Search Results (5)

This paper investigates the economic feasibility of utilising energy flexibility in aluminium production as a viable solution to leverage electricity surpluses arising from the increasing number of photovoltaic (PV) system installations. Future trends suggest that the generation capacity of PV systems will soon surpass consumption, leading to significant electricity surpluses, particularly during the summer. This surplus electricity, which is anticipated to be available at low prices, offers a unique opportunity to evaluate different investment and utilisation scenarios for aluminium production while simultaneously decreasing its environmental impact. The results demonstrate that, despite their high initial investment cost, large-scale PV power plants can potentially deliver maximum economic gains over a ten-year period. Conversely, the direct utilisation of surpluses without substantial investment can yield savings of up to EUR 17 million within the same time frame for Slovenia’s case with an aluminium smelter, which has a maximum power usage of 60 MW. The findings of this study have significant implications in terms of shaping future energy strategies and policies, emphasizing the value of integrating renewable energy sources and industrial processes for enhanced economic and environmental outcomes. Full article

In recent years, the demand for natural and synthetic zeolites has surged due to their distinctive properties and myriad industrial applications. This research aims to synthesise crystalline zeolites by co-recycling two industrial wastes: salt slag (SS) and rice husk ash (RHA). Salt slag, a problematic by-product of secondary aluminium smelting, is classified as hazardous waste due to its reactive and leachable nature, though it is rich in aluminium. Conversely, RHA, an abundant and cost-effective by-product of the agro-food sector, boasts a high silicon content. These wastes were utilised as aluminium and silicon sources for synthesising various zeolites. This study examined the effects of temperature, ageing time, and sodium concentration on the formation of different zeolite phases and their crystallinity. Results indicated that increased Na⁺ concentration favoured sodalite (SOD) zeolite formation, whereas Linde type–A (LTA) zeolite formation was promoted at higher temperatures and extended ageing times. The formation range of the different zeolites was defined and supported by crystallographic, microstructural, and morphological analyses. Additionally, the thermal behaviour of the zeolites was investigated. This work underscores the potential to transform industrial waste, including hazardous materials like salt slag, into sustainable, high-value materials, fostering efficient waste co-recycling and promoting clean, sustainable industrial production through cross-sectoral industrial symbiosis. Full article

The effect of rare-earth Ce on the evolution behaviour of inclusions in heavy rail steel was studied. The addition of Ce can significantly reduce the number and size of class A, B, D, and Ds inclusions in the heavy rail steel smelting process. According to the statistical analysis of the size of inclusions in steel, the number and size of A and B inclusions in steel tend to decrease significantly, while D and Ds inclusions disappear. Ce splits the aluminium inclusion into several small-sized inclusions and improves the morphology of the large-size aluminium inclusion, thereby making aggregation and growth difficult while facilitating easy floating and removal. Because the addition of Ce reduces the concentration of S element in steel, MnS inclusions are difficult to grow. The decrease in the number and size of core inclusions required for MnS growth leads to a corresponding decrease in the number and size of MnS inclusions. Meanwhile, the S element also easily gathers on the surface of CaO–MgO–Al₂O₃–SiO₂–CeO inclusions, forming composite inclusions that are more easily removed, thus reducing the quantity and size of MnS inclusions. Full article

The recovery of Mn and Al from two industrial waste of ferromanganese and aluminum production processes was investigated via implementing a high temperature smelting—aluminothermic reduction process. The experiments were carried out with or without CaO flux addition, and two dross qualities. It was observed that the prepared mixtures of the materials yield homogeneous metal and slag products in terms of chemical composition and the distribution of phases. However, the separation of produced metal phase from the slag at elevated temperatures occurs when a higher amount of CaO is added. Viscosity calculations and equilibrium study indicated that the better metal and slag separation is obtained when the produced slag has lower viscosity and lower liquidus. It was found that the process yields Al-Mn-Si alloys, and it is accompanied with complete recovery of Mn, Si and Fe and the unreacted Al in the process. Moreover, the quality of metal product was less dependent on the slightly different dross quality, and the concentration of minor Ca in metal is slightly increased with significant increase of CaO in the slag phase. Full article

This study covers an in-depth investigation into the properties and practicality of the utilization of up to 40% Alumina Waste Filler (AWF) as a partial Portland Cement (PC) replacement material. AWF is a by-product from the recycling of aluminium, produced when salt slag is smelted and cleaned. Its use in concrete will lessen the landfill requirements for AWF disposal, and reduce the strain of the growing requirements and cost of PC. The results obtained from this study showed that the addition of AWF to the concrete mix caused a reduction in the compressive and tensile splitting strength values, and a less-workable concrete was achieved for every increase in the quantity of AWF added to each mix. The addition of AWF influenced the hydration reaction process and reduced the cumulative production of the heat of hydration over time, whilst the permeability of the concrete decreased. Full article