Characteristics of volume change and heavy metal leaching in mortar specimens recycled heavyweight waste glass as fine aggregate

Choi, So Yeong,Choi, Yoon Suk,Yang, Eun Ik Elsevier 2018 Construction and Building Materials Vol.165 No.-

<P><B>Abstract</B></P> <P>Industrial waste, such as heavyweight waste glass, has become a global concern in terms of environmental safety and resource recycling. The reuse and recycling of heavyweight waste glass are necessary from the viewpoint of environmental protection. At the same time, concrete, three-quarters of which consists of aggregate, is one of the most widely used infrastructure materials, and it is being exhausted. The heavyweight waste glass being is considered as the most suitable substitute for aggregate due to its physical characteristics and chemical composition.</P> <P>In this study, to evaluate whether heavyweight waste glass could be as a concrete material, we carried out drying shrinkage, expansion by alkali-silica reaction (ASR) and heavy metal leaching of mortar. We found that when the heavyweight waste glass substitution ratio increased, the drying shrinkage decreased. Furthermore, the existing models predicted the experimental results, inversely. However, the expansion of ASR mortar gradually increased with an increase in the substitution ratio of heavyweight waste glass. When fly ash 20% or blast furnace slag 50% was mixed in mortar specimens, the ASR expansion could be controlled within the permitted limit of 0.1% at 14 days by the ASTM 1260 criteria. Moreover, the leached concentration of As, Cd, Cu and Hg from the mortar were detected below the criteria specified in drinking water regulatory levels, however, further investigation is needed to determine the leaching characteristics of Pb and Cr according to heavyweight waste glass substitution ratio in mortar specimens. Conclusively, the overall test results of this study have demonstrated that it may be feasible to utilize heavyweight waste glass as fine aggregate in mortar specimens.</P> <P><B>Highlights</B></P> <P> <UL> <LI> The mortar specimens containing heavyweight waste glass were investigated. </LI> <LI> Drying shrinkage decreased with the increase of heavyweight waste glass. </LI> <LI> ASR expansion and heavy metal leaching quantities increased with the content of waste glass. </LI> <LI> The heavyweight waste glass substitution has a significant effect on the properties mortar specimens. </LI> <LI> Results are expected to provide a motivation to use heavyweight waste glass in mortar. </LI> </UL> </P>

Expansion Properties of Mortar Using Waste Glass and Industrial By-Products

Park, Seung-Bum,Lee, Bong-Chun Korea Concrete Institute 2006 International Journal of Concrete Structures and M Vol.18 No.e2

Waste glass has been increasingly used in industrial applications. One shortcoming in the utilization of waste glass for concrete production is that it can cause the concrete to be weakened and cracked due to its expansion by alkali-silica reaction(ASR). This study analyzed the ASR expansion and strength properties of concrete in terms of waste glass color(amber and emerald-green), and industrial by-products(ground granulated blast-furnace slag, fly ash). Specifically, the role of industrial by-products content in reducing the ASR expansion caused by waste glass was analyzed in detail. In addition, the feasibility of using ground glass for its pozzolanic property was also analyzed. The research result revealed that the pessimum size for waste glass was $2.5{\sim}1.2mm$ regardless of the color of waste glass. Moreover, it was found that the smaller the waste glass is than the size of $2.5{\sim}1.2mm$, the less expansion of ASR was. Additionally, the use of waste glass in combination with industrial by-products had an effect of reducing the expansion and strength loss caused by ASR between the alkali in the cement paste and the silica in the waste glass. Finally, ground glass less than 0.075 mm was deemed to be applicable as a pozzolanic material.

Waste LCD Glass-Directed Fabrication of Silicon Particles for Lithium Ion Battery Anodes

( Woohyeon Kang ),( Jae-chan Kim ),( Dong-wan Kim ) 한국폐기물자원순환학회(구 한국폐기물학회) 2019 ISSE 초록집 Vol.2019 No.-

Silicon (Si) has been considered as the most potential alternative to commercial graphite anodes in lithium-ion batteries thanks to its high specific capacity (4200 mA h g^-1) and appropriate working voltage (~0.2 V vs. Li/Li⁺). Nonetheless, the drastic volume expansion (~300%) and low coulombic efficiency are still challenging for commercialization of Si anodes. Numerous research have been reported to solve the capacity fading with outperforming electrochemical energy density but most synthesis approaches include expensive precursors and hazardous processes. In terms of cost-effectiveness and environmental benignity, silica (SiO₂) in industrial wastes such as glass bottles and windshield glass can be promising precursors. In waste LCD panels, main component of LCD glass substrates is aluminoborosilicate which is an applicable precursor of Si particles. Until now, waste LCD panels have been buried in landfills but their abundance will increase to reach 5539 km2 until 2020 in a total display area. However, the synthesis of recycled LCD glass-derived Si particles has never been reported yet due to some inert metal oxides in waste LCD glass. Herein, we propose the low cost and eco-friendly fabrication of Si particles via a magnesiothermic reduction using waste LCD glasses and their application to lithium ion battery anodes. Firstly, in order to eliminate impurities except SiO₂, ball milling and acidic treatment of waste LCD glass was undertaken. Pre-processed waste LCD glass powders were reduced to Si at 650 °C for 6 hrs in argon through magnesiothermic reduction followed by further acidic treatment. From crystal structural and morpholgical analyses, the LCD glass was successfully converted into high-purity Si particles. The anodes prepared by these Si particles exhibited the large initial discharge capacity of 4290 mA h g^-1 but underwent rapid decrease in reversible capacities upon subsequent cycles. In order to improve electrochemical performances in cost-effective manner, we adopted anode post-treatment (called “maturation”) by storing the as-fabricated anodes in a humid chamber for 48 hrs. The matured waste LCD glass-directed Si anodes exhibited high reversible capacities and enhanced cycle life due to improved mechanical stability by the reinforcement of cohesion and adhesion between anode components and copper current collector.

Production of alumino-borosilicate foamed glass body from waste LCD glass

Korean Society of Industrial and Engineering Chemi 2013 Journal of industrial and engineering chemistry Vol.19 No.6

A foaming process for waste LCD glass is presented, in which waste LCD glass is recycled to produce alumino-borosilicate foamed glass, which can eventually be used as a heat-insulating material, a light-weight aggregate for civil engineering applications, or a carrier for sewage treatment. The effects on waste LCD glass foaming of a variety of carbon foaming agents, metal salt foaming agents, and bonding agents are examined, as well as other factors such as chemical composition, foaming temperature, and grain size of the raw materials from the waste LCD glass. After examining all the variables that influence the foaming process, it was confirmed that the waste LCD glass is suitable as a raw material for producing alumino-borosilicate foamed glass. The alumino-borosilicate foamed glass has excellent physical properties, with density less than 0.14g/cm<SUP>3</SUP>, heat conductivity less than 0.054W/(mK) ½0<SUP>o</SUP>C, bending strength more than 35N/cm<SUP>2</SUP>, compressive strength more than 39N/cm<SUP>2</SUP> and a coefficient of linear thermal expansion less than 4.5x10<SUP>-6</SUP>m/m<SUP>o</SUP>C. This clearly shows that the lightweight alumino-borosilicate foamed glass could be useful for various applications.

Production of alumino-borosilicate foamed glass body from waste LCD glass

이철태 한국공업화학회 2013 Journal of Industrial and Engineering Chemistry Vol.19 No.6

A foaming process for waste LCD glass is presented, in which waste LCD glass is recycled to produce alumino-borosilicate foamed glass, which can eventually be used as a heat-insulating material, a lightweight aggregate for civil engineering applications, or a carrier for sewage treatment. The effects on waste LCD glass foaming of a variety of carbon foaming agents, metal salt foaming agents, and bonding agents are examined, as well as other factors such as chemical composition, foaming temperature, and grain size of the raw materials from the waste LCD glass. After examining all the variables that influence the foaming process, it was confirmed that the waste LCD glass is suitable as a raw material for producing alumino-borosilicate foamed glass. The alumino-borosilicate foamed glass has excellent physical properties, with density less than 0.14 g/cm3, heat conductivity less than 0.054 W/(mK) @20 8C, bending strength more than 35 N/cm2, compressive strength more than 39 N/cm2 and a coefficient of linear thermal expansion less than 4.5x10-6 m/m 8C. This clearly shows that the lightweight aluminoborosilicate foamed glass could be useful for various applications.

Alkali Borosilicate Glass for Vitrification of Molybdenum-rich Nuclear Waste

Seon-Jin Kim,Jung-wook Cho 한국방사성폐기물학회 2023 한국방사성폐기물학회 학술논문요약집 Vol.21 No.1

Vitrification is one of the best ways to immobilize high-level radioactive waste (HLW) worldwide over the past 50 years. Since the glass matrix has a medium (3.0-5.5 A) and short (1.5-3.0 A) periodicity, it can accommodate most elements from the periodic table. Borosilicate glass is the most suitable glass matrix for vitrification due to its high chemical durability, high waste-loading capacity, and good radiation resistance. Mo is a fission product contained in liquid waste generated in the process of reprocessing spent nuclear fuel and exists in the form of MoO4 2- in the glass. MoO4 2- forms a depolymerization region without directly connecting with the glass network former. When the concentration of Mo increases in the depolymerization region, it combines with nearby alkali or alkaline earth cations to form a crystalline molybdate phase. Phase separation and crystallization in the glass can degrade the performance of the material because it changes the physical and chemical properties of the glass. In particular, since alkali molybdate has high water solubility when it forms crystals containing radioactive elements such as Cs, there is a risk of leakage of radionuclides by groundwater during deep underground disposal. Therefore, in this study, the most stable glass-ceramic composition was developed using various alkali elements, and the difference in phase separation and crystallization behavior in glass and the stability of the solidified body were analyzed by structural analysis of the glass network and alkali molybdate. The cause of the difference in crystallization of alkali molybdate according to the type of alkali cation is structurally analyzed, and using this, research is conducted to increase the Mo content in the glass without crystallization.

Valuable Recycling of waste glass generated from the liquid crystal display panel industry

Kim, Kicheol,Kim, Kidong Elsevier 2018 Journal of cleaner production Vol.174 No.-

<P><B>Abstract</B></P> <P>Due to the drastic growth of the liquid crystal display (hereafter LCD) industry in the last decade, lots of waste glass is being produced. There are three types of waste glass derived from LCD glass manufacturers, LCD panel manufacturers and end-of-life LCD devices. Among them cullet from Lber glass (hereafter E-glass). However, the recycling of waste glass from LCD panel (LPWGCD glass is being recycled into a raw material for commercial electric continuous fi) and end waste glass is limited due to various reasons such as contaminants, toxic components and inhomogeneous glass compositions etc. Despite use of LPWG in the cement industry, it is not an effective form of recycling, considering the characteristics of LCD glass. In this work, to examine the possibility of recycling LPWG in the E-glass industry, several glass batches containing LPWG were prepared. First, some optical properties of the prepared and commercial E-glass were examined. Then, the viscosity and liquidus temperature (T<SUB>L</SUB>) were determined. The effect of LPWG was negligible in the transmission and color of the resultant glasses, considering that commercial bulk E-glass has an emerald-green color due to refractory corrosion. With an increase in the LPWG content, the isoviscosity and liquidus temperatures showed opposite behaviors; the temperature (T<SUB>W</SUB>) corresponding to the fiber forming viscosity (10<SUP>3</SUP> dPas) decreased, whereas the T<SUB>L</SUB> increased. Based on T<SUB>W</SUB>-T<SUB>L</SUB>, the replacement of 50 wt% of the original E-glass with LPWG was recommended. Additionally, economic and environmental effects were discussed.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Recycling of LCD process waste glasses (LPWG) in E-glass was examined. </LI> <LI> Source of B<SUB>2</SUB>O<SUB>3</SUB> such as colemanite was replaced by LPWG. </LI> <LI> Effect of contaminants coated to the surface of LPWG was negligible. </LI> <LI> Two important melt properties for LPWG content showed an opposite behavior. </LI> <LI> Replacement of E-glass with LPWG up to 50% in glass batch was suggested. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Evaluation of the Mobility of Glass Fibers in the Environment of the Gyeongju Radioactive Waste Repository

Sang June Park,Moonoh Kim,Hyun Woo Song,Hang-Rae Cho,Suil Bang 한국방사성폐기물학회 2022 한국방사성폐기물학회 학술논문요약집 Vol.20 No.2

Glass wool, the primary material of insulation, is composed of glass fibers and is used to insulate the temperature of steam generators and pipes in nuclear power plants. Glass fiber is widely adopted as a substitute for asbestos classified as a carcinogen. The insulations used in nuclear power plants are classified as radioactive waste and most of the insulation is Very Low-Level Waste (VLLW). It is packaged in a 200 L drum the same as a Dry Active Waste (DAW). In the case of the insulations, it is packaged in a vinyl bag and then charged into the drum for securing additional safety because of the fine particle size of the fiberglass. A safety assessment of the disposal facility should be considered to dispose of radioactive waste. As a result of analyzing overseas Waste Acceptance Criteria (WAC), there is no case that has a separate limitation for glass fiber. Also, in order to confirm that glass fibers can be treated in the same manner as DAW, research related to the diffusion of glass fibers into the environment was conducted in this paper. It was confirmed that the glass fiber was precipitated due to the low flow velocity of groundwater in the Gyeongju radioactive waste repository and did not spread to the surrounding environment due to the effect of the engineering barrier. Therefore, the glass fiber has no special issue and can be treated in the same way as a DAW. In addition, it can be disposed of in the disposal facility by securing sufficient radiological safety as VLLW.

폐유리를 잔골재로 사용한 차폐채움재의 내구성 개선을 위한 혼화재료의 성능평가

황병일,김효정,송용순,이성태 한국구조물진단유지관리공학회 2019 한국구조물진단유지관리공학회 논문집 Vol.23 No.2

전자제품의 개발과 생산기술에 비교하여 폐유리의 재활용을 위한 기술개발은 상대적으로 미흡하여 자원낭비와 환경오염이 가속화되고 있다. 해외에서는 이 분야에 대한 기술개발이 활발하게 이루어지고 있으나 국내의 경우, 그 관심도가 부족하여 폐유리를 불법투기 또는 매립으로 처리하고 있는 실정이다. 폐유리는 시멘트와 수화반응시 포졸란 반응가능성이 있는 것으로 확인되어 경화 콘크리트의 물리적 성질을 향상시키고 굳지 않은 콘크리트의 레올로지 특성을 개선하여 블리딩의 저감 및 수화열 발생의 억제 등에 효과적인 것으로 보고되고 있다. 따라서 본 논문에서는 폐유리를 잔골재로 사용한 차폐콘크리트의 알칼리-실리카반응이 팽창에 미치는 영향을 분석하고 폐유리 혼입에 의한 알칼리-실리카반응의 팽창을 억제하기 위한 방안으로 적정 혼화재료를 사용하여 차폐콘크리트의 내구성능을 평가하였다. Compared to the development and manufacturing technology of electronic goods, the development of waste glass recycling technology is relatively insufficient, leading to the acceleration of waste of resources and environmental pollution. Although waste glass recycling technology is being actively developed overseas, waste glass recycling technology is insufficient in Korea, leading to the illegal dumping or burial of waste glass. Waste glass has been confirmed to have pozzolan reaction potential when having hydration reaction with cement. Waste glass is also reported to be effective in reducing bleeding and inhibiting the development of hydration heat by improving the physical properties of concrete and the rheology properties of fresh concrete. Therefore, this paper analyzed the strength characteristics and the effect of alkalic-silica reaction on the expansion of shielding concrete that used waste glass as fine aggregate. Where, suitable admixture materials were used as a measure to suppress the expansion.

Glass Property Models, Constraints, and Formulation Approaches for Vitrification of High-Level Nuclear Wastes at the US Hanford Site

Kim, Dongsang The Korean Ceramic Society 2015 한국세라믹학회지 Vol.52 No.2

Current plans for legacy nuclear wastes stored in underground tanks at the U.S. Department of Energy's Hanford Site in Washington are that they will be separated into high-level waste and low-activity waste fractions that will be vitrified separately. Formulating optimized glass compositions that maximize the waste loading in glass is critical for successful and economical treatment and immobilization of these nuclear wastes. Glass property-composition models have been developed and applied to formulate glass compositions for various objectives for the past several decades. Property models with associated uncertainties combined with composition and property constraints have been used to develop preliminary glass formulation algorithms designed for vitrification process control and waste-form qualification at the planned waste vitrification plant. This paper provides an overview of the current status of glass property-composition models, constraints applicable to Hanford waste vitrification, and glass formulation approaches that have been developed for vitrification of hazardous and highly radioactive wastes stored at the Hanford Site.