Development and Scale-Up of ‘The Bradford Process’ for the Production of Titanium and Titanium Alloys

Research was carried out on the “Bradford Process”; a method of metal production via calciothermic reduction of metal oxides, with unique pre-treatment step, to observe: scalability, alloy/part production potential, reaction mechanism and general process improvement. The research was primarily undertaken using laboratory grade Anatase Phase TiO2, Acetone, Distilled Water and HCl and evaluated via controlled partial/full reduction reactions. With analysis performed using scanning electron microscopy with energy dispersive X-rays (SEM-EDX), inert gas fusion (IGF), powdered X-ray diffraction (P-XRD) with Rietveld refinement, and particle size analysis (PSA). The research identified that the foundational works results (>99% purity titanium), could not be reproduced (highest obtained ~98.5%), and is unsuited for scaling due to calcium vaporisation, signification exothermic reaction (>1400°C), and purity issues. But that the observed issues are partially addressable via argon pressurised reduction, and controlled reactor feed design, but insufficient reduction still observed. It was further observed that while the process is ill-suited for alloy production from metal oxides (due to intermediates formation and poor reduction), the sponge like product is suitable for use in FAST (Field Assisted Sintering Technology) to produce parts. The reaction pathway appears the same for both untreated and treated TiO2. However, the reaction occurs sooner and is potentially benefitted (higher final reduction potential) via solvent treatment with acetone, evaluated to be due to induced lattice strain improving reaction kinetics. It is concluded that further foundational work needed to confirm original results and adoption of new methodology (pressurised, controlled-feed reactor) for scaling is required.

URI

https://bradscholars.brad.ac.uk/handle/10454/20840

Type

Thesis

Qualification name

PhD