Carbothermic Reduction Methods for Alumina

2019 ◽  
Author(s):  
Efthymios Balomenos ◽  
Dimitrios Gerogiorgis
Keyword(s):  
Carbothermic Reduction ◽  
Energy Savings ◽  
Greenhouse Gas Emission ◽  
Industrial Process ◽  
Primary Aluminum ◽  
Aluminum Carbide ◽  
Aluminum Production ◽  
Capital Costs ◽  
Reduction Methods ◽  
The 19Th Century

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.

Evaluation of the reactivity of treated spent pot lining from primary aluminum production as cementitious materials

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

Deactivation of Red Mud by Primary Aluminum Production Wastes

2021 ◽  
Vol 1040 ◽  
pp. 109-116
Author(s):  
V.Yu. Piirainen ◽  
A.A. Barinkova ◽  
V.N. Starovoytov ◽  
V.M. Barinkov
Keyword(s):  
Carbon Dioxide ◽  
Red Mud ◽  
Negative Impact ◽  
Waste Product ◽  
Primary Aluminum ◽  
Raw Material ◽  
Aluminum Production ◽  
Environmentally Safe ◽  
Primary Aluminum Production ◽  
Knowledge Intensive

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.

scholarly journals Optimal Regulation of Pumping Station in Water Distribution Networks Using Constant and Variable Speed Pumps: A Technical and Economical Comparison

Energies ◽  
2020 ◽  
Vol 13 (10) ◽  
pp. 2530 ◽  
Author(s):  
Luigi Cimorelli ◽  
Carmine Covelli ◽  
Bruno Molino ◽  
Domenico Pianese
Keyword(s):  
Distribution System ◽  
Energy Demand ◽  
Water Distribution ◽  
Energy Savings ◽  
Greenhouse Gas Emission ◽  
Distribution Networks ◽  
Variable Speed ◽  
Variable Speed Drives ◽  
Optimal Regulation ◽  
Energy Consuming

Greenhouse gas emission is one of the main environmental issues of today, and energy savings in all industries contribute to reducing energy demand, implying, in turn, less carbon emissions into the atmosphere. In this framework, water pumping systems are one of the most energy-consuming activities. The optimal regulation of pumping systems with the use of variable speed drives is gaining the attention of designers and managing authorities. However, optimal management and operation of pumping systems is often performed, employing variable speed drives without considering if the energy savings are enough to justify their purchasing and installation costs. In this paper, the authors compare two optimal pump scheduling techniques, optimal regulation of constant speed pumps by an optimal ON/OFF sequence and optimal regulation with a variable speed pump. Much of the attention is devoted to the analysis of the costs involved in a hypothetical managing authority for the water distribution system in order to determine whether the savings in operating costs is enough to justify the employment of variable speed drives.

Energy Savings in Aluminum Production, Use, and Recycling

JOM ◽  
1983 ◽  
Vol 35 (7) ◽  
pp. 51-54 ◽  
Author(s):  
Allen S. Russell
Keyword(s):  
Energy Savings ◽  
Aluminum Production

Introduction to Aluminum

2019 ◽  
Author(s):  
Alexey Sverdlin
Keyword(s):  
Ferrous Metal ◽  
Primary Aluminum ◽  
Aluminum Production ◽  
The World ◽  
Annual Consumption

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.

scholarly journals Environmental Footprint and Economics of a Full-Scale 3D-Printed House

2021 ◽  
Vol 13 (21) ◽  
pp. 11978
Author(s):  
Hadeer Abdalla ◽  
Kazi Parvez Fattah ◽  
Mohamed Abdallah ◽  
Adil K. Tamimi
Keyword(s):  
Life Cycle ◽  
3D Printing ◽  
Environmental Impacts ◽  
United Arab Emirates ◽  
Large Scale ◽  
Energy Savings ◽  
Raw Materials ◽  
Capital Costs ◽  
Construction Methods ◽  
3D Printed

3D printing, is a newly adopted technique in the construction sector with the aim to improve the economics and alleviate environmental impacts. This study assesses the eco-efficiency of 3D printing compared to conventional construction methods in large-scale structural fabrication. A single-storey 3D-printed house was selected in the United Arab Emirates to conduct the comparative assessment against traditional concrete construction. The life cycle assessment (LCA) framework is utilized to quantify the environmental loads of raw materials extraction and manufacturing, as well as energy consumption during construction and operation phases. The economics of the selected structural systems were investigated through life cycle costing analysis (LCCA), that included mainly the construction costs and energy savings. An eco-efficiency analysis was employed to aggregate the results of the LCA and LCCA into a single framework to aid in decision making by selecting the optimum and most eco-efficient alternative. The findings revealed that houses built using additive manufacturing and 3D printed materials were more environmentally favourable. The conventional construction method had higher impacts when compared to the 3D printing method with global warming potential of 1154.20 and 608.55 kg CO2 eq, non-carcinogenic toxicity 675.10 and 11.9 kg 1,4-DCB, and water consumption 233.35 and 183.95 m3, respectively. The 3D printed house was also found to be an economically viable option, with 78% reduction in the overall capital costs when compared to conventional construction methods. The combined environmental and economic results revealed that the overall process of the 3D-printed house had higher eco efficiency compared to concrete-based construction. The main results of the sensitivity analysis revealed that up to 90% of the environmental impacts in 3D printing mortars can be mitigated with decreasing cement ratios.

scholarly journals Reducing the Carbon Footprint: Primary Production of Aluminum and Silicon with Changing Energy Systems

2021 ◽  
Author(s):  
Gudrun Saevarsdottir ◽  
Thordur Magnusson ◽  
Halvor Kvande
Keyword(s):  
Primary Production ◽  
Carbon Footprint ◽  
Greenhouse Gas Emission ◽  
Industrial Processes ◽  
Main Trend ◽  
Aluminum Production ◽  
Infrastructure Development ◽  
Low Carbon ◽  
Carbon Footprints ◽  
Silicon Production

AbstractThe world now pushes for a low-carbon future, and international goals for greenhouse gas emission reductions have been set. Industrial processes, including metallurgical processes, make up more than a fifth of the total global emissions, and those have been rising with infrastructure development and the expansion of the middle-class worldwide. This paper focuses on two energy-intensive processes, aluminum production and metallurgical grade silicon production, and how the carbon footprints from these industrial processes have developed in recent decades. The main trend is that the increased demand for these metals has led to expanding primary production for both of them, based on energy with an increasing share of fossil-based electric power. In fact, the average carbon footprint of the energy used in aluminum and silicon production has increased by 38% and 43%, respectively, from 2000 to 2019. The change in energy mix offsets any progress in process efficiencies. This work addresses this and discusses opportunities for improvements. Graphical Abstract

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