Impurity Accumulation Research Articles

Performance improvement of space-resolved extreme ultraviolet spectrometer by use of complementary metal-oxide semiconductor detectors at the Experimental Advanced Superconducting Tokamak.

Two pairs of space-resolved extreme ultraviolet (EUV) spectrometers working at 5-138 Å with different vertical observation ranges of -7 ≤ Z ≤ 19 and -18 ≤ Z ≤ 8cm have been newly developed to observe the radial profile of impurity line emissions and to study the transport of high-Z impurity ions intrinsically existing in EAST tokamak plasmas. Both spectrometers are equipped with a complementary metal-oxide semiconductor (CMOS) detector (Andor Marana-X 4.2B-6, Oxford Instruments) with sensitive area of 13.3 × 13.3mm2 and number of pixels equal to 2048 × 2048 (6.5 × 6.5 µm2/pixels). Compared to the currently operating space-resolved EUV spectrometers with a charge-coupled detector (CCD: 1024 × 255 pixels, 26 × 26 µm2) working at 30-520 Å, this spectrometer's performance was substantially improved by using the CMOS detector. First, the spectral resolution measured at full width at half maximum was improved in the whole wavelength range, e.g., Δλ1/2_CMOS = 0.092 Å and Δλ1/2_CCD = 0.124 Å at C VI 33.73 Å and Δλ1/2_CMOS = 0.104 Å and Δλ1/2_CCD = 0.228 Å at Mo XXXI 115.999 Å, thus enabling a more accurate analysis of spectra with complicated structure such as tungsten unresolved transition array in the range 45-65 Å. Second, the temporal resolution was largely improved due to the high-speed data acquisition system of the CMOS detector, e.g., Δt_CMOS = 15 ms/frame and Δt_CCD = 200 ms/frame at routine operation in the radial profile measurement. Third, signal saturation issues that occurred when using the old CCD sensor during impurity accumulation now disappeared entirely using the CMOS detector due to lower exposure time at high readout rates, which largely improved the observation performance in similar impurity burst events. The above-mentioned performance improvements of the space-resolved EUV spectrometer led to a rapid change in the W XXXIII (52.22 Å) radial profile during a single cycle of low-frequency sawtooth oscillation with fst = 5-6Hz at a sufficient detector count rate.

An Online Identification Method of Thermal Dissipation State for Forced Air-Cooled System of Power Converters

Thermal stress is the primary cause of malfunction and failure in power modules. As the main heat dissipation component, the heatsink plays a significant role in improving the reliability of power converters. However, due to the continuous accumulation of dust and impurities on the heatsink’s air inlet side, the thermal dissipation performance of the cooling system constantly declines, which influences the reliable operation of power modules. In this article, a computational fluid dynamics (CFD)-based simulation analyzes the declining mechanism of the heatsinks’ thermal transfer performance. Moreover, a novel online method is proposed for the cooling system’s thermal dissipation state identification. This method regards the steady-state thermal resistance as the feature parameter of the thermal dissipation state evaluation. And a parameter identification method is employed to identify the steady-state thermal resistance due to the difficulty of obtaining it in the transient thermal process. In addition, an ac/dc/ac pulsewidth modulation (PWM) converter is built for verification. The experimental results demonstrate that the proposed method enables accurate and fast identification of the cooling systems’ thermal dissipation state. It can be one of a solution for replacing the existing off-line manual periodic detection method, which helps improve detection efficiency and decrease maintenance costs.

Gyrokinetic Stability Analysis of JET Pedestal Top Plasmas with Small-ELMs

In recent years, a strong effort has been dedicated to the development of tokamak plasma regimes alternative to the standard high confinement mode (H-mode) with type-I edge localized mode (ELM), i.e. ELM-free and small-ELM regimes, given the associated hardly sustainable energy and particle fluxes on plasma facing components.In this work, we will focus on new H-mode regimes with small-ELMs, the so-called baseline small-ELMs (BSE), characterized by high thermal confinement and low core impurity accumulation, which have been recently found at JET. In order to characterize the micro-turbulence at play at the top of the pedestal, an extensive local linear gyrokinetic analysis with the GKW code has been carried out. In particular, a comparison between a reference type-I ELM (#97395) and two BSE plasmas (#96994 and #94442) has been performed.The ion-scale (0.1 ≤ k θ ρ i ≤ 2) micro-turbulence is found to have different characteristics in the two regimes. Indeed, kinetic-ballooning modes (KBM) are destabilized in the type-I ELM regime at k θ ρ i ∼ 0.1, while they are stable in BSE regimes. In addition, negative (i.e. electron-diamagnetic-direction) frequency modes, identified as electron-temperature-gradient (ETG) modes, are destabilized at k θ ρ i ∼ 1.5 in the type-I ELM regime while BSE regimes are characterized by positive (i.e. ion-diamagnetic-direction) frequency modes. Meanwhile, at electron-scale (10 ≤ k θ ρ i ≤ 700) ETG modes are the dominant micro-instabilities in both regimes. Then, since BSE regimes are characterized by a higher impurity concentration at the pedestal, particular attention has been given to the role played by them. We found that impurities represent a critical player in the linear dynamics, strongly affecting the nature of micro-instabilities at ion-scale.

Development of the Composition and Technology for Production a Solid Dispersion System by Hot Melt Extrusion to Increase the Bioavailability of the Active Substance

Introduction. The solubility of an active pharmaceutical ingredient plays a major role in drug absorption. Hot melt extrusion is a batch or continuous process that allows creating solid dispersion systems based on various carriers in order to increase solubility and bioavailability of active substances. Development of effective and safe analgesics is one of the most vital tasks of organic and medicinal chemistry. An innovative non-opioid analgesic with very low toxicity and low dosage, but practically insoluble in water, was used in this work. It was suggested to obtain a solid dispersion by hot melt extrusion in order to increase bioavailability.Aim. Development a hot melt extrusion technology for production of a solid dispersion system of PAV-0056 as an active substance and Plasdone™ S-630 as a polymeric carrier to increase the solubility.Materials and methods. PAV-0056 (methyl-2-(7-nitro-2-oxo-5-phenyl-3-propoxy-2,3-dihydro-1H-benzo[e][1,4]diazepin-1-yl)acetate) (JSC "Organica", Russia) Figure 1; Plasdone™ S-630 (Boai NKY Pharmaceuticals Ltd., China); PEG-1500 (Clariant, Switzerland); acetonitrile for chromatography (Thermo Fisher Scientific, Germany). Extrudates were obtained using a HAAKE™ MiniCTW co-rotating twin-screw laboratory extruder (Thermo Fisher Scientific, Germany). Extrudates were examined by optical microscopy and differential scanning calorimetry, and time of water solution stability was determined. The quantitative content of the active substance and related impurities in the 2.5 % solid dispersion of PAV-0056 was determined by HPLC-UV.Results and discussion. Hot melt extrusion process conditions were established for a mixture of 2.5 % PAV-0056 and Plasdone™ S-630. Stability of the extrudate solution in water was studied, the content of the active substance and impurities in the extrudates was determined. Based on the binary mixture, a composition containing 10 % of PEG-1500 was developed. The optimal conditions for the extrusion process were chosen for obtaining a solid dispersion system that meets the requirements of the regulatory documentation for the content of the active substance and impurities.Conclusion. The binary mixture proved to be unsuccessful for the creation of SDS by hot melt extrusion due to significant accumulation of impurities during the extrusion process. By adding PEG-1500 to the composition, it was possible to considerably lower the operating temperature of the process, reduce the impurity content in the extrudate, and maintain satisfactory stability of the PAV-0056 solution in water.

Fluorine Substitution at the O-Site Imparts Enhanced Chemical Stability for Garnet-Structured Electrolytes

Garnet-based superionic conductors hold great promise in next-generation lithium-ion batteries (LIBs) because of their favorable ionic conductivity and unique stability against Li-metal anodes; however, they still face the challenge of air stability for mass production/practical application. Herein, we identify their structural features and tailor the functional elements to enhance the chemical stability via synergistic control of doping and non-stoichiometry. The optimal composition of Li6.25Ga0.2La3Zr2O11.85F0.15 (LGLZO-0.15F) garnet exhibits great air durability without noticeable impurity accumulation, even during continuous air exposure for 60 days, owing to the high affinity of the fluorine dopant for lithium occupying the octahedral site. Meanwhile, LGLZO-0.15F possesses an appreciable Li-ion conductivity of 8.4 × 10–4 S cm–1 with an activation energy of 0.29 eV. Benefiting from these properties, hybrid and all-solid-state lithium batteries constructed with LGLZO-0.15F electrolytes demonstrate low overpotential, high Coulombic efficiency, and stable cycling performance.

Uncovering the effects of Ce and superheat temperature on Fe-rich intermetallic and microporosity formation in aluminum alloy

The continuous accumulation of Fe impurities in recycled aluminum is a major obstacle for its wide application in fatigue sensitive parts due to the formation of Fe intermetallics and micropores. In this paper, we study the effects of rare earth elements and superheat temperature on the crystal structure of Fe-rich intermetallic and morphology of microporosity using micron-resolution phase-contrast lens magnification based X-ray computed tomography (XCT). Using image registration and U-net convolutional neural networks (CNN) algorithm, we first segmented the morphology of Fe-rich intermetallic and quantified their distribution as a function of Ce additions and superheating temperature. It was found that the addition of Ce elements promoted the microstructure refinement and restricted the growth of β-Fe intermetallics effectively. Lowering the superheat temperature from 780 °C to 680 °C does not show a linear relationship between porosity level and the reduction of the intermetallic volume fraction. In fact, we have found the size of eutectic Si and Fe-rich intermetallic is the smallest at 730 °C and the tensile strength at as-cast condition with a superheating at 730 °C and Ce addition can give the greatest elongation at 4.26%, and yield and tensile strengths at 175.3and 249.5 MPa, respectively. • Rare earth Ce refines microstructure of Al-Si-Mg alloys and thus reduces pore size. • Non-linear relationship between superheat and pore size were found. • 3D Segmentation of α-Fe and β-Fe intermetallics using U-net CNN algorithm were developed for CT data. • Minimizing negative impacts of Fe-intermetallics and pores on properties is achieved.

Failure analysis on silicon semiconductor device materials: optical and high-resolution microscopic assessments

Defects of silicon (Si) semiconductor epilayers are crucial to be identified at laboratory environs. The identification of failure and its rectification at laboratory settings is essential for large-scaling manufacturing of narrowed down semiconductor devices. This research documented the inspection, identification and the solution for defects found in the Si semiconductor epilayers, fabricated by a simple and conventional photolithography technique, with the integration of metal oxide nanomaterial, zinc oxide (ZnO). The semiconductor epilayers, Si wafer, Si oxide and ZnO coated SiO2 layer were formed and examined. Optical microscope images [high power microscope (HPM) and 3D profilometer] reveal smooth surface of semiconductor epilayers development through thermal oxidation and photolithography techniques. High power ultraviolet-visible (UV-Vis) justified the accuracy of wet thermal oxidation by examining the thickness of oxide layer on Si wafer at 3837.3 Å. The X-ray diffraction (XRD) analysis of sol-gel synthesized ZnO affirmed the hexagonal crystalline state and its nanoscale size at 54 nm. Field emission scanning electron microscopy (FESEM) has shown the insight of Si epilayer morphology with its elemental composition, which provides details of foreign substances on semiconductor surface. ZnO deposited Si epilayer was prepared through lamella preparation, prior to the cross-sectional field emission transmission electron microscopy (FETEM) analysis of the semiconductor, which revealed the uniformity of fabrication and ZnO distribution at Si epilayer. Failure analysis reported several defects on the Si epilayers in the state of patches and accumulation of impurities. The potential cause of the defects and the respective solutions are discussed as the accuracy and handling must be ensured throughout the fabrication process, to develop a flawless semiconductor for high performance applications.

De-Ironing of Aluminium Alloy Melts by High Shear Melt Conditioning Technology: An Overview

The main problem of recycling aluminium scrap is the gradual accumulation of impurities, especially iron, which tend to form undesired intermetallic compounds that affect the integrity and the mechanical performance of the castings. In this paper, we aim to provide an overview on the topic of iron removal from aluminium melts through primary intermetallic precipitation and the progress made during the LiME Hub project to understand the process and to develop a more efficient procedure. We cover both thermodynamic analysis and experimental validation. We found that high shear melt conditioning technology enhances the typically slow nucleation and growth of the dense primary intermetallics, speeding up their sedimentation and allowing a faster removal of Fe from the melt by simple gravity sedimentation. It also promotes the formation of smaller and more compact Fe-rich intermetallics, allowing an increased volume fraction recovery and mitigating their effect of being present in the final castings. The technology is not limited to batch processing, with a 90% efficiency, but can also be applied to continuous melt treatment of aluminium scrap, with currently 60% efficiency, and could be combined with other solid–liquid separation techniques to increase the purification efficiency even more.

Distribution of Trace Elements (Ag, Pd, Cd, and Mn) between Pyrite and Pyrrhotite and Selectivity of Surficial Nonautonomous Phases in a Hydrothermal System

The dual distribution coefficients (D) that are related to structurally and superficially bound trace element (TE) in pyrite (Py) and pyrrhotite (Po) associations, crystallized hydrothermally at 400 °C and 1 kbar pressure, were determined. Three independent methods were used to estimate the structural and surficial TE contents (Cstr and Csur) and the corresponding D Py/Po values (Dstr and Dsur), which were found, on average, to be 12.4, 0.8, 0.9, and 0.06 (Dstr) and 2.6, 0.7, 2.0, and 0.07 (Dsur) for Ag, Pd, Cd, and Mn, respectively. The coincidence of a dual D for several elements was a result of coupled changes in Csur and Cstr. The selectivity (S) of the surficial nonautonomous phases (NAPs) that were responsible for TE accumulation (which is the ratio of TE concentrations in surficial and structural modes) was determined. It was shown that the interpretation of TE uptake by surficial phases was adequate and that this phenomenon is common in nature, independently of the system where it occurs—i.e., in experimental autoclaves or in hydrothermal ore deposits. Studies of NAPs selectivity can help in evaluating the total element compatibility in minerals and the maximum possible contents of structurally bound admixtures of the element (solubility) in minerals under given conditions. A significant surficial impurity accumulation effect is most important and well-pronounced for incompatible micro-elements with concentrations of less than ~0.1 wt%. The surficial mode may be a source of Pd and other platinum group elements and more abundant and easily refined than the structurally bound mode.

A sustained high-temperature fusion plasma regime facilitated by fast ions.

Nuclear fusion is one of the most attractive alternatives to carbon-dependent energy sources1. Harnessing energy from nuclear fusion in a large reactor scale, however, still presents many scientific challenges despite the many years of research and steady advances in magnetic confinement approaches. State-of-the-art magnetic fusion devices cannot yet achieve a sustainable fusion performance, which requires a high temperature above 100 million kelvin and sufficient control of instabilities to ensure steady-state operation on the order of tens of seconds2,3. Here we report experiments at the Korea Superconducting Tokamak Advanced Research4 device producing a plasma fusion regime that satisfies most of the above requirements: thanks to abundant fast ions stabilizing the core plasma turbulence, we generate plasmas at a temperature of 100 million kelvin lasting up to 20 seconds without plasma edge instabilities or impurity accumulation. A low plasma density combinedwith a moderate input powerfor operation is key to establishing this regime by preserving a high fraction of fast ions. This regime is rarely subject to disruption and can be sustained reliably even without a sophisticated control, and thus represents a promising path towards commercial fusion reactors.

Temperature screening and cross-field impurity accumulation from a thermodynamic perspective

In a variety of different systems, high-Z ion species show a marked tendency to accumulate in regions of high plasma density. It has previously been suggested that the apparent universality of this behavior could be explained thermodynamically, in terms of the maximum-entropy state attainable when the system must obey an ambipolarity condition. However, the previous treatment did not allow for the possibility of temperature gradients. Here, tools from non-equilibrium (Onsager) thermodynamics are used to show that ambipolarity continues to play a key role in producing this behavior in the presence of temperature gradients, and to recover well-known temperature screening effects that appear in these cases.

THE AGING PROCESS OF MOTOR OILS DURING OPERATION

During the aging process, the composition of the oil becomes more complicated due to the accumulation of impurities in it, thermal or thermo-chemical decomposition of hydrocarbons and additives. These products enter into physical and chemical interactions with each other and with pollutants. There is also evaporation of light fractions of oil, the activation of additives, contamination with various mechanical impurities, water. To ensure minimal wear of engine parts, we suggest using oils of higher viscosity for hot climatic conditions.

A new form of impurity cluster in casting quasi-single crystalline silicon

The casting quasi-single crystalline silicon technology is very promising in the development of high quality and low cost crystals for manufacturing photovoltaic devices. In this study, we find a new type of impurity cluster named as “black spot” in the casting quasi-single crystalline, which is different from the “shadows” caused by SiC/Si3N4 particles discovered in previous research. The “black spot” is systematically studied and characterized using inductively coupled plasma mass spectrometry (ICP-MS), photoluminescence (PL), and infrared (IR) detectors. The test results show that the “black spot” is composed of metal impurities. According to our analysis, the formation mechanism of the “black spot” may be caused by the accumulation of the metal impurities in certain region of the solid/liquid interface. These clustering impurities are not absorbed by enough grain boundaries in the casting quasi-single crystalline after being solidified into the crystal and thus exhibit as “black spot”. An optimization method is proposed in the direction of numerical simulation and verified by experiments to avoid the formation of the “black spot”.

Enhancing P removal from primary Si by P-containing Al2Si2Sr phase during Al–Si solvent refining

In this paper, adding small amounts of Sr in Al–Si solvent to enhance the P removal from primary Si by the formation of P-containing Al2Si2Sr phase has been developed. By microstructure and EDS analysis, it is determined that the Al2Si2Sr phase precipitated in the melt is enriched with 0.8–1.2 at% P. The precipitation of the P-containing Al2Si2Sr phase consumes a large amount of P in the melt, which makes the P content in the primary Si decrease. With the addition of Sr-16000 ppmw, the P removal fraction in the primary Si is all over 93% and the highest removal fraction reaches 94.66%. The B content in primary Si does not change significantly with the increase of Sr addition. Some of the Al2Si2Sr phases are trapped and engulfed by the primary Si, which leads to the accumulation of Sr impurity in the primary Si. Moreover, the possibility of P behaving as the solute atom in the Al2Si2Sr solid solution is analyzed through first-principle calculations. The result shows that P replaces Si at its the atomic position in the Al2Si2Sr phase to achieve a more stable crystal structure. Finally, an evolution model of the interaction between the P-containing Al2Si2Sr phase and the primary Si in the Al–Si melt is established.

Nitrogen Poisoning of HDPE and LLDPE based on Chemically Recycled Post‐Consumer Plastic via a Kinetic and Microstructural Modeling Technique

AbstractChemical recycling of plastic waste has promise as a complementary technology to increase eco‐efficiency of plastics life cycles. Accumulation of impurities in feed streams can affect sensitive compounds such as the Ziegler–Natta catalyst systems commonly used to produce polyolefins such as high density polyethylene (HDPE) and linear low density polyethylene (LLDPE). In a poison study, the influence of impurities—more specifically NO and N2O—on the catalyst system are investigated comprehensively in terms of kinetic behavior and activity rates. A product composition analysis gives insights into product properties such as molecular weight distribution (MWD), comonomer composition distribution (CCD), melting point, and crystallinity. By applying known modeling techniques (kinetic modeling, MWD, and CCD deconvolution modeling), information beyond analytical data is obtained. The results of the study show that both poisons significantly affect catalyst kinetics and reduce catalyst activity. N2O influences primarily the MWD, while NO poisoning strongly affects the CCD of LLDPE samples. Since the mechanical properties of the polymers produced depend on factors such as MWD and CCD, NO and N2O poisoning may reduce their processability and applicability.

EAST steady-state long pulse H-mode with core-edge integration for CFETR

A recent EAST experiment has successfully demonstrated long pulse steady-state high plasma performance scenario and core-edge integration since the last IAEA in 2018. A discharge with a duration over 60 s with β P ∼ 2.0, β N ∼ 1.6, H98y2 ∼ 1.3 and an internal transport barrier on the electron temperature channel is obtained with multi-RF power heating and current drive. A higher β N (β N ∼ 1.8, β p ∼ 2.0, H98y2 ∼ 1.3, n e/n GW ∼ 0.75) with a duration of 20 s is achieved by using the modulated neutral beam and multi-RF power, where several normalized parameters are close or even higher than the phase III 1 GW scenario of CFETR steady-state. High-Z impurity accumulation in the plasma core is well controlled in a low level by using the on-axis ECH. Modeling shows that the strong diffusion of TEM turbulence in the central region prevents tungsten impurity from accumulating. More recently, EAST has demonstrated compatible core-edge integration discharges in the high β p scenario: high confinement H98y2 > 1.2 with high β P ∼ 2.5/β N ∼ 2.0 and f bs ∼ 50% is sustained with reduced divertor heat flux at high density n e/n GW ∼ 0.7 and moderate q 95 ∼ 6.7. By combining active impurity seeding through radiative divertor feedback control and strike point splitting induced by resonant perturbation coil, the peak heat flux is reduced by 20–30% on the ITER-like tungsten divertor, here a mixture of 50% neon and 50% D2 is applied.

Population balance modelling captures host cell protein dynamics in CHO cell cultures.

Monoclonal antibodies (mAbs) have been extensively studied for their wide therapeutic and research applications. Increases in mAb titre has been achieved mainly by cell culture media/feed improvement and cell line engineering to increase cell density and specific mAb productivity. However, this improvement has shifted the bottleneck to downstream purification steps. The higher accumulation of the main cell-derived impurities, host cell proteins (HCPs), in the supernatant can negatively affect product integrity and immunogenicity in addition to increasing the cost of capture and polishing steps. Mathematical modelling of bioprocess dynamics is a valuable tool to improve industrial production at fast rate and low cost. Herein, a single stage volume-based population balance model (PBM) has been built to capture Chinese hamster ovary (CHO) cell behaviour in fed-batch bioreactors. Using cell volume as the internal variable, the model captures the dynamics of mAb and HCP accumulation extracellularly under physiological and mild hypothermic culture conditions. Model-based analysis and orthogonal measurements of lactate dehydrogenase activity and double-stranded DNA concentration in the supernatant show that a significant proportion of HCPs found in the extracellular matrix is secreted by viable cells. The PBM then served as a platform for generating operating strategies that optimise antibody titre and increase cost-efficiency while minimising impurity levels.

Accumulation of Inert Impurities in a Polymer Electrolyte Fuel Cell System with Anode Recirculation and Periodic Purge: A Simple Analytical Model

Anode recirculation with periodic purge is commonly used in polymer electrolyte fuel cell systems to control the accumulation of nitrogen, water, and other impurities that are present in the fuel or diffuse through the membrane from the cathode compartment. In this work, we develop a simple, generalized analytical model that simulates the time dependence of the accumulation of inert impurities in the anode compartment of such a system. It is shown that, when there is transport out of the anode chamber, the inert species is expected to accumulate exponentially until equilibrium is reached when the rate of inert entering the anode in the fuel supply and/or via crossover from the cathode is balanced by the rate of leakage and/or crossover to the cathode. The model is validated using recently published experimental data for the accumulation of N2, CH4, and CO2 in a recirculated system. The results show that nitrogen accumulation needs to be taken into account to properly adjust system parameters such as purge rate, purge volume, and recirculation rate. The use of this generalized analytical model is intended to aid the selection of these system parameters to optimize performance in the presence of inerts.

New H-mode regimes with small ELMs and high thermal confinement in the Joint European Torus

New H-mode regimes with high confinement, low core impurity accumulation, and small edge-localized mode perturbations have been obtained in magnetically confined plasmas at the Joint European Torus tokamak. Such regimes are achieved by means of optimized particle fueling conditions at high input power, current, and magnetic field, which lead to a self-organized state with a strong increase in rotation and ion temperature and a decrease in the edge density. An interplay between core and edge plasma regions leads to reduced turbulence levels and outward impurity convection. These results pave the way to an attractive alternative to the standard plasmas considered for fusion energy generation in a tokamak with a metallic wall environment such as the ones expected in ITER.

International comparison of impurities mixing and accumulation in steel scrap

AbstractThe accumulation of impurities in the recycling of steel impacts the quality of secondary steel. Understanding impurity levels is crucial in the context of the proliferation of circular economy policies, expected high recycling rates, and growth of scrap consumption. By assuming the accumulation of impurities to be equal worldwide, the understanding of the extent and variation of the mixing and accumulation was limited in previous studies, and the factors influencing those variations were not considered. This is a first cross‐national comparison of impurity accumulation in recycled steel. In this study, the copper, tin, nickel, chromium, and molybdenum content was analyzed in over 500 samples of electric arc furnace rebars from China, Japan, Vietnam, Ukraine, and the Netherlands (representing northwestern Europe) with an optical emission spectrometer. The impurity content in rebars represents the content of impurities accumulated in steel scrap in the countries studied. The measured content of impurities was then used to determine the factors influencing the accumulation of those impurities. It was revealed that the recycling technology, the presence of a market for recovered metals, the quality of the material input, steelmaking practices, and the management of byproducts derived from a legislative or economic context played a role in the impurities content. By communicating on scrap chemical content, the collaboration between the recycling and steel industries could be enhanced in terms of matching the demand and supply and facilitating an increase in the scrap share in steelmaking.