Waste Liquid Crystal Display Glass Research Articles

Preparation and humidity control performance of aluminum containing mesoporous molecular sieve synthesis from liquid crystal display waste glass and sandblasting waste

Preparation and humidity control performance of aluminum containing mesoporous molecular sieve synthesis from liquid crystal display waste glass and sandblasting waste

Parameter optimization, characterization, and crystallization mechanisms underlying the synthesis of zeolite A using liquid crystal display waste glass and sandblasting waste as alternative raw materials

This paper examines the synthesis of zeolite A via hydrothermal alkali fusion using liquid crystal display waste glass (LCDWG) and sandblasting waste (SB). The design of the experiments was determined using the Box-Behnken method in conjunction with response surface design. Three factors were shown to have a pronounced effect on synthesis outcomes: (i) Si/Al molar ratio, (ii) crystallization temperature, and (iii) crystallization period. Synthesis parameters were optimized in accordance with the crystallinity (%) of the zeolite. XRD results revealed that increasing the Si/Al ratio improved the crystallinity and phase purity of the synthesized zeolite A. Increasing the crystallization temperature altered the crystal type and enhanced crystal purity; however, excessive temperatures reduced crystallinity and led to decomposition of the zeolite A phase. SEM results revealed that the resulting zeolite A possessed a cubic structure. ANOVA revealed that the Si/Al molar ratio had the most profound effect on the synthesis of zeolite A, followed by crystallization duration and crystallization temperature. The fact that the R2 value (0.95) was similar to the adjusted R2 value (0.8736) confirmed the efficacy of the proposed polynomial model. A highly significant F-value of 11.75 confirmed that the proposed model could be used for design purposes. The excellent water adsorption/desorption performance of the proposed zeolite A (49.83 g/ m2; meeting JIS A 1470 standards) indicates its suitability as a low-cost construction material for a variety of applications. The ultimate objective of this study was to overcome difficulties encountered in the disposal of industrial waste by converting LCDWG and SB into zeolite A.

Synthesis of aluminum-mesoporous MCM-41 humidity control material from thin-film transistor liquid crystal display waste glass and sandblasting waste and its application

The preparation of an aluminum-mesoporous A1-MCM-41 humidity control material (Al-MHCM) by hydrothermally synthesizing a mixture of thin-film transistor liquid crystal display (TFT-LCD) waste glass and sandblasting (SB) waste was studied. The product has a typical mesoporous structure, with a specific surface area of up to 1013m2/g, the pore size distribution calculated is 3–4nm, and the pore volume of 0.97cm3/g. All the aluminum atoms of the product are in the form of tetrahedral aluminum in the framework, which confirms the successful synthesis of Al-MHCM. Results show that when the hydrothermal synthesis temperature is 105°C, the product synthesized from a mixture with a Si/Al molar ratio of 41.8 exhibits excellent performance (91.45m3/m3) in terms of the equilibrium moisture content and moisture adsorption capacity. The results confirm that the equilibrium moisture content of Al-MHCM is better than the rape straw concrete and hemp concrete (9.8–17.8m3/m3), and that of a diatomite/ground calcium carbonate composite aterial (11.7m3/m3). The research results are expected to provide a new technology for synthesizing TFT-LCD waste glass and SB waste into novel high value-added humidity control materials.

Molecular sieve material from liquid–crystal-display waste glass and silicon carbide sludge via hydrothermal process with alkali fusion pretreatment

The goal of this paper was to synthesize eco-humidity-conditioned Al-MCM-41 mesoporous molecular sieves (CHCMs) from liquid–crystal-display waste glass (LCDWG) and silicon carbide sludge (SiCS) via an alkali fusion process. LCDWG and SiCS are primarily composed of SiO2 and Al2O3. The characterization of CHCM materials under different synthesis conditions and their humidity regulation effects were compared. The results showed that the CHCM materials exhibit type-IV isotherms and clearly defined capillary phenomena and were composed of hexagonal Al-MCM-41, which is a mesoporous material. When the optimal reaction temperature was 120 °C, and the liquid/solid ratio (L/S) was 15, the highest equilibrium moisture content of the synthesized CHCM sample was 66.84 m3/m3. In addition, the large surface area (1120 m2/g), pore size (5.2 nm), pore volume (0.93 cm3/g) and wall thickness (1.44 nm) of the samples improved the moisture absorption capacity of the equilibrium moisture content. The equilibrium moisture content of the CHCM samples was higher than those of rape straw concrete and hemp concrete (9.8–17.8 m3/m3) and that of a diatomite/ground calcium carbonate composite material (11.7 m3/m3). This study focused on the unique properties of synthesized CHCM samples and the utilization of LCDWG and SiCS to produce samples and thereby solve the disposal problem associated with LCDWG and SiCS. Therefore, CHCMs can be used in several applications, particularly as CHCM materials in construction.

Synthesis and characterization of a mesoporous Al-MCM-41 Molecular Sieve Material and its Moisture Regulation Performance in Water Molecule Adsorption/Desorption

In this study, liquid crystal display waste glass (LCD wg ) and chemical mechanical polishing sludge (CMP s ) were investigated as alternative sources of SiO 2 and Al 2 O 3 for the preparation of the mesoporous moisture regulation material Al-MCM-41 (MRMCM). The aluminosilicate supernatant from the alkali fusion of LCD wg and CMP s and the surfactant cationic cetyltrimethylammonium bromide (CTAB) were used as structure-directing agents. Synthesis was carried out by alkali fusion and hydrothermal methods, and the factor affecting the synthesis was the alkali fusion liquid-solid ratio. Reliable instruments and methods, including XRD, TEM, XRF, BET and BJH, were employed for characterization of the fabricated MRMCM. The results show that the pore size of these materials was between 3.0 and 4.5 nm, and with an increase in the liquid-solid ratio, the specific surface area of MRMCM increased to a maximum value of 1260 m 2 /g and exhibited a mesoporous structure. In addition, the hydrothermal temperature and the specific surface area also had a significant positive correlation as the temperature increased such that the surface area increased from 370 m 2 /g to 601 m 2 /g, which is a significant increase of 1.62 times. MRMCM exhibited a positive linear correlation between pore volume and specific surface area during 48 h of moisture absorption and desorption, and the amount of moisture absorbed by mesoporous MRMCM was determined. Thus, the mesoporous molecular sieves met Japan Industrial Standard JIS A 1470–1 2002, which regulates moisture regulation building materials (response to humidity variation > 29 g/m 2 ). Therefore, the materials can be utilized in multiple applications, particularly as moisture regulation materials in building engineering. • A new type of Al-MCM-41 mesoporous humidity control material is reported. • The influence of the liquid-solid ratio and hydrothermal temperature are discussed. • High adsorption/desorption capacity of water molecule were observed. • The mesoporous molecular sieves met Japan Industrial Standard JIS A 1470.

Study on preparation and performance of biocarriers using waste liquid crystal display glass after extracting indium

A large amount of waste liquid crystal display (LCD) glass becomes a secondary waste after extracting the scarce metal indium from waste LCD by acid leaching. The feasibility of preparing biocarriers from waste LCD glass as raw materials was studied. The effects of different types and contents of foaming agents, foaming temperature and time on the biocarriers were studied. Under the condition of foaming temperature of 1050 ℃ and foaming time of 20 min, a suitable biocarrier was prepared by adding 5 % CaCO3 as a foaming agent into the waste LCD glass (denoted as Biocarrier-CaCO3). The technical indicators, which including void fraction, specific surface area, compressive strength and others of the Biocarrier-CaCO3, met the standard of CJ/T 299-2008 for water treatment. When Biocarrier-CaCO3 was applied for Shewanella cultivating, the biomass of the biofilm reached as high as 38 mg/g. In contrast, Na2CO3 was not suitable for the preparation of biocarriers for its porcelainization; SiC also failed as a foaming agent because the strength of the biocarrier could not reach the technical requirements of the product. In all, this study provided a novel strategy to recycle waste LCD glass as biocarrier to support the development of microbes and biofilm.

Synthesis of Zeolite Using Aluminum Dross and Waste LCD Glass Powder: A Waste to Waste Integration Valorization Process

In the current investigation, we synthesize zeolite using two different waste streams, such as aluminum dross and waste glass powder, for its potential application in indium and tin recovery from the leach liquor of waste liquid crystal display (LCD) glass. The aluminum dross (Al resource) and waste glass powder (Si resource) were used as raw materials for the synthesis of zeolite. Zeolite was synthesized using different weight ratios of Al dross and waste LCD glass by hydrothermal synthesis route using NaOH. The weight ratio variations of Al dross and waste LCD glass in this study are 0.3:1, 0.5:1, 1:1, 2:1, 3:1, and 4:1 using 2 M NaOH hydroxide by the hydrothermal technique. The synthesized zeolite was analyzed by X-ray diffraction spectroscopy (XRD), scanning electron microscopy (SEM), and Brunauer–Emmett–Teller (BET) followed by the possible application for recovery/extraction of indium and tin from leach liquor of waste LCD glasses. The indium extraction of average 93.66%, and tin extraction of 93.10% could be achieved from mixed solution indium and tin chloride. The significant achievement of the current investigation is that it can address two environment problems simultaneously, i.e., waste LCD glass and Al dross, and can be used for value recovery from waste LCD, LCD etching waste like secondary resources.

Assessment of compressive strength of cement mortar with glass powder from the early strength

The sustainable development principle of replacing natural resources with renewable material is an important research topic. In this study, waste LCD (liquid crystal display) glass powder was used to replace cement (0%, 10%, 20% and 30%) through a volumetric method using three water-binder ratios (0.47, 0.59, and 0.71) to make cement mortar. The compressive strength was tested at the ages of 7, 28, 56 and 91 days. The test results show that the compressive strength increases with age but decreases as the water-binder ratio increases. The compressive strength slightly decreases with an increase in the replacement of LCD glass powder at a curing age of 7 days. However, at a curing age of 91 days, the compressive strength is slightly greater than that for the control group (glass powder is 0%). When the water-binder ratios are 0.47, 0.59 and 0.71, the compressive strength of the various replacements increases by 1.38-1.61 times, 1.56-1.80 times and 1.45-2.20 times, respectively, during the aging process from day 7 to day 91. Furthermore, a prediction model of the compressive strength of a cement mortar with waste LCD glass powder was deduced in this study. According to the comparison between the prediction analysis values and test results, the MAPE (mean absolute percentage error) values of the compressive strength are between 2.79% and 5.29%, and less than 10%. Thus, the analytical model established in this study has a good forecasting accuracy. Therefore, the proposed model can be used as a reliable tool for assessing the design strength of cement mortar from early age test results.

Value Recovery from Waste Liquid Crystal Display Glass Cullet through Leaching: Understanding the Correlation between Indium Leaching Behavior and Cullet Piece Size

For hydrometallurgical recovery of indium from glass cullet after dismantling a waste liquid crystal display (LCD), leaching is the rudimentary stage. Though size reduction of the cullet pieces adds convenience for recycling, from an efficiency and cost-effectiveness perspective regarding leaching process development, determining the proper cullet piece size is essential. Hence, in this study, leaching efficiency of indium as a function of cullet piece size was investigated, wherein the proper mechanical classification of crushed glass cullet could be addressed. The optimum conditions of 5 M mineral acid as the lixiviant, pulp density of 500 g/L, temperature of 75 °C, agitation speed of 500 rpm, 2 h process time were kept constant for the leaching studies. It was concluded that the size of the waste LCD cullet inversely affected the leaching efficiency of indium. For efficient leaching, a smaller cullet size is recommended; hence, waste LCD should be crushed to pieces 1 mm or smaller. Indium leaching behavior comparison using HCl, HNO3, H2SO4 revealed that all three mineral acids had similar leaching efficiencies. The reported process provides the missing link between physical dismantling and chemical processing for indium recovery via techno-economical-sustainable process development.

Effect of alkali activation thin film transistor-liquid crystal display waste glass on the mechanical behavior of geopolymers

This study investigated the effect of thin film transistor liquid crystal display waste glass (TLWG) (0–40 wt%) and SiO2/Na2O (S/N) ratio on the properties of metakaolin-based geopolymers (MKGP). The MKGP with 0% TLWG and an S/N ratio of 2.0 is shown for 60-days of curing had the highest flexural strength (10.4 MPa); increasing the S/N ratio was discovered to increase the low resonance frequency of the geopolymers. When the MKGP with TLWG replacement was measured using nuclear magnetic resonance spectroscopy, the peak frequency is −82.0 to −86.3 ppm. When the TLWG replacement level was increased from 10% to 40%, after a curing time of 28 days, the weight loss of MKGP from 230 to 400 °C increased from 16.11% to 25.64%. As the S/N ratio was increased from 1.6 to 2.0, after a curing time of 60 days, the weight loss of MKGP between 230 and 400 °C was observed to increase from 14.61% to 14.94%. However, the weight loss from 600 °C to 750 °C decreased from 2.17% to 0.31%. MKGP with 0–10% TLWG and an S/N ratio of 2.0 has the potential to partially replace metakaolin as a geopolymer material contained more structural denser beneficial to structure development.

A neural-based predictive model of the compressive strength of waste LCD glass concrete

The Taiwanese liquid crystal display (LCD) industry has traditionally produced a huge amount of waste glass that is placed in landfills. Waste glass recycling can reduce the material costs of concrete and promote sustainable environmental protection activities. Concrete is always utilized as structural material; thus, the concrete compressive strength with a variety of mixtures must be studied using predictive models to achieve more precise results. To create an efficient waste LCD glass concrete (WLGC) design proportion, the related studies utilized a multivariable regression analysis to develop a compressive strength waste LCD glass concrete equation. The mix design proportion for waste LCD glass and the compressive strength relationship is complex and nonlinear. This results in a prediction weakness for the multivariable regression model during the initial growing phase of the compressive strength of waste LCD glass concrete. Thus, the R ratio for the predictive multivariable regression model is 0.96. Neural networks (NN) have a superior ability to handle nonlinear relationships between multiple variables by incorporating supervised learning. This study developed a multivariable prediction model for the determination of waste LCD glass concrete compressive strength by analyzing a series of laboratory test results and utilizing a neural network algorithm that was obtained in a related prior study. The current study also trained the prediction model for the compressive strength of waste LCD glass by calculating the effects of several types of factor combinations, such as the different number of input variables and the relevant filter for input variables. These types of factor combinations have been adjusted to enhance the predictive ability based on the training mechanism of the NN and the characteristics of waste LCD glass concrete. The selection priority of the input variable strategy is that evaluating relevance is better than adding dimensions for the NN prediction of the compressive strength of WLGC. The prediction ability of the model is examined using test results from the same data pool. The R ratio was determined to be approximately 0.996. Using the appropriate input variables from neural networks, the model validation results indicated that the model prediction attains greater accuracy than the multivariable regression model during the initial growing phase of compressive strength. Therefore, the neural-based predictive model for compressive strength promotes the application of waste LCD glass concrete.

Prediction model of resistivity and compressive strength of waste LCD glass concrete

The purpose of this study is to establish a prediction model for the electrical resistivity (<TEX>$E_r$</TEX>) of self-consolidating concrete by using waste LCD (liquid crystal display) glass as part of the fine aggregate and then, to analyze the results obtained from a series of laboratory tests. A hyperbolic function is used to perform nonlinear multivariate regression analysis of the electrical resistivity prediction model, with parameters such as water-binder ratio (w/b), curing age (t) and waste glass content (G). Furthermore, the relationship of compressive strength and electrical resistivity of waste LCD glass concrete is also found by a logarithm function, while compressive strength is evaluated by the electrical resistivity of non-destructive testing (NDT). According to relative regression analysis, the electrical resistivity and compressive strength prediction models are developed, and the results show that a good agreement is obtained using the proposed prediction models. From the comparison between the predicted analysis values and test results, the MAPE value of electrical resistivity is 17.0-18.2% and less than 20%, the MAPE value of compressive strength evaluated by <TEX>$E_r$</TEX> is 5.9-10.6% and nearly less than 10%. Therefore, the prediction models established in this study have good predictive ability for electrical resistivity and compressive strength of waste LCD glass concrete. However, further study is needed in regard to applying the proposed prediction models to other ranges of mixture parameters.

Assessment of the compressive strength of recycled waste LCD glass concrete using the ultrasonic pulse velocity

This study uses a fixed weight ratio of 7:2:1 of cement, fly ash and slag powder as binder material and uses waste liquid crystal display (LCD) glass sand through a No. 4 sieve to replace 0%, 10%, 20% and 30% of the fine aggregate using the volumetric method, combined with water-binder ratios (w/b) of 0.28, 0.32 and 0.36 for a series of tests to determine the compressive strength and ultrasonic pulse velocity (UPV) of self-consolidating glass concrete (SCGC). The test results show that the compressive strength and UPV increase with age but decrease as the water-binder ratio increases. The compressive strength and UPV present a nonlinearly increasing relation curve, the water-binder ratio influences the curve insignificantly, and there is a right shift as the waste glass replacement increases. Therefore, the UPV of SCGC increases with the waste glass replacement G value, but the compressive strength decreases as the G value increases. In addition, this study uses the exponential function as a basis, combined with the compressive strength and UPV characteristics of waste LCD glass concrete; by considering the w/b, waste glass replacement G and UPV variables, the compressive strength prediction model is deduced. The analysis results show that the mean absolute percentage error (MAPE) value for the compressive strength test result and the assay value of SCGC is 6.45–7.97%; compared with the MAPE value, which is 8.61–12.51%, as obtained by linear function regression, the analysis result accuracy is increased by 25.1–36.3%. In the same way, the MAPE value of the WGCLSM (waste glass controlled low strength material) is 8.15–11.24%; compared with the MAPE value, which is 21.33–26.19%, as obtained by linear function regression, the accuracy is increased by 51.2–62.2%. Furthermore, the MAPE value obtained by a compressive strength prediction analysis of HPGC (high-performance recycled liquid crystal glass concrete) is 7.18–8.65%. Therefore, this study builds an analytical model that uses UPV to evaluate the compressive strength; its forecast accuracy is good, and it is applicable to waste LCD glass concrete for different functional requirements. It is very helpful for the safety assessment analysis of concrete structures with similar mix proportions and nondestructive testing UPV.

폐 LCD 유리를 이용한 흡음특성을 갖는 붕규산유리발포체 제조

폐 LCD 유리를 이용한 흡음특성을 갖는 붕규산유리발포체 제조

Study on the engineering properties and prediction models of an alkali-activated mortar material containing recycled waste glass

In recent years, the global temperature has risen as greenhouse gases increase. With Taiwan’s limited natural resources and the rise of environmental considerations, energy saving, carbon reduction and waste recycling are universal subjects at the present time. This study combined waste LCD (liquid crystal display) glass with alkali-activated slag mortar as a thermal insulating material and evaluated its engineering properties. Different liquid-solid ratios (L/S=0.45, 0.50, 0.55 and 0.60) were used. The alkali equivalent was fixed at 1%, and the slag was replaced by glass sand (0%, 20% and 40%). Various engineering properties were tested at the ages of 3, 7 and 28days. The results show that with more glass sand replacement and higher liquid-solid ratio values, the workability is better, and the slump and slump flow are higher. The compressive strength decreases as the liquid-solid ratio increases, and the compressive strength increases when the glass sand replacement is 0–20%. However, in contrast, when the replacement is 20–40%, the compressive strength decreases. The ultrasonic pulse velocity decreases as the glass sand replacement increases. The thermal conductivity increases with age, but the thermal conductivity decreases as the liquid-solid ratio initially increases, and the thermal conductivity is at its minimum when L/S=0.55. When the L/S increases continuously, the thermal conductivity increases accordingly. The resistance to sulfate attack increases with the replacement and the liquid-solid ratio. The effect is the best when L/S=0.60 and the glass sand replacement is 20%, meaning that a certain amount of waste LCD glass in the alkali-activated slag mortar can enhance the engineering properties. In addition, the prediction models for the compressive strength, ultrasonic pulse velocity and thermal conductivity of alkali-activated slag mortar material with waste LCD glass were deduced in this study. According to the comparison between the prediction analysis values and the test results, the compressive strength mean absolute percent error (MAPE) values are 4.37–5.52%, the ultrasonic pulse velocity (UPV) MAPE values are 0.01–1.53%, and the thermal conductivity (kt) MAPE values are 0.82–2.68%. All the MAPE values are smaller than 10%, so the analytical models built have good forecasting accuracy.

A study of engineering and electricity properties of cement mortar added with recycled materials and piezoelectric powders

Due to increasing global energy saving, carbon reduction, environmental considerations, and the environmental change resulting from the greenhouse effect, and because Taiwan is located on the plate junction, where earthquakes frequently occur, and because there is an abundance of rainfall during typhoon season, which often cause natural disasters, it is necessary to enhance the disaster prevention of buildings. This study uses recycled materials (fly ash, ground granulated blast furnace slag (GGBFS), and waste Liquid Crystal Display (LCD) glass powder) and Pd-Zr-Ti piezoelectric (PZT) to enhance intelligent functions of original substrates. The volumetric method is used for the design. The control group uses recycled materials to replace cement [0%, 10%, 20%, and 30%]. The PZT group uses a PZT powder to replace 5% of fine aggregates to make cement mortar to test the correlation between engineering and electricity properties of flow, compressive strength, water absorption, ultrasonic pulse velocity (UPV) and resistivity (electricity at 50V and 100V). The mechanical and electrical effects of cement mortar of various groups are discussed to determine the correlation between impedance characteristics and mechanical behavior of cement mortar in different electrical field environments and aqueous states, to build an engineering-electricity relation database for recycled materials and PZT, and to determine the relationships between various variables. A pozzolanic reaction occurs in GGBFS after 7days. A 30% GGBFS replacement (32.9MPa) has the maximum compressive strength. A 20% waste LCD glass powder replacement (31.8MPa) can fill up finer pores and accelerate hydration. The addition of GGBFS and waste LCD glass powder reduces water absorption and internal porosity. Water absorption increases when fly ash is replaced. The resistivity at 50V is higher than resistivity at 100V in an electrical field environment. Specifically, in a high voltage environment, the resistivity generated during the delivery process is reduced. Because the voltage increase improves conductivity inside the specimen, the resistivity is reduced. The resistivity increases in correlation with compressive strength in the SSD state of fly ash and GGBFS. The resistivity decreases when the compressive strength increases in the OD state. The resistivity increases when the waste LCD glass powder is replaced in SSD and OD states.

A study of the durability of recycled green building materials in lightweight aggregate concrete

In this study, waste tire powder and waste liquid crystal display (LCD) glass sand are used as recycled materials. With a fixed water to binder ratio (W/B=0.4), the use of fly ash and slag as cement-replacement materials. waste tire powder and waste LCD glass sand, which passed the sieve screen size # 30(0.595mm), were used to replace fine aggregates at 0%, 5% and 10% in producing lightweight aggregate concrete. The fresh property test was processed in accordance with ACI concrete mix proportion design. Harden and durability tests were performed at 7, 28, 56 and 91days. The results showed that the slump increased or decreased with the addition of different types of recycled materials, but still met the design slump of 150–180mm. Concrete workability and the unit weight decreased after adding rubber powder to concrete. As the replacement rates of waste glass sand and waste rubber powder increase, the compressive strength tends to decrease. At 56days, the ultrasonic wave velocity of normal concrete was higher than lightweight aggregate concrete; the lightweight aggregate concrete with 10% glass sand provided the highest ultrasonic wave velocity of the lightweight aggregate concretes. Sulfate resistance tests showed that the normal weight aggregate concrete was better than the lightweight aggregate. Mixing two kinds of recycled materials also resulted in better resistance. Studies showed that adding an appropriate amount of recycled materials might improve the durability of lightweight aggregate concrete.

An efficient rough vacuum-chlorinated separation method for the recovery of indium from waste liquid crystal display panels

In this study, an efficient rough vacuum-chlorinated separation method was developed for the recovery of indium from waste liquid crystal display (LCD) panels using NH4Cl as the chlorinating agent. High purity In2O3 and SnO2 were firstly investigated in a rough vacuum, air and nitrogen atmosphere. The results indicated that the rough vacuum atmosphere could increase the recovery ratio of indium and reduce the influence of tin simultaneously. Moreover, the indium chloride and NH4Cl can be selectively recovered under different condensing temperatures, and the thermodynamic principle of the recovery method was analyzed. Conditions of 400 °C, 10 min, rough vacuum atmosphere (0.09 MPa) and sufficient NH4Cl (molar Cl/In ratio of 6) were confirmed as the optimal conditions by pure substance experiments. The waste LCD glass powder was used to recover indium. The weight ratio of NH4Cl to glass powder and the optimum particle size were confirmed as 1 : 2 and less than 0.13 mm, respectively. The pure indium chloride was successfully recovered from the waste LCD panels using this method, and the recovery percentage of indium and the purity of indium chloride are 98.02 and 99.50%, respectively. This work presented a promising technology for the cyclic regeneration of the precious metal indium from waste LCD panels.

The utilization of thin film transistor liquid crystal display waste glass as a pozzolanic material

This investigation elucidates the pozzolanic behavior of waste glass blended cement (WGBC) paste used in thin film transistor liquid crystal displays (TFT-LCD). X-ray diffraction (XRD) results demonstrate that the TFT-LCD waste glass was entirely non-crystalline. The leaching concentrations of the clay and TFT-LCD waste glass all met the current regulatory thresholds of the Taiwan EPA. The pozzolanic strength activity indices of TFT-LCD waste glass at 28 days and 56 days were 89% and 92%, respectively. Accordingly, this material can be regarded as a good pozzolanic material. The amount of TFT-LCD waste glass that is mixed into WGBC pastes affects the strength of the pastes. The strength of the paste clearly declined as the amount of TFT-LCD waste glass increased. XRD patterns indicated that the major difference was the presence of hydrates of calcium silicate (CSH, 2 θ = 32.1°), aluminate and aluminosilicate, which was present in WGBC pastes. Portland cement may have increased the alkalinity of the solution and induced the decomposition of the glass phase network. WGBC pastes that contained 40% TFT-LCD waste glass have markedly lower gel/space ratios and exhibit less degree of hydration than ordinary Portland cement (OPC) pastes. The most satisfactory characteristics of the strength were observed when the mixing ratio of the TFT-LCD waste glass was 10%.

Evolution in France

This study investigated the effect of thin film transistor liquid crystal display waste glass (TLWG) (0–40 wt%) and SiO2/Na2O (S/N) ratio on the properties of metakaolin-based geopolymers (MKGP). The MKGP with 0% TLWG and an S/N ratio of 2.0 is shown for 60-days of curing had the highest flexural strength (10.4 MPa); increasing the S/N ratio was discovered to increase the low resonance frequency of the geopolymers. When the MKGP with TLWG replacement was measured using nuclear magnetic resonance spectroscopy, the peak frequency is −82.0 to −86.3 ppm. When the TLWG replacement level was increased from 10% to 40%, after a curing time of 28 days, the weight loss of MKGP from 230 to 400 °C increased from 16.11% to 25.64%. As the S/N ratio was increased from 1.6 to 2.0, after a curing time of 60 days, the weight loss of MKGP between 230 and 400 °C was observed to increase from 14.61% to 14.94%. However, the weight loss from 600 °C to 750 °C decreased from 2.17% to 0.31%. MKGP with 0–10% TLWG and an S/N ratio of 2.0 has the potential to partially replace metakaolin as a geopolymer material contained more structural denser beneficial to structure development.