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Successful Recovery of Chromite Fines
S. Chang, S. Yalcin, M. Oliazadeh
Present day ferrochrome demand is on the rise, as
more steel products require this material as an alloying
element. It is projected that the stainless steel
demands will grow by about 6% per year to 2020; as
such, the supply and demand for ferrochrome appears
promising. Chromite is the only economical source of
chromium, which is commonly upgraded by gravity
techniques and used to produce ferrochrome. The
gravity separation methods are not able to treat
particles finer than 0.1 mm efficiently. Therefore, in
processing chromite ore, a large quantity of fine
tailings; some 25% of the mineral values have been
reported as lost in slimes during processing. The
chromite content of these tailings is typically 10-20%
Cr2O3 and accumulates into a large stockpile/pond. A
chromite concentrator project in Canada, considers a
cut-off grade of 20% Cr2O3. This indicates further
processing might be required to recover chromite from
low-grade stockpile when the high-grade deposits are
depleted. Low-grade ores normally indicates
disseminated chromite ores with low liberation and
consequently fine comminution. This paper reviews
the techniques for treating chromite from fine material
and provides some examples of successful operations
in fine chromite recovery. Beneficiation techniques for
fine particles include gravity separation, magnetic
separation, and flotation. Several case studies are
presented here that used one of the aforementioned
methods or a combination of them.
