Page 18 - Mines and Minerals Reporter eMagazine - Volume December 2024

IRON ORE MINING

CHARACTERISATION AND PROCESSING
OF SOME IRON ORES OF INDIA

S. J. G. Krishna • M. R. Patil • C. Rudrappa •
S. P. Kumar • B. P. Ravi

ABSTRACT industry and depletion of massive compact high grade
anhydrous iron oxide ores necessitated the processing and
utilisation of sub and low grade iron ore lumps and fines and
ack of process characterisation data of the ores based mine waste dumps. The previous works by IBM [1, 2], FIMI [3]
on the granulometry, texture, mineralogy, physical, and Sahoo et al. [4] on iron ore processing comprises of size
Lchemical, properties, merits and limitations of process, reduction-sizing, washing—classification of fines, jigging of
market and local conditions may mislead the mineral fine-chips, crushing-closed circuit grinding to liberate values
processing entrepreneur. The proper implementation of followed by classification, gravity concentration, magnetic
process characterisation and geotechnical map data will concentration, selective dispersion of gangue—flocculation
result in optimised sustainable utilisation of resource by of iron ore slimes followed by desliming, inverse flotation
processing. A few case studies of process characterisation of of iron minerals, selective magnetic collector adsorption
some Indian iron ores are dealt with. The tentative ascending followed by magnetic separation, pyro-processing followed
order of process refractoriness of iron ores is massive by desliming, gravity concentration, magnetic concentration
hematite<magnetite<marine black iron oxide sands<laminated and agglomeration of concentrates. The industrial trend is to
soft friable siliceous ore fines<massive banded magnetite reduce the cost, both capital and operative, by enhancing unit
quartzite<laminated soft friable clayey aluminous ore capacities, reducing energy consumption, giving flexible flow
fines<massive banded hematite quartzite<jasper<massive sheet for pre-concentration of values at coarse sizes at site, as
clayey hydrated iron oxide ore<manganese bearing iron ores indicated by some of previous reviews of IBM [1, 2] and FIMI
massive<Ti–V bearing magnetite magmatic ore<ferruginous [3]. Iron ores are categorised as anhydrous iron oxide ores,
cherty quartzite. Based on diagnostic process characterisation, hydrated iron oxide ores, iron carbonate and iron silicate ores
the ores have been classified and generic process have been based on iron ore mineralogy. It is also categorised as massive
hematite, banded anhydrous iron oxide quartz [BHQ/banded
adopted for some Indian iron ores.
magnetite quartzite (BMQ)], friable hard/soft laminated ores,
laterites, beach black iron ore sands, marine oolitic ores,
Keywords: Characterisation Iron ores Beneficiation massive magmatic Ti/V magnetite ores, manganese bearing
iron ores and ferruginous cherty quartzite by IBM [1, 2] and
ABBREVIATIONS FIMI [3].

The process characterisation data of the ores based on
< Less than granulometry, texture, mineralogy, physical, chemical
> Greater than properties, merits and limitation of process, costs, market and
WHIMS Wet high intensity magnetic separation, local conditions may aid the mineral processing entrepreneur.
The proper implementation of process characterisation and
WLIMS Wet low intensity magnetic separation geotechnical map data will result in pragmatic sustainable
utilisation of resource by processing. The onus for solutions to
INTRODUCTION the problems associated with the assemblage of minerals and
processes lie with them only. Hence, the paper briefly
enumerates the mineral-process characteristics of some iron
The exponential demand, improved socio-economic ores mainly from India, based on ore characteristics, diagnostic
conditions, stringent environmental regulations on mining amenability test (DAT) and generic process results.

16 MINES & MINERALS REPORTER / DECEMBER 2024