Abstract:
Ilmenite and l1ltile are natural sources of Ti02 and titanium metal. Rutile, naturally
occuring pure Tin, i, prefen-ed to ilmenite as a raw materia!. Due to rapid decrease
;n sup1'l} of rutile, the necessity of alternate sources of rutile cannot be
ov~relllpha,i7ed_ As a l'esult, investigatlOns are bcmg carried out throughout the
world on the lIpgradation of low-gmde ilmenite 10 rutile. C()n.<equently, it has
become necessary to identitY the best possible route for the upgradallon of ilmenite
to what is known as sylllhclic rutile.
Ilmenite m~y contam malll minerals like hematite, magnetite etc In it, structure.
).iaturai weathering of llmcnilc rcsull, in the inL,ea,e in the '] iO, content of ilmenite
with incre •.,ing time of weathering, So detailed investigation into the exlent of
weatberlng of ilmenlle of a parlicular placer deposit is essential nOI only for the
qual itative assessment of tbe deposit but also to Improve the technique of produelion
of ,yntbetie n'tilc.
Samples of ilmenite containing 14.4 per cent FeO, 33.0 per cent Fe20J and 39,5 per
cent Ti01 were collected from the Beach Sand Exploitalion Center, Kalalli, Cox's
lla7.ar. The samples were tben subjected to magnetic and size Iractionation, The
phases present in the dlllerent fractlOns (both magnetle and size) were idenlified by
X-ray diffractions analysi:;, The chemical compositions oftlle dillcrent magnetic and
:;ize fractions were determined by wet chemical analysis. The fractions were reduced
lor 4 hour at I0500C by equal amounls of charma!. The exlent of reduction was
followed by chemical analysis of the reduced mass for metallic iron. The ,results
obtained were <upplemenled hy X-ray difti'action analysis and optical microscopy.
Samples of the different magnelic fractions and ,ize fractions were oxidi7ed for two
hour al 9000C and were reduced under otherwi,e identical conditions. The effects of
the oxidalion on the extent of reduction were followed by tlle determination of
mctalhc Iron content of the reduced samples. The efTeel of addilion of 10 per cenl
• V[I
N,'2CO, on lhe exlent of reduction of the diffcrent fractions (botb before and after
o~idation) under otherwi,e idenlical conditions were also investigaled.
from the chemical analysi.', il was found that Cox's Bazar ilmenite is
characteri"lically "imilar to Moheskh~li ilmenite. l're,ence of aHeration productl; of
ilm~nite, partlcularly pseudorutile, could nul be detected in the X_ray diffra~lion
pallems of any ot the ,ix magnetic fraclion, of this deposit. Attempt, were al;o made /
10 delect the presence of waler and hence the presence of pseudorutilc by
thermogra,imelri~ analysis. Thermogravimelric analy<is did not show any significant
change of weight ncar about 600°C for any magnelie lr~ction. Mineralogical study
has also been carried oul. The results of lhese investigations led to the conclusion
that Cox's I3anr ilmenite ha, not u'ndergune alteration to any signitlcant extent
This study ~Iso concentrated upon the reduetiun behavior of the different magnetic
lhetions ~s well a, UPOllreduelion behavior of dillcrcnt size tractions. II has bem,
concluded that separate reduclion procedures for the differenl fraclions (either
magnetic or size) i, not n~~e"ary.
