Development of a bench-scale Kroll reactor: Experimental results and preliminary findings

The Kroll process remains the predominant method for large-scale titanium sponge production, involving the reduction of titanium tetrachloride (TiCl₄) with molten magnesium (Mg) under an argon (Ar) atmosphere at 1000-1100 K producing molten magnesium chloride (MgCl2) as a by-product. Despite its wid...

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Main Authors: T.A. Ferguson, C. Reilly, S.L. Cockcroft, D․ M․ Maijer
Format: Article
Language:English
Published: Elsevier 2025-09-01
Series:Results in Engineering
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Online Access:http://www.sciencedirect.com/science/article/pii/S2590123025028671
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author T.A. Ferguson
C. Reilly
S.L. Cockcroft
D․ M․ Maijer
author_facet T.A. Ferguson
C. Reilly
S.L. Cockcroft
D․ M․ Maijer
author_sort T.A. Ferguson
collection DOAJ
description The Kroll process remains the predominant method for large-scale titanium sponge production, involving the reduction of titanium tetrachloride (TiCl₄) with molten magnesium (Mg) under an argon (Ar) atmosphere at 1000-1100 K producing molten magnesium chloride (MgCl2) as a by-product. Despite its widespread industrial use, the Kroll process has received limited attention in the scientific literature, with existing studies presenting limited process data with differing interpretations. This lack of comprehensive understanding has left key reaction mechanisms in the commercial process poorly defined. This study presents four experiments with varying process conditions using a benchtop-scale reactor with high-resolution temperature and pressure instrumentation. These process conditions include, with and without the initial presence of MgCl2, varying feed rates and different materials present in the reactor to assess their ability to serve as substrates for Ti-sponge formation. The experimental results showed that the Ti sponge can grow on any substrate material irrespective of electrical conductivity, indicating that electron transport through crucible walls is not essential for Ti growth. Instead, it was found that the capillary action of Mg through porous Ti sponge was the driving force behind the continuation of the reaction. Furthermore, the reaction rate changed throughout the TiCl4 feed, suggesting a changing surface area where the heterogenous reaction can occur.
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spelling doaj-art-5224a30fe7ec40fa87100cc51fc9eb932025-08-23T04:49:02ZengElsevierResults in Engineering2590-12302025-09-012710680310.1016/j.rineng.2025.106803Development of a bench-scale Kroll reactor: Experimental results and preliminary findingsT.A. Ferguson0C. Reilly1S.L. Cockcroft2D․ M․ Maijer3Corresponding author.; Department of Materials Engineering, University of British Columbia, 6350 Stores Rd, Vancouver, BC, CanadaDepartment of Materials Engineering, University of British Columbia, 6350 Stores Rd, Vancouver, BC, CanadaDepartment of Materials Engineering, University of British Columbia, 6350 Stores Rd, Vancouver, BC, CanadaDepartment of Materials Engineering, University of British Columbia, 6350 Stores Rd, Vancouver, BC, CanadaThe Kroll process remains the predominant method for large-scale titanium sponge production, involving the reduction of titanium tetrachloride (TiCl₄) with molten magnesium (Mg) under an argon (Ar) atmosphere at 1000-1100 K producing molten magnesium chloride (MgCl2) as a by-product. Despite its widespread industrial use, the Kroll process has received limited attention in the scientific literature, with existing studies presenting limited process data with differing interpretations. This lack of comprehensive understanding has left key reaction mechanisms in the commercial process poorly defined. This study presents four experiments with varying process conditions using a benchtop-scale reactor with high-resolution temperature and pressure instrumentation. These process conditions include, with and without the initial presence of MgCl2, varying feed rates and different materials present in the reactor to assess their ability to serve as substrates for Ti-sponge formation. The experimental results showed that the Ti sponge can grow on any substrate material irrespective of electrical conductivity, indicating that electron transport through crucible walls is not essential for Ti growth. Instead, it was found that the capillary action of Mg through porous Ti sponge was the driving force behind the continuation of the reaction. Furthermore, the reaction rate changed throughout the TiCl4 feed, suggesting a changing surface area where the heterogenous reaction can occur.http://www.sciencedirect.com/science/article/pii/S2590123025028671Kroll processMagnesiothermic reductionTitaniumMagnesiumTitanium tetrachloride
spellingShingle T.A. Ferguson
C. Reilly
S.L. Cockcroft
D․ M․ Maijer
Development of a bench-scale Kroll reactor: Experimental results and preliminary findings
Results in Engineering
Kroll process
Magnesiothermic reduction
Titanium
Magnesium
Titanium tetrachloride
title Development of a bench-scale Kroll reactor: Experimental results and preliminary findings
title_full Development of a bench-scale Kroll reactor: Experimental results and preliminary findings
title_fullStr Development of a bench-scale Kroll reactor: Experimental results and preliminary findings
title_full_unstemmed Development of a bench-scale Kroll reactor: Experimental results and preliminary findings
title_short Development of a bench-scale Kroll reactor: Experimental results and preliminary findings
title_sort development of a bench scale kroll reactor experimental results and preliminary findings
topic Kroll process
Magnesiothermic reduction
Titanium
Magnesium
Titanium tetrachloride
url http://www.sciencedirect.com/science/article/pii/S2590123025028671
work_keys_str_mv AT taferguson developmentofabenchscalekrollreactorexperimentalresultsandpreliminaryfindings
AT creilly developmentofabenchscalekrollreactorexperimentalresultsandpreliminaryfindings
AT slcockcroft developmentofabenchscalekrollreactorexperimentalresultsandpreliminaryfindings
AT dmmaijer developmentofabenchscalekrollreactorexperimentalresultsandpreliminaryfindings