Review of titanium feedstock selection for fluidized bed chlorinators

摘要

Titanium tetrachloride (TiCU) is the basic raw material for the production of titanium dioxide (TiO_2) pigment and titanium (Ti) metal. Worldwide, around 3.5 Mt of TiO_2 pigment is produced annually by the chloride process, consuming in the region of 4.5 Mt of titania feedstock. Titania feedstock is chlorinated in the presence of a carbonaceous reductant at temperatures of approximately 1000°C for the production of TiCl_4.Mintek has been associated with research work on titania feedstock since the early 1970s. The DC arc smelting process for production of titania slag from ilmenite was jointly developed and patented by Mintek and Anglo American. This technology is successfully used on a commercial scale at the Tronox-operated plants in South Africa. Over the years, Mintek has been working on various aspects of the chlorination of titania feedstock. Feedstock such as titania slag, synthetic rutile, upgraded slag, ilmenite, and rutile have all been evaluated in Mintek's laboratory-scale chlorination facility. Chlorination kinetics of various species present in the feedstock as well as the hydrodynamic properties of various titania feedstock materials, for example the effect of density and particle size on the quantity of blowovers from the chlorinator, have been investigated.This paper provides a review of the characteristics of the titania feedstock used in industrial fhuidized bed chlorinators, the effects of the chlorination kinetics of various species on the chlorinator bed composition, and the impact of the metal chlorides produced on the downstream operations in the production of TiCl_4 The information from the review may be useful for selecting titania feedstock for the production of TiCl_4 using fluid bed chlorination technology.