Introduction to Aluminum

Author(s):  
Alexey Sverdlin

Aluminum is the most heavily consumed non-ferrous metal in the world with an annual consumption of approximately 24 million tons of which it is estimate that 75% of this total amount is primary aluminum (aluminum extracted from ore). This article provides an overview of aluminum ores and their composition, reduction of aluminum, production of commercial quality aluminum, extraction, refinement and the production of ultrapure aluminum.

Author(s):  
Jorge Alberto Soares Tenório ◽  
Denise Crocce Romano Espinosa

Aluminum is the second most used metal in the world because of its properties including good corrosion resistance, low density, high electrical conductivity and good thermal conductivity. However, the negative environmental impact from production of primary aluminum is due to the corresponding impact of red mud and release of fluorides which is devastating to forests and the space required for waste disposal. Recycling, in addition to reducing the impact of disposal of the by-products of primary aluminum production also consumes a great amount of electricity. Therefore, recycling of aluminum scrap is of increasing interest. In this article, the following factors involved in aluminum recycling are discussed: environmental and energy impact, secondary metallurgy of aluminum, fundamentals of aluminum recovery using salt flux, recovery of aluminum drosses by milling and preliminary treatments of scrap.


2021 ◽  
Vol 170 ◽  
pp. 105584
Author(s):  
Victor Brial ◽  
Hang Tran ◽  
Luca Sorelli ◽  
David Conciatori ◽  
Claudiane M. Ouellet-Plamondon

2021 ◽  
Vol 1040 ◽  
pp. 109-116
Author(s):  
V.Yu. Piirainen ◽  
A.A. Barinkova ◽  
V.N. Starovoytov ◽  
V.M. Barinkov

Current global environmental challenges and, above all, global warming associated with a change in the carbon balance in the atmosphere has led to the need for urgent and rapid search for ways to reduce greenhouse gas emissions into the atmosphere, which primarily include carbon dioxide as a by-product of human activity and technological progress. One of these ways is the creation of industries with a complete cycle of turnover of carbon dioxide. Aluminum is the most sought-after nonferrous metal in the world, but its production is not environmentally safe, so it constantly requires the development of knowledge-intensive technologies to improve the technological process of cleaning and disposal of production waste, primarily harmful emissions into the atmosphere. Another environmental problem related to aluminum production is the formation and accumulation in mud lagoon of huge amounts of so-called highly alkaline "red mud," which is a waste product of natural bauxite raw material processing into alumina - the feedstock for aluminum production. Commonly known resources and technological methods of neutralizing red mud and working with it as ore materials for further extraction of useful components are still not used because of their low productivity and cost-effectiveness. This article describes the negative impact of waste in the form of "red" mud and carbon dioxide of primary aluminum production on the environment. The results showed that thanks to carbonization of red mud using carbon dioxide, it is possible to achieve rapid curing and its compact formation for safer transportation and storage until further use. Strength tests of concrete samples filled with deactivated red mud were also carried out, which showed the prospects of using concrete with magnesia binder.


Author(s):  
Efthymios Balomenos ◽  
Dimitrios Gerogiorgis

The Hall–Héroult process for the electrolytic reduction of alumina was developed at the end of the 19th century and is still currently the only industrial process for the production of primary aluminum. Today, this process is ranked among the most energy- and CO2intensive industrial processes. Direct carbothermic reduction of alumina has been proposed as an alternative process, which can substantially improve the sustainability of primary aluminum production, leading to energy savings of up to 21% and reduction in greenhouse gas emission of up to 52%, while plant capital costs can be reduced up to 50%. However, processes developed so far suffer from low aluminum yields, primarily due to aluminum carbide and oxycarbide formation and aluminum vaporization phenomena. This article presents a thermodynamic study of the Al–C–O system and a review on the alumina carbothermic processes developed so far.


2021 ◽  
pp. 902-915
Author(s):  
Alexey Vladimirovich Kuznetsov

The article shows that although the threat of rapid depletion of mineral resources in the world is largely exaggerated, imbalances in their distribution and consumption are gradually increasing. On the one hand, globalization intensifies the competition of countries for resources, as the global development of recent decades shows. On the other hand, globalization mitigates imbalances through foreign trade and direct investment. The article examines the role of Russian investor companies in these processes. The research is based on corporate materials, official statistics and the most authoritative sources of industry information. The contribution of Russian oil and gas TNCs, companies specializing in the construction and operation of nuclear power plants and hydroelectric power plants, as well as leading investors in the field of non-ferrous metal industry was studied. A distinctive feature of Russian TNCs is the limited geography of their foreign business, especially in the countries of the global South. Usually we can see the preference of a narrow circle of countries which had long history of good political relations with Russia. At the same time, reliance on purely economic considerations is less pronounced than that of leading Western competitors. As a result, external shocks (whether political cataclysms in individual countries in the case of the oil and gas sector or sharp fluctuations in the international conjuncture in the case of non-ferrous metal industry) can greatly affect the scale of foreign activity of Russian TNCs. For the time being, it is more likely that we can still talk about the initial stages of internationalization of Russian business, which has little effect on the nature of global development with its investment activity. The article also shows that since in the future the scarcity of land and water resources will increase in the global economy, additional opportunities will open up for Russian companies to strengthen our country’s international positions. However, so far the activity of Russian TNCs is not observed there because it is limited mainly by the increase in grain exports to developing countries.


Author(s):  
R.S. Lima ◽  
A.S. Takimi ◽  
M.D. Lima ◽  
C.P. Bergmann

Abstract The polyethylene terephtalate (PET) is a polymer with a high melting (265°C) and glass transition (67°C) temperatures, insensitive to moisture and common solvents. Also it has an wide range of mechanical properties attainable by variations of molecular weight, orientation and crystallinity. Due to these characteristics allied with the glass-like transparency, light weight and unbreakable character, PET is used to form high performance bottles for carbonated soft drinks, wines, beers and food packing. The world annual consumption of PET for these purposes is increasing, with impressive prospects for the future. This characteristic leads to other situation. The consumption of energy and natural resources together with the environmental problems caused by disposable plastics, make the engineering and materials scientists try to find for different ways to recycled plastics. The characteristics of PET mentioned above seen to be very proper to use as a material for coating.


2008 ◽  
Vol 49 (2) ◽  
pp. 84-89 ◽  
Author(s):  
A. V. Proshkin ◽  
A. M. Pogodaev ◽  
P. V. Polyakov ◽  
V. V. Pingin ◽  
I. A. Yarosh

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