Publications related to Bayer process

Insights on the role of alumina content and the filler effect on the sulfate requirement of PC and blended cements

Karen Scrivener, Franco Alberto Zunino Sommariva

Understanding the mechanism controlling the sulfate requirement of blended cements is crucial for a successful deployment of these technologies towards a more sustainable industry. Particularly, clarification regarding the role of alumina content on the su ...

Pergamon-Elsevier Science Ltd2022

Iron incorporation in synthetic precipitated calcium silicate hydrates

David Lyndon Emsley, Paul Bowen, Brennan James Walder, Jirawan Siramanont

Effect of Fe3+ on the precipitation of synthetic calcium silicate hydrates (C-S-H) under controlled conditions has been evaluated. Using extremely basic either initial calcium nitrate or sodium silicate solutions (pH > 11), incipient formation of ferrihydr ...

Pergamon-Elsevier Science Ltd2021

Kinetic processes in the high-temperature pressure-infiltration of Al into Al2O3

Andreas Mortensen, Ludger Weber, Marta Fornabaio, Gionata Schneider

We explore the influence (i) of the interaction between aluminium and alumina, and (ii) of sodium impurities present in Bayer alumina, on the pressure infiltration of alumina particle preforms with molten aluminium. At 1000°C or above, although the alumini ...

2020

Limestone calcined clay cements (LC3): raw material processing, sulfate balance and hydration kinetics

Franco Alberto Zunino Sommariva

Limestone calcined clay cements (LC3) are blended cements that combine clinker, limestone, calcined clay and gypsum. The availability of the materials required to produce LC3 and the good performance that it achieves, makes LC3 suitable as a sustainable re ...

EPFL2020

Méthodes numériques liées à la distribution d'alumine dans une cuve d'électrolyse d'aluminium

Thomas Frédéric Hilke

Metallic aluminium plays a key role in our modern economy. Primary metallic aluminium is produced by the transformation of aluminium oxide using the Hall-Héroult industrial process. This process, which requires enormous quantities of energy, consists in pe ...

EPFL2019

Rapid screening tests for supplementary cementitious materials: past and future

Karen Scrivener, Ruben Anton Snellings

Rapid screening tests for supplementary cementitious materials (SCMs) have been in use for over 150 years. Over the years a multitude of methods have been put forward to predict the strength development of SCMblended mortars and concrete. This paper summar ...

Springer2016

Approximation numérique des écoulements turbulents dans des cuves d'électrolyse de l'aluminium

Jonathan Rochat

Aluminium is a metal extracted from bauxite ore using electrolysis process in cells of big size. A huge electric current goes in the cell through an electrolytic bath and aluminium liquid. These currents generate strong magnetic forces that allow the bath ...

EPFL2016

Limestone reaction in calcium aluminate cement–calcium sulfate systems

Karen Scrivener, Julien Bizzozero

This paper reports a study of ternary blends composed of calcium aluminate cement, calcium sulfate hemihydrate and limestone. Compressive strength tests and hydration kinetics were studied as a function of limestone and calcium sulfate content. The phase e ...

Pergamon-Elsevier Science Ltd2015

Field effect modulated nanofluidic diode membrane based on Al2O3/W heterogeneous nanopore arrays

Jürgen Brugger, Philippe Renaud, Arnaud Bertsch, Songmei Wu, Fabien Patrick Wildhaber

We developed Al2O3/W heterogeneous nanopore arrays for field effect modulated nanofluidic diodes. They are fabricated by transferring self-organized nanopores of anodic aluminium oxide into a W thin film. The nanopores are ∼20 nm in diameter and 400 nm in ...

American Institute of Physics2013

Freeze granulation: Powder processing for transparent alumina applications

Paul Bowen, Michael Stuer, Zhe Zhao

Use of freeze granulated powders is successfully used as an industrially viable alternative to loose powder sintering for transparent polycrystalline alumina (PCA). Freeze granulation with narrow granule size distribution was realized after suspension cond ...

2012

The influence of aluminium on the dissolution of amorphous silica and its relation to alkali silica reaction

Karen Scrivener, Theodor Alexandre Emmanuele Chappex

It is known that the addition of supplementary cementitious materials (SCMs) in concretes reduces or even stops expansion due to alkali silica reaction (ASR). It has been widely shown that the main mechanism controlling ASR in blends is the alkali fixation ...

Pergamon-Elsevier Science Ltd2012

Predictive hydrogeochemical modelling of bauxite residue sand in field conditions

David Andrew Barry, Laurin Wissmeier

The suitability of residue sand (the coarse fraction remaining from Bayer´s process of bauxite refining) for constructing the surface cover of closed bauxite residue storage areas was investigated. Specifically, its properties as a medium for plant growth ...

Elsevier2011

Numerical Simulation and Optimization of the Alumina Distribution in an Aluminium Electrolysis Pot

Thomas Hofer

This thesis is about the numerical simulation and optimization of the alumina repartition in the bath of an aluminium electrolysis pot. A mathematical model is set up which contains the feeding of alumina particles to the bath, the dissolution of the parti ...

EPFL2011

Tetraalkylammonium Salts of Weakly Coordinating Aluminates: Ionic Liquids, Materials for Electrochemical Applications and Useful Compounds for Anion Investigation

Michael Graetzel, Mingkui Wang, Ines Raabe

In this study, we investigated the tetraalkylammonium salts of the weakly coordinating fluorinated alkoxyaluminates pftb (Al(O(C(CF3)(3))(4)) hfip (Al(OC(H)-(CF3)(2))(4)) and hftb (Al(OC(CH3)(-) (CF3)(2))(4)) in order to obtai ...

2009

Atomistic Simulation of Y-Doped alpha-Alumina Interfaces

Paul Bowen, Ulrich Aschauer, Sandra Caroline Galmarini

The exact mechanism of creep resistance enhancement due to yttrium (Y) doping in a-alumina is still subject to speculation, although it is known that dopants segregate strongly to grain boundaries. The current work applies atomistic simulation techniques t ...

2008