Lead Alloys Research Articles

Unusual Composition of the Sarezzano Reliquary Busts

The interdisciplinary study of two reliquary busts from Sarezzano (Piedmont, Italy) is a perfect example of the necessity to provide for material characterisation as a recurring common practice in historical studies and a mandatory step in conservation assessment. Furthermore, the diagnostics of cultural heritage play a crucial role in art historical research, providing relevant information on artefacts’ genesis, production technology, and conservation history. The study of the materials of the reliquary busts was performed by non-invasive (portable X-ray fluorescence spectrometry) and micro-invasive (stereomicroscope, attenuated total reflection Fourier transform infrared spectroscopy and powder X-ray diffraction analysis) methods. According to the results, the busts were found to be made of a tin–lead alloy, a rather unusual material for mediaeval reliquary busts. Moreover, the outcome suggests that the busts were originally silvered, except for the hair and beard which are still gilded. The analysis reveals the use of colophony as an adhesive buffer layer on the busts’ alloy, as well as inside them, to favour the metal working process, since it is found as degraded residue. Finally, even the typology of alloy decay is defined. All this information has enabled us to determine the artistic technique and estimate the value and quality of the material employed. In addition, it has led to the correct choice of materials and methods to be adopted during the restoration, and therefore the usage of more suitable solvents and tools.

Refining of Secondary Pb with Retention of Sn Using Al and Ca Additions

AbstractLead grid from spent lead-acid batteries contains significant amounts of tin and antimony. In classical pyro-refining processes of lead, tin oxidizes and is transferred to dross, making its recovery problematic and expensive. This paper presents an innovative method of pyro-refining lead using metallic aluminum and calcium to purify the lead from contaminants while retaining a higher amount of tin than in the traditional process. The changes in the chemical composition of an impure lead alloy containing tin, under the influence of refining by adding Al and/or Ca, are discussed based on laboratory-scale studies. Microanalysis of the metallic dross formed during the process was conducted. Analyses of the metallic dross microstructures showed that lead impurities, such as Sb, As, Cu, Se, and Te, tend to accumulate in areas containing Al or Ca. The amount and form of dross produced in industrial practice indicate that its removal would be challenging. Therefore, in the second part of the study, the metallic dross was subjected to a reduction process, and the resulting products were analyzed for their chemical and phase composition. The analyses indicate that the degree of impurities return to the lead during reduction varied significantly depending on the method used.

Electrochemical Separation of Pb-Ag-Sb Alloys in the KCl-PbCl2 Melt

Anode dissolution of lead, silver, antimony and liquid lead-bismuth-antimony alloys has been studied by the polarization method depending on the alloy composition in the molten KCl-PbCl2 eutectic. Lead was found to dissolve and to form Pb2+ ions within the whole range of anode current densities in the Pb-Ag-Sb (49.0–28.0-23.0) and Pb-Ag-Sb (11.0-55.0-34.0) melts. The limiting diffusion current of lead dissolution was observed at the anode current density of 0.34 А cm−2 in the Pb-Ag-Sb (5.0-65.0-30.0) alloy. At the anode current densities exceeding these values the antimony dissolution was observed. To define a mechanism of metals electro dissolution, the number of electrons participating in the electrode reactions was calculated. Based on the polarization curves analysis the regime of electrochemical separation of lead alloys was selected. Metallic lead and the remaining Ag-Sb-Pb alloy with the valuable components concentration exceeding 90 wt% were obtained in the laboratory-scale electrolytic cell.

Thermodynamics of Sodium–Lead Alloys for Negative Electrodes from First-Principles

Thermodynamics of Sodium–Lead Alloys for Negative Electrodes from First-Principles

Apport des aides technologiques dans l’extraction des corps étrangers orbitaires

Background: Removal of orbital foreign bodies is a surgical challenge. The purpose of this study is to report our experience in the removal of orbital foreign bodies and to evaluate the usefulness of various technological aids in their removal.Materials and Methods: We conducted a single-center retrospective study at Nice University Hospital (France) from January 2017 to December 2023. All patients undergoing surgery for an orbital foreign body during the study period were included. Data recorded included the nature of the orbital foreign body, its size, location, surgical route, outcome (success, partial success, failure), and technological aids used (intraoperative navigation, intraoperative imaging scope, orbital magnet). Concurrently, we designed a dedicated orbital magnet, which was tested in the anatomy laboratory and in two of our patients.Results: Six patients, all young men, were included during the study period. Removal was successful, partially successful, or unsuccessful in one-third of cases, respectively. Failure was associated with orbital foreign bodies located in the intraconal or posterior orbital space. Preoperatively, the use of a “low-artifact” scanner allowed us to better determine the exact size and shape of the orbital foreign body. Intraoperative navigation was not accurate enough, due to the mobility of the orbital bodies within the orbital fat. In our experience, intraoperative scope imaging was more accurate. The use of a dedicated orbital magnet was successfully tested in the anatomy laboratory and allowed the removal of a small orbital foreign body in one of our patients. Intraoperative surgical videos are provided.Conclusion: Vegetal orbital foreign bodies must be systematically removed. Removal of non-vegetal orbital foreign bodies should be considered on a case-by-case basis based on their size, best assessed using a “low artifact” scanner, their location, and their intrinsic ferromagnetism. Intraoperative navigation does not appear useful, while intraoperative scope imaging does. A dedicated orbital magnet might be helpful in removing ferromagnetic orbital foreign bodies. However, an orbital magnet may be ineffective in removing intraorbital bullets, since they are made primarily of an alloy of copper and lead.

Synthesis of ultrathin hybrid membranes via the co-polymerization of acrylic acid, styrene and molybdenum disulfide and their high adsorption selectivity for lead(II) in the mixture of metal ions

Lead(II) is a potential carcinogen of heavy-metal ions (HIs). With the wide application of Pb-bearing products including lead alloy products, and new-energy lead-ion batteries, lead pollution has become a tricky problem. To solve such a difficulty, novel ultrathin MoS2-vinyl hybrid membranes (MVHMs) with a “spring” effect were synthesized via co-polymerization of acrylic acid, styrene and molybdenum disulfide (MoS2) and their adsorptions for HIs were explored. The “spring” effect derived from the interaction between the tendency of the short polyacrylic acid (PAA) chain connected with MoS2 to spread outward and the coulomb force between layers from MoS2 (s-MoS2), which enlarge the spacing of MoS2 layers without changing the number of layers after membrane formation, which changes the swelling membrane to a dense membrane and reduces the original thickness from 0.5 cm to 0.011 mm in the thickness direction. The adsorption experiment revealed that these MVHMs had super adsorption performance and high selectivity for Pb2+ by comparison with other five metal ions: Cu2+, Cd2+, Ni2+, Cr3+ and Zn2+. Especially, the adsorption quantity of MVHMs for Pb2+ could approach 2468 mg/g and the maximum adsorption ratio of qe[Pb2+]/qe[Cu2+] can reach 10.909. These values were much larger than the data obtained with the adsorbents reported in the last decade. A variety of models are applied to evaluate the effect of ionic groups. It was confirmed that –COOH plays a key role in adsorption of HIs and s-MoS2 also has a certain contribution. Conversely, ion exchange plays only a minor role during the period of adsorption process. Effective diffusion coefficient (Deff) of Pb(II) had the largest values among these metal ions. Hence, these hybrid membranes are promising adsorbents for the removal of Pb2+ from water containing various ions.

Evaluation of Improved Imaging Properties with Tungsten-Based Parallel-Hole Collimators: A Monte Carlo Study

Abstract Objectives The purpose of a parallel-hole collimator in a scintillation camera system is to transmit only those photons that have an emission angle close to the direction of the hole. This makes it possible to receive spatial information about the origin of the emission, that is, radioactivity decay. The dimension, shape, and intrahole thickness determine the spatial resolution and, by a tradeoff, sensitivity. The composition of the collimator material also plays an important role in determining a proper collimator. In this study, we compared tungsten alloys as a potential collimator material replacement for the conventional lead antimony material used in most of the current camera systems. Materials and Methods Monte Carlo simulations of a commercial scintillation camera system with low energy high resolution (LEHR), medium-energy (ME), and high-energy (HE) collimators of lead, tungsten, and tungsten-based alloy were simulated for different I-131, Lu-177, I-123, and Tc-99m sources, and a Deluxe rod phantom using the SIMIND Monte Carlo code. Planar images were analyzed regarding spatial resolution, image contrast in a cold source case, and system sensitivity for each collimator configuration. The hole dimensions for the three collimators were those specified in the vendor's datasheet. Results Using Pb, W, and tungsten alloy (Wolfmet) as collimator materials, the full width at half maximum (FWHM) measures for total counts (T) for LEHR with Tc-99m source (6.9, 6.8, and 6.8 mm), for ME with Lu-177 source (11.7, 11.5, and 11.6 mm), and for HE with I-131 (6.2, 13.1, and 13.1 mm) were obtained, and the system sensitivities were calculated as 89.9, 86.1, and 89.8 cpsT/MBq with Tc-99m source; 42.7, 17.4, and 20.9 cpsT/MBq with Lu-177 source; and 40.1, 69.7, and 77.4 cpsT/MBq with I-131 source. The collimators of tungsten and tungsten alloy (97.0% W, 1.5% Fe, 1.5% Ni) provided better spatial resolution and improved image contrast when compared with conventional lead-based collimators. This was due to lower septal penetration. Conclusion The results suggest that development of a new set of ME and HE tungsten and tungsten alloy collimators could improve imaging of I-131, Lu-177, and I-123.

Communication—Improving Corrosion Resistance of Lead-Alloy Positive Grid of Lead-Acid Battery by an Electrochemical Prepassivation Interphase

Lead-acid battery (LAB) has a huge world market in both energy storage and power supply. However, most LAB failures are caused by the serious corrosion of positive grids. To this, we propose an electrochemical prepassivation strategy to form a compact interphase on the lead-alloy grid surface composed of lead oxides and lead sulfate, exactly the same as lead paste. The results show that the corrosion resistance of pre-passivated lead alloy is improved due to the inhibition of vertical growth of corrosion layer, providing a feasible solution to prolong the service life of LAB.

Smelting a Zn – Pb Sulfide Ore with Magnetite and Carbon for the Production of a Silicon Alloy and Extraction of Zinc and Lead into Sublimates

The article presents the results of thermodynamic prediction and electric smelting of Shalkiya sulfide zinc-lead-bearing ore in the presence of magnetite and coke. Using the HSC-6.0 software package, it was found that under equilibrium conditions in the presence of Fe3O4 and carbon, the reduction and formation of gaseous zinc from ZnS (according to ∆G° = 0) occurs at a temperature of 1205.7 °C, and the formation of ferroalloy at the interaction of the sulfide ore with magnetite and carbon begins at 1200 °C. About 58% of silicon is extracted into the ferroalloy at 1800–1900 °C; almost all zinc and 83–88% of lead turns into a gaseous state. Electric smelting of the sulfide ore in the presence of magnetite concentrate and coke makes it possible to obtain the FS45 grade ferrosilicon (42–43% of Si); the silicon extraction degree was 84–88%. At the same time, 97.3% of lead and 99.2% of zinc are extracted into the sublimates. The developed method for processing zinc sulfide ores allows us to increase the degree of raw materials' comprehensive use due to the extraction of not only zinc and lead, but also silicon. The technology can be used to process raw materials containing zinc, lead and silica, such as zinc ore concentration tailings.

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

Ancient Roman Coins from the Republican Age to the Imperial Age: A Multi-Analytical Approach

We report here the results of a multi-analytical approach to characterize twelve Roman coins dating from the third century B.C. to fifth century A.D. that were found in the surroundings of Rome and for which the year of minting is determined by numismatic analysis. The coins were studied using SEM-EDS, EMPA, XRD, and FTIR techniques, enabling semi-quantitative and quantitative determinations of the chemical and mineralogical composition of the alloys and corrosion products. SEM-EDS analyses highlighted the occurrence of corrosion products on the surfaces and wide chemical variations due to selective enrichment or depletions of the alloying metals. The EMP analyses showed that three of the twelve coins are made of copper (1), one is a copper–tin alloy (2), five are copper–tin–lead alloys with elements in different proportions (3), two are copper–lead alloys (4), and another one is a subaerata coin (5). In addition, the physical parameters of the coins, i.e., density, weight, and diameters, were measured to have an overall characterization.

The implication of the technology and chronology reflected in the metal assemblage from the middle‐class Xiongnu burials at Tamiryn Ulaan Khoshuu, Mongolia

AbstractBronze and iron objects from the middle‐class Xiongnu burials at Tamiryn Ulaan Khoshuu were examined for technology and chronology. The bronze objects were made from copper–tin–lead alloys, mostly for ornamental purposes, while the iron objects were household items made of cast iron. Radiocarbon measurements dated the site to the 4th century bce to the 1st century ce. The results revealed two key factors: (1) Xiongnu style material culture established by incorporating various contributions from across Eurasia at an earlier date than previously supposed; and (2) the emergence of regionally stratified material culture suggesting intimate political relationships consistently maintained between geographically distant Xiongnu communities.

Effects of Die Entry Angle on the Mechanical Properties of Extruded Lead Alloy

The use of lead to produce wire, power cable sheathing, guide plates, and other wide-range applications require fine-grain structures. Researchers adopted severe plastic deformation, as a means of attaining ultra-fine grain structure. However, this technique is rather expensive and time-consuming. Thus, this study is focused on the application of a simple extrusion technique to achieve fine grain structure in the lead alloy by using different die entry angles to study the microstructural and mechanical properties of lead alloy. Lead alloy samples were cast into cylindrical billets in a sand mould, machined, and tapered at the edge to ease entry into the die for the extrusion process. The die tools were made of mild steel with die entry angles of 15°, 30°, 45°, 60°, 75°, and 90°. Subsequently, the extrusion was performed with the aid of a hydraulic press machine that provided pressure on a cylindrical punch and forced the billet through the extrusion die. The mechanical and microstructural properties were studied, using the micro-hardness tester and metallurgical microscope, respectively. The results show that the maximum extrusion stress of 70 MPa of lead alloy occurred at a die entry angle of 45°, which is three times that of the conventional alloy (18 MPa) with crystal clustering and fine microstructure. The ductility of lead alloy improved when processed at a 60° die entry angle with extrusion stress of 63.3 MPa, with no significant increase in hardness with die entry angles (7.7-9.0 HV). The grains show an appreciable reduction in size and enhanced surface finish

ANÁLISE DE FRAGMENTOS BALÍSTICOS POR MEIO DE EXAMES MICRO BALÍSTICOS, DETERMINAÇÃO DA COMPOSIÇÃO QUÍMICA E ANÁLISE ISOTÓPICA DO CHUMBO: UMA REVISÃO

BALLISTIC FRAGMENTS ANALYSIS BY MICRO BALLISTIC EXAMINATIONS, CHEMICAL COMPOSITION AND LEAD ISOTOPE RATIOS: A REVIEW. Firearms and ammunition identification produces important information for the elucidation of the crime and also in cases of confirmation of the offender. In a crime scene, when a suspect weapon and its ammunition are found, it is possible to clarify and conclude an investigation using qualitative analysis and standards. However, in some cases only the fragments of ammunition are found, which makes difficult to identify the weapon using traditional techniques. Therefore, alternative methods are needed such as the determination of elemental composition of the lead alloy and the verification of the lead isotopic ratios. The present work includes a review of the basic concepts of ballistics and conventional techniques of ballistic confrontation, the existing studies related to the chemical analysis of ballistic fragments and its application in criminalistics and, finally, the articles involving the lead isotopic analysis as a tool for ballistic identification.

Segregation of Antimony along the Cross Section of Lead Castings as a Cause of Defects in Isostatic Pressing of Lead Alloy Products

Segregation of Antimony along the Cross Section of Lead Castings as a Cause of Defects in Isostatic Pressing of Lead Alloy Products

Influence of low-melting-point SnPb alloy powder on the performance of polylactic acid in injection molding

Polylactic acid is a thermoplastic polymer material known for its excellent biocompatibility, although it suffers from subpar rheological and mechanical properties. In this study, an investigation was carried out to assess how low filling degree, low melting point tin–lead alloy powder affects the mechanical and rheological properties of the PLA matrix during the injection molding process. The results of the study indicated that SnPb alloy powder could effectively enhance the melt flow of PLA during processing and serve as a solid filler after molding, resulting in a significant improvement of the material’s mechanical properties.

Understanding the corrosion properties of rolled anodes made of lead alloys with various additions

Understanding the corrosion properties of rolled anodes made of lead alloys with various additions

The influence of lead concentration on the properties of the electrodeposited zinc–lead alloy coatings

The effects the concentration of lead on zinc-lead alloys obtained from sulphate baths under continuous current deposition are described. The deposit morphology was analyzed using Scanning Electron Microscopy (SEM) and X-Ray Diffraction (XRD) was used to determine the preferred crystallographic orientations of the deposits. Protection against corrosion properties studied in a solution of 3 % NaCl in the potentiodynamic polarization measurements (Tafel), It has been observed that the Zn–Pb alloy is characterized by enhanced the resistance of corrosion compared to the Zn alloys and the addition of Pb in the Zn-Pb increases the micro-hardness, XRD and SEM results an identify any coatings Zn-Pb alloy composition reveals that. Zinc - rich (η- phase).

Advancement Toward the Experimental Measurement of the Lead–Bismuth Eutectic Thermal Properties Using Differential Scanning Calorimetry Technique

Abstract The differential scanning calorimetry (DSC) method has recently emerged as a sophisticated and precise technique for promising contributions to the thermal analysis of various materials, including heavy liquid metal (HLM) coolants. However, there is a lack of experimental studies on the thermal properties of lead-based fluids, such as lead–bismuth eutectic (LBE) and lead–lithium eutectic, which are potential candidates for use as coolants, breeders, and neutron multipliers in advanced nuclear systems like the fourth-generation lead-cooled fast reactor. The available experimental data on the thermal properties of LBE and other lead-based fluids is limited, and the measurements have significant uncertainty. In addition, the composition of components used in the previous studies is inconsistent, and the environmental conditions were often unknown. Therefore, to fill these gaps and advance the thermal properties measurement technique for heavy liquid metal coolants, ENEA Brasimone, in collaboration with DICI-UNIPI, has installed a DSC instrument setup. The experiments performed at the installed DSC setup are focused on measuring some essential thermal properties of LBE using DSC. The experience gained from this work will facilitate the measurement of other fluids based on lead alloy, especially lead–lithium eutectic, a potential candidate for breeder, coolant, and neutron multiplier in demonstration power plant fusion reactors. This study represents the first effort to advance the DSC approach for accurately measuring the thermal characteristics of heavy liquid metals that are highly reactive, such as lead–lithium, which has significant potential in advanced nuclear systems.

Perovskite single crystals with tin–lead gradient for improved ionization radiation detection

Compared with the pure lead-based MAPbBr3 (MA = CH3NH3) perovskite single crystals (PSCs), tin–lead alloy (MAPbxSn1−xBr3) PSCs with higher carrier mobility and longer carrier lifetime are expected to perform as better-quality ionization radiation detectors. In this work, we design MAPbBr3–MAPb0.9Sn0.1Br3–MAPb0.8Sn0.2Br3 structure detectors by employing solution-process epitaxial growth. Because of the gradient change in tin element proportion, the relatively low mismatch rates between different PSC layers can effectively reduce defects generated at the interface, which improves charge collection efficiency. Moreover, band barriers between different PSC layers form depletion layers due to the differences in band structure, and the high resistivity and built-in electric field of depletion layers can suppress dark current under high voltages. The optimized detector exhibits a high x-ray detection sensitivity of 6.76 × 104μC Gy−1 cm−2 and the lowest detectable dose rate of 7.4 nGy s−1 under 40 kVp x-ray radiation. Based on 241Am (5.95 MeV) α particle irradiation, tin–lead HD has lower detection noise and more obvious response compared to MAPbBr3 PSCs. The electron mobility was indicated as high as 612 cm2 s−1 V−1, and the mobility-lifetime (μτ) products were measured to be 3.5 × 10−3 cm2 V−1 using the Hecht equation, demonstrating superior transport properties.