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The Reactivity of New Zealand Ilmenites

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posted on 2021-11-05, 02:56 authored by Metson, James Bernard

The dissolution of West Coast, South Island, New Zealand ilmenite in acid solutions was studied under a variety of conditions, including concentrations approaching those used industrially. The major dissolution medium considered was hydrochloric acid (1-->10 M), at temperatures of 50-->80 degrees C. The series of experiments undertaken souqht to establish the factors affecting the reactivity of the ilmenite samples. Concentrations of dissolved components of the ilmenite were followed by Atomic Absorption spectrometry and the structure and composition of the residual ilmenite was examined by X-ray powder diffraction, X-ray fluorescence, electron microprobe and scanning electron microscopy. Evidence for the rapid dissolution of an iron-rich surface phase was observed, but the dominant feature of early reaction is selective attack along zones parallel to the basal plane of the ilmenite structure. After the initial phase of rapid dissolution, reaction rate declines and all extended period of concentration/time linearity follows. This decline in rate appears to relate to polymerisation and. transport of dissolved titanium within the porous solid. The addition of phosphate and fluoride to the system, has been shown to seriously affect the properties and transport of dissolved titanium. The effects of other interfering reagents such as additional titanium and iron were also considered. The observed behaviour of these ilmenites in dissolution, was related to the pattern of natural weathering identified in other ilmenite concentrates The structure and composition of a range of these materials was examined by X-ray diffraction, Electron microprobe and Mossbauer spectroscopy.

History

Copyright Date

1980-01-01

Date of Award

1980-01-01

Publisher

Te Herenga Waka—Victoria University of Wellington

Rights License

Author Retains Copyright

Degree Discipline

Chemistry

Degree Grantor

Te Herenga Waka—Victoria University of Wellington

Degree Level

Doctoral

Degree Name

Doctor of Philosophy

Victoria University of Wellington Item Type

Awarded Doctoral Thesis

Language

en_NZ

Victoria University of Wellington School

School of Chemical and Physical Sciences

Advisors

Johnston, J H; Duncan, J F