sponge iron industry –past-present-future - SIMA
sponge iron industry –past-present-future - SIMA
sponge iron industry –past-present-future - SIMA
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iii. Green ball induration by drying, pre heating &<br />
firing, and<br />
iv. Cooling of hardened pellets.<br />
Such pellets would have the following advantages<br />
over raw <strong>iron</strong> ore:-<br />
l The rotary kiln can produce about 20% more<br />
without any changes in design.<br />
l Specific consumption of coal will come down by<br />
about10%<br />
l Campaign life will increase substantially to the<br />
tune of about 50%<br />
l As there will be no accretion and no fused lump<br />
formation, the refractory repairing cost will be<br />
reduced by 50%<br />
l Metallization will be better compared to a situation<br />
where lump ore is used.<br />
l There will be less fines in the finished product..<br />
l There are no losses of handling <strong>iron</strong> ore, as<br />
pellets will not break during transport or<br />
handling,and<br />
l There will be better working env<strong>iron</strong>ment.<br />
Before pelletizing the <strong>iron</strong> ore fines, it is essential<br />
that a suitable beneficiation plant is put up adopting<br />
a process flow sheet based on the following test work<br />
to optimize the degree of combination of gravimetric<br />
and magnetic separation processes.<br />
l Chemical analysis of the samples (Fe(t), FeO,<br />
, P, LOI)<br />
SiO ,Al O<br />
2 2 3<br />
l Weight percentage size fraction wise.<br />
l Sizing of the – 38um material using ultrasonic<br />
bath screening at 20um, 10um & 5um.<br />
l Bulk density and specific gravity determination<br />
l Density characterization of the – 32+8 mm and –<br />
8+0.15 mm material using the Mineral Density<br />
Separator (MDS)<br />
l Heavy Liquid Separation test work on the – 32+8<br />
mm and – 8+1 mm material<br />
l Elutriator (hindered setting) test work on – 1+0.15<br />
mm and – 0.15 mm fractions<br />
l Compressive and tensile strength<br />
l Bond work indices<br />
l Angle of Repose<br />
l Magnetic susceptibility<br />
l Flotation on the fine material, if required, and<br />
l Mineralogical evaluation of sample to understand<br />
the liberation characteristics of the material<br />
A typical feed specification and product specification<br />
in case of <strong>iron</strong> ore beneficiation plant appears at<br />
Annexure – 1.<br />
In this context it is also pleaded that a part of rich<br />
grade <strong>iron</strong> ore deposits provide dedicated linkages<br />
to <strong>sponge</strong> <strong>iron</strong> plants, as many of these are<br />
graduating to mini steel plants filling a significant void<br />
of shortfall in production through primary steel sector.<br />
Annexure-2 and Annexure-3 furnish general<br />
flowsheets of <strong>iron</strong> ore beneficiation and pelletising<br />
plants.<br />
Non-Coking Coal for <strong>sponge</strong> <strong>iron</strong> plants<br />
The properties of non-Coking Coal which are relevant<br />
for use in <strong>sponge</strong> <strong>iron</strong> making are:-<br />
a. Parameters related to Proximate Analysis:-<br />
Ash
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