TECHNICAL FIELD
The present invention relates to the field of metallurgy and mineral processing. Particularly,
the present invention provides a process for selective reduction of iron present in ferruginous
manganese ore (FMO). Said process comprises subjecting a feed blend comprising the ore to
smelting in a cupola furnace to obtain concentrated manganese oxide (MnO) slag and pig
iron.
BACKGROUND OF THE DISCLOSURE
Manganese alloys are used mainly in steel production process as a deoxidising agent, alloying
agent, etc. There are various kinds of manganese alloys such as Ferromanganese (HC Fe-Mn
with 65 to 80% Mn and 6 to 8% C), SilicoManganese (Si: 14-28%, Mn: 50-74%, C: 2.5%),
Spiegeleisen (Mn: 6-30%; C: 4.5-6.5%). Selection of alloy for steel making depends on
purpose (eg. deoxidising agent, alloying agent, cleansing) and targeted grade of steel (low
carbon, medium carbon, high and ultrahigh carbon steel).
These alloys are produced by smelting reduction of Manganese ores and fluxes using a
suitable reducing agent. The Mn content and Mn/Fe ratio of ore play vital role during
production of high quality Manganese alloy. Most of the manganese ore resources found in
the world contain iron and its higher presence (>20%) makes these manganese ores unusable
to produce high quality manganese alloys. High grade manganese ore resources are depleting
rapidly and therefore, there is a dire need to upgrade the high iron containing manganese
ores.
Reduction of these high iron containing manganese ores in a carbon deficient atmosphere
leads to conversion of the iron into pig iron and the manganese in turn gets converted into
MnO with the production of slag. These components can be separated and used as separate
products for different applications. However, excess reduction of ores may lead to equal
distribution of Mn in slag and metal phases which may lead to lower Mn content in slag
which has limited applications.
Low grade ferruginous manganese ores (Mn: 20-35%, Mn/Fe<1.5) can be smelted in the blast
furnace and electric arc furnace to produce spiegeleisen and other manganese alloys.
However, ferruginous Mn ore reduction in said furnaces require relatively high energy and
these furnaces provide poor control on selective reduction of iron. Such poor control over
process parameters such as temperature poses challenges related to distribution of Mn in slag

and metal. Further, high slag volume leads to additional operational challenges. Said furnaces
are also associated with refractory related issues, increasing the overall process costs and
adversely hampering process feasibility. Thus, the methods known in the art are known to be
associated with difficulties such as challenges in maintaining slag metal composition, high
process cost mainly due to operational issues, and lack of process control due to low slag
basicity. The need of the hour is to develop a method for effective utilization of low grade
ferruginous manganese ores to achieve high grade manganese product. Further, it is necessary
that the method is able to selectively reduce iron oxides in the ores, facilitate better process
control and reduce the energy consumption in such processes. Accordingly, the present
disclosure aims to address the aforesaid concerns and provide an improved method for
reduction of manganese ores.
STATEMENT OF THE DISCLOSURE
Accordingly, the present disclosure relates to a process for selective reduction of iron present
in ferruginous manganese ore (FMO), in a cupola furnace, comprising -
subjecting a feed blend comprising the ferruginous manganese ore, coke and at least
one substance selected from a group comprising quartz, dolomite, cast iron and binder
to smelting reduction in the cupola furnace to obtain concentrated manganese oxide
(MnO) slag and pig iron,
wherein the blend ferruginous manganese ore comprises manganese (Mn) at wt% of
about 25% to 35%, iron (Fe) at wt% of about 20% to 35%, silica (SiO2) at wt% of
about 1% to 8% and aluminium oxide (Al2O3) at wt% of about 5% to 10%, and the
obtained concentrated manganese oxide (MnO) slag comprises MnO at wt% of about
23% to 36%, Fe at wt% of about 2% to 12%, SiO2 at wt% of about 22% to 35%, Al2O3
at wt% of about 15% to 25%, calcium oxide (CaO) at wt% of about 5% to 10% and
magnesium oxide (MgO) at wt% of about 3% to 8%.
In an embodiment, in the feed blend of the present disclosure, the coke is at wt% ranging
from about 30% to 50% of the ore, the quartz is at wt% ranging from about 2% to 15% of the
ore, the dolomite is at wt% ranging from about to 2% to 15% of the ore, the cast iron is at
wt% ranging from about 10% to 15% of the ore, the binder is at wt% ranging from about 1%
to 5% of the ore and wherein the binder is selected from a group comprising sodium silicate,
cement and molasses or any combination thereof.

In another embodiment of the present disclosure, the obtained pig iron comprises Mn at wt%
of about 1% to 3%, carbon (C) at wt% of about 1% to 3.5%, silicon (Si) at wt% of about
<3.2% and Fe at wt% of about 93.5% to 98%.
In a further embodiment, the process of the present disclosure reduces Fe in the ferruginous
manganese ore by about 20% to 85%, preferably about >80 %.
DETAILED DESCRIPTION OF THE DISCLOSURE
As used herein, the symbols ‘Fe’, ‘Mn’, ‘SiO2’, ‘Al2O3’, ‘MnO’, ‘MgO’ and ‘CaO’ refer to
Iron, Manganese, Silicon dioxide/Silica, Aluminium Oxide, Manganese Oxide and Calcium
Oxide, respectively.
As used herein, the term ‘feed blend’, alternatingly referred to by the term ‘feed’, refers to the
combination of substances fed to the furnace for smelting.
As used herein, the term ‘ferruginous manganese ore’ refers to manganese ore having iron
content having >20%.
As used herein, the abbreviation ‘FMO’ refers to the ferruginous manganese ore described
above, alternatingly referred to as ‘ore’. Further ‘blend ferruginous manganese ore’ refers to
the FMO in the feed blend.
As used herein, the phrases ‘concentrated manganese oxide (MnO) slag’ or ‘high manganese
oxide (MnO) slag’ refer to the slag emerging from the furnace after the smelting process,
wherein concentration of manganese ore ranges from about 23% to 36%.
With respect to the use of substantially any plural and/or singular terms herein, those having
skill in the art can translate from the plural to the singular and/or from the singular to the
plural as is appropriate to the context and/or application. The various singular/plural
permutations may be expressly set forth herein for sake of clarity. The use of the expression
“at least” or “at least one” suggests the use of one or more elements or ingredients or
quantities, as the use may be in the embodiment of the disclosure to achieve one or more of
the desired objects or results. Throughout this specification, the word “comprise”, or
variations such as “comprises” or “comprising” wherever used, will be understood to imply
the inclusion of a stated element, integer or step, or group of elements, integers or steps, but
not the exclusion of any other element, integer or step, or group of elements, integers or steps.

The present disclosure provides a process for selective reduction of iron present in
ferruginous manganese ore so as to upgrade the high iron containing manganese ores.
Particularly, the present disclosure relates to a process for selective reduction of iron in
ferruginous manganese ore in a cupola furnace.
The present disclosure provides a process for selective reduction of iron present in
ferruginous manganese ore (FMO), in a cupola furnace, comprising -
subjecting a feed blend comprising the ferruginous manganese ore, coke and at least
one substance selected from a group comprising quartz, dolomite, cast iron and binder
to smelting reduction in the cupola furnace to obtain concentrated manganese oxide
(MnO) slag and pig iron.
Cupola is a type of melting furnace used in foundries and commonly used for melting of cast
iron. It is cylindrical equipment and arranged vertically, usually supported by four legs.
Though Cupola furnace is known for melting of metals, it is not commonly used for reduction
of metal oxides. The cupola furnace is used for smelting reduction of manganese carbonates
ores to produce spiegeleisen (Mn: 6% - 30%; C: 4.5% - 6.5%). However, most of the times it
has shown ineffectiveness for reduction of metal oxides mainly due to rapid heating which
causes melting of metal oxides rather than reduction and poses challenges for metal
production, primarily owing to its design.
In an embodiment of the present disclosure, the ferruginous manganese ore of the blend
comprises manganese (Mn) at wt% of about 25% to 35%, iron (Fe) at wt% of about 20% to
35%, silica (SiO2) at wt% of about 1% to 8% and aluminium oxide (Al2O3) at wt% of about
5% to 10%.
In an embodiment, the obtained concentrated manganese oxide (MnO) slag comprises MnO
at wt% of about 23% to 36%, Fe at wt% of about 2% to 12%, SiO2 at wt% of about 22% to
35%, Al2O3 at wt% of about 15% to 25%, calcium oxide (CaO) at wt% of about 5% to 10%
and magnesium oxide (MgO) at wt% of about 3% to 8%.
In the process of the present disclosure, concentration of constituents in the feed blend is
determined based on the quantity of ore being processed. Accordingly, in an embodiment of
the present disclosure, in the feed blend, the coke is at wt% ranging from about 30% to 50%
of the ore, quartz is at wt% ranging from about 2% to 15% of the ore, the dolomite is at wt%

ranging from about 2% to 15% of the ore and the cast iron is at wt% ranging from about 10%
to 15% of the ore. Said concentrations may be varied as per batch size. In an embodiment, the
batch size of feed blend varies between about 0.3 ton to 1.3 tons.
In all embodiments of the present disclosure, particle size of the feed blend subjected to the
selective reduction process ranges from about 5mm to 50mm.
Further, based on the energy requirements for operation of the cupola furnace (cupola), the
feed may comprise additional coke to facilitate ignition and heating.
In an embodiment, ash content in the coke ranges from about 20%-35%. In a non-limiting
embodiment, the coke is pet coke, hard coke or a combination thereof. Additionally, coke
with lower ash content may be used for energy generation.
In an embodiment of the disclosure, the feed blend comprises the ferruginous manganese ore,
coke, quartz and dolomite; or,
wherein the feed blend comprises the ferruginous manganese ore, coke, quartz, dolomite and
cast iron; or
the ferruginous manganese ore, coke, quartz and dolomite; or
the ferruginous manganese ore, coke, quartz, dolomite and the binder; or,
the ferruginous manganese ore, coke, dolomite and cast iron.
In an embodiment, the feed blend is subjected to smelting reduction in the cupola furnace at a
temperature ranging from about 1100˚C to 1400˚C for a time-period of about 2 hours to 3
hours.
In an embodiment, about 1 ton of low grade ferruginous manganese ore(s) (Mn: 25%-35%,
Fe: 20%-35%, SiO2:1%-8%, Al2O3 :5%-10%) is melted in a cupola furnace (Diameter: 1m,
Height:1.5-2.4m), wherein the feed blend further comprises coke (30%-50% of ore), quartz
(2%-15 % of ore), dolomite (2%-15% of ore) and cast iron (10% -15 % of ore). Reduction is
carried out in the furnace for about 2 hours to 3 hours at a temperature between 1100˚C to
1400˚C. Post said reduction, slag and metal generated from the furnace are separated. On
analysis of slag quality and the pig iron produced shows that slag constituents are found to be
the following: MnO: 25%-36%, Fe(t): 2%-12%, SiO2: 22%-35%, Al2O3:15%-25%, CaO: 5%-
10%, MgO: 3%-8%, and the pig iron is found to be composed of Fe: 93.5%- 98%, Mn: 1%-
3%, C: 1%-3.5% and Si: 3.2%. Therefore, reduction of Fe content in the slag as compared to

the feed is very significant wherein reduction of more than 80% of Fe is achieved by the end
of said process. Further, the quantity of the concentrated MnO slag generated during the
process is found to vary between 750kg to 850kg for per ton of ore processed.
As described above, the process of the present disclosure produces concentrated manganese
oxide (MnO) slag and pig iron. The pig iron obtained by the smelting process of the present
disclosure comprises Mn at wt% of about 1% to 3%, carbon (C) at wt% of about 1% to 3.5%,
Fe at wt% of about 93.5% to 98% and Si at wt% of about 3.2 %.
In an embodiment, the process of the present disclosure does not generate any process reject.
In other words, the products obtained in the present process are utilizable in various
applications based on the requirements.
The MnO slag quality obtained by the selective reduction process of the present disclosure is
further enhanced by varying process parameters, coke quality, particle size, blend
composition or pre-processing the ore. Furnace design, coke quality and particle size
particularly play a vital role during reduction of low grade Mn ores in the cupola furnace.
In an embodiment of the present disclosure, for further enhancement of slag quality, the
ferruginous manganese ore is roasted prior to formulation of the feed blend, and subjecting
said feed blend comprising roasted ore to the smelting reduction process. Said roasting of the
ore is carried out by roasting ore lumps in presence of charcoal for about 24 hours using
about 8% - 15% charcoal.
In another embodiment of the present disclosure, the slag quality is also improved by
subjecting the feed blend to the cupola furnace wherein the feed blend is in the form of
agglomerates. Said agglomerates of the feed blend are prepared by combining the feed blend
composition with a binder. In an embodiment, the binder is selected from a group comprising
sodium silicate, molasses, cement or any combination thereof.
In yet another embodiment of the present disclosure, agglomerates of ore fines and pet coke
(low ash) are made and subjected to the selective reduction process to further improve the
slag composition.

In still another embodiment of the present disclosure, the slag quality is improved by
reducing silica content in the feed blend. In an exemplary embodiment, enhancement of slag
quality is facilitated by limiting silica content in the feed to about 1% to 3% (wt%).
Furthermore, air flow rate is regulated for process enhancement to achieve high quality MnO
slag during the process. In an embodiment, air flow rate inside the cupola furnace is
maintained at about 3 cubic meter/hour to 30 cubic meter/hour. Air flow rate is regulated
such that it is slowly increased from 0% to 10% at the beginning of the process and till 100%
after about 50 minutes of subjecting the feed blend to smelting in the cupola furnace.
In an embodiment of the present disclosure, each of the above described process
embodiments/improvements are used alone or in combination with each other.
In an exemplary embodiment, the process of the present disclosure employs one or more of
the following features/conditions:
the feed blend is prepared in the form of agglomerates by mixing the feed blend
components with a binder;
the feed blend is prepared with reduced silica content;
the ferruginous manganese ore of the feed blend is roasted prior to preparation of the
feed blend; and
air flow rate inside the cupola furnace during the reduction process is gradually
increased from about 0 cubic meter/hour to about 3 cubic meter/hour and finally to
about 30 cubic meter/hour after about 50 minutes of feed charging.
In an embodiment of the present disclosure, the selective reduction process comprises:
subjecting the feed blend to smelting reduction in the cupola furnace at a temperature of
about 1100˚C to 1400˚C for a time-period of about 2 hours to 3 hours;
gradually increasing air flow rate during the reduction process from about 0 cubic
meter/hour to about 3 cubic meter/hour and finally to about 30 cubic meter/hour after
about 50 minutes of feed charging;
adding additional coke to the furnace at a quantity of about 10% (wt%) of the coke in the
feed blend,
to produce the concentrated MnO slag and pig iron.

In the above described process, the total time-period of the smelting process ranges from
about 2 hours to 3 hours, including the smelting conducted after addition of additional coke.
Further, in the above described process, regulation of air flow rate is coupled with use of
lower grade coke for energy generation, in order to facilitate slow heating and controlled air
flow rate inside the furnace to provide sufficient time for reduction of iron oxides. In an
embodiment, lower grade coke comprises fixed carbon content of about 67% - 80%.
In another embodiment of the disclosure, the selective reduction process comprises:
preparing feed blend as agglomerate blocks wherein the ferruginous manganese ore at a
wt% of about 90% - 95% and pet coke at a wt% of about 0% - 5% are mixed with a
binder at a concentration of about 1% - 5% to prepare the agglomerate blocks;
charging the agglomerate blocks into the cupola furnace for smelting reduction,
to produce the concentrated MnO slag and pig iron.
In an embodiment, the binder for preparation of the feed blend agglomerates is selected from
a group comprising sodium silicate, molasses, cement or any combination thereof. Said
agglomerates is prepared by virtue of mixing the feed blend with the binder.
In another embodiment, the agglomerates are shaped as blocks, wherein the blocks are made
of a size of about 10”×6”×3”. Said blocks are further broken into size of about <10” and
charged into the furnace for smelting. In an embodiment, dolomite is added to the furnace
during the smelting process.
In a further embodiment of the present disclosure, the selective reduction process comprises:
subjecting a low silica (SiO2) containing feed blend comprising the ferruginous
manganese ore, hard coke, dolomite and cast iron at a ratio of about 7:1:1:1 to smelting
reduction in the cupola furnace;
regulating air flow, wherein 90% air flow is closed between about 0 minutes to 20
minutes, and full air flow is allowed after 20 minutes;
adding additional feed blend, additional coke and additional dolomite to the cupola
furnace,
to produce a concentrated MnO slag, and pig iron.
In the above described process, low silica refers to silica (SiO2) content of about 1% to 3% of
the ore in the feed blend. Further, in an embodiment, additional feed blend, additional coke

and additional dolomite added to the cupola furnace is in a quantity of about less than 10% of
the ore initially charged into the furnace.
In still another embodiment of the present disclosure, the selective reduction process
comprises roasting the ore prior to formulation of the feed blend. Said process of the present
disclosure comprises:
roasting the ferruginous manganese ore, wherein ore lumps of diameter of about 0 mm to
30 mm are roasted for about 24 hours in presence of charcoal;
preparing the feed blend and subjecting the feed blend comprising the roasted ferruginous
manganese ore, hard coke, dolomite and cast iron at a ratio of about 10:1:1.8:0.8 to
10:1:2.5:1 to reduction smelting in the cupola furnace,
to produce a concentrated MnO slag and pig iron.
The pre-roasting of ore in the process of the present disclosure is performed with the
objective of achieving higher Fe metallization in short duration to reduce coke rate and coke
ash inputs in slag.
In an embodiment, about 20% to 85% of Fe in the ferruginous manganese ore is reduced by
the process of the present disclosure. In another embodiment, about 40.12% to 84.41% of Fe
in the ferruginous manganese ore is reduced by the process of the present disclosure. In a
preferred embodiment, 60% to 80% of Fe in the ferruginous manganese ore is reduced by the
process of the present disclosure. In a most preferred embodiment, the process of the present
disclosure results in >80 % reduction of Fe in the ferruginous manganese ore.
In a non-limiting embodiment of the disclosure, for per ton of the ore processed, the selective
reduction process generates about 750kg to 850kg of concentrated MnO slag and about
120kg to 230kg of pig iron.
In an embodiment of the present disclosure, the concentrated MnO slag can be used as
synthetic ore for Mn alloy production or any application requiring higher grade Mn. Further,
the pig iron produced also has various applications including but not limiting to MnSO4
production, production of Hadfield steel etc.
Overall, the process of the present disclosure provides an efficient method for effective
utilization of low grade manganese ore resources to obtain higher grade Mn products without
generating any process reject. Without being bound by any theory, said process may have

obvious variants such as but not limited to utilization of different quality coke, varied particle
size, different blends or use of different forms of feed blend and pre-treated ore. Further, the
process provides multiple advantages such as:
• Minimized possibility of reduction of manganese oxides in the ores due to selective
reduction of iron oxides in the cupola furnace facilitated by the low temperature
profile, limited availability of CO in the carbon deficient atmosphere and short
retention time in the furnace.
• Requirement of lower temperature than conventional furnaces such as blast furnace or
arc furnaces, thereby minimizing the energy requirement.
• Permits use of coke as a cheap energy source.
• Easy relining and operation in cupola furnace helps in better process control over an
electric arc furnace to control the product grade.
• Efficient method for effective utilization of low grade manganese ore resources
without generation of any process reject.
• Achieving improved/selective reduction of Fe wherein preferably >80 % of Fe is
selectively reduced in the ferruginous manganese ore.
In an embodiment, the foregoing descriptive matter is illustrative of the disclosure and not a
limitation. Providing working examples for all possible combinations of optional elements in
the composition and process parameters is considered redundant.
While considerable emphasis has been placed herein on the particular features of this
disclosure, it will be appreciated that various modifications can be made, and that many
changes can be made in the preferred embodiments without departing from the principles of
the disclosure. Those skilled in the art will recognize that the embodiments herein can be
practiced with modification within the spirit and scope of the embodiments as described
herein.
EXAMPLES
EXAMPLE 1: Smelting reduction with controlled air flow rate
A feed blend was prepared with Mn Ore: 250 Kg (Mn: 27.36%, Fe :26.17%, SiO2 :6.7%,
Al2O3 :12.63%), Hard Coke: 25 kg, Dolomite: 20 Kg, Quartz: 25 Kg. The prepared feed
blend was charged to the furnace. Flow rate was started at 0%, increased to 10 % and finally

further increased to 100% (30 cubic meter/hour) after 50 minutes of feed charging.
Additional coke (10% of total coke added to the blend initially) was also added during this
process. Low grade coke was used for energy generation to ensure slow heating.
The high concentration MnO slag and pig iron produced after the reduction process were
subjected to chemical analysis.
The slag achieved was found to have the following composition Fe: 10%-12% & MnO: 23%-
25% (Typical chemical analysis: Fe (t): 10.68%, MnO: 23.88%, SiO2: 35.69%,
Al2O3:18.78%).
Composition of pig iron was found to be C: 2.51%, Mn: 2.61%, Si: 2.65%, rest Fe. Quantity
of metal recovered was 15kg -18kg.
It was thus found that 20%-30% iron in the MnO ore can be reduced and converted into
metallic iron i.e. the pig iron.
EXAMPLE 2: Smelting reduction by employing Agglomerates
A feed blend was made of Mn Ore: 300 kg (Mn: 27.36%, Fe :26.17%, SiO2 :6.7%, Al2O3
:12.63%), pet coke: 20 kg and it was agglomerated using sodium silicate (~3%) as a binder.
The blocks were made of a size of about 10”×6”×3’’. These were broken into size <10” and
charged into the furnace. During the smelting process, 20kg of Dolomite was added to the
furnace. The high concentration MnO slag and pig iron produced after the reduction process
were subjected to chemical analysis.
The slag produced was found to have the following composition - Fe: 6.72%, MnO: 23.6%,
SiO2: 27.03%, Al2O3: 24.18%.
Thus, about 72% Fe reduction was observed. No significant change was observed in
composition of the pig iron.
EXAMPLE 3: Smelting reduction with Low Silica Burden
A feed blend with low SiO2 burden was prepared by mixing the following: Mn Ore (Mn:
27.36%, Fe: 26.17%, SiO2: 6.7%, Al2O3: 12.63%): 700Kg, Hard Coke: 100kg, Dolomite:
100Kg and Cast Iron: 100kg. Additional coke (10 % of initial charge) was given for heating
and smelting. Air flow inside the furnace was regulated such that 90% air flow was closed

initially and after 20 minutes full air flow was allowed. At 50 minutes, additional feed blend
was added to the furnace and after another 20 minutes, 40 kg coke was fed into the furnace.
Approximately another 10-15 kg of dolomite was also added to improve material flow.
After about 2.5 hours, the discharge emerging from the furnace was analyzed. The following
was observed:
Total batch weight-900 Kg,
High MnO slag-560 Kg and
Pig iron-120 Kg.
Composition of the high MnO slag is analyzed. The slag composition is found to be:
Fe: 7.86 %, MnO: 36.4%, SiO2: 25.17%, Al2O3:15.25%, CaO: 6.63% and MgO: 3.6 %
Thus, the Fe reduction is found to be about 84.41%. So, Fe reduction reached up to >80 %
Quartz less trial. Said analysis of the slag indicates that MnO in the slag increased
significantly as compared to the feed blend. The pig iron composition did not change
remarkably.
EXAMPLE 4: Smelting reduction with pre-roasted ore
Roasting of ores was done as a pre-reduction activity to enhance reduction of Fe.
Ore lumps of 0-30mm are roasted for about 24 hours using 8%-15% charcoal.
Feed blend is made using the roasted Mn Ore: 300-500 Kg, Hard Coke: 30-50 kg, Dolomite:
75-90 kg and cast iron 30-40 kg. After feeding the material, in 50 minutes, the material was
tapped. Material flow was good, and the heat level inside the furnace was also maintained at
approximately between 1100˚C to 1400˚C. Time taken to smelt the material was about one
hour, which was more than the usual batch (example 1). Extra coke was added to the furnace.
After about 2 hours, the discharge emerging from the furnace was analyzed. The following
was observed:
Total batch weight: 438 Kg,
High MnO slag: 260 Kg and
Pig iron 48.46 Kg.

Composition of the high MnO slag is analyzed. The slag composition is found to be:
Fe: 8.26%, MnO: 27.18%, SiO2: 26.82%, Al2O3: 16.55%.
No change in the pig iron composition is observed.
Thus, the Fe reduction was found to be between about 72 %- 79%.

WE CLAIM:
1. A process for selective reduction of iron present in ferruginous manganese ore (FMO), in
a cupola furnace, comprising -
subjecting a feed blend comprising the ferruginous manganese ore, coke and at least
one substance selected from a group comprising quartz, dolomite, cast iron and binder
to smelting reduction in the cupola furnace to obtain concentrated manganese oxide
(MnO) slag and pig iron,
wherein the blend ferruginous manganese ore comprises manganese (Mn) at wt% of
about 25% to 35%, iron (Fe) at wt% of about 20% to 35%, silica (SiO2) at wt% of
about 1% to 8% and aluminium oxide (Al2O3) at wt% of about 5% to 10%, and the
obtained concentrated manganese oxide (MnO) slag comprises MnO at wt% of about
23% to 36%, Fe at wt% of about 2% to 12%, SiO2 at wt% of about 22% to 35%, Al2O3
at wt% of about 15% to 25%, calcium oxide (CaO) at wt% of about 5% to 10% and
magnesium oxide (MgO) at wt% of about 3% to 8%.
2. The process as claimed in claim 1, wherein the coke is at wt% ranging from about 30% to
50% of the ore, the quartz is at wt% ranging from about 2% to 15% of the ore, the
dolomite is at wt% ranging from about to 2% to 15% of the ore, the cast iron is at wt%
ranging from about 10% to 15% of the ore, the binder is at wt% ranging from about 1% to
5% of the ore and wherein the binder is selected from a group comprising sodium silicate,
cement and molasses or any combination thereof.
3. The process as claimed in claim 1, wherein the obtained pig iron comprises Mn at wt% of
about 1% to 3%, carbon (C) at wt% of about 1% to 3.5%, silicon (Si) at wt% of about
<3.2% and Fe at wt% of about 93.5% to 98%.
4. The process as claimed in any of the preceding claims, wherein the ferruginous
manganese ore is roasted prior to subjecting the feed blend to smelting reduction in the
cupola furnace, wherein the roasting is carried out by roasting ore lumps in presence of
charcoal for about 24 hours.
5. The process as claimed in any of the preceding claims, wherein the coke is pet coke, hard
coke or a combination thereof, and comprises ash content ranging from about 22% to
35%.
6. The process as claimed in any of the preceding claims, wherein the coke is pet coke
comprising ash content of <22%.

7. The process as claimed in any of the preceding claims, wherein the feed blend comprises
the ferruginous manganese ore, the coke, the quartz and the dolomite; wherein the feed
blend comprises the ferruginous manganese ore coke, the quartz, the dolomite and the
cast iron; wherein the feed blend comprises the ferruginous manganese ore, the coke, the
quartz and the dolomite; wherein the feed blend comprises the ferruginous manganese
ore, the coke, the quartz, the dolomite and the binder; or, wherein the feed blend
comprises the ferruginous manganese ore, the coke, the dolomite and the cast iron.
8. The process as claimed in any of the preceding claims, wherein the feed blend is fed to
the cupola furnace as agglomerates, wherein the agglomerates are prepared by combining
the feed blend with the binder.
9. The process as claimed in any of the preceding claims, wherein the smelting reduction in
the cupola furnace is conducted at a temperature ranging from about 1100˚C to 1400 ˚C
for a time-period of about 2hours to 3hours.
10. The process as claimed in any of the preceding claims, wherein air flow rate inside the
cupola furnace is maintained at 3 cubic meter/hour - 30 cubic meter/hour, and wherein
said air flow rate is slowly increased from 0% to 10% at the beginning of the process and
till 100% after about 50 minutes of subjecting the feed blend in the cupola furnace.
11. The process as claimed in any of the preceding claims, wherein the process comprises:
subjecting the feed blend to smelting reduction in the cupola furnace at a temperature of
about 1100˚C to 1400 ˚C for a time-period of about 2hours to 3hours;
gradually increasing air flow rate during the reduction process from about 0 cubic
meter/hour to about 3 cubic meter/hour and finally to about 30 cubic meter/hour after
about 50 minutes of feed charging;
adding additional coke to the furnace at a quantity of about 10% (wt%) of the coke in the
feed blend;
to produce the concentrated MnO slag and pig iron.
12. The process as claimed in any of the preceding claims, wherein the process comprises:
preparing feed blend as agglomerate blocks wherein the ferruginous manganese ore at a
wt% of about 90% - 95% and the pet coke - 5% are mixed with the binder at a
concentration of about 1% - 5% to prepare the agglomerate blocks;
charging the agglomerate blocks into the cupola furnace for smelting reduction,
adding dolomite at a quantity of about <10% (wt%) of the ore in the feed blend to the
furnace during said reduction,
to produce the concentrated MnO slag and pig iron.

13. The process as claimed in any of the preceding claims, wherein the process comprises:
subjecting a low silica (SiO2) containing feed blend comprising the ferruginous
manganese ore, hard coke, dolomite and cast iron at a ratio of about 7:1:1:1 to smelting
reduction in the cupola furnace;
regulating air flow, wherein 90% air flow is closed between about 0 minutes to 20
minutes, and full air flow is allowed after 20 minutes;
adding additional feed blend, coke and dolomite to the cupola furnace at a quantity of <
10% (wt%) of the ore in the feed blend,
to produce a concentrated MnO slag, and pig iron.
14. The process as claimed in any of the preceding claims, wherein the process comprises:
roasting the ferruginous manganese ore, wherein ore lumps of diameter of about 0 mm to
30 mm are roasted for about 24 hours in presence of charcoal;
subjecting the feed blend comprising the roasted ferruginous manganese ore, hard coke,
dolomite and cast iron at a ratio of about 10:1:1.8:0.8 to 10:1:2.5:1 to reduction smelting
in the cupola furnace,
to produce a concentrated MnO slag and pig iron.
15. The process as claimed in any of the preceding claims, wherein the process comprises:
Preparation of the feed blend in the form of agglomerates by mixing the feed blend
components with a binder;
Preparation of the feed blend prepared with reduced silica content;
Roasting of the ferruginous manganese ore of the feed blend prior to preparation of the
feed blend; and
Gradually increasing air flow rate inside the cupola furnace during the reduction process
gradually from about 0 cubic meter/hour to about 3 cubic meter/hour and finally to about
30 cubic meter/hour after about 50 minutes of feed charging
to produce a concentrated MnO slag and pig iron.
16. The process as claimed in any of the preceding claims, wherein said process reduces Fe in
the ferruginous manganese ore by about 20% to 85%, preferably about >80 %.