Pb-Sb Alloys Research Articles

Clean and efficient separation of Pb-Sb alloy by vacuum gasification - Fractional condensation

The Lead (Pb) - Antimony (Sb) alloy derived from Jamesonite (Pb4FeSb6S14) using the "Roasting - Reduction Smelting" method is typically isolated through a separation method known as "High Temperature Ash Blowing - Low Temperature Ash Blowing - Electrolytic Refining". However, the "Low Temperature Ash Blowing" separation method encounters several challenges, including elevated production pressure of refined Pb, significant emissions of smoke and dust, and suboptimal separation efficiency. This study utilizes the "Vacuum Gasification - Fractional Condensation" method as an alternative to the "Low Temperature Ash Blowing" method. The experimental findings demonstrate that by implementing specific optimal experimental conditions, such as a condensation temperature range of 904–1054K, a vacuum degree of 5Pa, a gasification temperature of 1173K, a holding time of 7h, and a height-diameter ratio of 0.27, condensates with Sb content exceeding 99.5 wt% can be procured, resulting in a direct Sb yield of 33 %. The remaining residues, with an Sb content ranging from 14 to 15 wt%, serves as a valuable input for the "Electrolytic Refining" process. This utilization significantly alleviates the burden on refined Pb production during the "Electrolytic Refining" process. The treatment procedure does not require the utilization of chemical reagents, and it generates no wastewater or exhaust gas.

Separation of antimony from lead-antimony alloy by molten salt electrolysis

Lead-acid batteries (LABs) are widely used in electric motorcycles, uninterruptible power systems, and stationary energy storage devices. However, spent LABs should be recycled to reuse lead (Pb) and thereby close the Pb cycle and avoid Pb contamination. In order to reuse the recovered Pb, the purity of recovered Pb should meet the required standard. Since antimony (Sb) is a common alloying element in Pb alloy grid such as the Pb-Sb alloy, separating Sb from the recovered Pb is necessary. In this paper, we proposed a molten salt electrolysis method to separate Sb from liquid Pb-Sb alloys in terms of forming a solid Ca-Sb intermetallic at the top of the liquid Pb-Sb cathode. The electrochemical separation process was performed in molten NaCl-CaCl2. The content of Sb (atomic percent) in the Pb-Sb alloy was reduced from 1% to less than 0.01% (atomic ratio). The recovery principle lies in the different alloying potentials between Ca-Sb and Ca-Pb. Hence, molten salt electrolysis is a promising separation method to recover pure Pb from spent Sb-containing Pb alloys.

Prediction of buckling failure load of 304 stainless-steel column at elevated temperatures using lead–antimony alloys

A novel prediction model for the buckling failure load of 304 stainless steel under compression was developed using lead–antimony (Pb–Sb) alloys. The temperature-dependent modulus of elasticity of 304 stainless steel was characterized by changing the Sb concentration of the Pb–Sb alloys from 0 to 15 wt%. Slender Pb–Sb plate columns with a rectangular cross section were fabricated by casting. Buckling tests were performed with Pb–Sb alloys under compression at room temperature and compared with numerical simulations that considered the nonlinearity of the specimen, such as initial bending. Based on the buckling failure load and the modulus of elasticity measurements, the linear relationship between the normalized buckling failure loads and the normalized modulus of elasticity was obtained for both Pb-Sb alloy and 304 stainless steel. The relationship between these two correlations makes it possible to predict the buckling failure load of 304 stainless steel at elevated temperatures up to 1200 °C.

Discussion On Failure Behavior of Piping Systems Under Extremely Large Seismic Loads in BDBE

Abstract To investigate the failure behavior of piping systems under severe seismic loads considering beyond design basis event (BDBE), an experimental approach to use pipes made of simulation materials was applied. "Simulation material" means the substitute material for steel to realize the structural experiment by the existing testing facilities. The simulation materials adopted in this study were pure lead (Pb) or lead-antimony (Pb-Sb) alloy. Using pipe elbows made of simulation materials, static loading tests on elbows and shaking table tests on simple piping system models composed of one or two elbows and an additional mass were conducted. From the static loading tests, the load-deflection relationship of an elbow under monotonic loading was obtained as well as the fatigue failure modes under cyclic loading depending on the several cyclic displacement levels. From the shaking table tests, several failure modes were obtained, namely, "Collapse by self-weight", "Collapse by a few cycles of input", "Ratchet and subsequent collapse", "Overall deformation", and "No failure". It was considered that the occurrence of these failure modes was affected by the ratio of the input frequency to the specimen's natural frequency, the ratio of additional mass weight to the limit mass weight, the configuration of the specimen, and the input acceleration level. The experimental results indicated that it was crucial to understand the structure's ultimate behavior when treating BDBE, and that the research approach using simulation material is effective to investigate the ultimate behavior of piping systems.

Temperature-dependent mixing behavior of Pb–Sb alloys in liquid state

We have extended a computational model used to research the thermodynamic properties of binary liquid alloys to study chemical short-range order parameters and diffusion coefficients. Numerous simulations have also been employed for surface properties such as surface concentration and surface tension. The propensities for phase separation of the Pb–Sb alloy were also observed with a temperature rise. The structural and thermodynamic properties of the alloys were measured using the same interaction parameters that are suitable for the free energy of mixing and mixing enthalpy. The interaction parameters are discovered to be temperature-dependent but concentration-independent. Our results indicate that the liquid alloy Pb–Sb has a weakly interacting composition. According to the surface property review, the element Sb having a higher surface concentration than its bulk concentration segregates over the surface of the alloy.

Thermodynamic characteristics of liquid metallic alloys containing lead, antimony and bismuth

An improved construction of the electrochemical cell and optimized technique for measuring the electromotive forces (EMF) of liquid metallic Pb-Bi-Sb, Pb-Bi and Pb-Sb alloys in the KCl-PbCl2 melt are described in this paper. Proposed extensions allowed studying alloys of three different compositions simultaneously and increasing the reliability of the experimental EMF values. A simplified procedure for calculating integral molar thermodynamic functions of binary and ternary systems by the Darken method using only standard Excel tools is described in detail. Dependences of the integral excess Gibbs energy and entropy, integral molar Gibbs energy, mixing entropy and mixing enthalpy on the antimony mole fraction are calculated at 973 K for the Bi-Sb system, which cannot be studied by the EMF method due to the proximity of Bi and Sb potentials in the electrochemical series. The results confirm that the developed techniques are promising for determining thermodynamic characteristics of one of the binary systems without experimental study.

Experimental and theoretical investigation of Pb–Sb alloys as a gamma-radiation shielding material

Metal alloys with variable lead and antimony content have been prepared using fusion technique. The prepared alloys formula is (PbxSbyCu0.15Al0.1) with [x = 0.5–0.3 - 0.1–0] and [y = 0.25–0.45 - 0.65–0.75] respectively. A comparative study was conducted to find the optimum shielding parameters for the synthesized metal alloys. In terms of total mass attenuation coefficient MAC μm, linear attenuation coefficient LAC μl, half-value layer HVL, tenth-value layer TVL, mean free path MFP, effective atomic number Zeff, electron density number Neff, the exposure build-up factor EBF and the energy absorption build-up factor EABF the optimum shielding parameters are provided. Theoretical results were obtained from WinXCom software and interpolated at definite energy values. Simulation of the transmission experiment was conducted using FLUKA-MC software. Experimental results of the prepared metal alloys were compared with the theoretical ones, and a good agreement was found between them. It was found that present work prepared alloys composition can be used effectively as a shielding material for gamma rays with comparable attenuation percentage with high lead content alloys.

Mechanism of action of tin on the semi-conductive properties of PbO layer in lead acid battery

Although antimony in alloys for lead-acid batteries has better mechanical and electrochemical performance, it reduces the excessive potential for hydrogen evolution, resulting in excessive water loss and self-discharge of the battery. This paper aims to examine the action of tin in PbSn using different techniques. In this work, the addition of tin in PbCa was intended to suppress the premature capacity loss (PCL) caused by the substitution of antimony in the PbSb alloy by calcium that has good mechanical properties and a high hydrogen evolution potential (200 mV higher than that of antimony). This substitution induces the formation of a passive film composed mainly of α-PbO. The mechanism of action of tin on the anodic film obtained at 700 mV vs. Hg/Hg2SO4/K2SO4 saturated electrode with Pb – (0–5) wt.% Sn in 0.5 mol/L sulfuric acid solution at 25 °C was studied using electrochemical impedance spectroscopy (EIS), AC voltammetry, Mott–Schottky plots and X-ray diffraction (XRD) of the film obtained. It was found that tin stops the growth of the anodic film due to the co-precipitation of certain conductive oxides which reduce the thickness of the passive film and increase its conductivity. A mechanism of action of tin on the electrochemical behavior of the anodic film was suggested based on the results.

Recycling of lead from spent lead-acid battery by vacuum reduction-separation of Pb-Sb alloy coupling technology

Until today, there are still many problems that must be solved through innovative research to make the recycling of spent lead-acid batteries and the separation of Pb-Sb alloy more environmentally friendly and energy-saving. In this paper, a novel method for regenerating lead paste, by vacuum reduction reaction coupling with separation of Pb-Sb alloy, was developed. In this process, antimony from Pb-Sb alloy is used to reduce desulfurized lead paste into lead under vacuum, while it is oxidized into volatile Sb2O3 as by-product. The results showed that direct recovery ratio of Pb from desulfurized lead paste reached 99.29% and Sb-content in Pb-Sb alloy decreased from 46% to 0.98% under following conditions: the mass ratio of desulfurized lead paste to Pb-Sb alloy of 1.50, residual gas pressure of 30 Pa, reduction temperature of 810 °C for 50 min. By this method, not only the lead paste can be recovered with high atom economy, but also the Pb-Sb alloy can be separated efficiently at zero cost and without “three wastes” generation. Therefore, this method is very useful for the recycling of spent lead-acid battery and the separation of Pb-Sb alloy.

Efficient separation of lead and antimony metals from the Pb-Sb alloy by super-gravity technology

The Pb-Sb alloy was obtained during the pyrometallurgical processing of jamesonite (Pb4FeSb6S14). To effectively separate lead and antimony metals from the Pb-Sb alloy, an innovative approach of super-gravity technology was introduced in the current study. The super-gravity technology plays a significant role in enhancing mass transfer and phase migration of heterogeneous phases as the interfacial tension between different phases will become insignificant. The theoretical calculation of separating efficiencies based on the lever principle of Pb-Sb phase diagram was investigated. The effect of the super-gravity field on Pb-Sb alloys and the corresponding mechanism of filtrating were discussed. With the help of scanning electron microscopy-energy dispersive spectroscopy, metallographic microscopy and X-ray diffraction methods, it demonstrated that the lead phase migrated to the bottom of the sample along the super-gravity direction, whereas almost all of the antimony-rich phase accumulated along the opposite direction. As a step further, the Pb-Sb alloy was separated effectively by the filter in the super-gravity field, and the separating efficiency increased with the increasing of the gravity coefficient (G) within the range of G ≥ 50. With an optimized separation condition T = 533K (260 °C), G = 450, dpore = 48 μm and t = 210 s, the mass fraction of Pb in the filtrated lead phase reached 85 wt%, which was close to the theoretical separation value 88.8 wt% based on the phase diagram of the Pb-Sb alloy, and the mass fraction of Sb in the residue antimony-rich phase exceeded 91 wt%.

Correction to Density, Surface Tension, and Viscosity of Liquid Pb–Sb alloys

Correction to Density, Surface Tension, and Viscosity of Liquid Pb–Sb alloys

Chemical and Lead Isotope characterisation of First World War shrapnel balls and bullets used on the Alpine Austrian–Italian Front

Chemical and lead isotope characterisation was carried out on shrapnel balls and bullets dating back to the First World War (WWI). These ammunitions were widely utilised in the Alpine Austrian–Italian front located in the Italian Alps. The investigation has been performed using inductively coupled plasma quadrupole mass spectrometry equipped with an octopole reaction system (ORS-ICP-QMS). The main goal of this work was to identify the elemental and lead isotope composition of raw materials and to discriminate between the military objects analysed. The results of multi-elemental analysis indicate that the shrapnel ball samples consisted of soft Pb or hard Pb with Sb depending on the use, the weapon type and the specific nation. The Italian shrapnel balls were made from hard Pb, as opposed to those of the Austrian–Hungarian samples. Through the investigation of lead isotope ratios, it has been possible to differentiate most of the Italian shrapnel balls from those of Austrian–Hungarian origin. Furthermore, some Italian shrapnel balls had a different lead isotope composition depending on their calibre. The elemental composition and lead isotopic signature of bullets show a clear discrimination between the external jacket and the core in relation to projectile type and nationality. The bullet cores consist of Pb–Sb alloy regardless of the region of origin. This work allowed us to investigate the potential applications of trace elements and lead isotope analyses to discriminate military artefacts of different origins.

Effect of cross-section-change induced advective flow on the primary dendrite array morphology of hypoeutectic Pb-Sb alloys during directional solidification

The morphology and distribution of primary dendrites have been examined in Pb-2.2, 5.8 and 10.8 wt. pct. Sb alloy samples directionally solidified (DSed) in ampoules shaped like an hour-glass to examine the influence of cross-section change induced advective flow on the cellular/dendritic interface. This sample design increases the advective flow of the melt towards the array tips, as the liquid-solid interface enters the neck of the ampoule, and then decreases it as the interface exits the neck. The warm solute-rich melt flowing towards the growth front suppresses the extent of side-branching, decreases the primary dendrite spacing, and increases the primary dendrite trunk diameter as observed in the Pb-5.8 and 10.8 Sb alloys. The flow appears to suppress the formation of cells. A cellular interface growing in the Pb-2.2Sb alloy became planar as the solidification front entered the neck, becoming cellular again as it exited the neck.

Electrochemical Corrosion of Pb-Sn and Pb-Sb Alloys for Lead-Acid Battery Applications

Electrochemical Corrosion of Pb-Sn and Pb-Sb Alloys for Lead-Acid Battery Applications

Correction: Microstructure characterization and corrosion resistance properties of Pb-Sb alloys for lead acid battery spine produced by different casting methods.

[This corrects the article DOI: 10.1371/journal.pone.0195224.].

Phase Equilibria of a Pb–Sb–Ag Alloy during Vacuum Distillation

The saturated vapor pressures of lead, silver, and antimony are calculated for Pb–Ag and Pb–Sb alloys at temperatures of 1073–1773 and 823–1073 K, respectively. High ratios (pSb*/pPb*) × 103 = 15.0–1.8 and pPb*/pAg* = 2.9 × 103–74.0 create theoretical possibilities for sequential selective separation of these metals by vacuum distillation, during which the vapor is enriched in antimony and then lead and the liquid is enriched in silver. For vapor–liquid equilibrium (VLE) diagram, the lever rule (the rule of line segments) can be used to predict the amounts of substance, residue, and sublimate at a given temperature. Calculations of the ternary-alloy parameters can be performed by the Wilson equation using parameters obtained for the binary systems. The fractional Gibbs free energy (–ΔGPb/Sb/Ag = (2.1–22.4)/(1.9–25.5)/(18.1–50.0)), the enthalpy (ΔHPb/Sb/Ag = ±(0.2–16.9)/–(0.2–1.8)/(105–140) J/(K mol)), and the entropy (ΔSPb/Sb/Ag = (2.4–13.4)/(2.2–15.2)/(20.8–30.0) J/(K mol)) of the components of the Pb–Sb–Ag melts are calculated. As the fractions of metals in a starting alloy increase, the thermodynamic parameters decrease. The negative and positive values of the enthalpy indicate exothermic and endothermic processes in the melt during distillation of components, respectively. The calculated and experimental thermodynamic parameters are shown to agree satisfactorily: the standard relative deviation is 1.9% and the root-mean square deviation is 0.1 kJ/mol.

Density, Surface Tension, and Viscosity of Liquid Pb–Sb Alloys

With the use of the discharge crucible method, the density, surface tension, and viscosity of Pb–Sb liquid alloys were determined. The experiments were performed in the temperature range between 573 and 1050 K. The measurements were conducted in a glovebox filled with high-purity argon, which was continuously circulated between the glovebox and the purification system. The measurements were conducted for four alloys of the composition 16.75, 40, 60, and 90 atom % Sb. The experimental data on the surface tension and viscosity were compared to those from modeling. The new experimental data and the corresponding model-predicted values exhibit good agreement, and only small differences in linear changes between the surface tensions of Pb and Sb can be observed. This can be attributed to small negative deviations of the thermodynamic properties from Raoult’s law and a relatively small difference between the surface tensions of the pure components. In the case of viscosity, the measured data were in excellent a...

Microstructure characterization and corrosion resistance properties of Pb-Sb alloys for lead acid battery spine produced by different casting methods.

The aim of this study is to find out the microstructure, hardness, and corrosion resistance of Pb-5%Sb spine alloy. The alloy has been produced by high pressure die casting (HPDC), medium pressure die casting (AS) and low pressure die casting (GS) methods, respectively. The microstructure was characterized by using optical microscopy and scanning electron microscopy (SEM). The hardness was also reported. The corrosion resistance of the spines in 0.5M H2SO4 solution has been analyzed by measuring the weight loss, impedance spectroscopy and the potentiodynamic polarization techniques. It has been found that the spine produced by HPDC has defect-free fine grain structure resulting improvement in hardness and excellent corrosion resistance.

Vacuum dynamic oxidation process for separating Pb-Sb alloy

Up to now, separating Pb-Sb alloy obtained from jamesonite by conventional pyrometallurgy processes has many drawbacks such as long technological process, high energy consumption, and unsatisfactory separation efficiency. Thinking about the facts that antimony is used mainly in the form of Sb2O3, and separation of Sb2O3 with good volatility from the lead melt is very easy under vacuum, vacuum dynamic oxidation process, a new and effective process for separating lead and antimony from Pb-Sb alloy, was developed in this work. Experimental results revealed that the content of antimony in Pb-Sb alloy decreased from 42% to 0.30%, that the removal percent of antimony reached 99.59%, and that the PbO content in the distillate was 0.12% under melt temperature of 953 K, vacuum treatment time of 210 min, and air flow rate of 3 L/min, corresponding to the system pressure of 14 kPa. This study is of significance for separating Pb-Sb alloy obtained from jamesonite.

THERMODYNAMICS AND STRUCTURAL CONDITION OF PB-SB ALLOYS

In this paper we study the structural condition and thermodynamic functions of a melt of the Pb-Sb. The investigations were performed for alloys with an antimony content of 5.0-20.0% (wt.), the rest is lead. To determine the structural condition of alloys we use microstructure analysis, differential thermal and X-ray structural analyses. The phase composition of alloys was determined in relation to the temperature of the liquid heating above the liquidus curve and to the cooling rate. With accounting for the first degree approximation of high-temperature expansion of the thermodynamic potential in expression for the Gibbs energy of a melt of the binary Pb-Sb alloy we find the curve of thermodynamic stability of the liquid depending on the antimony content in alloy. This approach enables to give the most complete description of the alloys’ melt from the thermodynamic point of view and to determine a thermodynamic stability curve, above which there are no microcomplexes in the phase. The results of the calculations obtained in this paper are in good agreement with the experimental data.