scholarly journals Formulation of Non-Fired Bricks Made from Secondary Aluminum Ash

Coatings ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 2
Author(s):  
Hongjun Ni ◽  
Weiyang Wu ◽  
Shuaishuai Lv ◽  
Xingxing Wang ◽  
Weijia Tang
Keyword(s):  
Primary Aluminum ◽  
Raw Material ◽  
Hydration Reaction ◽  
Secondary Aluminum ◽  
Dense Structure ◽  
Hydration Mechanism ◽  
Slaked Lime ◽  
Metal Aluminum ◽  
Fired Bricks ◽  
Calcium Aluminate Hydrate

The secondary aluminum ash is the black slag left after the primary aluminum ash is extracted from the metal aluminum. To address the environmental pollution and resource waste caused by the accumulation and landfill of aluminum ash, this study fabricated non-fired bricks by using secondary aluminum ash as the principal raw material, which was supplemented by cement, slaked lime, gypsum and engineering sand. The effects of mix proportions of various admixtures on the mechanical properties of non-fired bricks were investigated, and on this basis, the hydration mechanism was analyzed. The results showed that the mix proportions were 68.3% aluminum ash, 11.4% cement, 6.4% slaked lime, 4.2% gypsum and 9.7% engineering sand. The compressive strength of the fabricated bricks reached 22.19 MPa, and their quality indicators were in line with the MU20 requirements for Non-fired Rubbish Gangue Bricks. Evident hydration reaction occurred inside the non-fired bricks, with main products being calcium silicate hydrate (CSH), calcium aluminate hydrate (CAH) and ettringite (AFt). Besides, a dense structure was formed, which enhanced the brick strength.

A Study of Stabilization and Recycling for Aluminum Dross

2013 ◽  
Vol 275-277 ◽  
pp. 2237-2240 ◽  
Author(s):  
Hsieh Kuo Cheng ◽  
T.H. Ueng ◽  
Ching Chyi Chen
Keyword(s):  
Calcium Oxide ◽  
Manufacturing Process ◽  
Raw Materials ◽  
Aluminum Carbide ◽  
Raw Material ◽  
Hydration Reaction ◽  
Secondary Aluminum ◽  
Stabilizing Agents ◽  
Alkaline Environment ◽  
Aluminum Dross

In this study, a recycling process for stabilized secondary aluminum dross is proposed. Calcium oxide-containing materials, such as de-sulfur slag produced from steel manufacturing process, are used as stabilizing agents for secondary aluminum dross. The de-sulfur slag was first hydrolyzed. Due to the high content of calcium oxide (about 45%), hydration of de-sulfur slag can produce a solution with strong alkalinity (pH≧12). In the strong alkaline environment, the residual pernicious components in the aluminum dross, such as aluminum nitride, aluminum carbide and metal aluminum, are hydrolyzed and decomposed rapidly, resulting in the stabilization of secondary aluminum dross. The stabilized aluminum dross, therefore, was used as the raw material for preparing concrete bricks. In the subsequent concrete brick manufacturing process, the hydration reaction between stabilized aluminum dross and other raw materials can also produce strong alkaline environment (pH≧12), which further stabilizes the aluminum dross wastes, and produce high-pressure concrete bricks with satisfactory performance.

Performance and Hydration of Blended Cements with Fly Ash and Sugar Filter Mud

2013 ◽  
Vol 838-841 ◽  
pp. 2334-2337
Author(s):  
Chao Qian ◽  
Wen Yuan Gao ◽  
Chun Yuan Luo ◽  
Gui Shan Liu ◽  
Hong Shun Hao ◽  
...  
Keyword(s):  
Tricalcium Silicate ◽  
The Body ◽  
Raw Material ◽  
Hydration Reaction ◽  
Insulation Material ◽  
Closed Porosity ◽  
Dense Structure ◽  
Blended Cements ◽  
Xrd Techniques ◽  
Filter Mud

Thermal insulation material with flexural strength 0.597 MPa, compressive strength 1.1111 MPa and porosity 46.71% shows that its density of the materials decreases down to 0.5466 g/cm3 using sugar filter mud as raw material. The closed porosity and dense structure of sample has been observed by photograph and the main crystalline phases of the sample using XRD techniques are tricalcium silicate and ettringite. These mineral reacting with water will occur the hydration reaction and is contribute to improve the strength of the body.

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.

Production Levels of Bauxite and Aluminum: Global Historical Survey (1850–2015)

2019 ◽  
Author(s):  
Charles Christopher Sorrell ◽  
Pramod Koshy
Keyword(s):  
Primary Aluminum ◽  
Data Sets ◽  
List Type ◽  
Historical Survey ◽  
Secondary Aluminum ◽  
Comprehensive Data ◽  
Conversion Rates ◽  
Global Data

The present work provides a concise examination of the historical global production levels of bauxite, primary aluminum, and secondary aluminum from 1850 to 2015. It also provides a contextual background to these data by summarizing the main etymological, technical, and commercial developments throughout most of this period. It further includes comprehensive data for the pricing of primary aluminum in both historical and 2015 dollars on the basis of economy cost. The syntheses of the data include the following: Global production levels of bauxite based on three data setsGlobal production levels of primary aluminum based on three data setsGlobal production levels of secondary aluminum based on three data setsComparative global production levels of secondary aluminum based on five data setsPrices of primary aluminum in historical US dollars and in US dollars indexed to 2015 values based on four data setsConversion rates for historical US dollars against 2015 valuesIn addition to the preceding global data, extensive pre-1900 data for French, Swiss, and US production levels and French and US prices of primary aluminum are compiled.

scholarly journals Possibility of Calcium Oxide from Natural Limestone Including Impurities for Chemical Heat Pump

Energies ◽  
2020 ◽  
Vol 13 (4) ◽  
pp. 803
Author(s):  
LanXin Lai ◽  
Toshio Imai ◽  
Motohiro Umezu ◽  
Mamoru Ishii ◽  
Hironao Ogura
Keyword(s):  
Heat Pump ◽  
Calcium Oxide ◽  
Waste Heat ◽  
Heat Pumps ◽  
Raw Material ◽  
Hydration Reaction ◽  
Chemical Heat ◽  
Chemical Heat Pump ◽  
Thermogravimetric Analyzer ◽  
Save Energy

Improving energy recycle is an important way to save energy resources and preserve the global environment. Chemical heat pump (CHP) is a technology for saving energy, which utilizes chemical reactions to store thermal energy such as waste heat and solar heat, then release it to provide heat for heating/cooling/refrigeration. For a practical CHP, it is necessary to find cheaper and more stable supply materials. In order to evaluate the possibility of calcium oxide from natural Ofunato natural limestone including impurities, we compare Ofunato limestone with Kawara natural limestone and Garou natural limestone from Japan. These calcium oxides worked as a reactant for CaO/H2O/Ca(OH)2 CHP by repeated hydration/dehydration reaction cycle experiments in a thermogravimetric analyzer. As a result, Ofunato CaO exhibits a high hydration reaction rate after decarbonization at 1223 K for 5 h. The reactivity increased by the repeated hydration reaction although the first hydration rate was low. Furthermore, the sintering of impurities in Ofunato limestone occur easier than that in Kawara limestone with lower impurities. The impurities adhered to the surface of the CaO particle to make specific surface area of CaO particle smaller, which could inhibit hydration reaction of CaO particle. Even if Ofunato limestone contains some impurities, it can be utilized as a raw material for chemical heat pumps.

scholarly journals Mechanism of Alkali-Activated Copper-Nickel Slag Material

2020 ◽  
Vol 2020 ◽  
pp. 1-10 ◽  
Author(s):  
Tingting Zhang ◽  
Haoliang Jin ◽  
Lijie Guo ◽  
Wenchen Li ◽  
Junan Han ◽  
...  
Keyword(s):  
Compressive Strength ◽  
Testing Machine ◽  
Raw Material ◽  
Hydration Reaction ◽  
Reaction Products ◽  
X Ray Diffraction ◽  
Copper Nickel ◽  
Activating Agent ◽  
Cementing Material ◽  
Alkali Activated

A copper-nickel slag-based alkali-activated cementing material (CNSCM) for backfilling was prepared using copper-nickel slag as a raw material and sodium silicate (SS) as an activating agent. The effects of SS content (6%, 8%, and 10%) and curing humidity on the compressive strength of CNSCM were investigated using an electronic universal testing machine. Types of hydration products and microstructures were analyzed by X-ray diffraction, Fourier transform infrared spectroscopy, and scanning electron microscopy. The results indicated that by increasing the SS content, the compressive strength of the CNSCM exhibited an increasing trend, followed by a decreasing trend. The optimal content was 8%. Humidity was identified as another factor affecting compressive strength, which reached 17 MPa after curing for 28 d under standard conditions. A decrease in humidity could improve the compressive strength of the material. The main hydration reaction products of the CNSCM were C-S-H gel, Fe (OH)2 or Fe (OH)3 gel, and CaCO3.

scholarly journals The Integrated Fuzzy AHP and Goal Programing Model Based on LCA Results for Industrial Waste Management by Using the Nearest Weighted Approximation of FN: Aluminum Industry in Arak, Iran

2016 ◽  
Vol 2016 ◽  
pp. 1-13 ◽  
Author(s):  
Ramin Zare ◽  
Jafar Nouri ◽  
Mohammad Ali Abdoli ◽  
Farideh Atabi ◽  
Majid Alavi
Keyword(s):  
Waste Management ◽  
Evaluation Method ◽  
Fuzzy Ahp ◽  
Weighted Approximation ◽  
Primary Aluminum ◽  
Secondary Aluminum ◽  
Aluminum Dross ◽  
Problematic Issue ◽  
Management Alternative ◽  
Gp Model

The worldwide recycled aluminum generation is increasing quickly thanks to the environmental considerations and continuous growing of use demands. Aluminum dross recycling, as the secondary aluminum process, has been always considered as a problematic issue in the world. The aim of this work is to propose a methodical and easy procedure for the proposed system selection as the MCDM problem. Here, an evaluation method, integrated FAHP, is presented to evaluate aluminum waste management systems. Therefore, we drive weights of each pair comparison matrix by the use of the goal programming (GP) model. The functional unit includes aluminum dross and aluminum scrap, which is defined as 1000 kilograms. The model is confirmed in the case of aluminum waste management in Arak. For the proposed integrated fuzzy AHP model, five alternatives are investigated. The results showed that, according to the selected attributes, the best waste management alternative is the one involving the primary aluminum ingot 99.5% including 200 kg and the secondary aluminum 98% (scrap) including 800 kg, and beneficiation activities are implemented, duplicate aluminum dross is recycled in the plant, and finally it is landfilled.

scholarly journals Potential climate change mitigation of Indian Construction Industry through a shift in energy efficient technology by 2050

2018 ◽  
Vol 45 ◽  
pp. 155-162 ◽  
Author(s):  
Priyanka Jajal ◽  
Trupti Mishra
Keyword(s):  
Climate Change ◽  
Energy Efficiency ◽  
Energy Efficient ◽  
Raw Materials ◽  
Raw Material ◽  
Reference Scenario ◽  
Efficient Technology ◽  
Fired Bricks ◽  
Energy Efficient Technology ◽  
Cement Manufacturing

Abstract. Climate change is a growing concern that is attracting international efforts. India, as a developing country, has committed to reducing its emission intensity of GDP up to 30 %–35 % by 2030. The emission intense sectors would be targeted to achieve climate commitment. One of the emission intense sector is construction raw material manufacturing that contributes 10 % share in the total emissions making it one of the potential mitigation sector. The study examines emissions from the construction raw materials namely, cement, steel, and brick manufacturing and presents two emission scenarios up to 2050. Energy efficient scenario (S2) is compared with a reference scenario (S1) developed based on a bottom-up approach. The results indicate that a moderate energy efficiency improvements and technological shifts lead to a decrease in emissions of 72 MT CO2 by 2030 and 137 MT CO2 by 2050. Further, the steel industry has the highest reduction potential, as the current technologies are energy inefficient. Similarly, the current dependency on fired bricks may be shifted to cement setting blocks leading to emission reductions. Cement manufacturing, on the other hand, shows limited scope for emission reduction that may be achieved through energy efficiency improvements. Efforts towards energy efficiency improvements in construction raw material manufacturing would result in reductions beyond the existing commitment of the Paris Agreement for India by 2030.

Development of the Potential for the Cheap Explosives in Russia

2021 ◽  
pp. 7-14
Author(s):  
S.D. Viktorov ◽  
◽  
A.E. Frantov ◽  
I.N. Lapikov ◽  
◽  
...  
Keyword(s):  
Raw Materials ◽  
Liquid Waste ◽  
Oil Products ◽  
Production Costs ◽  
Raw Material ◽  
Material Base ◽  
Waste Oil ◽  
Energy Potential ◽  
Secondary Aluminum ◽  
Technical Literature

The most accessible and popular means of destruction of rocks, which are used in the extraction of ores, non-metallic minerals, mining and chemical raw materials, are the cheap explosives, in the Russian technical literature called granulites or AS-DT, in the foreign — ANFO. The article presents the research carried out to improve the formulation and explosive properties of granulites A6, Igdanit, Igdanit-P, A3. They are aimed at using the modern raw material base, increasing the efficiency of blasting, the safety of manufacturing and loading drill holes and boreholes, maintaining a balanced composition, and preserving physical stability, providing energy potential with secondary aluminum additives. Further development of granulites is aimed at creating a line of formulations using saltpeter with variable technical parameters, mixed fuels in the form of liquid (waste oil products, fuel mixtures, diesel fuel) and solid (coal powder, coke fines, rubber crumbs) phases. Based on the use of the cheap explosives in the formulation of recycling materials formed at the mining enterprises, blasting technologies are being improved, and mixing and charging equipment is being developed. The proposed approaches are aimed at maintaining high technical and economic indicators of the use of explosives, ensuring the stationarity of the explosive process and the completeness of detonation of granulites reducing the sensitivity to mechanical and thermal influences, and maintaining susceptibility to initiation by practical means of an explosive pulse. When compiling the new formulations of granulites to reduce production costs, it is proposed to use the most economical types of oxidants and fuels with ensuring quality control of mixing components with different technological properties and conditioning the temperature-viscosity properties of the waste oil products.

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