Up-grading of Sri Lankan ilrnenite

Abstract

Ilrnenite, rutile and leucoxene are the only naturally-occurring titanium bearing minerals that have been seriously considered as suitable feed stock for either the metal producing or pigment industries. The existence in many places in the coast of Sri Lanka of natural concentrates of titanium bearing mineral sands such as ilrnenite and rutile with a high degree of purity has been known as far back as 1903. These deposits are found as beach sands on the east and north-west coast and occur in association with others, namely, rutile, zircon and monazite. The beach sand industry of the country, operated by the Ceylon Minerals Sands Corporation produces about 70.000 tonnes of ilrnenite per year and about 10,000 tonnes per year of rutile. If Sri Lanka were to convert the ilrnenite produced here into a value added product, instead of exporting the raw material as such, it would enable us to make sizeable strides in industrial development. The work carried out showed that Sri Lankan ilrnenite can be converted to synthetic rutile containing about 95 % Ti02 by oxidation-reduction-leach process. The oxidized ilrnenite was reduced with carbonaceous materials to reduced rutile and ' iron. Iron can be leached out using dilute HC1 acid. Reduced rutile phase was calcined to obtain synthetic rutile. The paper will discuss the main steps involved in this process.