Aluminum Melt Research Articles

Risk assessment in sociotechnical systems based on functional resonance analysis method and hierarchical fuzzy inference tree

Effective risk assessment is crucial for ensuring safety and preventing severe consequences in complex socio-technical systems. Traditional probabilistic risk assessment methods have limitations in capturing the systemic complexities and the role of human operators, necessitating the advancement of methodologies. The present study aims to develop a comprehensive risk assessment methodology tailored for complex socio-technical systems, integrating the functional resonance analysis method, soft computing, natural language processing, and multi-criteria decision-making. Novel approaches, including expressing timing and precision variability through Z-numbers, employing Z-TOPSIS for their integration, utilizing a hierarchical fuzzy inference systems to model variability propagation, and text classification to compute the amplification factor using near-miss data, were introduced in the study. Further analyses were also conducted to identify critical couplings and paths. Additionally, the concept of degree centrality was utilized to identify functions that are impacted by multiple upstream functions and those that exert influence on several downstream functions. The methodology’s application to an anode change operation in an aluminum smelter highlighted its effectiveness. For practitioners, the framework offers a structured, data-driven tool for risk assessment. Its implementation can improve safety, reduce accidents, and prevent economic losses from disruptions and injuries.

Spatial extent and age-related bioaccumulation of fluoride in the bones of house sparrows around aluminium smelting operations.

Spatial extent and age-related bioaccumulation of fluoride in the bones of house sparrows around aluminium smelting operations.

Optimized fluorine recovery and regulated synthesis of aluminum fluoride hydroxy hydrate from waste cryolite via chemical equilibrium modeling and DFT analysis.

Optimized fluorine recovery and regulated synthesis of aluminum fluoride hydroxy hydrate from waste cryolite via chemical equilibrium modeling and DFT analysis.

Lipid profile of Siberian larch needles under chronic exposure to aluminum smelter emissions (Eastern Siberia, Russia).

The lipid composition of Larix sibirica needles, a key forest-forming species of boreal forests of Eastern Siberia (Irkutsk region, Russia), exposed to emissions from the Bratsk aluminum smelter, one of the world's largest aluminum producers, was studied. The production emissions of this smelter contain multiple pollutants, with fluoride compounds and polycyclic aromatic hydrocarbons (PAHs) demonstrating the highest phytotoxicity. Lipid profiles of needles were analyzed using thin-layer chromatography across a pollution gradient ranging from background to critical levels. The content of pollutant elements (F, S, metals and metalloids) in the needles was determined using inductively coupled plasma atomic emission spectrometry (ICP-AES) and spectrophotometry. The oxidative stress markers (hydrogen peroxide and malonic dialdehyde (MDA) levels) were also measured using spectrophotometric methods. It was shown that unlimited input of pollutants initiates the development of oxidative stress in larch needles. This is evidenced by a 1.3-4.5 fold increase in H2O2 concentration in needles compared to background (unpolluted) tree-stands and a close positive relationship between these parameters (r = 0.69-0.87, P ≤ 0.05, n = 29). Analysis of the lipid profile of L. sibirica needles at different pollution levels revealed a significant effect of pollutant elements on the content of neutral (r = 0.0.87, (r = 0.79, P ≤ 0.05, n = 29) and polar lipids (r = 0.67, P ≤ 0.05, n = 29). In the fraction of neutral lipids, with an increase in the pollution level, the content of higher aliphatic alcohols increased by 2.6 times, hydrocarbons by 3.1 times, esters of sterols by 4.3 times, 1.3-diglycerides by10 times compared to background values. The content of sterols and wax, on the contrary, decreased by 1.6 times. In the polar lipid fraction at low, moderate, and high pollution levels the quantitative content of sphingolipids increased up to 7.3 times, glycolipids - up to 2.3 times, phospholipids - up to 1.9 times, at the critical level the content of all fractions decreased. The revealed changes in the quantitative and qualitative composition of total lipids in needles indicate an increase in membrane microviscosity and a decrease in fluidity at low, moderate and high pollution levels, due to which the flow of pollutants inside cells is reduced. At critical pollution levels, these mechanisms are significantly weakened. The results obtained, revealing the specific mechanism of physiological and biochemical adaptation of L. sibirica to industrial pollution, have important applied value for developing highly sensitive bioindicator methods based on lipid biomarkers; integrated assessment of forest ecosystems sustainability under technogenic impact, and modeling of long-term consequences of anthropogenic load on boreal forests - a key component of the global carbon cycle and a major reservoir of biological diversity.

Research into the possibility of air separation of cake at the Pavlodar aluminum smelter

Air separation can play a key role in the sintering process of the charge material in the alumina production at the Pavlodar Aluminum Plant. During sintering, sinter dust is formed, which must be effectively separated from the bulk material, since its fine fraction is a source of formation of a solid phase carried away with the solution, which increases the number of secondary losses of valuable components. The use of air separation will solve this problem, providing a high degree of separation of the sinter product into coarse and fine fractions, thereby intensifying the further process of hydrochemical processing of the sinter from the sintering furnaces. The main goal of these studies was to reduce the loss of valuable components from the sinter, namely aluminum oxides and alkali, which are carried away with the solid phase of the tubular apparatus effluent. This paper considers the preliminary classification of sinter dust in air separators and its separate leaching. Extensive (pilot) laboratory tests determined the separation boundary of sinter classes (– 0.25 mm), which allows increasing alumina extraction by ~ 2% and suggests a reduction in the number of operating furnace lines by 0.26 units by reducing ballast flows, and the optimal indicator of air separation efficiency was determined to be ~ up to 97%. The results demonstrate the importance of air separation in ensuring the quality of the sinter product and improving the efficiency of alumina production technology as a whole.

A Review of the Properties and Potential of Melting and Smelting Slag-Reinforced Aluminum Matrix Composites (AMCs)

A Review of the Properties and Potential of Melting and Smelting Slag-Reinforced Aluminum Matrix Composites (AMCs)

Bladder cancer risk in aluminum production workers: A systematic review.

Bladder cancer risk in aluminum production workers: A systematic review.

Material recycling and hardware re-use for Moon and Martian settlement

Abstract The next big leap in institutional and commercial space exploration is inextricably linked to the human desire to reach the Moon and Mars and to establish a permanently off-Earth inhabited colony [1], [2]. In the last decades, this has been one of the major, more demanding challenges for industry and agencies, since this imposes a creative re-thinking of previous mission approaches. Earth dependency has always represented the bottleneck for freely conceiving a human outpost on the Moon and Mars. It is widely recognized that a key enabler to any sustainable presence in space is the ability to manufacture necessary structures and spare parts in-situ and on-demand by recycling and re-using the available resources [3]. This will reduce cost, volume, and up-mass constraints, being also in line with the ESA space debris mitigation policy towards environmentally sustainable space activities. In this frame, the scope of this paper is to present the concepts investigated during ESA’s (European Space Agency) HARMONISE activity concerning both in-situ materials recycling and partial or complete re-use of end-of-life hardware to serve different purposes during Moon/Mars exploration missions. The investigation approach was threefold: recycling of polyethylene Ziplock® bags into 3D-printable filament; melting and casting of scrap aluminium for tools fabrication, and partial re-utilisation of rack blind panels for habitat furniture design. For each of these strategies, a dedicated demonstrator has been designed, manufactured, and tested with respect to pre-defined success criteria, to fulfil functional requirements for both Earth and lunar/Martian scenarios. The HARMONISE (Hardware Recycling for Moon and Martian Settlement) activity will contribute to ushering a new, more sustainable space exploration era, supporting an emerging circular economy through in-orbit servicing and off-Earth manufacturing by 2050.

Impact of Melt Refining on Secondary Al-Si Alloys’ Microstructure and Tensile Mechanical Performance

Secondary Al-Si alloys typically encompass several impurities that substantially influence the materials’ microstructure and mechanical performance. This study employed a composite addition of chlorinated salt fluxing and an aluminum–boron master alloy to reduce the levels of the impurity elements magnesium (Mg), titanium (Ti), and vanadium (V) in secondary Al-Si alloys. The investigation of the performance mechanism revealed that the distribution of alloys’ grain orientation and the ratio of small-angle grain boundaries were modified via synergistic purification, leading to the refined microstructure and mechanical performance of secondary Al-Si alloys. The removal rates of impurity elements under these optimal refining conditions were 89.9% for Mg, 68.9% for Ti, and 61.5% for V. The refined alloy exhibited a 45.5% decrease in grain size and a 28.7% improvement in tensile strength compared to the raw material. These findings demonstrate that fluxing can improve the extraction of Ti and V from secondary Al-Si alloy melts of aluminum–boron master alloys, providing a new cost-effective strategy for the removal of impurities and the optimization of the properties of secondary Al-Si alloys.

Ecosystem recovery following post environmental change near an aluminium smelter in Žiar nad Hronom, Slovakia

Ecosystem recovery following post environmental change near an aluminium smelter in Žiar nad Hronom, Slovakia

The role of the melt aluminum saturation index in controlling gold and molybdenum proportions in porphyry copper deposits: An experimental investigation

The role of the melt aluminum saturation index in controlling gold and molybdenum proportions in porphyry copper deposits: An experimental investigation

Aluminum smelting temperature prediction using GCN with correlation aggregation strategy and LSTM with dynamic attention

Aluminum smelting temperature prediction using GCN with correlation aggregation strategy and LSTM with dynamic attention

Effect of TiC Coating Thickness on Carbon Fiber Surface on Microstructure and Properties of Aluminum Matrix Composites

In this paper, the synthesis of TiC-coated carbon fibers (TiC-CFs) with varying thicknesses is achieved through the manipulation of the molten salt reaction, along with the fabrication of TiC-coated carbon fiber-reinforced aluminum matrix (TiC-CF/Al) composites via the vacuum pressure infiltration technique. The results show that modulating the holding time of the molten salt reaction significantly enhances the wettability between the carbon fiber (CF) and the aluminum, thereby augmenting the mechanical integrity of the composite materials. Should the holding time be excessively short, the coating on the CF surface develops an uneven distribution, and its efficacy in obstructing the direct interaction with the aluminum is inadequate. As the holding time prolongs, the TiC coating thickens, achieving a comprehensive coverage after 2 h of holding. The presence of a pristine TiC coating on the CF surface not only optimizes the wettability with the aluminum melt but also mitigates the reaction between the CF and aluminum. However, an excessively thick coating not only reduces the strength of the fibers, due to excessive reactions, but also makes the coating prone to detachment during the preparation process due to stress. At a holding time of 3 h, the tensile strength of the CF/Al composite material reaches its highest value, with a tensile strength of 103.93 MPa and an impressive 72.35% enhancement over that of the aluminum.

Mold Design for Injection Molding Machine Using Recycled Aluminum

The use of aluminum is widely spread from beverage cans, car parts, airplanes, trains, and household furniture. This is due to its lightweight and good corrosion resistance. However, as a metal aluminum waste is difficult to be decomposed naturally. Aluminum metal takes 80 to 100 years to decompose. So the accumulation of untreated scrap aluminum can pollute the environment. One of the solutions is to recycle aluminum by melting and re-casting it into a new shape: a mold for polymer processing. The waste of beverage cans was cleaned from any dirt and adhesive. Then, they were turned into small parts by a crusher. The melting process was done at 650oC. The molten aluminum was poured into a sand mould in the shape of mould of a tensile testing specimen. The recycled product can be used to prepare tensile testing samples of polymer or polymer-based composite with injection molding technique. To evaluate the quality of recycled aluminum, a hardness test was done with a value of 69.31 + 3.02 HB. This value is lower than first-use aluminum. This is due to a combination of microstructural changes due to repeated heating, the presence of additives and impurities, and the effects of heat treatment and open cooling. Metallographic testing was carried out to evaluate the microstructure of the material resulting from the smelting of scrap aluminum using sand molds. In this test, the etching solution used consisted of 100 ml of water and 20 g of sodium hydroxide. The results of the metallographic images on the recycled aluminum material show the presence of a stand-alone silicon (Si) element and an aluminum-copper alloy (CuAl₂).

Effect of Al-3Ti-4.35La Master Alloy on the Aggregation and Sedimentation Characteristics of TiC in Al-7Si Alloys

The Al-Ti-C alloy is the most widely used grain refiner for Al-7Si alloys. However, TiC particles in Al-7Si alloys tend to aggregate and settle, thereby reducing their refinement efficiency. In the present paper, a novel Al-3Ti-4.35La master alloy was developed, and its influence on the stability of TiC particles in Al-7Si alloys was investigated by XRD, SEM, and TEM. The results show that when the Al-TiC alloy is added to the Al-7Si alloy, TiC will accumulate and settle obviously after holding the alloy for a certain time (15 min, 30 min, and 60 min). When the Al-TiC alloy and the Al-3Ti-4.35La master alloy are added to the Al-7Si alloy, the aggregation and settlement of TiC are weakened under the same holding time. Additionally, the refinement effect of TiC is enhanced. The Ti and La elements dissolved by Ti2Al20La in the Al-3Ti-4.35La master alloy are absorbed on the surface of the TiC particles, which improves the wettability between the TiC particles and the aluminum melt, reduces the agglomeration and sedimentation of TiC particles in the aluminum melt, and improves its stability.

Microstructure, Mechanical Property, and Linear Expansion Coefficient of ZrO2@Diamond/2024 Composite

This study investigates the preparation and properties of diamond/2024 composites with a diamond content of 15 vol% and ZrO2‐coated diamond/2024 composites (ZrO2@diamond/2024). ZrO2 is coated onto diamond particles using evaporation crystallization, and the effects of different thermal decomposition temperatures and durations on the coating are examined. The results show that a smooth and uniform ZrO2 coating is achieved at a thermal decomposition temperature of 600 °C with a holding time of 2 h. In diamond/2024 composites, noticeable voids are observed at the interface, while the ZrO2@diamond/2024 composites exhibit a flat, well‐bonded interface without cracks, voids, or Al4C3 formation. The ZrO2 coating effectively prevents direct contact between diamond and aluminum melt, inhibiting Al4C3 formation, which leads to a tensile strength increase of ZrO2@diamond/2024 composites to 200.1 MPa, 10.8% higher than the uncoated composites. Additionally, the linear expansion coefficient and dimensional change rate of ZrO2@diamond/2024 composites are lower than those of diamond/2024 composites, indicating better interface bonding and thermal expansion constraint.

Fabrication of a Sustainable Charcoal-Fired Crucible Furnace for Recycling Aluminum Waste Cans

Aluminum recycling is a vital process in minimizing environmental degradation and conserving energy. This paper presents the design, fabrication, and performance evaluation of a charcoal-fired crucible furnace specifically constructed for melting aluminum waste cans. The project aims to promote local recycling efforts by offering a cost-effective and energy-efficient solution using locally available materials. The furnace was constructed using mild steel, fire bricks, refractory cement, and insulation materials. The crucible was made from graphite-clay composite. Performance evaluation showed that the furnace reached a temperature of 750°C within 25 minutes, melting aluminum efficiently with an average recovery rate of 85%. This design offers a sustainable and scalable solution for small- to medium-scale aluminum recycling operations, particularly in developing countries.

Investigation of incipient cavitation in various liquids based on PIV quantification and numerical simulations

This work experimentally and analytically investigated the incipient cavitation behavior in four liquids with different physical properties: ethanol, de-ionized water, glycerine, and aluminum melt under ultrasonic irradiation close to the cavitation threshold with a frequency of 20 kHz. To identify the cavitation structure development and bubble motion of different liquids, cavitation structure under condition close to the cavitation threshold was in-situ observed via high-speed photography for optically transparent liquids and synchrotron radiation X-ray radiography technology for aluminum melt. The dynamic process of the cavitation bubble was numerically simulated on the bubble wall motion. Bubble characteristics were analyzed by more accurate relevant dimensionless quantities comparison obtained from the translational maximum bubble velocity measured by Particle Image Velocimetry (PIV). Based on the simulation results through multi-technology combination methods and dynamic simulation, the incipient cavitation characteristics of various liquid bulks in experimental conditions were estimated and compared. The insights gained from this study are valuable for improving the design and optimization of industrial processes involving cavitation, such as ultrasonic degassing, ultrasonic-assisted metal casting, and material processing. Understanding these cavitation characteristics can lead to more efficient and controlled applications in these fields and help in identifying more suitable transparent media for simulating the cavitation behavior of metal melts.

Efficient removal of titanium and vanadium impurities in aluminum melt by adding Al–B alloy containing AlB12

Efficient removal of titanium and vanadium impurities in aluminum melt by adding Al–B alloy containing AlB12

Influence of Pulse Pressure Source Parameters on Wave Fields in a Metal Melt

Based on mathematical modeling, the influence of the magnetic-pulse, the electric-discharge and the combined sources of the pulsed pressure on wave fields in aluminum melt was studied. An increase in the intensity of the wave fields in the melt with an increase in the amplitude, the pulsation period and the attenuation time of pressure pulsations created by pulsed sources was observed. The occurrence of cavitation in the melt under the action of the considered sources of pressure pulses was determined. A significant influence of the parameters of pulsed pressure sources on the change in the density of the internal energy of the melt was noted.