FIELD OF THE INVENTION
The present method relates to a method f agglomeration of Ferroalloy fines
such as Ferromanganese, Ferrosilicon and Ferrochrome fines,
.More specifically the present invention relates to a method of agglomeration of
Ferromanganese fines resulted in breaking/sizing of ferromanganese cake
produced by bed and mould casting of the molten ferromanganese alloys,
BACKGROUND OF THE INVENTION
To produce satisfactory steel specially in Open Hearth, it is necessary to add to
the charge, bath, ladle and the mold manganese, silicon, chromium, phosphorus
etc in the form of ferroalloys containing from as little as 5 to as such as 85
percent of the desired element, Important ferroalloy product are Ferrosilicon
high carbon Ferromanganese and ferrochrorrium, silicomanganese, and calcium
silicide which are usually manufactured in electric furnace. However low grade
ferroalloys are produced more cheaply in the blast furnace, from silicon,
manganese or chromium bearing ores or oncentrates, Such ferroalloys are
produced in the form of cake. The ferroalloys cake such as Ferromanganese.
ferrosilicon or ferrochromium are broken down to 10 to 150 mm size lumps
according to customer requirements. The fe roalloy fines of < 10mm size are
generated during crushing to different size of lumps. The generated fines are
relatively cheaper than the ferroalloy lumps.
In the state of arts agglomeration of iron ores and concentrates through the
routes of nodulizing, palletizing or briquetting and sintering are known. But
agglomeration of ferroalloy fines is yet to be developed in this field of
technology.
The present invention has proposed to remove the above difficulties of prior art
on development of a method of agglomeration of Ferro-alloy fines specifically

Ferromanganese, ferrochrome and Ferrosilicon fines to enable the customers of
industry to get cheaper source of ferroalloys than ferroalloy lumps.
DESCRIPTION OF THE INVENTION
The proposed invention has developed a method of agglomeration of ferroalloy
fines through the steps of crushing the material below 3mm size, mixing binder
phenol-formaldehyde on characterize evaluation of agglomerates resulted with
desired strength of tumbler index, compressive and tensile strength, compacting
the mix in a conventional compression machine of 5 ton load Capacity, curing the
compact at 150° to 200° C, to result agglomerated ferroalloy products with
required strength of handling properties.
Principal object of the invention is to develop agglomerate from Ferroalloy fines
via expropriate sizing of fines, mixing with a specific binder and compacting.
Another object of the invention is to select a specific binder phenol formaldehyde
for the agglomeration on test evolution having its materials characteristics as
different from conventional sodium silicate or Bentonite binder.
DETAILD DESCRIPTION OF THE INVENTION WITH AN EMBODIMENT
The proposed invention has been exemplified by an embodiment for
agglomeration of Fe-Mn fines however the same embodiment is applicable to
agglomeration of Fe-si and Fe-cr fines also, with the same method steps and
conditions maintained in steps of Ferromanganese fines agglomeration.
There are various kind of binders available in market for agglomeration of ore
fines. The nature of Ferromanganese fines (0-3mm) is very different as from
iron ore and conventional binder (Sodium Silicate, Bentonite) could not be able
to produce agglomerate of Ferroalloy with suitable handling properties (Tumbler
Index, Compressive, and Tensile Strength) for plant scale operations. Phonel
formaldehyde resin is selected used as a binder for Ferromanganese fines (0-
3mm) to produce agglomerate on characterize testing for desired strength.

Various proportions in weight % in the range of 2 to 10% of the binder were
tested for the ferromanganese fines and found that 3 to 5% binder content is
optimum content to achieve the desired properties with minimum cost.
The proposed invention will be better understood from the accompanying
drawing in which Figure 1 relates to a Process flow sheet to produce
ferromanganese agglomerate with desired strength.
The steps of the agglomeration of ferroalloy fines as shown in figure 1
are as follows:
a. Crushing the oversize (>3mm) particles: In the process of sizing of
casted ferromanganese cakes, the material generated below 10mm is
termed as fines in ferroalloy industry. These fines cannot be agglomerated
by conventional agglomeration methods and crushing is required to
reduce <3mm size range.
b. Binder Mixing: the binder in wt% is mixed with the fines for proper
distribution of binder in the material. Binder properties are given in table-
1.


c. Compaction: The 60 gm of mixed material is kept in die of diameter of 3
cm compressed by using any conventional compressive machine upto 5-
ton load. The load is applied for 10 to 15 seconds and the prepared
agglomerate removed and stored for further processing. The green
strength of me agglomerate is 7 drops from 500cm height. The
agglomerate is a cylindrical briquette of 3 cm diameter and 2.0 cm length.
d. Curing: The prepared agglomerate was cured at 150°C to 200°C for one
hour in the furnace and allowed to cool for another one hour in the
furnace. This product was stored and can be used in place of
ferromanganese lumps.
e. Testing: The handling properties of material play vital rote for plant scale
operations and generation of fines is undesired. The compressive strength
of the agglomerate was tested using UTM machine and its properties are
listed below in Tabte-2.


A comparative test result of strength characteristics between the resulted
agglomerates of ferromanganese and ferromanganese lumps are enumerated
below in table 3.

The prepared agglomerates can be used as a replacement of ferromanganese
lumps. The agglomerates are very cheaper than tire ferromanganese lumps. The
physical properties of the agglomerates are comparable to ferromanganese
lumps. These agglomerates can be used in the processes like refining the steel in
the ladle vessel. The bulk density of agglomerates was 5208 - 5210 kg/m3 and
those do not float on the slag, sink properly in the metal, and shows better
dissolving characteristics. The compressive strength and tumbler index (TI) of
material are suitable for the transportation circuit and do not generate excessive
fines.
The proposed invention as narrated herein should not be read in restrictive
manner as various adaptations, modifications and alterations regarding process
steps and process conditions are possible within the scope and ambit of tire
invention as defined in the appended claims.

WE CLAIM:
1. A method of agglomeration of ferroalloy fines such as ferromanganese,
ferrochrome and ferrosilicon fines comprising the steps of crushing
ferroalloy fines below 10mm size obtained from ferroalloy casting floor
and obtaining 0-3mm size fraction on sieving; mixing the resulted fines
with a phenol formaldehyde resin binder in a vessel; compacting the
mixed fines in a compressive machine upto 5 ton load capacity in batches
on conveying the mix in the compressive machine to obtain agglomerates
of ferroalloys; curing the agglomerates on heating in a furnace in the
range of 150-200°C for an hour and furnace cooled for another one hour;
followed by characterize testing of the cured agglomerates for their tensile
strength, tumbler index, bulk density, compressive strength and abrasion
index.
2. A method of agglomeration of ferroalloy fines as claimed in claim 1
wherein the binder is a conventional phenol-formaldehyde resin of Ivarez
515 resin, PH (1% solution) - 7.15, specific gravity 1.18, solid content
70.65%, viscosity at 25°C, 200cps. min and carbon 38% and is mixed with
ferroalloy fines in a proportion of 3-5% by wt.
3. A method of agglomeration of ferroalloy fines as claimed in claim 1
wherein in a test 60 gms of mixed fines is kept in a die of diameter 3 cm
of the compressive machine, compressed for 10-15 seconds to obtain
agglomerates with green strength of 7 drops from 500 cm height.

4. A mettiod of agglomeration of ferroalloy fines as claimed in claim 1
wherein the resulted cured agglomerates has cylindrical size of 3cm dia
and 2cm height, area 0.0007065, volume 0.000014, weight 0.073 gm,
bulk density 5208 - 5210 kg/M3, breaking load - 39,000 Newton,
compressive strength 55 Mpa, tumbler index-65-81%, abrasion index -
15-23%, which meet the required material strength characteristic during
handling of the agglomerates.
5. A method of agglomeration of ferroalloy fines as claimed in claim 1
wherein during gathering 0-3 mm size specification of fines the gathered
fines during breaking of cakes of ferroalloy and fines, from casting floor is
first sieved to 0-3mm size and the remaining fines above 3mm size is
crushed to 0-3mm size and added to first gathered 0-3mm size.
6. A mettiod of agglomeration of ferroalloy fines as claimed in the preceding
claims wherein the resulted agglomerates have compressive strength of
55 to 70 MPa, bulk density 5208-5210 kg/M3, which are comparable to
physical properties of ferroalloy lumps of 50-85 Mpa compressive strength
and 6227-7185 kg/M3 bulk density.
7. A method of agglomeration of ferroalloy fines as claimed in the preceding
claims wherein the resulted agglomerates of ferroalloys are used as
substitute for ferroalloy lumps and when used for refining of steels do not
float on the slag, sink properly in the metal and show belter dissolving
characteristics.

This invention relates to a method of agglomeration of ferroalloy fines such as
ferromanganese, ferrochrome and ferrosilicon fines comprising the steps of
crushing ferroalloy fines below 10mm size obtained from ferroalloy casting
floor and obtaining 0-3mma size fraction on sieving; mixing the resulted fines
with a phenol formaldehyde resin binder in a vessel; compacting the mixed
fines in a compressive machine upto 5 ton load capacity in batches on
conveying the mix in the compressive machine to obtain agglomerates of
ferroalloys; curing the agglomerates on heating in a furnace in the range of
150-200°C for an hour and furnace cooled for another one hour; followed by
characterize testing of the cured agglomerates for their tensile strength,
tumbler index bulk density, compressive strength and abrasion index.