scholarly journals Recovery of Iron and Aluminum from Bauxite Residue by Carbothermic Reduction and Slag Leaching

2021 ◽  
Author(s):  
K. E. Ekstroem ◽  
A. Voll Bugten ◽  
C. van der Eijk ◽  
A. Lazou ◽  
E. Balomenos ◽  
...  
Keyword(s):  
Large Volume ◽  
Calcium Aluminate ◽  
Volume Expansion ◽  
Carbothermic Reduction ◽  
Bauxite Residue ◽  
Pig Iron ◽  
Post Processing ◽  
Reaction Surface

Abstract The recovery of major components of bauxite residue by carbothermic reduction at 1550–1750 °C and subsequent slag leaching in a Na3CO3(aq) solution is studied. Iron recovers primarily to pig-iron and lime is added to tune the calcium aluminate slags towards the highly leachable mayenite phase. The concentration of aluminum in the leachate correlates well with the occurrence of mayenite and aluminum recoveries up to 50–60% are observed. However, slags with low CaO additions are vulnerable to gehlenite formation and display reduced leachabilities. Formation of an inhibiting layer of CaCO3(s) on the reaction surface of calcium-aluminate particles during leaching and immobilization of aluminum in CaTiO3(s) are also suggested to play important roles in limiting the aluminum leachability. Costs related to post-processing may be reduced by achieving disintegrating slags, a behavior which is observed for slags holding high γ- to β-Ca2SiO4 ratios. The disintegration is caused by the large volume expansion associated with the β-to-γ transformation and as such, various factors that are known to stabilize the β-polymorph are discussed. Graphical Abstract

scholarly journals The Utilization of Bauxite Residue with a Calcite-Rich Bauxite Ore in the Pedersen Process for Iron and Alumina Extraction

2021 ◽  
Author(s):  
Adamantia Lazou ◽  
Casper Van Der Eijk ◽  
Kai Tang ◽  
Efthymios Balomenos ◽  
Leiv Kolbeinsen ◽  
...  
Keyword(s):  
Calcium Aluminate ◽  
Bauxite Residue ◽  
Reduction Process ◽  
Analytical Techniques ◽  
Pig Iron ◽  
Mass Ratio ◽  
Smelting Reduction ◽  
Bauxite Ore ◽  
Metal Phases ◽  
Alumina Recovery

AbstractMetallurgical grade alumina is produced worldwide through the well-known Bayer process, which unavoidably generates bauxite residue (BR, also known as red mud) in almost equal amounts to alumina. This study aims the valorization of BR through a smelting-reduction process to obtain calcium aluminate slags that can be a proper feed for alumina recovery via the Pedersen process. It investigates the thermodynamics and characteristics of the slags and pig iron produced from mixtures of BR, a bauxite beneficiation byproduct, and lime. In this context, the evolution of the different phases in the slags is studied with advanced analytical techniques and thermodynamic calculations. According to the results, a CaO/Al2O3 mass ratio within 1.3 to 1.4 in the slags can yield more Al2O3-containing leachable phases, such as CaO·Al2O3 and 12CaO·7Al2O3. The cooling dictates the amount and the characteristics of these phases, and the slower cooling rate yields improved slag characteristics. The distribution of the elements between the slag and metal phases shows that iron is separated, and the majority of the P, Cr, Ni, and V are distributed in the produced pig iron, while S, Ti, and Si are mostly concentrated in the slags.

Graphite@Silicon embedded in Carbon Conformally Coated Tiny SiO2 Nanoparticles Matrix for High-Performance Lithium-Ion Batteries

2021 ◽  
Author(s):  
Huitian Liu ◽  
Xu Liu ◽  
Zhaolin Liu ◽  
Junyan Tao ◽  
Xiaoqian Dai ◽  
...  
Keyword(s):  
Lithium Ion Batteries ◽  
Large Volume ◽  
Volume Expansion ◽  
Anode Materials ◽  
High Performance ◽  
Lithium Ion ◽  
Sio2 Nanoparticles ◽  
Carbon Composites ◽  
Effective Strategy ◽  
Si Anode

Engineering of graphite@Si/carbon composites is considered as an effective strategy to surmount the shortcomings of low conductivity and large volume expansion of bare Si anode materials for lithium-ion batteries. Nevertheless,...

Asynchronous reactions of “self-matrix” dual-crystals effectively accommodating volume expansion/shrinkage of electrode materials with enhanced sodium storage

2019 ◽  
Vol 55 (62) ◽  
pp. 9076-9079 ◽  
Author(s):  
Youchen Hao ◽  
Xifei Li ◽  
Wen Liu ◽  
Hirbod Maleki Kheimeh Sari ◽  
Jian Qin ◽  
...  
Keyword(s):  
Large Volume ◽  
Volume Expansion ◽  
Electrode Materials ◽  
Volume Changes ◽  
Sodium Storage

The dual-crystal FeS2 shows a better tolerance towards large volume changes because of the asynchronous reaction.

Uniform yolk–shell structured Si–C nanoparticles as a high performance anode material for the Li-ion battery

2020 ◽  
Vol 56 (3) ◽  
pp. 364-367 ◽  
Author(s):  
Xuequan Li ◽  
Yufeng Xing ◽  
Jun Xu ◽  
Qibo Deng ◽  
Li-Hua Shao
Keyword(s):  
Anode Material ◽  
Large Volume ◽  
Volume Expansion ◽  
High Performance ◽  
Li Ion Battery ◽  
Void Space ◽  
Li Ion ◽  
Si Anode

Uniform yolk–shell Si–C nanoparticles with a well-defined void space allowing large volume expansion of the Si anode for the Li-ion battery.

Reaction Sintering Property of Green Compact of Si and TiC Mixed Powders in Nitrogen

1991 ◽  
Vol 251 ◽  
Author(s):  
Yoshiyuki Yasutomi ◽  
Masahisa Sobue ◽  
Shin-Ichi S. Shinozaki ◽  
John Hangas ◽  
Shin-Ichi S. Shinozaki
Keyword(s):  
Powder Mixture ◽  
Large Volume ◽  
Volume Expansion ◽  
Nitrogen Atmosphere ◽  
Free Carbon ◽  
Reaction Sintering ◽  
Sintering Process ◽  
Composite Ceramics ◽  
New Type ◽  
Near Net Shape

ABSTRACTWe have developed a new type of near net shape sintering process using nitridation of Si and other inorganic powders. In this report, the sintering property of powder mixture compacts of TiC (10μm or 0.9μm) and Si (0.9μm) in a nitrogen atmosphere at 1350°C was investigated.A large portion of the Si formed Si3N4 on reaction with nitrogen, while TiC formed TiN and free carbon. A small portion of this free carbon was converted into β-SiC on reaction with Si and about 98% of the free carbon remained in the sintered body. Thus, composite ceramics having a composition of Si3N4·TiC·TiN·C·β-SiC were obtained. The porosity of this composite was much smaller than that of ordinary Si3N4 bonded ceramics, because of the large volume expansion for formation of free carbon. The pore size under 5μm can be got using TiC powder with an avarage size of 0.9μm.

scholarly journals ON THE WRAPPING CORRECTION TO SINGLE MAGNON ENERGY IN TWISTED ${\mathcal N}=4$ SYM

2009 ◽  
Vol 24 (31) ◽  
pp. 5803-5817 ◽  
Author(s):  
MATTEO BECCARIA ◽  
GIAN FABRIZIO DE ANGELIS
Keyword(s):  
Large Volume ◽  
Volume Expansion ◽  
Closed Formula ◽  
Impurity States

We apply Zeilberger summation to derive a closed formula for the wrapping correction to one-impurity states in the [Formula: see text] sector of the β-deformed [Formula: see text] SYM theory at β = 1/2. As an application depending heavily on the result, we compute the large volume expansion of the wrapping correction.

In situ TEM study of lithiation into a PPy coated α-MnO2/graphene foam freestanding electrode

2018 ◽  
Vol 2 (8) ◽  
pp. 1481-1488 ◽  
Author(s):  
Mohammad Akbari Garakani ◽  
Sara Abouali ◽  
Jiang Cui ◽  
Jang-Kyo Kim
Keyword(s):  
Electrical Conductivity ◽  
Lithium Ion Batteries ◽  
Large Volume ◽  
Volume Expansion ◽  
Low Cost ◽  
Lithium Ion ◽  
In Situ Tem ◽  
The Many ◽  
Charge Discharge

Even with the many desirable properties, natural abundance and low cost of α-MnO2, its application as an anode in lithium-ion batteries has been limited because of its low intrinsic electrical conductivity and large volume expansion occurring during charge/discharge cycles.

Carbothermic Reduction of Nickeliferous Laterite Ores for Nickel Pig Iron Production in China: A Review

JOM ◽  
2013 ◽  
Vol 65 (11) ◽  
pp. 1573-1583 ◽  
Author(s):  
Mingjun Rao ◽  
Guanghui Li ◽  
Tao Jiang ◽  
Jun Luo ◽  
Yuanbo Zhang ◽  
...  
Keyword(s):  
Carbothermic Reduction ◽  
Iron Production ◽  
Pig Iron ◽  
Laterite Ores ◽  
Nickeliferous Laterite

A soft, multilayered lithium–electrolyte interface

2016 ◽  
Vol 9 (1) ◽  
pp. 112-116 ◽  
Author(s):  
Claudiu B. Bucur ◽  
Adrian Lita ◽  
Naoki Osada ◽  
John Muldoon
Keyword(s):  
Thin Film ◽  
Large Volume ◽  
Volume Expansion ◽  
Self Healing ◽  
Electrolyte Interface ◽  
Lithium Deposition

It is desirable that a thin film lithium–electrolyte interface is flexible and self-healing to accommodate the large volume expansion during lithium deposition without rupturing and impede electrolyte decomposition.

scholarly journals Carbothermic Reduction of Bauxite Residue.

1999 ◽  
Vol 115 (8) ◽  
pp. 611-617 ◽  
Author(s):  
Takaya KITAJIMA ◽  
Eiki KASAI
Keyword(s):  
Carbothermic Reduction ◽  
Bauxite Residue
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