Ji‐Whan Ahn
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View article: Application of Integrated Physical Separation for the Enrichment of Rare Earth Elements from Circulating Fluidized Bed Coal Fly Ash
Application of Integrated Physical Separation for the Enrichment of Rare Earth Elements from Circulating Fluidized Bed Coal Fly Ash Open
Rare earth elements (REE) are crucial for new technology; however, do not have effective substitutes and are scarce in the earth’s crust. Among secondary resources of REE, circulating fluidized bed coal fly ash has been proposed as a poten…
View article: Inhibition of Total Nitrogen Loss in Urine through Integrated Alkali Stabilization and Carbonation
Inhibition of Total Nitrogen Loss in Urine through Integrated Alkali Stabilization and Carbonation Open
In this paper, total nitrogen (TN) has been recovered from waste diapers through alkaline stabilization as a liquid fertilizer. Nitrogen is one of the most dominant as well as difficult key nutrients to recover from human urine. However, n…
View article: Acid Mine Drainage Treatment by Potential Carbon Mineralization: A Step Toward a Circular Economy
Acid Mine Drainage Treatment by Potential Carbon Mineralization: A Step Toward a Circular Economy Open
Acid Mine drainage is produced mainly from the two sources such as mineral and mining industries and there are a factors to enhance the AMD formation: i) atmospheric moisture, ii) pH, iii)temperature, and iv) surface area of sulfide minera…
View article: A Comparative Study on the Calcination and Hydration of Dolomite Using Microwave and Electric Furnaces
A Comparative Study on the Calcination and Hydration of Dolomite Using Microwave and Electric Furnaces Open
백운석(dolomite)은 파분쇄 된 제품으로 제강, 유리, 비료, 골재용 등에 사용되고, 소성 제품으로 제강용, 내화물, 폐수정화, 가스정화 등에 사용된다. 본 연구에서는 폐수정화, 가스정화에 적용을 위한 고반응성 경소백운석(CaO·MgO) 제조를 목표로 하였다. 내부 가열 방식인 마이크로웨이브 진공 소성과 외부 가열 방식의 전기로로 상압 소성을 실시하여 실험을 진행하였다. XRD, XRF, SEM, BET 등을 분석하고,…
View article: A Brief review on Global Plastic Regulation Trends
A Brief review on Global Plastic Regulation Trends Open
플라스틱은 다른 재료들에 비해 가볍고 저렴하면서 다양한 형태로 제작 가능하다. 또한 내구성과 열화에 대한 내성으로 인해 분해되지 않아 다양한 분야에서 광범위하게 사용되고 있어 매년 생산량도 꾸준히 증가하고 있는 추세이다. 플라스틱은 현재 인간의 생활에 필수품이 되었으며 인간이 있었던 곳이라면 어디서든 발견되고 있다. 이러한 플라스틱은 주로 일회용품으로 생산돼 최근에는 많은 국가들이 플라스틱 처리로 인해 규제를 시행하고 있으며…
View article: Emerging Technologies for Plastic Recycling and their Potential Applications
Emerging Technologies for Plastic Recycling and their Potential Applications Open
Owing to plastic’s multi-functionalities such as lightweight, processability, and reasonable price, plastic materials have been used in various manufacturing industries. It is undeniable that increasing demand for different commodities pro…
View article: North Korea Cement Industry in Satellite Imagery
North Korea Cement Industry in Satellite Imagery Open
The possibility of economic exchange with North Korea is increasing, but there is still a shortage of information of cement industry, which occupies the largest proportion of North Korean construction material industry.Therefore, this stud…
View article: Sulfation–Roasting–Leaching–Precipitation Processes for Selective Recovery of Erbium from Bottom Ash
Sulfation–Roasting–Leaching–Precipitation Processes for Selective Recovery of Erbium from Bottom Ash Open
Bottom ash (BA) is mainly composed of compounds of Al, Fe, Ca, and traces of rare earth elements (REEs). In this study, the selective recovery of erbium (Er) as REEs by means of sulfation–roasting–leaching–precipitation (SRLP) using BA was…
View article: Opportunities for Mineral Carbonation in Australia’s Mining Industry
Opportunities for Mineral Carbonation in Australia’s Mining Industry Open
Carbon capture, utilisation and storage (CCUS) via mineral carbonation is an effective method for long-term storage of carbon dioxide and combating climate change. Implemented at a large-scale, it provides a viable solution to harvesting a…
View article: Utilization of CFBC Fly Ash as a Binder to Produce In-Furnace Desulfurization Sorbent
Utilization of CFBC Fly Ash as a Binder to Produce In-Furnace Desulfurization Sorbent Open
Circulating fluidized bed combustion (CFBC) power generation technology is known to efficiently reduce the emission of air pollutants, such as SO2 and NO2, from coal combustion. however, CFBC coal ash contains high contents of free CaO, ma…
View article: Preparation of Mullite-Silica Composites Using Silica-Rich Monophasic Precursor Obtained as a Byproduct of Mineral Carbonation of Blast-Furnace Slag
Preparation of Mullite-Silica Composites Using Silica-Rich Monophasic Precursor Obtained as a Byproduct of Mineral Carbonation of Blast-Furnace Slag Open
Previously, mineral carbonation of blast-furnace slag was carried out to sequestrate CO2 and attain pure CaCO3 crystals. In this process, amorphous silica-alumina nanoparticles were obtained as a byproduct. In this study, the crystallizati…
View article: Preparation of Silica-Alumina Nanoparticles via Blast-Furnace Slag Dissolution in Low-Concentration Acetic Acid for Carbonation
Preparation of Silica-Alumina Nanoparticles via Blast-Furnace Slag Dissolution in Low-Concentration Acetic Acid for Carbonation Open
Blast-furnace slag (BFS) has been used as a feedstock for CO2 sequestration by indirect mineral carbonation to produce calcium carbonate precipitates and solid residues. The most-abundant elements in these residues, Si and Al, are usually …
View article: Effect of Calcination on the Hydration Activity and Production ofPrecipitation Calcium Carbonate
Effect of Calcination on the Hydration Activity and Production ofPrecipitation Calcium Carbonate Open
Precipitated calcium carbonate (PCC) is known as purified and refined synthetic calcium carbonate. PCC is synthesized through calcination process to convert limestone to quicklime, hydration process to make slaked lime and carbonation proc…
View article: Effects of Experimental Parameters on the Extraction of Silica and Carbonation of Blast Furnace Slag at Atmospheric Pressure in Low-Concentration Acetic Acid
Effects of Experimental Parameters on the Extraction of Silica and Carbonation of Blast Furnace Slag at Atmospheric Pressure in Low-Concentration Acetic Acid Open
Blast furnace slag (BFS), a calcium-rich industrial byproduct, has been utilized since 2005 as a mineral carbonation feedstock for CO2 sequestration, producing calcium carbonate precipitates. In this study, the conditions for the dissoluti…
View article: Utilization of Circulating Fluidized Bed Combustion Ash and Related Specifications for Mine Backfills
Utilization of Circulating Fluidized Bed Combustion Ash and Related Specifications for Mine Backfills Open
순환유동층(CFBC) 보일러 방식의 석탄화력발전소에서 발생하는 석탄재는 유리 석회와 무수석고의 함량이 풍부하고 자경성을 가지는 것을 특징으로 하는 물질로서 유용하게 활용해야 할 자원 중 하나이다. 최근 CFBC 석탄재를 포함하여 석탄화력발전소 부산물을 활용한 광산 채움 기술 및 광해 관리에 대한 관심이 점차 증가하고 있는 가운데, CFBC 석탄재를 광산 채움 분야에 적용하기 위해서는 기술에 대한 검토와 함께 관련 규격에 대해…
View article: A Case Study of Mine Environmental Restoration using Coal Ash
A Case Study of Mine Environmental Restoration using Coal Ash Open
전 세계적으로 매년 증가하는 발전회의 매립을 위한 부지는 현저히 부족한 실정이며, 이를 재활용 하는 방안에 관한 연구는 지금까지 활발히 진행 중이다. 또한, 휴 폐광산의 갱구, 폐석 더미, 지하공동에서 발생하는 다양한 광해는 심각한 인명피해 및 환경오염을 일으킨다. 따라서 본 연구에서는 국내 석탄, 금속, 석회석 광산에서 발생하는 AMD (Acid Mine Drainage), 지반침하 등의 광해방지에서 발전회의 활용 가능성에…
View article: Study on the Free CaO Analysis of Coal Ash in the Domestic Circulating Fluidized Bed Combustion using ethylene glycol method
Study on the Free CaO Analysis of Coal Ash in the Domestic Circulating Fluidized Bed Combustion using ethylene glycol method Open
에틸렌글리콜법을 활용하여 국내 순환유동층보일러형 발전소에서 발생되는 석탄회의 물리화학적 특성 및 Free CaO 평가를 수행하였다. 물리화학적 특성결과, 각 발전사마다 많은 CaO 함량 차이를 나타내었는데, 이는 황산화물 배출농도 규제 차이 및 보일러 제작사가 다른 발전소의 운전특성이 복합적으로 반영된 것으로 판단된다. Free CaO의 함량은, 비산재는 1.96 ~ 10.78 %, 바닥재는 0.07 ~ 4.24%로 비산재가…
View article: A perspective of chemical treatment for cyanobacteria control toward sustainable freshwater development
A perspective of chemical treatment for cyanobacteria control toward sustainable freshwater development Open
One of the most threatening consequences of eutrophic freshwater reservoirs is algal blooming which typically occur after the long a mega drought or/and irregular rainfall under influence of climate change. The long-term experiences of che…
View article: Hydration Characteristics of Natural Hydraulic Lime Depending on Silica Fume and Anhydrite Replacement
Hydration Characteristics of Natural Hydraulic Lime Depending on Silica Fume and Anhydrite Replacement Open
본 연구에서는 무기질 첨가재인 실리카 흄과 석고 첨가에 따른 천연수경성석회 (NHL)의 수화특성에 대해 연구를 수행하였다. 연구에서 사용된 천연수경성석회는 국내 저품위 석회석을 활용하여 제조하였다. 천연수경성석회 페이스트의 수화특성은 무기질 첨가재의 혼합비 및 수화시간에 따라 조사되었다. 또한, EU 규격에 의한 방법으로 모르타르를 제작하여 압축강도 측정을 실시하였다. 실리카 흄과 석고를 혼합하여 제조한 천연수경성석회 페이스…
View article: Trends in Research and Technical Development of Sorbents for Hot Gas Desulfurization for H<sub>2</sub>S Removal
Trends in Research and Technical Development of Sorbents for Hot Gas Desulfurization for H<sub>2</sub>S Removal Open
청정석탄기술 중 하나인 석탄가스화 복합발전기술의 이론적 고찰 및 주요단위공정에 사용되는 고온건식 탈황제의 연구 및 기술개발 동향을 조사하였다. 고온건식 탈황제 개발의 중요한 요소는 반응성, 내구성 및 내마모성에 있으며, 탈황제 종류는 칼슘계, 아연계, 망간계, 철계, 구리계 등이 있다. 현재 고온건식 탈황제의 경우 선진국을 중심으로 아연계 탈황제 제조기술이 가장 상용화 단계에 있으며, 국내에서도 다양한 지지체를 사용하여 가격…
View article: Characterizations of High Early-Strength Type Shrinkage Reducing Cement and Calcium Sulfo-aluminate by Using Industrial Wastes
Characterizations of High Early-Strength Type Shrinkage Reducing Cement and Calcium Sulfo-aluminate by Using Industrial Wastes Open
In this study, the utilization of the by-products of various industries was examined using raw materials of CSA high-functional cement such as coal bottom ash, red mud, phosphate gypsum, etc. Technology to improve energy efficiency and red…
View article: Characteristics of Hydraulic Lime using Low-grade Dolomitic Limestone
Characteristics of Hydraulic Lime using Low-grade Dolomitic Limestone Open
This study aims to produce dolomitic hydraulic lime (D-NHL) using domestic low grade dolomitic limestone and to determine the effect of adding blast furnace slag (BFS) and gypsum as part of an investigation of the hydration properties of D…
View article: The Use of Oyster Shell Powders for Water Quality Improvement of Lakes by Algal Blooms Removal
The Use of Oyster Shell Powders for Water Quality Improvement of Lakes by Algal Blooms Removal Open
In this year, Koreans have a shortage in agricultural and drinking water due to severe algal blooms generated in major lakes. Waste oyster shells were obtained from temporary storage near the workplace at which oysters were separated from …