Cleaner Production Assessment of the Aluminium Industry

Cleaner Production (CP) practices comprised environmental strategy perpetually applied in the production, processes, and services to bolster efficiency, safety, and environmental friendliness. Combining with the mindset of sustainable stocks and resources, this exercise of cleaner production provides advantages of minimum toxic wastes and residues. In this study, we prioritize this practice to be applied in the aluminum industry, of which cleaner production action has not yet been employed. This study aimed to assess the application of cleaner production in the aluminum industry. The method used is assessing cleaner production using the criteria of raw materials, production processes, water and wastewater, energy use, good housekeeping, solid waste and gas, human resources, and environmental performance. The assessment results of the cleaner production application indicate that the Mandiri industry type is generally at level 2 with a frequency of 13 industries. In general, SMAR’S is at level 3 with a frequency of 11 industries, and in the BLK industry, it is at level 2 with 11 industries. These results can be used as a recommendation for the government to increase cleaner production in the Jombang Regency.

The application of MFA for rural industrial symbiosis assessment

One of proposed strategies to solve current environmental challenges includes the industrial symbiosis. However, proper evaluation methods are required to measure the potential benefits of industrial symbiosis, one of those includes the material flow analysis (MFA). MFA develops a unified database and a Step-by-Step process starting from the input, process, and output process to clarify the distribution of waste and the recycling process in the aluminum industry. The aluminum industry is regarded as an energy-intensive and high-pollution industry. The development of industrial symbiosis in the aluminum industry has significantly reduced environmental pressures and facilitated green development and green industry. Home industries that process aluminum slag raw materials require high energy thereby generating high waste during the production process. The applied method includes material flow analysis (MFA). The MFA results indicated that the production elements of the aluminum slag industry consist of 11 elements ranging from raw materials, fuel, clean water, human resources, capital, production processes, production equipment, housekeeping, products produced, waste to waste utilization. Approximately 44% of the industry sold waste to other industries, 42% of the waste was reprocessed, and 14% of the aluminum industry stockpiles production was in the form of waste in open spaces. The industrial symbiosis in the aluminum industry was an open cycle, indicating that the symbiosis produces waste, which had not been fully utilized; but in fact, the waste had potential as a source of raw materials, energy, and materials in other industrial processes.

Kaolinite clays as a source of raw materials for the aluminum industry of the Republic of Kazakhstan

Kaolinite clays can serve as an additional source of alumina in the Republic of Kazakhstan. The most promising is the Alekseevsky kaolinite deposit. To obtain high-quality kaolinite and quartzite products, it is necessary to develop special enrichment techniques, since no satisfactory results were achieved when using standard methods of gravitational enrichment of kaolinites. The paper presents the results of studies of the effect of preliminary chemical activation during the processing of kaolinite clays of the Alekseevsky deposit. Previously, the method of preliminary chemical activation of raw materials in a solution of sodium bicarbonate has proven itself well in the processing of various mineral raw materials. It was determined that during the preliminary chemical activation in a solution of sodium bicarbonate, changes occurred in the phase composition of the kaolinite fraction: the content of muscovite decreased almost twice; the phase of sodium aluminosilicate was formed. The dependence of the yield of Al2O3 in the kaolinite fraction on the temperature of chemical activation, duration, and the ratio of L:S and the concentration of the sodium bicarbonate solution during chemical activation. The optimal mode of preliminary chemical activation of kaolinite clay of the Alekseevsky deposit has been established: the temperature is 150 oC, the duration is 120 minutes and the concentration of sodium bicarbonate solution is 120 g/dm3. A basic technological scheme is proposed for the processing of kaolinite clays.

Proven Anti-Wetting Properties of Molybdenum Tested for High-Temperature Corrosion-Resistance with Potential Application in the Aluminum Industry

The behavior of Mo in contact with molten Al was modelled by classical molecular dynamics (CMD) simulation of a pure Mo solid in contact with molten Al at 1200 K using the Materials Studio®. Results showed that no reaction or cross diffusion of atoms occurs at the Mo(s)–Al(l) interface, and that molten Al atoms exhibit an epitaxial alignment with the exposed solid Mo crystal morphology. Furthermore, the two phases {Mo(s) and Al(l)} are predicted to interact with weak van der Waals forces and give interfacial energy of about 203 mJ/m2. Surface energy measurements by the sessile drop experiment using the van Oss–Chaudhury–Good (VCG) theory established a Mo(s)–Al(l) interface energy equivalent to 54 mJ/m2, which supports the weak van der Waals interaction. The corrosion resistance of a high purity (99.97%) Mo block was then tested in a molten alloy of 5% Mg mixed in Al (Al-5 wt.%Mg) at 1123 K for 96 h, using the ALCAN’s standard “immersion” test, and the results are presented. No Mo was found to be dissolved in the molten Al-Mg alloy. However, a 20% mass loss in the Mo block was due to intergranular corrosion scissoring the Mo block in the ALCAN test, but not as a result of the reaction of pure Mo with the molten Al-Mg alloy. It was observed that the Al-Mg alloy did not stick to the Mo block.

A Novel Concept for Sustainable Food Production Utilizing Low Temperature Industrial Surplus Heat

Low temperature industrial surplus heat represents a major energy source that is currently only rarely utilized due to its low quality. An agricluster allows for the leveraging of this low-quality heat and, hence, may improve the overall energy efficiency. This paper presents the novel concept of an agricluster driven by available surplus heat from industrial processes. We propose the integration of greenhouse production, insect rearing, fish rearing, and drying of seaweed using low temperature surplus heat from the aluminum industry. Each of these processes is already used in or investigated for utilization of surplus heat and partly coupled with other processes, such as in aquaponics. However, the integration of all processes in an agricluster—as proposed in this paper—may result in improved utilization of the surplus heat due to the different seasonality of the heat demand. The potential synergies of this integration approach are discussed in this paper. Furthermore, waste from one process can be utilized as an input stream to other processes, reducing the demand for external material input to the system. The proposed concept of an agricluster is especially interesting for the Nordic countries, as they are dependant on fresh food imports due to the low outside temperatures.

Increasing the Durability of Trimming Dies Used to Clean Anodes in the Aluminum Industry

Increasing the durability of trimming dies used to clean anodes is a very important goal in order to reduce the costs involved in obtaining aluminum. The research focused both on choosing an optimal material for the execution of trimming dies and on the application of technologies for plating active areas and, at the same time, on optimizing the geometric shape of the active area of the trimming die. In order to choose an optimal material from which to make the trimming dies, it was taken into account that they are usually made of X210Cr12 steel. In the stage of choosing an optimal material for the execution of the trimming dies, five steels were taken into account, namely: K105, K107, K110, K360, and K460. Analyses of the metallographic structure of the passage area were performed between the metal deposited by welding and the base material, demonstrating the fact that hot welding plating allows obtaining a more homogeneous metallographic structure compared to cold welding plating. The choice of new material was not a solution to increase the durability of the trimming die. Change in the trimming die geometry determined a reduction in deformations of about 13.8 times and of the equivalent stresses of about 7 times compared to those obtained in the case of the old trimming die. In addition, the durability of the trimming die with the new construction shape increases approximately three times compared to the trimming die with the old geometric shape. This demonstrates that the solution to increasing the durability of the trimming die is to adopt an optimal geometry of the active part at the expense of choosing an optimal material.

The Application of Two Models of Life Cycle Assessment (Lca) for Transition to the Low-Carbon Economy: a Case Study in the Aluminum Industry

This study examined two approaches that account for recycled materials in LCA studies, the recycled content (RC) approach and the end-of-life recycling (EOL) approach, which were reviewed with reference to aluminum. Interviews were conducted to obtain best practices in using these two approaches and carbon footprinting was used as an environmental performance metric. The interview results showed that across the stakeholder groups there was no unanimity or preferences regarding either approach where LCA studies involved metals/aluminum. The case study of aluminum recycling applied a custom computer model developed for a Canadian primary producer that compared the carbon emissions of producing 1 metric ton (mt) of aluminum for the two approaches. The average value of mt CO2 eq. produced per mt aluminum was lower using the EOL approach versus the RC approach in every scenario. Percentage differences indicated substantial differences in the results when the two approaches were compared.

The Application of Two Models of Life Cycle Assessment (Lca) for Transition to the Low-Carbon Economy: a Case Study in the Aluminum Industry

This study examined two approaches that account for recycled materials in LCA studies, the recycled content (RC) approach and the end-of-life recycling (EOL) approach, which were reviewed with reference to aluminum. Interviews were conducted to obtain best practices in using these two approaches and carbon footprinting was used as an environmental performance metric. The interview results showed that across the stakeholder groups there was no unanimity or preferences regarding either approach where LCA studies involved metals/aluminum. The case study of aluminum recycling applied a custom computer model developed for a Canadian primary producer that compared the carbon emissions of producing 1 metric ton (mt) of aluminum for the two approaches. The average value of mt CO2 eq. produced per mt aluminum was lower using the EOL approach versus the RC approach in every scenario. Percentage differences indicated substantial differences in the results when the two approaches were compared.

Waste and Solar Energy: An Eco-Friendly Way for Glass Melting

In this work, concentrated solar energy (CSE) was applied to an energy-intensive process such as the vitrification of waste with the aim of manufacturing glasses. Different types of waste were used as raw materials: a hazardous waste from the aluminum industry as aluminum source; two residues from the food industry (eggshell and mussel shell) and dolomite ore as calcium source; quartz sand was also employed as glass network former. The use of CSE allowed obtaining glasses in the SiO2-Al2O3-CaO system at exposure time as short as 15 min. The raw materials, their mixtures, and the resulting glasses were characterized by means of X-ray fluorescence, X-ray diffraction, and differential thermal analysis. The feasibility of combining a renewable energy, as solar energy and different waste for the manufacture of glasses, would highly contribute to circular economy and environmental sustainability.