Waste LCD Research Articles

A study of the engineering properties of alkali-activated waste glass material (AAWGM)

This study used industrial by-product slag as the base material and applied different liquid–solid ratios (0.50, 0.55, 0.60), different alkaline solutions (0.5%, 0.75%, 1%) and waste LCD glass sand to replace the slag (0%, 10%, 20%) to produce mortar. The workability was analyzed. When the specimen was hardened, the engineering properties were tested at 3, 7 and 28days.The results showed that the slump increases with the liquid–solid ratio and alkaline solution. The slump was 100mm when the alkaline solution was 1% and the liquid–solid ratio was 0.50, which was higher than the slump when the liquid–solid ratio was 0.60 by 22mm. When the alkaline solution was 0.75% and the liquid–solid ratio was 0.5, the slump flow increased 1.26–1.67 times as the replacement of glass sand increased. The slump flow increased with the replacement of glass sand. When the liquid–solid ratio was 0.55 and the alkaline solution increased from 0.5% to 1%, the initial setting and final setting time were shortened by 45min and 100min. The compressive strength decreased as the liquid–solid ratio increased, but the compressive strength increased with the alkaline solution and glass sand replacement. The ultrasonic pulse velocity decreased as the liquid–solid ratio increased but increased with the alkaline solution and glass sand replacement. The weight loss significantly increased in the first two cycle tests for sulfate attack, but the weight loss decreased in the third cycle due to the saturation of the internal porous crystal.

HYDROMETALLURGICAL METHODS OF INDIUM RECOVERY FROM OBSOLETE LCD AND LED PANELS

The paper shows a review of the literature data on the possibilities of indium recovery from ITO layers of waste LCD and LED displays. A short characterization of indium, its compounds, resources, production and applications are presented. Structure and operation of LCD displays were shown. Detailed analysis of ITO leaching, methods of indium(III) ions separation from the leachate solutions (SX, HoLLE, IX) as well as recovery of final products (precipitation, cementation, electrowinning) were discussed.

Analytical Model of Ultrasonic Pulse Velocity of Waste LCD Glass Concrete

The purpose of this study is to establish a prediction model for the ultrasonic pulse velocity (UPV) of waste LCD glass concrete and then analyze the results obtained from a series of laboratory tests. The power function is used to perform the nonlinear-multivariate regression analysis of the UPV prediction model, with parameters such as water-binder ratio (w/b), curing age (t) and waste glass content (G). According to the relative regression analysis, the UPV prediction model is developed. The calculated results are in accord with the laboratory- measured data, which are the concrete UPV of various mix proportions. The regression analysis results show that a good agreement is obtained using the proposed prediction model. Therefore, the predicted results for UPV are highly accurate for waste LCD glass applied in concrete. Additionally, the proposed prediction model exhibits a good predictive capacity when it is adapted to calculate the UPV of high-performance recycled liquid crystal glass concrete (HPGC), as performed in a previous study. However, further study is needed as regards applying the proposed prediction model to other ranges of mixture parameters.

A Semantic Information Services Framework for Sustainable WEEE Management Toward Cloud-Based Remanufacturing

Sustainable management of waste electrical and electronic equipment (WEEE) has attracted escalating concerns of researchers and industries. Closer information linking among the participants in the products's lifecycle should take place. How to interoperate among the distributed and heterogeneous information systems of various participants is a challenge faced. Targeting the cloud-based remanufacturing, this article aims to develop a semantic information services framework for sustainable WEEE management. In the proposed framework, an ontology based approach is developed to integrate and represent the lifecycle information from multiple local data sources within an information services provider. Meanwhile, a semantic information services management platform is introduced for the advertisement, matchmaking and retrieval of semantic information services. Some relevant techniques used to build the framework are introduced extensively. A demonstration case study on waste LCD TV is used to illustrate the effectiveness and significance of the proposed framework.

Prediction of Compressive Strength Using Ultrasonic Pulse Velocity for CLSM with Waste LCD Glass Concrete

Prediction of Compressive Strength Using Ultrasonic Pulse Velocity for CLSM with Waste LCD Glass Concrete

Resource recovery from waste LCD panel by hydrothermal transformation of polarizer into organic acids

Based on the significant advantages of hydrothermal technology, it was applied to treat polarizer from the waste LCD panel with the aim of transforming it into organic acids (mainly acetic acid and lactic acid). Investigation was done to evaluate the effects of different factors on yields of organic acids, including the reaction temperature, reaction time and H2O2 supply, and the degradation process of polarizer was analyzed. Liquid samples were analyzed by GC/MS and HPLC, and solid-phase products were characterized by SEM and FTIR. Results showed that at the condition of temperature 300°C and reaction time 5min, the organic materials reached its highest conversion rate of 71.47% by adding 0.2mL H2O2 and acetic acid was dominant in the products of organic acids with the yield of 6.78%. When not adding H2O2 to the system, the yields of lactic and acetic acid were respectively 4.24% and 3.80% at a nearly equal degree, they are suitable for esterification to form ethyl lactate instead of separating them for this case. In the hydrothermal process, polarizer was first decomposed to monosaccharides, alkane, etc., and then furfural and acids are produced with further decomposition.

폐 평판디스플레이 패널유리의 재활용 연구 동향

Although Korea is a top market sharing and world leading producer and developer of flat panel display devices, relevant recycling technology is not up to her prestigious status. Besides, most of the waste glass arising from flat panel displays is currently land-filled. The present paper mainly reviews on development of recycling systems for waste TFT-LCD glass from end-of-life LCD TVs and monitors and TFT-LCD process waste of crushed glass particles with target end uses of raw material for high strength concrete pile and glass fibers, respectively. Waste LCD glass was recycled to fabricate ingredients for high strength concrete piles with enhanced physical properties and spherical foam products. The waste LCD glass recycling technology is already developed to fabricate long and short fibers at commercial level. In view of these, future R & D on waste LCD glass materials is to be directed toward implementation of commercial materials recycling system therefrom.

Predictive models of hardened mechanical properties of waste LCD glass concrete

Predictive models of hardened mechanical properties of waste LCD glass concrete

A predictive model for compressive strength of waste LCD glass concrete by nonlinear-multivariate regression

Abstract. The purpose of this paper is to develop a prediction model for the compressive strength of waste LCD glass applied in concrete by analyzing a series of laboratory test results, which were obtained in our previous study. The hyperbolic function was used to perform the nonlinear-multivariate regression analysis of the compressive strength prediction model with the following parameters: water-binder ratio w/b , curing age t, and waste glass content G. According to the relative regression analysis, the compressive strength prediction model is developed. The calculated results are in accord with the laboratory measured data, which are the concrete compressive strengths of different mix proportions. In addition, a coefficient of determination R 2 value between 0.93 and 0.96 and a mean absolute percentage error MAPE between 5.4% and 8.4% were obtained by regression analysis using the predicted compressive analysis value, and the test results are also excellent. Therefore, the predicted results for compressive strength are highly accurate for waste LCD glass applied in concrete. Additionally, this predicted model exhibits a good predictive capacity when employed to calculate the compressive strength of washed glass sand concrete.

Preparation of spherical foamed body with function of media for waste water treatment by using waste LCD glass

Using waste LCD glass as a base material helped developed the manufacturing process of the spherical foamed body and its varied functionality. Also, the manufactured spherical foamed body showed great performance as a water treatment media. By mixing 90wt% of waste LCD glass, 100 parts by weight of glass mixture that has 10wt% kaolinite as a shaping agent, 1.0 part by weight of carbon foaming agent, and mixture of each 1.5 parts by weight of Na2CO3, CaCO3 and Na2SO4 as foaming agents and the MgO as a parting agent for 10min of foaming calcination in the rotary kiln at 970–1000°C, the spherical foamed body can be manufactured effectively. The manufactured spherical foamed body performed as a great water treatment media by showing 70.5% of SS removal efficiency, 56.1% of BOD removal efficiency, 57.5% of COD removal efficiency, 28.6% of denitrification and 49.8% of phosphorous removal.

Investigating the properties of lightweight concrete containing high contents of recycled green building materials

In this study, the cement and aggregate used in lightweight aggregate concrete were replaced with recycled green building materials (e.g., waste LCD glass sand and waste tire rubber particles). The influence of the maximum replacement amount on the fresh mixture (slump, unit weight, setting time, bleeding), hardened (compressive strength and ultrasonic pulse velocity) and durability (quadruple type resistance and length change) was investigated to determine the influence of high contents of recycled aggregate and recycled pozzolanic admixtures on the properties of the concrete. The findings showed that the addition of recycled green building materials maintained good workability of the concrete as the replaced amount increased. The unit weight was reduced by approximately 1.4times (600kg/m3); the setting time and bleeding rate were increased by 1.5times (73min and 190min) and 1.4times (8%), respectively. The compressive strength, ultrasonic pulse velocity and length change were reduced by 9.8times (37.18MPa), 1.4times (1131m/s) and 3.7times (−0.115%), respectively. The resistance was increased by 1.8times (27.8kΩcm). A database will be constructed in the future for related studies to facilitate an increase in waste recycling value and to maximize the environmental protection benefits.

폐(廢) 디스플레이의 해체(解體) 및 성분조사(成分調査)

Although Korean domestic production of flat panel displays totalled more than 48 trillion KRW in 2007, most of the flat panel display wastes have been land-filled or incinerated, which greatly overshadows Korean national prestige as a world leading pro- ducer and developer of flat panel display devices. Countries such as Japan or EU possess quite limited land-fill capability and have sought ways to dispose of WEEEs from environment-friendly perspective rather than recovery of valuable materials from the wastes. Considering relatively short cycle of about 5 years for flat panel display devices, it is estimated that more than 5 mil- lion units will be accumulated as wastes by 2015. Urban mining is a most suitable countermeasures against China's monopoly of rare and rare earth metals, which are contained in flat panel display wastes. Therefore, materials recycling of waste LCD units has to be developed and commercialized soon enough for economic and environment-friendly recovery of valuable resources hidden in LCD wastes.

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

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/cm3, heat conductivity less than 0.054W/(mK) @20°C, bending strength more than 35N/cm2, compressive strength more than 39N/cm2 and a coefficient of linear thermal expansion less than 4.5×10−6m/m°C. This clearly shows that the lightweight alumino-borosilicate foamed glass could be useful for various applications.

A Study of Engineering Properties of Concrete Containing Recycled Materials in Hot Spring Environment

Taiwan is gifted with special geothermal resources, such as hot springs. In recent years, due to rapid development of the hot spring tourism and medical industry, massive constructions at the side slopes in hot spring areas are requiring the large amount of concrete material. Thus, the engineering properties of concrete material in the hot spring environment are an important research subject. Taiwan yields a large output of fly ash, slag and waste LCD glass annually. If these recycled materials can be added into concrete materials as mineral admixture, the construction quality will be improved, while contributing to waste reduction. Therefore, this study used the concrete without and with different recycled materials (e.g., slag, fly ash and glass waste powder) respectively to make specimens in fixed water-binder ratio W/B=0.44, and tested the compressive strength, splitting strength, ultrasonic pulse velocity and rate of volume change in general water curing and hot spring water curing conditions. The results showed that the strength deterioration and volume expansion of the concrete with recycled materials could be postponed in the hot spring water environment, and the glass waste powder had the best effect.

Mechanical Properties and Fracture Morphology of Blends of PC with PMMA

Abstract The poly methyl methacrylate (PMMA) and polycarbonate (PC) residues were collected from waste LCD panels for use as raw materials to prepare PC/PMMA polymer blends (1/99, 3/97, 5/95, 10/90), which were extruded in a twin screw extruder. The extrudates were subsequently pelletized and then dried in an oven before injection molding into tensile bars of ASTM D638-91, type I. The tensile bars were placed in an Instron-type tensile tester and the load-elongation curves of tested 5/95 specimens demonstrated distinctively varied yielding before final brittle fracture but 10/90 showed some sign of ductile behavior, peak in the load-elongation curve attributable to formation of a neck. The tensile strength increased from 569.6 to 633.3 kgf/cm2 with PC concentration in the range of 1 to 5 wt% while it decreased at 10 wt% PC. On the contrary, transverse rupture strength increased with added amount of PC. Addition of PC could have toughened recycled PMMA matrix under impact test conditions. Finally, the fractured surfaces were examined by scanning electron microscopy and numerous fine particles dispersed in the matrix of 10/90 are regarded as PC phase, in reasonable agreement with literature results. On the other hand, fracture surface of 5/95 showed nearly homogeneous matrix phase of PC/PMMA.

Properties of recycled green building materials applied in lightweight aggregate concrete

This study uses recycled green building materials based on a Taiwan-made recycled mineral admixture (including fly ash, slag, glass sand and rubber powder) as replacements for fine aggregates in concrete and tests the properties of the resulting mixtures. Fine aggregate contents of 5% and 10% were replaced by waste LCD glass sand and waste tire rubber powder, respectively. According to ACI concrete-mixture design, the above materials were mixed into lightweight aggregate concrete at a constant water-to-binder ratio (W/B = 0.4). Hardening (mechanical), non-destructive and durability tests were then performed at curing ages of 7, 28, 56 and 91 days and the engineering properties were studied. The results of these experiments showed that, although they vary with the type of recycling green building material added, the slumps of these admixtures meet design requirements. Lightweight aggregate yields better hardened properties than normal-weight concrete, indicating that green building materials can be successfully applied in lightweight aggregate concrete, enabling an increase in the use of green building materials, the improved utilization of waste resources, and environmental protection. In addition to representing an important part of a "sustainable cycle of development", green building materials represent a beneficial reutilization of waste resources.

Study on Method of Recycling Liquid Crystal from Waste LCD Based on Supercritical CO<sub>2</sub> Fluid Technology

For recycling liquid crystal from waste LCD with high value, the method based on supercritical CO2fluid technology is proposed. The principle of extracting liquid crystal using supercritical CO2fluid is analyzed and the factors influencing liquid crystal recycling effect are discussed. The solubility of supercritical fluid is enhanced by adding polar entrainer in order to raise the recycling rate. The procedure for recycling liquid crystal with supercritical fluid technology is studied. Choosing TFT mode LCD as researching object, selecting different temperature and pressure and adopting isothermal and depressurization method, a series of recycling experiments are completed. The results show that the recycling rate of liquid crystal can reach 90% with the aid of supercritical carbon dioxide fluid technology and the purity and recycling efficiency of liquid crystal are high.

A Study on Engineering Properties of Self-Compacting Concrete Containing Waste LCD Glass

This study investigates self-compacting glass concrete(SCGC), which was used at water-to-binder ratios (w/b) of 0.28, with four kinds of glass sand replaced at various volume replacement ratios (0%, 10%, 20%, and 30%). Fly ash, blast furnace slag and superplasticizer were also added to research the engineering properties of concrete. With increasing amounts of replacement up to 30%, results show that: (1) slump flow and V-funnel time are increased; (2) 340 mm is passed at 0min, and the filling level is elevated at 45 min; (3) the compressive strength of SCGC aged 28 days at various replacement ratios rises up to 60 MPa. The ultrasonic pulse velocity and electrical resistance are also enhanced with increasing age and replacement. After 56 days, the electric resistivity is higher than 20 KΩ-cm, and the shrinkage of SCGC falls within 0.2%. This study suggests than SCGC has superior engineering properties. A mechanism for LCD optical waste glass usage can be established to achieve industrial waste minimization, resource recycling, and economic security

고에너지 밀링으로 제조된 폐디스플레이 패널 분말의 밀링시간에 따른 인듐 용출특성

【In this research, the indium dissolution properties of the waste LCD panel powders were investigated as a function of milling time fabricated by high-energy ball milling (HEBM) process. The particle morphology of waste LCD panel powders changed from sharp and irregular shape of initial cullet to spherical shape with an increase in milling time. The particle size quickly decreased to 15 ${\mu}m$ until the first minute, then decreased gradually about 6 ${\mu}m$ with presence of agglomerated particles after 5 minutes, which increased gradually reaching a uniform size of 13 ${\mu}m$ consist of agglomerated particles after 30 minutes. The glass recovery, after dissolution, was over 99% at initial cullet, which decreased to 90.1 and 78.6% with increasing milling time of 1 and 30 minute respectively, due to a loss in remaining powder of the surface ball and jar, as well as the filter paper. The dissolution amount of indium out of the initial cullet was 208 ppm before milling, turning into 223 ppm for the mechanically milled powder after 1 minute, and nearly 146~125 ppm with further increase in milling time because of the reaction surface decrease of powders due to agglomeration. With this process, maximum dissolving indium amount (223 ppm) could be achieved at a particle size of 15 ${\mu}m$ with 1 minute of milling.】

Recovery of indium from indium tin oxide by solvent extraction

Recovery of indium from LCD screen wastes, which contain indium in the form of indium tin oxide (ITO) as the electrode material, is becoming economically and environmentally justified. Indium is a valuable metal and the present work was aimed to recover indium from ITO as the starting material to study the recovery of indium from waste LCD screens by solvent extraction. The apparent rate of dissolution in acidic media is slow requiring six hours for complete dissolution of the ITO sample in 1 M of either H 2SO 4 or HCl. Complete dissolution in HNO 3 took significantly longer. The acid concentration was found to have a major effect on both the amount and rate of leaching allowing some leaching selectivity. Three solvent systems were chosen to study their selectivity for the separation of indium from tin: TBP, D2EHPA and a mixture of both. With either 1 M of TBP or 0.2 M of D2EHPA + 0.8 M of TBP, tin could be selectively extracted from a 1.5 M HCl solution of this metal. D2EHPA extracts both indium and tin from H 2SO 4 media but indium could be selectively stripped with HCl from the loaded D2EHPA. Based on these results, a scheme for separating and concentrating indium from ITO by solvent extraction is proposed. The scheme includes dissolving ITO into 1 M of H 2SO 4, then extracting indium and tin to D2EHPA followed by selective stripping of indium into 1.5 M of HCl. With this process, HCl solution containing 12.2 g/L of indium could be achieved.