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Modelling and Optimization of Sub-Grade Iron Ore
Beneficiation Using Response Surface Method with Three Level
Three Factor Box Benken Design
G.V. Rao
MDC Limited, Donimalai, Karnataka, India
S. K. Jain, M. Jayapal Reddy, Dilip Kumar Mohanty
NMDC Limited, Hyderabad, India
ABSTRACT: This paper investigates the beneficiation of sub-grade iron ore from the Bailadila region in India,
which contains about 40% Fe and 40% SiO₂, with hematite as the main ore mineral and quartz as the gangue.
The goal is to upgrade the ore to a concentrate with 62% Fe and less than 5% SiO₂ using a Multi-Gravity
Separator (MGS). Experiments were conducted with MGS, known for its efficiency with low-grade ores. The
process was modelled and optimized using a Three-Level Three-Factor Box-Behnken design, identifying key
variables and developing predictive mathematical models. The study demonstrates the MGS’s effectiveness
and provides insights into the interaction of process parameters with product quality. Optimized parameters
include Drum Inclination, Wash Water Flow Rate, and Drum Rotational Speed. The developed models aid in
process control, showing potential for sustainable use of low-grade iron ore in the Bailadila region, aligning with
industry goals for high-quality output and reduced environmental impact.
Keywords: Sub-Grade Iron Ore, Multi-Gravity Separator, Beneficiation, Optimization, Bailadila, Hematite,
Quartz, Box-Behnken Design, Surface Plots, Model Equations, Pellet Grade Concentrate.
INTRODUCTION
As high-grade iron ore reserves deplete, the mining industry
must focus on exploiting and utilizing low-grade ores. The
accumulation of low-grade lumps and fines has increased
with regular iron ore production, but simple processes like
washing/scrubbing are insufficient to upgrade these ores for
sinter or pellet making. This investigation aimed to develop
a cost-effective flow sheet to beneficiate these ores for
industry use. The Bailadila range holds significant reserves
(30–35 million tons) of sub-grade iron ore, containing
Banded Hematite Quartzite (BHQ), Banded Hematite
Jasper (BHJ), and Banded Hematite Chert (BHC), with
iron content between 35–50%. NMDC focuses on mineral
conservation and develops methods to utilize resources sus-
tainably. To conserve iron ore and upgrade low-grade ores
for steelmaking, NMDC plans to beneficiate sub-grade
ores from Bailadila and Donimalai mines. The goal is to
produce suitable feed for blast furnaces or direct reduc-
tion processes, using the upgraded sub-grade iron ore from
Deposit No. 5, Bacheli, Bailadila, India, for lump, sinter
feed, or pellet feed.
Modelling and Optimization of Sub-Grade Iron Ore
Beneficiation Using Response Surface Method with Three Level
Three Factor Box Benken Design
G.V. Rao
MDC Limited, Donimalai, Karnataka, India
S. K. Jain, M. Jayapal Reddy, Dilip Kumar Mohanty
NMDC Limited, Hyderabad, India
ABSTRACT: This paper investigates the beneficiation of sub-grade iron ore from the Bailadila region in India,
which contains about 40% Fe and 40% SiO₂, with hematite as the main ore mineral and quartz as the gangue.
The goal is to upgrade the ore to a concentrate with 62% Fe and less than 5% SiO₂ using a Multi-Gravity
Separator (MGS). Experiments were conducted with MGS, known for its efficiency with low-grade ores. The
process was modelled and optimized using a Three-Level Three-Factor Box-Behnken design, identifying key
variables and developing predictive mathematical models. The study demonstrates the MGS’s effectiveness
and provides insights into the interaction of process parameters with product quality. Optimized parameters
include Drum Inclination, Wash Water Flow Rate, and Drum Rotational Speed. The developed models aid in
process control, showing potential for sustainable use of low-grade iron ore in the Bailadila region, aligning with
industry goals for high-quality output and reduced environmental impact.
Keywords: Sub-Grade Iron Ore, Multi-Gravity Separator, Beneficiation, Optimization, Bailadila, Hematite,
Quartz, Box-Behnken Design, Surface Plots, Model Equations, Pellet Grade Concentrate.
INTRODUCTION
As high-grade iron ore reserves deplete, the mining industry
must focus on exploiting and utilizing low-grade ores. The
accumulation of low-grade lumps and fines has increased
with regular iron ore production, but simple processes like
washing/scrubbing are insufficient to upgrade these ores for
sinter or pellet making. This investigation aimed to develop
a cost-effective flow sheet to beneficiate these ores for
industry use. The Bailadila range holds significant reserves
(30–35 million tons) of sub-grade iron ore, containing
Banded Hematite Quartzite (BHQ), Banded Hematite
Jasper (BHJ), and Banded Hematite Chert (BHC), with
iron content between 35–50%. NMDC focuses on mineral
conservation and develops methods to utilize resources sus-
tainably. To conserve iron ore and upgrade low-grade ores
for steelmaking, NMDC plans to beneficiate sub-grade
ores from Bailadila and Donimalai mines. The goal is to
produce suitable feed for blast furnaces or direct reduc-
tion processes, using the upgraded sub-grade iron ore from
Deposit No. 5, Bacheli, Bailadila, India, for lump, sinter
feed, or pellet feed.