Lead Oxide Content Research Articles

Application of Laser-Induced Breakdown Spectroscopy for Quantitative Analysis of the Chemical Composition of Historical Lead Silicate Glasses

The study of the chemical composition of historical glasses is widely used in archaeometry. The results of such analyses provide information on the probable date, place, and technological features of their production. Over time, a weathered layer may form on the surface of the glass, which differs in composition from the original one. To determine the initial composition using conventional methods (for example, X-ray fluorescence spectroscopy), the weathered layer should be removed. For historical objects, such manipulation is unacceptable and should be minimized. One of the methods for analyzing the chemical composition with minimal damage to a sample is laser-induced breakdown spectroscopy. The aim of this work was to develop a LIBS method, which makes it possible to perform a quantitative analysis of lead silicate glasses, including glasses containing a weathered layer. Reference glasses with a variable content of potassium, silicon, and lead oxides were synthesized, and based on the LIBS spectra, a calibration dependence was obtained that made it possible to measure the concentration of lead and potassium oxides in glasses within 70–85 and 5–20 wt%, respectively. The method was applied to analyze the composition of the glaze on a historic glazed tile from the burial church in the Euphrosinian monastery in Polotsk (the second half of the 12th century AD). The crater formed with the laser beam on the glazed surface was about 200 microns. Such damage is negligible compared to the total surface area of the tile (~10 cm2). The thickness of the weathered glaze layer was 70 microns, which was determined using variation in lead oxide content.

Analysis of the composition of ancient glass products based on Spearman's correlation coefficient

Ancient glass stored underground for a long time has undergone different degrees of weathering, which has led to changes in its chemical composition and affected the correct judgment of its category. Based on this, this paper uses various algorithms such as Spearman correlation coefficient, chi-square test and cluster analysis to establish a comprehensive model for glass composition evaluation. The results show that: (1) The surface weathering degree of glass artifacts is significantly correlated with their types; (2) The content of Lead oxide can be used to make a general distinction between high-potassium glass and lead-barium glass; (3) Among the known glass samples, high-potassium glass can be divided into three categories and lead-barium glass can be divided into four categories; (4) According to the reasonableness test, it is known that the model has good reliability and can provide guidance for the study of ancient glass.

Research on Composition Analysis and Identification of Ancient Glass Products

Glassware was the witness of the ancient Silk Road trade. The paper focuses on the component analysis and identification methods of ancient glass products. The decision tree model was established and analyzed to obtain the classification rules of high potassium glass and lead barium glass. Based on the cluster analysis method, appropriate chemical elements were selected for each type to conduct cluster analysis. The result showed that high potassium glass and unweathered lead barium glass can be classified by their content of silicon dioxide. However, weathered lead barium glass needed to be classified by their content of lead oxide. The random forest regression model was used to classify glass cultural relics by their chemical elements. The chemical element data of glass cultural relics with known types were used as samples, and the chemical element data of glass cultural relics with unknown types were inputted into the trained model. Finally, the types of glass cultural relics were predicted and sensitivity analysis was conducted.

Exploration And Analysis of Weathering Factors of Glass Artefacts Based on Cluster Analysis and Grey Correlation Analysis

The aim of this paper is to investigate the relationship between the chemical composition of ancient glass artefacts after weathering and to construct a model for classifying and predicting the class of artefacts based on some of the characteristics of the ancient glass artefacts obtained. Cardinality tests, information entropy, cluster analysis, support vector machines and grey correlation are mainly used to conduct the study. Through chi-square test, the relationship between weathering of glass relics and glass type, glass color and glass pattern is explained. Finally, the relationship between weathering and glass type is closer. Information entropy was used to explain the relationship between the weathering of cultural relics and the content of chemical components contained in cultural relics. Among them, potassium oxide ( O) and calcium oxide (CaO) had the largest information gain. The effective information gain of lead barium is silicon dioxide (Si ), potassium oxide (PbO), copper oxide (CuO) and sodium oxide ( O). By using cluster analysis, the law analysis and corresponding subcategories of high-potassium cultural relics and lead-barium cultural relics are made, and 3-5 subcategories are formed. Support vector machine was used to judge the type of glass relics, and the final result was that A1, A6 and A7 were high potassium. A2, A3, A4, A5, A8 are lead barium; The correlation coefficient matrix was used to analyze the correlation between the chemical components in different kinds of cultural relics, and the differences were explained based on the results of grey correlation degree analysis. Finally, the conclusion was drawn: in the firing process of high-potassium glass, the substance with high potassium content as the co-solvent did not have an essential effect on the formation of high-potassium glass. However, lead barium glass is different. As lead ore (high content of lead oxide and barium oxide) is added as co-solvent in the firing process, lead barium glass produced by firing contains a large amount of lead oxide and barium oxide.

Decision tree based classification of glass artefact types

This paper uses logistic regression, SVM, and decision trees in machine learning to analyse 67 data items from question C of the 2022 GCSE Cup National Student Mathematical Modelling Competition. The data were analysed using systematic clustering, the clustering coefficients were analysed, the number of clusters K was further determined by the "elbow" method, a clear classification pattern between the glasses was obtained, and a grid search method was used to classify the glasses. The results show that the new excavated glass artefacts have been classified using the "elbow" method. The results show that newly excavated glass artefacts are classified by varying PbO content. If the lead oxide (PbO) content is below 5.46%, they are considered high-potassium glasses and vice versa for lead-barium drinks. The content of silica was further used as a boundary to divide the high-potassium glass into two subclasses. Lead-barium glasses are divided into three subclasses using the lead oxide and silica content as the boundary. Using a series of models and algorithms, the classification patterns of different types of glass and their subclasses were clarified, and the results were tested for reasonableness and sensitivity. Such a model can be used to classify newly excavated glass artefacts and can also be modified based on this model for the identification and analysis of other ancient artefacts.

An investigation of the significance of the association of each attribute of ancient glass products based on cardinal distribution

The Silk Road was a key channel for trade and cultural exchange between China and the West in ancient times, and one of the gems of the early exchange was glass products. The composition and properties of glass from the East and the West often differ greatly because of the different production processes, but the problem of glass identification has been an ancient challenge. For the analysis of the composition and origin of ancient glass products, this paper is a mathematical approach to model design, avoiding the duplication of labor into this area. This paper uses chi-square test and correspondence analysis to first determine which factors are significantly correlated with glass products, and then further determine the correlation with the factors. The use of box-line plots allows for a very visual analysis of the statistical patterns of the presence or absence of chemical composition content on the surface of artifact samples. For predicting the chemical composition content before weathering, the approximate chemical composition content was first estimated based on the average rate of change of each chemical composition before and after weathering, and then a multiple linear regression model was used to correct for the chemical composition content. It was finally concluded that the weathering of glass surface was significantly correlated with glass type, and high potassium glass was not easily differentiated, while lead-barium glass was easily weathered; the silica content changed most significantly before and after weathering of high potassium glass, with an average change rate of 25.98%, and the silica and lead oxide content changed most significantly before and after weathering of lead-barium glass, with average change rates of 29.75% and 23.77%, respectively.

Identification of glass products based on cluster analysis and random forest model

The main chemical composition of glass is silica (SiO2). Due to the high melting point of pure quartz sand in the raw material of glass production, flux should be added in order to reduce the melting temperature. The main chemical composition varies with the flux added. In this paper, through the grey correlation analysis can be concluded that the key factors influencing the classification to the content of lead oxide, and barium oxide, and through the random forest, hierarchical clustering, and K - Means method to classify different types of glass and the division of the class, the glass can be divided into high potassium, high potassium not weathering, lead, barium, lead, barium not weathering four categories of two classes, a total of eight classes, Through the test of classification sensitivity and reliability, it shows that the three models are reasonable and can be applied.

Identification of Weathered Glass Artifacts Components Based on NSGA-II Algorithm with Entropy TOPSIS Method

Glass has a long history and was one of the first man-made materials invented by man. Since glass artifacts are highly susceptible to weathering, the surface composition of artifacts is easily altered. This situation affects the judgement of the type of artefact greatly. In this regard, this paper investigates the data of lead-barium glass and high potassium glass before and after weathering. Firstly, in order to demonstrate that the weathering of high potassium and lead-barium glass is related to the chemical composition of its surface, the relationship between the weathering of glass and the proportion of the chemical composition content of the glass surface needed to be investigated. In addition, it was decided to carry out an analysis using an independent sample rank sum test to obtain a pattern between weathered glass and the proportion of chemical composition content, as most of the data did not conform to a normal distribution. Finally, using the obtained information, a mechanism analysis model was designed based on the chemical kinetic theory, and a multi-objective optimization model was established using the NSGA-II Algorithm with Entropy Topsis Method. The resulting predictive equations for the chemical composition of lead-barium glass and high potassium glass before and after weathering were acquired. The results show that the discrimination between two types of glass based on the percentage of lead oxide content and the percentage of barium oxide content can procure reliable results in general.

A model for compositional analysis of ancient glass products based on correlation analysis

In response to question 1, the key lies in the need to study the relationship between weathering and type, ornamentation and color on the surface of glass products, as well as the relationship and law between each glass type and chemical composition content. By establishing decision trees, chi-square tests, and multiple linear regression models, after eliminating two sets of invalid data from samples 15 and 17, it was concluded that the type and ornamentation of glass products have a greater influence on weathering, and the color of glass products has a smaller relationship with weathering The relationship between glass type and weathering is smaller, and the variation of chemical composition content with and without weathering is more obvious for different glass types, and the statistical pattern of these data is used to predict the chemical composition content of each glass type before weathering. For problem 2, different categories of glass need to be subclassified according to chemical composition. By establishing a decision tree model, the classification rules of glass types were found out, such as lead oxide content higher than 5.46 for lead-barium glass and lower than 5.46 for high-potassium glass, and the entropy weighting method was used to determine the weights of various chemical components for high-potassium glass with or without weathering and lead-barium glass with or without weathering, so that the chemical components with higher weights were selected to classify four types of glass: high-potassium weathered, high-potassium unweathered, lead-barium weathered, and lead-barium unweathered, respectively. The classification results were obtained by using the systematic hierarchical clustering algorithm, and the classification results of different types of glass differed, and then the results were analyzed for reasonableness and sensitivity.

Physical, neutron, and gamma-rays shielding parameters for Na2O–SiO2–PbO glasses

The present study investigated the physical and neutron- and gamma-ray-shielding features of a sodium oxide (Na2O)-doped lead (Pb)–silicate glass system. The chemical composition of the glass system is described by the formula xNa2O–50SiO2·(50 − x)PbO, where x = 0, 10, 20, 30, 40 and 50 mol%. Moreover, the shielding features were investigated by utilizing the Geant4 simulation code and the Xcom program. The density of the glasses (ρglass) was enhanced from 2.460 to 6.995 g/cm3. The mass attenuation coefficient (MAC, μ/ρ) was calculated. The MACs were arranged in the order of (NSP50)MAC> (NSP40)MAC> (NSP30)MAC> (NSP20)MAC> (NSP10)MAC> (NSP0)MAC. The half-value layer varied from 14.23 to 2.55 cm for NSP0 to NSP50, respectively, at 0.015 MeV. The mean free path (MFP) values ensured the shielding capacity for NSP-glasses, as it was found to possess the shortest MFP, and its value at 0.015 MeV changed from 20.53 to 3.68 cm for NSP0 and NSP50, respectively. The NSP50 glass sample has the highest Zeff, which increased from 32.70 to 76.93. The calculated exposure buildup factor values were greater than those of the energy absorption buildup factor at fixed energy and penetration depth for all studied glasses. The fast neutron removal cross-section ∑R(cm−1) increased gradually with the increase in lead (II) oxide content. Finally, one can conclude that the investigated NSP0–NSP50 glasses are superior materials for neutron and γ-ray shielding.

Effect of lead oxide on the electrical transport properties of lithium–iron–borate glasses

The electrical conductivity and dielectric properties of the glass system (70-x) B2O3–(x) Pb3O4–10Fe2O3–20Li2O [where 0 ≤ x ≤ 35] have been investigated in the temperature range from 300 to 530 K, at four fixed frequencies [0.12, 1, 10, and 100 kHz]. Ac conductivity is found to obey the universal relation, σ(ω) = Aωs, where s is the frequency exponent factor and its value is less than unity. Investigation of σac results and the s factor reveals that the polarons hopping over barrier between Fe2+ and Fe3+ ions is the probable applicable mechanism for σac for these glasses. The dc activation energy values are found to increase from 0.67 to 1.61 eV as the lead oxide content increases. These remarks are explained using Mossbauer Effect (ME) spectrometer and molar volume calculations. The observed higher records of the dielectric constant for the lead-free sample could be attributed to some precipitated iron in the form of α-Fe2O3, which increases the polarized space charges in the glass network.

УТИЛИЗАЦИЯ ОТХОДОВ СВИНЦОВОГО ПРОИЗВОДСТВА ПУТЕМ ИЗВЛЕЧЕНИЯ ОКСИДОВ СВИНЦА И ЦИНКА

Information is given about the need to dispose of waste from the Shymkent lead plant in the form of slags, which have accumulated about 2 million tons. It is proved that lead production slags contain a large number of toxic compounds, such as lead, zinc, osmium, and cadmium, which are dangerous sources of environmental pollution. According to the results of X-ray diffractometric analysis and DTA, it was found that the slag of lead produc- tion contains a fairly high number of non-ferrous metal compounds: the content of lead oxide up to 2 %, zinc oxide up to 17% and copper oxide up to 1.25% of the total weight of the sample. The qualitative composition and content of non-ferrous metals of lead slags makes it possible to make the process of recycling toxic waste from lead production technically and economically feasible. The results of preliminary tests allow us to select a technology for more complete and selective extraction of lead and zinc oxides from the slag waste of lead production. When using a selective method for extracting non- ferrous metals, it is expected to improve the ecological state of the environment and reduce the negative impact on human health due to the disposal of toxic slags from lead production. At the same time, a significant contribution is made to the development of the system of rational use of natural and secondary resources.

Development of Mullite Based Refractory Pot for High Lead Containing Glass Melting

Radiation shielding window (RSW) glass for nuclear reactor is primarily required for protecting the operating personnel from harmful radioactive rays produced during nuclear energy generation in nuclear hot cells. In this respect, the production of high lead (>70% PbO) containing RSW glass is generally made using platinum pot through bottom pouring flow casting technique. However, owing to low capacity (40 L max.) of high cost platinum pot, the production of glass slab is limited to a maximum dimension of 400×400×100 mm3. Therefore, an alternate cost effective technology is highly required for making higher dimension glass slabs. To fulfill the requirement, low cost and higher volume refractory pot based tilt casting technology can be adopted. In this regard, the refractory pot is to be developed with adequate thermal, chemical and mechanical stabilities towards sustaining high corrosive lead oxide containing molten glass at 1100°-1200°C. For this purpose, a clay based alumino-silicate pot material enriched with mullite has been developed and characterized systematically. The rectangular bars have been fabricated by slip casting technique and the fabricated bars have been fired between 1450° and 1550° C. The fired materials have been characterized in terms of bulk density, apparent porosity, cold and hot modulus of rupture, etc. The RSW glass with more than 70% lead oxide content has successfully been melted in the pot. The quality of RSW glass produced using the pot has also been studied. In an optimized composition of the pot, the formation of higher content of mullite phase having high thermal shock and corrosion resistance with the desired mechanical stability is the key factor behind the stability of the refractory pot for making defect free RSW glass slabs. This cost effective refractory pot technology can substitute the platinum pot technology for producing larger dimension RSW glass slabs.

Mix Design of High-Strength Concrete Incorporating Spherical and Crushed CRT Funnel Glass Waste

Cathode ray tube (CRT) funnel glass, due to its high content of lead oxide (PbO), is considered as hazardous waste. The growing volume of the disposed CRTs technology presents a risk of environmental contamination owing to the potential of toxic Pb metals leaching from glass. A typical way of recycling CRT funnel glass waste is by crushing it and partially replaced the cement and fine aggregates. However, this approach has been facing serious issues in terms of leaching of Pb. Hence, a new recycling method has been developed, that is by performing proper melting and annealing operations in producing the spherical CRT funnel glass (GS). GS does not show any harmful risk of the release of Pb to the environment. The Pb leaching value of CRT concrete specimens with GS is significantly lower than the allowable limit although it contains high concentration of PbO, 25%. While the performance of GS in leaching aspects have been determined, the optimum mix designs of high-strength concrete incorporating both GS and crushed CRT funnel glass (GC) as coarse aggregates yet remains to be investigated. Predominantly to provide a safe method of recycling CRT funnel glass as aggregate and to increase the confidence level of the industries, this paper addresses the mix design of high-strength concrete with GS and GC as coarse aggregates. Given the importance of selecting the materials and its contents, the influence of five parameters, i.e. water/binder (w/b) ratio, coarse aggregate (CA) content, superplasticizers (SP) dosage, and silica fume (SF) content were evaluated. It was found that the incorporating of GS and GC that differ in terms of morphologies (size, shape, texture) and water absorption rate than the natural rock have led to the increase of workability of CRT concrete mixtures, however, decrease the compressive strength. But the results also have highlighted that the CRT specimens that were designed with w/b ratio 0.31, 43% content of CA, 2% SP, and 10% SF were able to achieve the highest strength of 61 MPa, which was only 9% lower than control specimens. The optimum mix design of CRT concrete has greatly improved the strength of concrete and enhance its potential for future applications.

A novel vacuum/oxygen hot press sintering approach for the fabrication of transparent PLZT (7.4/70/30) ceramics

Transparent Lanthanum-modified lead zirconate titanate ceramics (PLZT 7.4/70/30) with low content of excess lead oxide (PbO) were successfully prepared by a novel vacuum/oxygen hot press sintering process. The phase structure, microstructure, electrical properties and electro-optic scattering performance of PLZT ceramics as a function of excess PbO in the starting powders have been studied and analyzed. As a result, these ceramics exhibited an ultra-high optical transmittance (>69.4% at 1064 nm; thickness 1 mm) from visible to near-infrared wavelength. Herein, we significantly reduce the use of PbO as an auxiliary agent for sintering. This puts forward a good route to meet the objectives of environmental protection and sustainable development.

Effect of Gamma Irradiation on High Lead Borate Glass Doped with Tungsten Oxide

X-ray, Ultraviolet and Fourier Transform infrared spectral properties of tungsten ions doped in a host lead borate glass have a composition [60%PbO and 40%B2O3 weight%] was studied. Effect of gamma irradiation on the prepared glass samples was surveyed. Amorphization of the studied glass samples have been checked by X ray. Deep inspection for density, molar volume, UV and FTIR for base glass and tungsten oxide with different concentrations (0.15-2.28) weight% proved that the tungsten ions are pronounced as structural groups mostly in the hexavalent W6+. The constancy of optical absorption spectral curves reversed the shielding behavior for this combined glass towards successive gamma irradiation. Glasses containing high lead oxide content are extensively used for multi-applications including lead crystal glass and some special optical glasses, low-melting solder glasses and radiation protection windows and even in immobilization of radioactive nuclear wastes.

Gamma, neutron shielding and mechanical parameters for lead vanadate glasses

Abstract Alkali lead vanadate glasses with moderate concentrations of PbO were prepared and analyzed to test their use as promising candidates for radiation shielding. The physical parameters of these glasses are specified and discussed in details. The code MCNPX was utilized to determine the mass attenuation coefficient μm that is used to evaluate the interaction of radiation with shielding materials. The results were then compared with the values collected from the XMuDat program and XCOM. The simulation results overlaps and highly correlated with XMuDat and XCOM. In addition, the results showed that μm, the effective atomic number (Zeff), removal cross-sections, (ΣR) and experimental results of the prepared glasses increase, while the half value layer (HVL), exposure and energy absorption build-up factor (EBF and EABF) values decrease with the increase of lead oxide (PbO) content from 30 to 45 mol%. In order to maximize the benefits from the determination of the radiation factors, the experimentally determined physical parameters and the elastic coefficients of this type of glass were also calculated.

Microstructure properties of lead silicate glasses

In the present work, lead silicate glasses have been prepared withdifferent amount of lead oxide content. Structure properties such asX-ray diffraction, AFM, and FTIR analyses have been done. Theexceeding of PbO content more than 25wt% revealed a decreasing indensity. The X- ray revealed that the strongest peak related toHexagonal silica dioxide and the other crystal phases formed wererelated to silica oxide (SiO2) and lead oxide (PbO). Growth anddecayed phases in X-ray have been observed with changing leadoxide content. Homogeneous surface was obtained using AFManalyzer with an average diameter around 100 nm. Infrared spectrumis characterized by the presence of large absorption band between1200 and 900cm-1 and have its maximum at 1080 cm-1 which istypical to stretching vibrations of Si–O–Si bonds, another bandsnoticed were attributed to Pb–O–Pb, Pb–O–Si, [AlO4]-tetrahedron,and to Si–O–Al bond.

Study of SiO2-PbO-CdO-Ga2O3 glass system for mid-infrared optical elements

Glasses based on SiO2-PbO-CdO-Ga2O3 system have been studied for the first time for fabrication of mid-infrared optical elements. Gallium oxide concentration was gradually increased, replacing silicon dioxide, for different cadmium and lead oxide content. The thermal and optical properties were investigated for different compositions. It was observed that the thermal stability, refractive index, and the transmission in the infrared range increased with increase of gallium and lead concentrations. The most thermally stable glass composition was selected for fabrication of optical elements such as optical fibers. We also successfully fabricated mid-infrared lenses by hot embossing for potential application in compact gas detectors.

Parametric optimization of dry sliding wear and friction of germanium doped lead calcium titanate borosilicate glass ceramic

In this study, specific wear rate (SWR) and coefficient of friction (COF) of the synthesized samples in 55[(PbxCa1−x)O.TiO2]−44[2SiO2.B2O3]−1Ge with (0 ≤ x ≤ 0.7mol%) system of glass ceramics was optimized using Taguchi method. The ASTM standards were used for preparing the samples for friction and wear tests on a pin-on-disc tribometer. The glass ceramic samples were used as pin materials that slid against a disc made up of EN32 steel. For assessing the tribological properties of the glass ceramics, three control factors, viz. material-compositions with varying fraction of x (x = 0.0, 0.1, 0.3, 0.5 and 0.7mol%), sliding speeds (2.61, 3.14, 3.66, 4.18 and 4.71m/s) and loads (10, 15, 20, 25 and 30N) were considered in an L25 orthogonal array design. The optimum input parameters for the minimum SWR and COF were selected based on signal to noise ratios and main effect plots. Analysis of variance (ANOVA) revealed that the sliding speed and lead oxide content of the material are the most contributing factors on SWR and COF, respectively. The optimization for minimizing the SWR and COF was carried out and confirmed. The surface morphologies of the tested glass ceramic sample were studied using scanning electron microscope (SEM) and the elemental analysis of the samples was done using energy dispersive analysis of X-rays (EDAX). The Vickers hardness at the free surface of the glass ceramic samples increased up to 9.59mol% of lead oxide with the maximum hardness of 23.59GPa. The compressive strength of glass ceramic samples could reach up to 190MPa.