존재하기 때문에 강력한 분해 공정이 필요하다. 본 연구에 사용된 광석 시료는 TREO(total rare earth oxide) 함량이 약 3%로 비교적 높은 수준에 속하나 함희 토류 광물이 광석 전체에 분산되어 있고, 일부 희토류 광 물들은 맥석광물 속에 갇혀 있어 물리적 선별법을 통해 희 토류 성분을 농축하기가 용이하지 않아 난용성 광석에 속 한다. 유사한 형태의 광석이 브라질 Araxá 광산에서 발견 되는데, 해당 광석 또한 5.01% TREO라는 높은 희토류 함 량에도 불구하고 물리적 선별법의 적용이 가능하지 않은 것으로 알려져 있다. 이와 같은 광석들은 광석 처리의 초기 단계부터 습식제련법의 적용이 요구된다. 그러나 맥 석광물의 영향으로 목적 금속에 대한 직접 침출이 용이하 지 않기 때문에 침출 단계에 앞서 맥석광물에 대한 화학적 분해가 선행되어야 한다. 실제로 앞서 언급된 Araxá 광석 의 경우 희토류 광물이 함철광물 속에 갇혀 있고, 50% 가 량의 희토류 광물이 20 μm 이하의 매우 낮은 입도로 분포 하고 있어 물리적 선별 과정이 생략되었고, 농황산 분해 후 수침출 하는 공정을 택하였다. 본 연구에서는 기존 의 희토류 광물 분해에 적용되는 알칼리 분해법이 본 연구 의 광석에 함유된 맥석광물 분해 및 희토류 광물 침출 거 동에 미치는 영향에 대하여 조사하고 최적 분해 및 침출 조건을 규명∙확립하고자 한다.","PeriodicalId":17385,"journal":{"name":"Journal of the Korean Institute of Resources Recycling","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89310104","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}

{"title":"Study on the Detoxification of Asbestos-Containing Wastes (ACW) Using SiC Plate","authors":"M. Hong, Hyeoksun Choi, S. Joo, C. Lee, Jin-Ho Yoon","doi":"10.7844/KIRR.2020.29.1.35","DOIUrl":"https://doi.org/10.7844/KIRR.2020.29.1.35","url":null,"abstract":"Even asbestos-containing waste (ACW) are highly harmful to humans, it continues being produced due to the massive disposal of asbestos-containing products. A development of asbestos detoxification and recycling technologies is required. Heat treatment using microwave is the most efficient method for ACW detoxification. However, microwave heat treatment method has the limitation that asbestos does not absorb microwave at room temperature. That is why, in this study, ACW was detoxified by microwave heat treatment adding the ACW between SiC plates, which are inorganic heating elements that absorb microwaves at room temperature. In order to improove the heat transfer, ACW was crushed and pulverized and then heated using microwave. Microwave heat treatment temperature and time variables were adjusted to investigate the detoxification properties according to heat treatment conditions. After heat treatment, treated ACW was analyzed for detoxification properties through crystal structure and microstructure analysis using X-ray diffraction (XRD) and scanning electron microscopy (SEM). 36 홍명환 · 최혁목 · 주소영 · 이찬기 · 윤진호 J. of Korean Inst. Resources Recycling Vol. 29, No. 1, 2020 1. 서 론 화성암의 일종인 석면(asbestos)은 천연 섬유 모양의 규산 화합물로 사문석계와 각섬석계 두 그룹으로 나뉜 다. 사문석계에는 chrysotile이 있으며, 각섬석계 석면으로 는 crocidolite, amosite, anthophyllite asbestos, actinolite asbestos, tremolite asbestos이가 있다. 석면 섬유는 길 이 5 μm 이상의 길이 대 폭의 비가 3 : 1 이상인 물질로 단열 성, 내열성, 절연성 등의 우수한 물성과 가격이 저렴하여 백 석면으로 불리는 Chrysotile, 청석면으로 불리는 crocidolite 및 갈석면으로 불리는 amosite가 산업적인 용도로 주로 사용되었다. 이러한 우수한 특성으로 인하여 20세기 이 후 석면은 건설, 자동차 제조 및 가정용품 등에 이르기까 지 다양한 분야에서 3,000여 종류에 달하는 공업 제품에 사용되었다. 전 세계적으로 거의 모든 경제 분야에 석면 이 사용되어 왔으며 오랫동안 석면을 대체할 만한 물질은 없는 것으로 여겨졌다. 또한 과거에 석면은 광물성 규산 염이기 때문에 건강에 큰 문제가 없는 것으로 판단하여 석 면 분진으로 인한 인체 유해성에 대해서는 일반 분진 경우 와 차이를 두어 취급되지 않았다. 이렇듯 석면이 현재와 같이 유해물질로 취급되지 않았기 때문에 사용량은 증가 하였으며 세계 생산량이 1966년 280만 톤에서 1975년 520만 톤으로 증가하였다. 그러나 1970년대 후반부터 석면 분진에 대한 인체 위 해성이 알려졌으며, 석면 분진 노출은 20년에서 40년의 잠복기를 거쳐 석면폐, 악성중피종, 폐암 등의 치명적인 질병 유발의 주요 원인으로 확인되었다. 1987년 세계 보건기구 산하 국제암연구소에서 석면을 1급 발암물질로 지정하며 석면의 유해성이 알려지면서 석면대체물질이 개발되어 사용되고 있어 현재는 감소하는 추세이다. 그 동안 사용된 석면 함유 폐기물(asbestos-containing waste: ACW)은 매립지에 매립하는 것도 가능하나 매립지의 부 족, 자원의 재활용 등의 이유로 석면을 무해화 하는 기술 개발에 대한 필요성이 대두되었다. 석면을 무해화하기 위하여 표면 고착화, 열 및 열화학 적 방법, 화학적방법 등 다양한 방법이 연구되었다. 캡 슐화 방법은 석면을 해체하지 않고 불침투성 층을 형성하 여 석면이 대기 중으로 유출되는 것을 방지하는 방법으로 비교적 적은 비용으로 처리가 가능하다. 하지만 석면 형 태 및 손상 정도에 따른 적용에 한계가 존재하며 시간이 지남에 따라 재료가 손상될 경우 석면 방출의 가능성이 있 어 완전한 석면 무해화는 아니다. 폐석면의 무해화에 있 어 가장 효율적인 방법은 고온 열처리에 의한 석면 섬유를 무해한 구조로 변환시키는 방법이다. 석면 함유 폐기 물의 열처리 방법은 1,200°C 이상의 고온으로 가열하여 석면의 구조를 변환시키는 것으로 화학 물질을 첨가하여 1,200°C 이하의 온도에서도 무해화가 가능하다. 그러 나 석면과 석면 함유 폐기물의 주성분인 시멘트의 낮은 열 전도율로 인한 에너지 소비가 높아짐에 따라 다량으로 처 리하는 것이 어려우며 화학물질 추가 시 처리비용이 높아 진다. 마이크로웨이브를 이용한 열처리는 빠르고 균일 한 온도 상승 특성으로 인하여 폐석면을 열처리하기 위한 기존의 오븐 또는 열 플라즈마를 대체할 수 있는 기술로 고려되고 있다. 하지만 SiO2, CaCO3, A12O3와 같은 시 멘트의 주성분은 상온에서 마이크로웨이브를 투과하여 마이크로웨이브 에너지를 거의 흡수하지 않으며 마이크 로웨이브 흡수를 위해서는 일정 온도까지 가열 되어야 한 다. 본 연구에서는 상온에서 마이크로웨이브를 흡수 하여 발열이 가능한 무","PeriodicalId":17385,"journal":{"name":"Journal of the Korean Institute of Resources Recycling","volume":"19 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89328897","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}

{"title":"Field Applicability and Manufacturing of Foam Concrete as Filler with the Low-strength and High-flow for Repair System of Ground Subsidence","authors":"Young Ma, Beom-Seok Kim, Yang-Yi Woo, Kyung Jung, Hun Song","doi":"10.7844/KIRR.2020.29.1.43","DOIUrl":"https://doi.org/10.7844/KIRR.2020.29.1.43","url":null,"abstract":"The objectives of this study were to identify the optimal mix of foam concrete with the low-strength and high-flow for the repairing ground subsidence situation emergently by utilizing a large amount of industrial by-products and evaluate the possibility by applying it to the site. The factors of the experiment were the mixing ratio of mixing water and a foaming agent and the mixing ratio of foam over paste volume. The optimal mix identified by the experiment was applied to the field and basic properties were evaluated. The results of the experiment showed that the optimal mixing ratio of mixing water and the foaming agent was 10%. Moreover, when the mixing ratio of pre-foam over paste volume was 170%, it satisfied the target. However, to ensure stable quality when applying to the field, the foam mixing ratio was set 140% for the field application. The field application test of foam concrete with the low-strength and high-flow using an eco-friendly binder satisfied all target performances. Therefore, the possibility of using it as a mixture and construction method for a ground repair system is confirmed. However, there was a quality deviation between the upper part and the lower part due to the separation between foam and paste. Consequently, further studies are needed to improve it.","PeriodicalId":17385,"journal":{"name":"Journal of the Korean Institute of Resources Recycling","volume":"29 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73271201","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}

{"title":"Current Status of Plastic Recycling in Korea","authors":"Sang-hun Lee","doi":"10.7844/kirr.2019.28.6.3","DOIUrl":"https://doi.org/10.7844/kirr.2019.28.6.3","url":null,"abstract":"Recently, plastic waste in Korea has been recognized as a critical issue due to an increase in massive production of plastics, difficulty in disposal of waste plastics, and public recognition of toxicity in micro-plastics, etc. To resolve those problems, the regulation to reduce plastics consumption may be primarily considered but, in this case, clarification should be made on the rationales and the action plans in the regulation for individual waste plastic items. Another problem is the small capital sizes of domestic recycling companies, which leads to poor R&D capacity, low recycling yields and thus lowering values of recycling items. This adversely affects consumers' perception. The R&D toward recycling technical progress should take into account the environmental friendliness and recyclability from the early product design stages. Certainly, this should be supported in governmental policy and public action plans. In addition, by referring to advanced policies of i.e. European Union, the recycling industry should be recognized as an opportunity toward new investment & employment. If necessary, the regulation of plastic consumption through a formal evaluation process such as Life Cycle Assessment (LCA) will also be helpful. The values of recycled plastics should be improved through the identification and elimination of harmful chemical substances potentially contained in the products.","PeriodicalId":17385,"journal":{"name":"Journal of the Korean Institute of Resources Recycling","volume":"77 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90297078","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}

{"title":"Current State of Domestic·Overseas Quality Standards of Tin and\u0000Comparison of Qualities between Virgin and Recycled Tin Products","authors":"Yong Hwan Kim, S. Son, Ho Jung ShinID, C. Han, S. C. Park, Man Seung Lee","doi":"10.7844/kirr.2019.28.6.9","DOIUrl":"https://doi.org/10.7844/kirr.2019.28.6.9","url":null,"abstract":"The use of rare metals in increasing along with the growth of the Fourth industrials revolution and new energy industries, and the recycling of rare metals becomes more important as the used of rare metals increase. In this paper, the domestic and international quality standards of tin metal, one of the rare metals, and the performance test of recycled tin were investigated. As a results of the performance test, it was analyzed that there is no difference in performance between the natural and recycled tin.","PeriodicalId":17385,"journal":{"name":"Journal of the Korean Institute of Resources Recycling","volume":"57 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84841939","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}

{"title":"Study on Selective Lithium Leaching Effect on Roasting Conditions of the Waste Electric Vehicle Cell Powder","authors":"Y. Jung, S. Son, S. C. Park, Yong Hwan Kim, B. Y. Yoo, Man-Seung Lee","doi":"10.7844/kirr.2019.28.6.79","DOIUrl":"https://doi.org/10.7844/kirr.2019.28.6.79","url":null,"abstract":"Recently, the use of lithium ion battery(LIB) has increased. As a result, the price of lithium and the amount spent lithium on ion battery has increased. For this reason, research on recycling lithium in waste LIBs has been conducted. In this study, the effect of roasting for the selective lithium leaching from the spent LIBs is studied. Chemical transformation is required for selective lithium leaching in NCM LiNixCoyMnzO2) of the spent LIBs. The carbon in the waste EV cell powder reacts with the oxygen of the oxide at high temperature. After roasting at 550 ~ 850 C in the Air/N2 atmosphere, the chemical transformation is analysed by XRD. The heat treated powders are leached at a ratio of 1:10 in D.I water for ICP analysis. As a result of XRD analysis, Li2CO3 peak is observed at 700 C. After the heat treatment at 850 °C, a peak of Li2O was confirmed because Li2CO3 · Received : November 1, 2019 · Revised : November 19, 2019 · Accepted : November 25, 2019 § Corresponding Author : Seong Ho Son (E-mail : shson@kitech.re.kr) Surface R & D Group, Korea Institute of Industrial Technology, 156 Gaetbeol-ro, Yeonsu-gu, Incheon 21999, Korea cThe Korean Institute of Resources Recycling. All rights reserved. This is an open-access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/3.0/), which permits unrestricted non-commercial use, distribution and reproduction in any medium, provided the original work is properly cited. 80 정연재 ·손성호 ·박성철 ·김용환 ·유봉영 ·이만승 J. of Korean Inst. Resources Recycling Vol. 28, No. 6, 2019 is decomposed into Li2O and CO2 over 723 °C. The produced Li2O reacted with Al at high temperature to form LiAlO2, which does not leach in D.I water, leading to a decrease in lithium leaching ratio. As a result of lithium leaching in water after heat treatment, lithium leaching ratio was the highest after heat treatment at 700 C. After the solid-liquid separation, over 45 % of lithium leaching was confirmed by ICP analysis. After evaporation of the leached solution, peak of Li2CO3 was detected by XRD.","PeriodicalId":17385,"journal":{"name":"Journal of the Korean Institute of Resources Recycling","volume":"299 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74999429","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}

{"title":"Physical Characteristics of Cement Mortar Prepared Using Waste Glass and Graphene Oxide","authors":"Kyoungseok Kim, Yong-sik Chu","doi":"10.7844/kirr.2019.28.6.54","DOIUrl":"https://doi.org/10.7844/kirr.2019.28.6.54","url":null,"abstract":"This study investigated on the compressive strength and the length change test with using the waste glass and graphene oxide for recycling the waste glass as the aggregate. Curing on 3-day and 7-day, the compressive strength was enhanced as the usage of waste glass was increased. Especially, the huge difference in the compressive strength was observed when the amount of substituting on the waste glass was used on 10~50%. With 50% of waste glass condition, the compressive strength was portionally enhanced as the usage of graphene oxide was increased and its value was 42.6 N/mm with 0.2% of graphene oxide. In terms of the length change test, the use of high content of waste glass led length change value to increase, but it was dropped down as the portion of waste glass was above 50%. Furthermore, in the case of using 50% of waste glass, the use of high amount of graphene oxide tended to decrease the length change value. That is, graphene oxide may contribute on boosting the cement hydration reaction and blocking the ion’s movement.","PeriodicalId":17385,"journal":{"name":"Journal of the Korean Institute of Resources Recycling","volume":"75 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86174345","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}

{"title":"Properties of Cement Mortar as Particle Size and Hydrothermal Synthesis Temperature Using Scheelite Tailing","authors":"Yong-sik Chu, S. Seo, Sung Bum Choi, Gyoung man Kim, S. Hong","doi":"10.7844/kirr.2019.28.6.46","DOIUrl":"https://doi.org/10.7844/kirr.2019.28.6.46","url":null,"abstract":"Cement mortar was hydrothermal-synthesized with particle size of tailings using scheelite tailings deposited without proper treatment, and its physical properties were investigated. The mixing ratios of water-cement and sand-cement were fixed at 75 % and 400 %, respectively, during preparing cemnt mortar, and the sand was replaced by the tailings at 0 ~ 50 %. The particle size of tailings was controlled at 9.3 ~ 53.0 oC, and the hydrothermal temperature was kept at 60 ~ 180 °C for 6 hours after the temperature increased to pretermined temperature with 2 °C heating rate. The compressive strength increased with increasing hydrothermal temperature. The compressive strengths were 55.2 MPa and 54.5 MPa when the mortars were prepared with 30 % low arsenic and high arsenic tailings after 60 min grinding. The compresiive strenght was enhanced 300 % compared with reference sample.","PeriodicalId":17385,"journal":{"name":"Journal of the Korean Institute of Resources Recycling","volume":"52 5 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75790565","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}

{"title":"Trajectory Simulation of ASR Particles in Induction Electrostatic Separation","authors":"Beom-uk Kim, C. Park","doi":"10.7844/kirr.2019.28.6.96","DOIUrl":"https://doi.org/10.7844/kirr.2019.28.6.96","url":null,"abstract":"Automobile shredder residue (ASR) is the final waste produced when end-of-life vehicles (ELVs) are shredded. ASR can be separated using mineral-processing operations such as comminution, air classification, magnetic separation, and/or electrostatic separation. In this work, trajectory analyses of conductors (copper) and non-conductors (glass) in the ASR have been carried out using induction electrostatic separator for predicting or improving the ASR-separation efficiency. From results of trajectory analysis for conductors, the trajectories of copper wire by observation versus simulation for coarse particles of 0.5 and 0.25 mm showed consistent congruity. The observed 0.06 mm fine-particles trajectory was deflected toward the () attractive electrode owing to the charge-density effects due to the particle characteristics and relative humidity. In the case of non–conductors, the actual trajectory of dielectric glass deflected toward the () electrode, showing characteristics similar to those of conductive particles. The analyses of stereoscopic microscope and SEM & EDS found heterologous materials (fine ferrous particles and conductive organics) on the glass surface. This demonstrates the glass decreasing separation efficiency for non–ferrous metals during electrostatic separation for the recycling of ASR. Future work will require a pretreatment process for eliminating impurities from the glass and advanced trajectory-simulation processes.","PeriodicalId":17385,"journal":{"name":"Journal of the Korean Institute of Resources Recycling","volume":"11 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88234401","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}