Reduction of New Zealand Titanomagnetite Ironsand by Hydrogen Gas in a Fluidised Bed System

In New Zealand (NZ), titanomagnetite (TTM) ironsand has been commercially processed in a coal-fired rotary kiln process. However, this approach produces high emissions of CO2. Fluidised bed (FB) process allows the use of pure hydrogen gas to reduce ironsand, and as a result, does not produce CO2. However, for conventional hematite ores, reduction in a FB system is usually limited by the onset of particle sticking at temperatures ≳ 800°C. This thesis investigates the reduction of NZ ironsand by hydrogen in the FB system with a key focus on ore sticking behaviour. A laboratory-scale experimental FB reactor has been designed and built for the hydrogen reduction study at high temperatures. Quantitative X-ray diffraction (q-XRD) has been used to determine the metallisation degree of partially reduced samples. Phase evolution during the reaction has also been analysed using q-XRD alongside scanning electron microscopy (SEM).