Cathode Ray Tube Research Articles

Production of lightweight geopolymer concrete with foam glass aggregate derived from cathode-ray glass waste

This work focused on producing an eco-friendly lightweight structure by recycling the cathode ray tube glass waste (CRT-GW)to prepare a foam glass aggregate (FGA) and using metakaolin to prepare a geopolymer binder (GP). The geopolymer binder replaces cement to decrease the release of gas generated during cement production. The silicon carbide (SiC) was used as a foaming agent at 1 wt% to prepare the FGA. The foaming temperature effect was investigated for the FGA characterization included: bulk density, volume expansion, apparent porosity, uniaxial compressive strength, and leaching tests for lead and barium. The foam glass aggregate was sintered at different temperatures 725 °C, 750 °C, 775 °C, and 800 °C. These temperatures were selected depending on heating microscopy analysis results, where the maximum expansion height was 119 % at 800 °C. The main characterization ranges of foam glass were: bulk density 0.58–1.26 g/cm3, volume expansion 8–77 (vol%), uniaxial compressive strengths 1.55–9.98 MPa, and thermal conductivity 0.063–0.097 W/m.K.The lightweight geopolymer (LWGP) was prepared with 30 vol% of FGA sintered at different temperatures and 70 vol% of GP. These samples hardened at room temperature. The bulk density and compressive strength were measured for the lightweight geopolymer samples after a curing time of 28 days. A higher compressive strength was 9.11 MPa with a bulk density of 1.21 g/cm3 for lightweight geopolymer-containing foam glass aggregate sintered at 775 °C.

Archaeologies and Organologies: Towards an alternative history of early synthetic video and image processing practices 1939–1969

Abstract This article focuses on the early history of two related techniques deployed within artistic contexts; the distortion of pre-existing television raster images and the generation of synthetic images through the application of external signals to cathode-ray tube deflection systems. Organology and media archaeological techniques are used to begin to trace an additional technical history of these complex visual instruments.

Effect of Interface Property on the Agglomeration Characteristic of Inclusions in High Al Steel with Different Al Contents

Herein, a 3D stability diagram is established in the AlON system. Based on that, four sets of experiments with different Al contents are designed to prepare different inclusions. Subsequently, the agglomeration behavior of inclusion is observed in situ by using confocal laser scanning microscopy (CLSM) combined with an infrared image furnace. The sample with inclusions is heated to melt and the agglomeration behavior of inclusion is recorded by the CRT monitor of CLSM. The calculated agglomeration force of inclusion shows that when the Al content increases from 0.5 to 3 pct, the agglomeration force of Al2O3 inclusions decreases from 7.2 × 10−16 ≈ 6.0 × 10−14 N to 1.2 × 10−16 ≈ 3.2 × 10−15 N. As the Al content increases from 6.5 to 10 pct, the agglomeration force of AlN inclusions increases from 2.2 × 10−17 ≈ 1.1 × 10−15 N to 1.7 × 10−16 ≈ 7.9 × 10−15 N. The theoretical calculation also shows that the agglomeration force of Al2O3 inclusions decreases and that of AlN inclusions increases with the increasing Al content. When the Al content is >4.7 pct, the agglomeration force of AlN inclusions is larger than that of Al2O3 inclusions.

X- and gamma rays cross sections and nuclear shielding performance of recycled cathode ray tube doping with high concentrations of Na2CO3

In an attempt to mitigate the increasing number of waste Cathod Ray Tube (CRT) glass in the environment, provide a safe, cheaper, and environmentally attractive recycling route for the glasses, and provide an alternative material for gamma radiation absorption applications, this study investigated the influence of adding Na2CO3 on the density, and gamma photon-absorbing prowess of CRT glass. Using the powder metallurgy process, CRT-NCx glasses consisting of CRT glass powder mixed with two distinct weight concentrations (20% (CRT-NC20 and 40% (CRT-NC40)) of Na2CO3 powder were prepared. The mass attenuation coefficients (μρ) of the prepared glasses were obtained using FLUKA simulations for 15 keV–15 MeV photons. The density of CRT, CRT-NC20, and CRT-NC40 were 3.117 g/cm3, 2.987 g/cm3, and 2.894 g/cm3, respectively. The range of μρ for CRT, CRT-NC20, and CRT-NC40 corresponded to 0.0326–45.5236 cm2/g, 0.030–35.0662 cm2/g, and 0.0278–26.9813 cm2/g, respectively. The half-value layer and mean free path was found to vary within the range 0.005–6.822 cm and 0.007–9.842 cm for CRT; 0.007–7.748 cm and 0.010–11.178 cm for CRT-NC20; and 0.009–8.633 cm and 0.013–12.455 cm for CRT-NC40. The minimum and maximum values of μenρ were 0.0216 and 37.7566 cm2/g for CRT, 0.0202 and 29.1167 cm2/g for CRT-NC20, and 0.01921 and 22.4430 cm2/g for CRT-NC40. CRT-rich glass showed higher radiation absorbed doses for the same beam energy and glass thickness. Na2CO3-rich glasses had lower buildup factors BFs, hence preferable in broad beam transmission scenarios. The investigated CRT-NCx glasses are more attractive for radiation protection functions in contrast to some well-known radiation shielding materials considering their lower mean free paths. The present glass system provides and alternative and effective gamma radiation shield, and also proffers a way of upcycling waste CRT glasses.

Effect of microstructure on the physicochemical characteristics of foam glass made by soda lime -CRT glasses and aluminium dross

Foam glass, an inorganic insulation material, is primarily manufactured from recycled glass or sand combined with a foaming agent. During fabrication, gas bubbles are generated in the softened glass, causing it to expand and form a cellular structure. Critical parameters such as cell size, type (closed or open cells), distribution, and uniformity significantly influence the physical and chemical properties of foam glass, ensuring sustained thermal efficiency. This research aims to produce foam glass exclusively from waste materials, thereby promoting the circular economy by utilizing container glass, cathode ray tube (CRT) glass, and aluminium dross. A comprehensive microstructural analysis, employing computer tomography and scanning electron microscopy, elucidated key properties including density, thermal conductivity, and water absorption. The manufactured foam glass exhibited lightweight characteristics, with a density ranging from 0.15 to 0.18 g/cm³. Additionally, the foam glass demonstrated low thermal conductivity (between 0.038 W/m·K and 0.05 W/m·K), which can be attributed to the heterogeneous distribution of cells that effectively reduce heat convection. This property makes foam glass an excellent thermal insulator. Furthermore, both high-absorption (open porosity) and low-absorption (closed porosity) foam glasses were successfully produced.

Derivation of Glaze from Cathode Ray Tubes (CRTs) for Ceramic Wares

Introduction of digital display makes cathode ray tube to be largely obsolete. The tube with its screen becomes waste at the end of the products lifecycle. This study, which combined laboratory experimentation and studio practices, aimed at production of glass glaze with cathode ray tube screen. Cathode ray tubes of four different colours were used for the study. The tubes were washed, pulverized and sieved according to their colour, elementally analysed using Particle Induce X-ray Emission, and milled into two batches per colour with first batch mixed with ball clay and second batch mixed with ball clay and additive chemical material of borax. The glaze batches were applied on eight bisque-fired tiles and fired at 1100 0C. The glazes yielded greenish grey, greyish purple, transparent grey and dark grey. This is significance towards the diversification of Nigeria’s economy for solving solid waste disposal challenges for a better and safe environment. The study has proven that cathode ray tubes with addition of borax and ball clay are suitable for glaze production and provided elemental information to guide the glaze formulation.

USE OF CATHODE RAY TUBE (CRT) COMPOSITE WASTE GLASS FOR NUCLEAR SHIELD TILES

This research is aimed at producing radiation shield tiles from cathode ray tube waste glass, borosilicate waste glassand soda lime silicate waste glass. The waste glasses were sourced for and crushed to powder. The powder wassieved through a 0.25 mm sieved with mesh number 60 and analysed using XRF spectrometer to ascertain theirchemical constituents. Twenty-one samples were generated using a 21-point triaxial blend of the three wasteglasses. The various samples were poured into moulds, fired in an electric furnace at 1000oC and soaked for anhour. Radiation shielding test using a radioactive source (cobalt 60) was carried out. The radiation shielding testsshows that sample 1 which comprises of 100% CRT had the highest radiation shielding ability with 0.178 cm-1linear attenuation coefficient and sample 21 which is made up of 100% soda lime silicate glass had the leastradiation shielding ability with 0.109 cm-1 linear attenuation coefficient.According to the 49th NCRP report,conventional tiles HVL for 60-Co gamma is 6.2 cm; whereas HVL for the RST in this work ranges between 3.8-6.3cm which shows that the RST is within the range of offering a good radiation protection. The results obtained in thisstudy showed that the radiation shielding tiles developed can be used as wall tiles in nuclear power facilities andmedical X-ray systems.

Recycled cathode ray tube waste glasses for radiation shielding applications: Role of Na2CO3

The aim of the study is to evaluate the ability of cathode-ray tube funnel waste glasses (CRT-F) to shield photons (gamma and X-ray) and other forms of radiation with rest masses (i.e., neutrons and charged particles) after their Pb content was reclaimed. The lead (Pb) content of cathode-ray tube funnel waste glasses (CRT-F) was reduced using Na2CO3 as the reducing agent CRT-F(Na2CO3). CRT-F and CRT-F(Na2CO3) were produced using the melt and quench processes using the powder of pristine funnel glass from discarded cathode ray tube glass and the reduced glass powder, respectively, as the starting materials. The X-ray fluorescence technique was adopted for determining the chemical composition of CRT-F and CRT-F(Na2CO3) glasses. The parameters relating to the gamma photon, fissile neutron, moderated neutron, slow neutron, and charged radiation (β, H+, He2+, and C6+) attenuation abilities of pristine CRT-F and CRT-F(Na2CO3) were evaluated. The FLUKA simulation code and XCOM were used to estimate the mass attenuation coefficient of the glasses. The stopping power (Sp) and range (R) of β, H+, and He2+ were evaluated by using the NIST data-based calculators (ESTAR for β, PSTAR for H+, and ASTAR for He2+) while Sp and R data for C6+ was determined using SRIM. The cross section for fast, thermal (25 meV), and slow neutrons (0.1–10 meV) was also estimated. The Pb reclamation from the CRT-F drastically increased the half value layer of photons by at least a factor of 4 at 0.1 MeV and by more than 90 % at 10 MeV. The CRT-F interacts more with fissile and thermal neutrons compared to CRT-F(Na2CO3). Although, CRT-F showed a better ability to attenuate all the radiation types considered, both glasses are better absorbers of radiation (especially photons) than some common shields. The reduction of Pb weight in CRT-F resulted in a drastic reduction in the ability of the glass to attenuate radiation; the resulting glass (CRT-F(Na2CO3)) is however, an environmentally safer glass shield.

An alternative classification approach for waste electronic and electrical equipment (WEEE) recovery in low-income countries: case study in Burkina Faso.

Waste electrical and electronic equipment (WEEE) is defined as "urban mines" due to the various recoverable minerals they contain. However, current WEEE classification methods are mostly limited to their physical characteristics, focusing on collection, transport, and treatment purposes rather than on valorization. In the present study, our aim is to propose an alternative classification approach adapted for low-income countries for WEEE recovery that highlights their content of precious and valuable metals. A typology of WEEE was created based on WEEE generated in Ouagadougou (Burkina Faso). Principal component analysis (PCA) and the moving center technique (K-means) were used for the classification method. Ultimately, we have found that to improve the recovery of WEEE, they can be classified into three main groups: (i) a group of WEEE-containing batteries, (ii) a group of WEEE-containing valuable and precious metals, and finally, (iii) a group of WEEE made up of cathode ray tube televisions (CRT-TV) waste. The WEEE belonging to the second group are the ones that could generate higher economical values. This alternative classification approach will help investors and operators to better orient their valorization activities towards WEEE types that present the best precious metals recovery potential, maximizing their profits. On the other hand, decision-makers will find this classification useful for reorganizing the WEEE value chain.

СТРУКТУРА ПОР ЯЧЕИСТОГО БЕТОНА С ОТХОДАМИ СТЕКЛОБОЯ ЭЛЕКТРОННО-ЛУЧЕВЫХ ТРУБОК

To date, the issue of handling toxic unsorted waste of cathode ray tubes (CRT) glass cullet remains relevant. The present paper proposes to replace part of the fine aggregate of cellular concrete intended for sound, heat or radiation protection with CRT glass waste heat-treated in the presence of a sodium hydroxide solution. The purpose of the research is to study the structure formation of the cellular concrete pores in case of replacement of part of the aggregate. The microscopy of the samples fracture was studied both visually and using software that made it possible to estimate the pore size when convert-ing the image to the relief mode. The study showed that the aggregate replacement results not only in quantitative changes in pore size, but also in qualitative changes related to the mechanism of the pore structure formation. Thus, when adding unsorted waste heat-treated in an alkaline environment, with a particle diameter of no more than 630 μm, there was a decrease in pore size and a decrease in size distribution compared with the reference sample. The changes are caused by structure formation, which can be divided into two stages - the formation of conglomerates and their swelling. With a decrease in the diameter of the part of the waste of a maximum size of 90 μm, a decrease in the pore size was recorded compared to the reference value, but due to the concrete skeleton formation before the end of gas development, destruction of the pore walls was observed.

Cathode Ray Tube Glass as an Aggregate: A Step Towards Greener Concrete

The use of Cathode Ray Tube (CRT) glass as an aggregate in concrete is a promising approach for sustainable construction. The CRT technology, once innovative, is now obsolete, leading to the accumulation of millions of CR tubes globally, posing disposal challenges due to their toxic composition. The CRT glass, consisting mainly of silica along with various oxides and heavy metals, holds potential for recycling and reuse applications. Recycling methods for CRT glass, including closed-loop and open-loop recycling, offer avenues to mitigate waste and conserve resources. Integrating CRT glass into concrete improves mechanical properties and durability. Although replacing natural sand with CRT glass may slightly reduce compressive strength, innovative mix designs offset this effect. Concrete with CRT glass exhibits resistance to environmental factors, making it suitable for diverse construction applications. Addressing environmental concerns related to CRT glass disposal requires efficient recycling technologies and stringent regulations. Overall, integrating CRT glass into concrete presents a sustainable solution to mitigate environmental impacts while enhancing concrete performance.

Development of an Integrated Process Flowsheet to Recover Valuable Metals from Waste Cathode Ray Tubes and Printed Circuit Boards

Electrical and electronic waste is considered a valuable stream of secondary metal resources because it contains metals such as copper, silver and gold. However, it is also classified as hazardous waste as it contains toxic heavy metals such as lead and cadmium. If electronic waste is not managed properly, the toxic metals may pose serious risks to the environment and human health, especially complex fractions such as printed circuit boards (PCBs) and cathode ray tubes (CRTs). The current study investigated a new process for the thermal treatment of CRTs and PCBs in an integrated flowsheet for metal recovery. Smelting tests were conducted to demonstrate that oxidative smelting of PCB concentrate and recycled CRT slag can produce a crude copper alloy with a grade of more than 95%. Another set of smelting tests was conducted to demonstrate that reductive smelting of CRT funnel glass and recycled PCB fume can produce a crude lead alloy with a grade of more than 95%. The investigations were undertaken in a pilot-scale top blown rotary converter (TBRC). The PCBs were smelted under mildly oxidising conditions at temperatures up to 1350 °C. The CRTs were smelted under mildly reducing conditions at temperatures up to 1250 °C. The study demonstrated that it is technically feasible to produce crude alloys of copper and lead from electronic waste, using an integrated process flowsheet.Graphical

Effect of Using Recycled Colemanite Waste and Cathode Ray Tube Glass in the Cement Mortar on Physical and Mechanical Properties

In this study, the performance of colemanite, which is a valuable boron waste, and recycled cathode ray tube glass (CRT) in the cement mortar was examined by experimentally. Colemanite waste (CW) and CRT were replaced with cement and aggregate and used as mineral additives, and their effect on the physical and mechanical properties (PP and MP) of mortar was investigated. In addition to the reference sample that didn’t contain CW or CRT, seven more samples were used. In these samples, cement was used at a rate of 2.5% along with CW, and the aggregate was replaced with CRT at the rates of 10%, 20%, and 30%, and with the combination of CW and CRT. The workability, unit weight, and water absorption, compressive strength (CS), flexural strength (FS), and abrasion resistance properties of the mortars were compared. As a result of this study, it has been observed that the use of waste materials can make positive contributions to some of the PP and MP of the mortar. Thus, the goal of both improving the properties of the mortar and making it affordable by using waste materials were achieved.

Recycling of Yttrium and Europium from Microwave-Roasted Waste Cathode Ray Tube Phosphor Powder

Recycling of Yttrium and Europium from Microwave-Roasted Waste Cathode Ray Tube Phosphor Powder

Functionalization of mesoporous Al-MCM-41 for indoor humidity control as building humidity conditioning material

This study sought to overcome the high energy consumption of mechanical dehumidifiers by synthesizing humidity control materials using alumino-silicate raw materials extracted from stone sludge and cathode ray tube (CRT) waste panel glass. The structure of the synthesized materials matches that of Mobil Composition of Matter No. 41 (MCM-41) mesoporous molecular sieves, which was subjected to amine functionalization using (3-Aminopropyl) triethoxysilane at various concentrations (2.5, 5, 7.5 vol.%). The resulting materials were characterized using X-ray fluorescence analysis, small angle X-ray diffractometry, Fourier transform infrared spectroscopy, transmission electron microscopy, the Brunauer–Emmett–Teller method, and 27Al solid-state nuclear magnetic resonance spectrometry. Al-MCM-41 molecular sieves with 5.0% grafted amine functional groups presented high specific surface area and high pore uniformity resulting in the highest equilibrium moisture content (39.4 kg/kg). The high thermal and humidity buffer capacity of the proposed material could greatly enhance the comfort of interior spaces without the energy consumption of mechanical dehumidifiers.

Effect of Partial Replacement of Fine Aggregate with Copper Slag and CRT With Addition of Aramid Kevlar Fiber

Abstract: Concrete is the most widely used construction material and the second most consumed substance in the world. Different Copper Slag and CRT concretes were created in this study by using Aramid Kevlar fiber in place of fine Aggregates. Every construction makes use of a significant amount of concrete because of its importance. Cathode-Ray Tube (CRT) technology has lagged behind as a result of the constant replacement of new technologies, such as LED Display Panel and Liquid Crystal Displays (LCD), which is leading to an increase in the number of discarded CRTs that need to be disposed of each year globally. The heavy waste material known as CRT funnel glass can increase the weight per unit of concrete. In terms of the components of products made during the copper production process, copper slag qualifies as an industrial product. It is a crystalline granular substance that can be utilized as a finer aggregate in concrete because of its high density and sand-like particle size. Aramid Kevlar fiber are completely synthetic organic polymers, aromatic polyamides are sometimes known as kevlar fiber.

E-waste CRT panel glass reinforced magnesium composite processed through powder metallurgy: fabrication and mechanical performance evaluation

Cathode Ray Tube (CRT) panel glass with higher silica content has a potential to be used as reinforcement material in magnesium matrix composites. The present study aims to formulate a wear resistant magnesium hybrid composite by reinforcing silica rich E-waste CRT panel glass powder (0, 10 and 20 wt. %) and boron nitride (0, 2 and 4 wt. %) solid lubricant processed through powder metallurgy route. Composition of the CRT panel glass powder is identified through EDS and XRD analysis is performed for both base material and reinforcements. The developed green MMC shows increased hardness (∼53 %), porosity (∼7 %) and density (∼7 %) with respect to addition of CRT reinforcement. Porosity of hybrid composite increased vastly to 9.2 % when the CRT and BN content are increased to 20 % and 4 % respectively. A slight increment in (10 %) hardness is observed for 2 % addition of BN with Mg and Mg/CRT composite whereas hardness of the Mg and Mg/CRT MMC decreases with further addition of BN. The wear resistance of the composite enhanced with raise in CRT and BN content whereas the co efficient of friction decreases with increases in BN percentage. Corrosion behaviour of Mg is also analysed and found enhanced with reinforcement addition. It is identified from the results that the addition of CRT% up to 10 % yields significant results whereas further increase in CRT % to 20 provides only minor enhancements in properties. Further, it is suggested to restrict the addition of BN to 2 %.

Value-added recycling of cathode ray tube funnel glass into high-performance radiation shielding concrete

This study proposed a novel method for recycling cathode ray tube (CRT) glass as heavy aggregates to prepare radiation shielding concrete (RSC). Microstructure, physical properties, radiation shielding characteristics, as well as economic and environmental benefits of CRT glass-based RSC were evaluated. Compared to conventional RSC, the CRT glass-based RSC showed a 13.8 % higher gamma ray shielding capacity. Although the mechanical properties of CRT glass-based RSC slightly decreased by 25.7 % due to the weak interfacial transition zone, the 28-day compressive strength of CRT glass-based RSC still fulfilled the requirement of criteria (> 30 MPa). Based on the cost-benefit assessment, there was 166.7 $/m3 profit in CRT glass-based RSC. Furthermore, CRT glass-based RSC demonstrated 47.7 % and 37.0 % reduction in fossil fuel depletion and carbon emissions compared with barite-based RSC.

Recovery of lead and chlorine via thermal co-treatment of municipal solid waste incineration fly ash and lead-rich waste cathode-ray tubes: Analysis of chlorination volatilization mechanism

In this study, a new lead (Pb) and chlorine (Cl) recovery process via the thermal co-treatment of Municipal solid waste (MSW) incineration fly ash (FA) and waste cathode-ray tubes (CRT) was developed and the synergistic effects under different CRT ratios, temperatures, and residence times were comprehensively investigated. Thermogravimetric experiments revealed that the co-processing of FA and CRT exhibited a remarkable synergistic effect as evidenced by the considerable increase in mass loss and mass-loss rate when compared with the theoretical values. When the mixtures with 50% CRT addition was treated at 1200 °C for 60 min, Pb removal rate reached the maximum value of 98.67%, and the Cl removal rate considerably increased by 37.32% compared to that with FA treatment alone. Additionally, the Cl content in the residue was < 2%. It was mainly attributed to the volatilization of chlorides, such as PbCl2, NaCl, and KCl. CaCl2 generated from the decomposition of CaClOH in FA was conducive to improve Pb removal in CRT through indirect chlorination and destroying the glass structure in CRT. Co-processing of FA and CRT demonstrates promising potential for several benefits, including the reduction in melting temperature, recovery of Pb and Cl from secondary fly ash, and the reutilization of calcium-rich slag.

Shielding parameters of leaded cement mortar

&lt;p&gt;The Cathode ray tubes (CRTs) represent more than 70% of global e-waste sets. The glass of the CRT is doped with lead to prevent emission of radiations especially electrons. The glass at the panel and neck of the CRT along with the cement mortar, a mixture of 70% neck glass and 30% cement (mix70), are investigated mathematically as shielding materials from photons having energies in the range 0.06-3 (MeV). Experimentally the material mix70 is tested at energies 0.238 and 0.583 (MeV). Good agreement was recognized between the calculated shielding parameters and that obtained experimentally while complete equality between the calculated parameters carried out using the online XCom software or Phy-X software except at low energies for concrete material. Glass from panel, neck and mix70 have acceptable shielding characteristics at and below the energy 0.238 (MeV) or generally at the X-ray region. Neck glass has good shielding parameters at the chosen energy region and it is nominated as a shielding material for many nuclear applications. To enhance the shielding characteristics of the material mix70 it should be compacted during preparation to get higher density. The present work tested the shielding properties of leaded glass composites to find out its integrity for practical shielding applications and radiological safety.&lt;/p&gt;