Ilmenite & Rutile

Ilmenite and rutile are two chief minerals of titanium Ilmenite (FeO, TiO₂) theoretically contains 52.6% TiO₂ and 47.4% FeO, whereas the composition of rutile is TiO₂ containing 60% Ti and 40% O₂. Besides extraction of metal, there are two other principal industrial applications in which these minerals find use. The principal industrial application of ilmenite is in the manufacture of titanium dioxide or synthetic rutile, which in turn is used to manufacture white paints. Two processes, namely, sulfate Process and chloride process are suitable for conversion of ilmenite to titanium dioxide. The principal industrial application of rutile is in the manufacture of titanium dioxide or synthetic rutile (as in the case of Ilmenite) and welding rod coating. For conversion of rutile to titanium dioxide, the chloride Process is suitable, This process in also deployed for extraction of titanium metal from both ilmenite and rutile.

The above mentioned three uses of ilmenite and rutile namely extraction of titanium metal, manufacture of points and welding rod coating are discussed below:

 (a)      Titanium Metal: -

This is produced by chlorinating of titanium dioxide to form titanium tetrachloride, which is then mixed with molten magnesium. The BIS has not standardized any specification at either for the natural ore or for intermediate product titanium metal is in infant stage, being produced by the Defense Metallurgical Laboratory. Therefore, a clear picture regarding preferences of the user industry is yet to emerge so far as this and use of ilmenite and rutile in concerned.

 (b)      Paints:

The BIS has standardized specification for titanium dioxide which is prepared by processing ilmenite and rutile and which is nothing but an intermediate stage in the manufacture of white paints. Two grades namely Grade-A and Grade-B have been specified by BSI (IS 411-1953). There are as below:

i	Volatile Matter by sight (max.)	0.5%	0.5%
ii	Residue on sieve by weight (max.)	0.1%	0.1%
iii	Oil absorption	within 5% of the approved sample or 15% to 35% in the absence of an agreed sample.	within 5% of the approved sample or 15% to 35% in the absence of an agreed sample.
iv	Color	Close match to the approved sample	Close match to the approved sample
v	Reducing power	Not inferior to the approved sample	Not inferior to the approved sample
vi	Matter soluble in water by weight (max.)	0.5%	1.5%
vii	Acidity (as H2SO4) by weight (max.)	0.1%	0.1%
viii	Alkalinity (as Na2CO3) by weight (max.)	0.1%	0.1%

 However, there is no specification for ilmenite for rutile ore.

(c) Welding Rod Coating: -

Rutile is used for coating are welding electrodes. There are two types of electrodes namely according to the type of an electrode. There is no BIS specification, and as per the present practice in the user industry, the following are the two grades of rutile.

The reserves of ilmenite and rutile in beach sand are not at present estimated directly. The total reserve of beach sand is estimated in the usual manner. This beach sand is then subjected to pre-concentration for obtaining a composite heavy mineral concentrate which is subsequently subjected to physical separation into different fractions like monazites, ilmenite, rutile, leucoxene, sillimanite, kyanite, garnet zircon etc. The Percentage shares of ilmenite and rutile in the total estimated. On this basis the reserves of ilmenite and rutile are being estimated at present. It is obvious that while estimating their reserve there is no scope for estimating the contents of the main constituent TiO₂ and the different deleterious constituents within the in situ ilmenite and rutile. Consequently, the reserves estimated by AEC, IRL, KMML, etc. are expressed in terms of ilmenite and rutile minerals only, without any reference to their end use grades.

Therefore, in the inventory of titanium mineral as on 1-1-85 the reserves have not been classified according to the end use grades and the total reserves of ilmenite sand and rutile sand have been indicated separately, Besides reserves two other titanium minerals namely leucoxene and titaniferous vanidiferous magnetite have also been indicated in the inventory.

After examining the present practice of estimation of reserves, the Group is of the opinion that it in not possible to estimate and classify the reserved of finite mad rutile according to their and use grades, and the present practice of estimating the total reserves of these minerals may be continued.

 

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