FIELD OF INVENTION
[0001] The present invention relates to a starch based polymeric composite
material, adopted for use as an effective flocculating agent and a methodology of
preparing such flocculant.
[0002] The present disclosure provides a novel polymeric flocculant comprising of
starch, poly acryl amide and polystyrene sulphonate in different proportions through
free radical polymerization technique, which is observed to be biodegradable and
excellent flocculant and also used in solid-liquid separation process for waste water
treatment in general and other oxide ore system.
BACKGROUND AND PRIOR ART
[0003] Background description includes information that may be useful in
understanding the present subject matter. It is not an admission that any of the
information provided herein is prior art or relevant to the presently claimed subject
matter, or that any publication specifically or implicitly referenced is prior art.
[0004] Iron ore is mined and processed through crushing, screening and washing
before dispatching it to the works to be fed in the blast furnace for hot metal production.
In Indian iron ores alumina is contributed by clay (kaolinite), gibbsite, lateritic material
as well as solid solutions in hydrated iron oxides. In general, the practice adopted by
major steel plants in India is to consume medium to high-grade ores (+62% Fe).
Therefore, major focus of beneficiation is to meet the physical standards as required
for iron making. The use of sub grade iron ores in steel making will be possible only
after proper beneficiation. This will generate huge quantity of tailings.
Environmentally acceptable and proper disposal of these fines, slimes and tailings is a
challenge for the iron ore beneficiation industries. The tailings/slime consists of finely

divided particles of 0.001 -10 μm diameter, which does not settle from suspension by
gravity because of the surface charge and extremely small size. Slime is stored in huge
tailing ponds. High degree of fineness in slime particles results in poor settling
characteristics of solids and poor compaction of solids. Process water often loaded with
impurities (clay, alumina silica etc.) play an adverse role in beneficiation process such
as jigging and classification. Ultrafine size fractions in the slime result in poor
dewatering characteristics of the tail sludge. In this context, we tried to find a better
solution for the settling of fines and enhanced water recovery from the process.
[0005] In recent years, polysaccharides are extensively used in mineral industries
as flocculant, selective flocculant and depressants in froth flotation. In polysaccharide,
the monosaccharide units are linked together with glycosidic linkage. Mainly carbonyl
and hydroxyl groups are the main functional groups present in polysaccharide moiety.
They are non-toxic, renewable, hydrophilic and biodegradable. Since long time, starch
has been used as selective flocculant for selective removal of iron oxide. Starch, a
natural polysaccharide is combination of two major components, amylose and
amylopectin. Both starch and polyacrylamide are individually used as flocculants for
iron ore recovery.
[0006] Amongst starch and polyacrylamide, starch is the more selective one. But
conventionally, the flocculants generally used often failed to provide the desired
efficacy. Hence, there is always a need to come up with a better flocculant. These two
ingredients have not been combined together to provide any effective flocculant, where
the styrene sulphonate further improves the mechanical properties and provides
functionality. Therefore, it is imperative to combine the properties of both natural and
synthetic polymers towards application in flocculation.
[0007] The present invention meets the long felt need.

OBJECTS OF THE INVENTION
[0008] Some of the objects of the present disclosure, which at least one
embodiment herein satisfy, are listed hereinbelow.
[0009] A general object of the present disclosure is to provide an anionic polymeric
flocculant having a general formula of St-g-(pAAm-co-pSS) comprised of starch, poly
acryl amide and polystyrene sulphonate in different proportions.
[0010] Another object of the present disclosure is to provide an anionic polymeric
flocculant, which is effective in flocculation of iron ore fines and ultra-fines and
thereby enabling of solid-liquid separation.
[0011] Another object of the present disclosure is provide an anionic polymeric
flocculant, which is biodegradable and hence eco-friendly.
[0012] Further object of the present disclosure is provide an anionic polymeric
flocculant , which is efficient even at lower dosages, would be effective compared to
commercially available flocculants and thus would be cost-efficient.
[0013] Another object of the present disclosure is provide an anionic polymeric
flocculant, which has have highly shear stable and controlled biodegradable.
[0014] Further object of the present disclosure is provide a method of producing
anionic polymeric flocculant, which is eco-friendly and rapid.
[0015] Further object of the present disclosure is provide a method of producing
anionic polymeric flocculant, which is cost effective and simple.
SUMMARY OF INVENTION
[0016] While the embodiments of the disclosure are subject to various
modifications and alternative forms, specific embodiment thereof have been shown by
way of the figures and will be described below. It should be understood, however, that
it is not intended to limit the disclosure to the particular forms disclosed, but on the

contrary, the disclosure is to cover all modifications, equivalents, and alternative falling
within the scope of the disclosure.
[0017] This summary is provided to introduce concepts related to a process to
utilize non-coking coal for producing a metallurgical coke. The concepts are further
described below in the detailed description. This summary is not intended to identify
key features or essential features of the claimed subject matter, nor is it intended to be
used to limit the scope of the claimed subject matter.
[0018] The present disclosure relates an anionic polymeric flocculant for iron ore
comprising of starch, poly acryl amide and polystyrene sulphonate in different
proportions.
[0019] In an aspect, the polymeric flocculant having a general formula of St-g-
(pAAm-co-pSS), is prepared by grafting of starch with poly acrylamide by free radical
polymerization technique followed by copolymerization with poly styrene sulphonate.
[0020] In an aspect, the anionic graft copolymeric flocculant St-g-(pAAm-co-pSS)
is observed to be an excellent flocculating agent for settling of iron ore fines and ultra-
fines, thus enabling effective solid-liquid separation.
[0021] In an aspect, the flocculant is biodegradable and hence eco-friendly, can be
developed by simple and cost-effective technique. It would be efficient even at lower
dosages, would be effective compared to commercially available flocculants and thus
would be cost-efficient. It is observed to have highly shear stable and controlled
biodegradable.
[0022] In another aspect, the present invention also provides a method for
preparing the polymeric flocculant , which comprises the steps of dissolving of starch
in distill water at a temperature of 70°C for 12 hour along with constant stirring and
aqueous potassium persulphate was added to it under nitrogen bubbling for 15 min to
create the inert atmosphere; further addition of aqueous mixture of acrylamide (AAm)
and TEMED, followed by mixing of sodium p-styrenesulfonate (SS) ; continue with

the reaction for another 3 hour with continuous nitrogen purging followed by cooling
off and exposed in air atmosphere at room temperature (25°C); precipitation of reaction
mixture into acetone for removal of uncontrolled formed homopolymer and unreacted
monomer; drying of the final product in a vacuum oven at a temperature of 60°C, which
then subjected to various characterization tests.
[0023] Various objects, features, aspects, and advantages of the inventive subject
matter will become more apparent from the following detailed description of preferred
embodiments, along with the accompanying drawing figures in which like numerals
represent like components.
[0024] It is to be understood that the aspects and embodiments of the disclosure
described above may be used in any combination with each other. Several of the aspects
and embodiments may be combined to form a further embodiment of the disclosure.
[0025] The foregoing summary is illustrative only and is not intended to be in any
way limiting. In addition to the illustrative aspects, embodiments, and features
described above, further aspects, embodiments, and features will become apparent by
reference to the drawings and the following detailed description.
BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS
[0026] The illustrated embodiments of the subject matter be best understood by
reference to the drawings. The following description is intended only by way of
example, and simply illustrates certain selected embodiments of method, systems, that
are consistent with the subject matter as claimed herein, wherein:
[0027] FIG. 1 illustrates FTIR spectra of (a) Starch (b) AAm (c) SS and (d) St-g-
(pAAm-co-pSS).
[0028] FIG. 2 illustrates 1H NMR spectrum of starch (Solvent: DMSO-D6).

[0029] FIG. 3 illustrates 1H NMR spectrum of St-g-(pAAm-co-pSS) (Solvent:
D2O).
[0030] The figures depict embodiments of the disclosure for purposes of
illustration only. One skilled in the art will readily understand from the following
description that alternative embodiments of the structures and methods illustrated
herein may be employed without departing from the principles of the disclosure
described herein.
DETAILED DESCRIPTION OF THE PRESENT INVENTION WITH
PREFERRED EMBODIMENTS
[0031] The present disclosure relates to a novel polymeric flocculant based on
starch grafted with poly acryl amide and polystyrene sulphonate.
[0032] In the present document, the word "exemplary" is used herein to mean
"serving as an example, instance, or illustration." Any embodiment or implementation
of the present subject matter described herein as "exemplary" is not necessarily to be
construed as preferred or advantageous over other embodiments.
[0033] While the disclosure is susceptible to various modifications and alternative
forms, specific embodiment thereof has been shown by way of example in the drawings
and will be described in detail below. It should be understood, however that it is not
intended to limit the disclosure to the forms disclosed, but on the contrary, the
disclosure is to cover all modifications, equivalents, and alternatives falling within the
scope of the disclosure.
[0034] The terms “comprises”, “comprising”, “includes” or any other variations
thereof, are intended to cover a non-exclusive inclusion, such that a setup, device or
method that includes a list of components or steps does not include only those
components or steps but may include other components or steps not expressly listed or

inherent to such setup or device or method. In other words, one or more elements in a
system or apparatus proceeded by “comprises… a” does not, without more constraints,
preclude the existence of other elements or additional elements in the system or
method.
[0035] In the following detailed description of the embodiments of the disclosure,
reference is made to the accompanying drawings that form a part hereof, and in which
are shown by way of illustration specific embodiments in which the disclosure may be
practiced. These embodiments are described in sufficient detail to enable those skilled
in the art to practice the disclosure, and it is to be understood that other embodiments
may be utilized and that changes may be made without departing from the scope of the
present disclosure. The following description is, therefore, not to be taken in a limiting
sense.
[0036] The present disclosure relates to a novel polymeric flocculant based on
starch grafted with poly (acrylamide) and poly styrene sulphonate having a general
formula of St-g-(pAAm-co-pSS), wherein the starch was grafted with poly acrylamide
by free radical polymerization technique followed by copolymerization with
polystyrene sulphonate.
[0037] The quantity of all ingredients in the polymeric flocculant are as follows:
i) Starch – ...0.5 to 2.eq,
ii) Acrylamide – 4 to 8....eq,
iii) polystyrene sulphonate – 0.75 to 3.75 eq.
[0038] The anionic graft copolymeric flocculant is observed to be effective
flocculating agent for the settling of iron ore fines and ultra-fines, thus enabling
effective solid-liquid separation. The flocculant is biodegradable and hence eco-
friendly, can be developed by simple and cost-effective technique. The flocculant can

also be used for solid-liquid separation processes for waste water treatment in general
and other oxide ore systems.
[0039] In accordance with another embodiment of the present invention, there is
provided a solution for effective settling of fine and ultra-fine particles for solid-liquid
separation by developing the polymeric reagent by combining starch, acrylamide and
styrene sulphonate in definite proportions to produce an anionic flocculant. The
copolymer was synthesized using free radical polymerization technique. The two-
necked round bottom flask was joined with an oil-bath, coil-heater and electrical
magnetic stirrer for synthesis of copolymer.
[0040] The method of producing the polymeric flocculant comprises the steps of:
i. Dissolving of starch in distill water at a temperature of 65°C-75°C for
12 hour along with constant stirring and aqueous potassium persulphate was added
to it under nitrogen bubbling for 15 min to create the inert atmosphere;
ii. Further addition of aqueous mixture of acrylamide (AAm) and TEMED
(Tetramethylethylenediamine), followed by mixing of sodium p-styrenesulfonate (SS);
iii. Continue with the reaction for another 2.5-3.5 hour with continuous
nitrogen purging followed by cooling off and exposed in air atmosphere at room
temperature (25°C);
iv. Precipitation of reaction mixture into acetone for removal of
uncontrolled formed homopolymer and unreacted monomer to form a product;
v. Drying of the final product in a vacuum oven at a temperature of 60°C,
which then subjected to various characterization tests.
[0041] In the method 0.5 to 2eq. starch is dissolved in 40 to 100eq distilled water
and 0.01 to 0.05 eq potassium persulphate was added to it. 4 to 8 eq acrylamide and
0.05 to 0.25eq TEMED were utilized in this method.

[0042] The synthesis reaction for preparation of St-g-(pAAm-co-pSS) are given
below:

[0045] Initially, 0.5 g of starch was dissolved in 20 mL of distilled water at 70°C
temperature for 12h with constant stirring (400 rpm). Then, aqueous potassium
persulphate (5.56 × 10 5 mol) was added under nitrogen bubbling for 15 min to create
the inert atmosphere. Afterwards, the aqueous mixture of acrylamide (AAm) (4.22 ×
10-2 mol) and TEMED (6.52 × 10-4 mol) was added, followed by addition of sodium
p-styrenesulfonate (SS) (9.69 × 10-3 mol). The reaction was continued for another 3h
in the same condition with continuous nitrogen purging. Then, the reaction was allowed
to cool and exposed in air atmosphere at room temperature (25°C). The reaction
mixture was precipitated into acetone to remove uncontrolled formed homopolymer
and unreacted monomer. Finally, the product was dried in a vacuum oven at 60°C and

the dried product was characterized by various characteristics technique and used
flocculation process.
[0046] The final product has undergone different characterization process.
Characterization
[0047] FTIR spectra were recorded using FTIR spectrometer (Cary 600 series,
Agilent Technologies) using KBr pellet method with scan range of 400 to 4000 cm-1.
1H NMR spectra of starch (DMSO-D6 as a solvent) and St-g-(pAAm-co-pSS) (D2O
as a solvent) were recorded in a 400 MHz NMR spectrophotometer (JEOL, Japan).
Results and discussion
[0048] Synthesis
[0049] The free radical polymerization technique has been employed for the
synthesis of copolymer St-g-(pAAm-co-pSS). In this process, potassium persulphate
(KPS) was used a radical initiator on starch backbone. The formed reactive free radical
on starch further reacts with vinylic bonds of monomers (i.e. AAm and SS) and forms
a long polymeric chain attached with starch backbone. The entire propagation step of
monomers was catalyzed by TEMED. The formation of St-g-(pAAm-co-pSS) follows
the synthetic steps as described before.
[0050] Fig 1 illustrates the FTIR spectra of (a) Starch (b) AAm (c) SS and (d) St-
g-(pAAm-co-pSS).
[0051] Characterization
[0052] As illustrated in FIG.1, the FTIR spectrum of starch reveals that the peaks
at 3371, 2926, 1156 and 1080 cm-1 are attributed to O-H stretching, C-H stretching
and C-O-C stretching vibrations, respectively. The peaks at 3350, 2809, 1673 and 1423

cm-1 in the FTIR spectrum of Acrylamide (Figure) are characterized for the N-H bond
stretching, C-H bond stretching, amide I and amide II bonds stretching vibration,
respectively. The FTIR spectrum of sodium p-styrenesulfonate (Figure), the vibration
frequencies at 1047 and 984 cm-1 are characterized for -SO3Na group, 1193 and 1132
cm-1 are the stretching frequencies of S=O bonds, 1658, 1618 and 1400 cm-1 are the
main characterized band of aromatic C-C bonds. Finally, in the spectrum of grafted
gels, in addition of characteristics peaks of starch, other new peaks were observed. The
new frequencies at 1653 and 1406 cm-1 are corresponds to aromatic C-C bonds, the
peak at 1135 cm-1 for S=O bonds and peak at 1032 cm-1 for -SO3Na group of sodium
p-styrenesulfonate while the bands observed at 1440 cm-1 for stretching vibration of
amide II of AAm. Therefore, the presence of main characteristics band of starch, AAm
and SS in the spectrum of final product St-g-(pAAm-co-pSS) supports the successfully
grafting of AAm and SS monomers on starch.
[0053] FIG. 2 illustrates the 1H NMR spectrum of starch. The chemical shichs
appeared at 5.48 ppm represents the anomeric proton (H1). (Ref IJBIOMAC) The OH
protons at 3, 4 and 6 positions (OH3,4,6) demonstrates chemical shift at 5.08 ppm and
the OH proton attached with C2 carbon (OH2) exhibits chemical shift at 4.54 ppm.
(Ref IJBIOMAC) The chemical shifts at 3.63-3.32 ppm are responsible for ring
protons (H2-6). (Ref IJBIOMAC)
[0054] The 1H NMR spectrum of St-g-(pAAm-co-pSS) has been demonstrated in
FIG. 3. The chemical shifts appeared at 5.70, 5.31 and 3.86-3.54 ppm are corresponds
to anomeric proton (H1), OH protons (OH2-6) and the ring protons (H2-6) of starch
moiety.(Ref IJBIOMAC) The protons (H 10 and H11) attached to the newly formed
sp3 carbons by the polymerization of the vinylic group of monomer of sodium p-
styrene sulphonate demonstrate the chemical shifts at 1.67 and 2.23 ppm respectively.
The aromatic protons (H13 and H14) exhibit chemical shifts at 7.53 and 7.68 ppm
respectively. Again the protons (H 7 and H8) attached to the newly formed sp3 carbons
by the polymerization of the vinylic group of monomer of acrylamide demonstrate

chemical shifts at 1.55 and 2.12 ppm. The amide protons (H9) appeared at 6.89 ppm.
The presence of all the characteristic peaks of starch, polyacrylamide, and poly(sodium
p-styrene sulphonate) suggests the presence of these three components on the graft co-
polymeric structure. Moreover the appearance of chemical shifts of protons (H7, H8,
H10 and H11) attached to the newly formed sp3 carbons suggest the successful
polymerization two monomers (acrylamide and sodium p-styrene sulphonate).
TECHNICAL ADVANTAGES
[0055] The present disclosure relates to a polymeric material based on starch
grafted with poly acrylamide and poly styrene suphonate, to be used as effective
flocculant for iron ore.
[0056] The present disclosure provides a polymeric composite which can be used
as an excellent flocculating agent for settling of iron ore fines and ultra-fines and thus
enabling effective solid-liquid separation.
[0057] The present disclosure provides an anionic flocculant which is bio-
degradable and hence eco-friendly and cost efficient.
[0058] The present invention also provides a method for producing the polymeric
flocculant through free radical polymerization technique.
Equivalents:
[0059] The specification has described a process to utilize non-coking coal for
producing a metallurgical coke. The illustrated steps are set out to explain the
exemplary embodiments shown, and it should be anticipated that ongoing
technological development will change the manner in which particular functions are
performed. These examples are presented herein for purposes of illustration, and not
limitation. Further, the boundaries of the functional building blocks have been

arbitrarily defined herein for the convenience of the description. Alternative boundaries
can be defined so long as the specified functions and relationships thereof are
appropriately performed. Alternatives (including equivalents, extensions, variations,
deviations, etc., of those described herein) will be apparent to persons skilled in the
relevant art(s) based on the teachings contained herein. Such alternatives fall within the
scope and spirit of the disclosed embodiments. Also, the words "comprising," "having,"
"containing," and "including," and other similar forms are intended to be equivalent in
meaning and be open-ended in that an item or items following any one of these words
is not meant to be an exhaustive listing of such item or items, or meant to be limited to
only the listed item or items. It must also be noted that as used herein and in the
appended claims, the singular forms “a,” “an,” and “the” include plural references
unless the context clearly dictates otherwise.
[0060] Finally, the language used in the specification has been principally selected
for readability and instructional purposes, and it may not have been selected to
delineate or circumscribe the inventive subject matter. It is therefore intended that the
scope of the invention be limited not by this detailed description, but rather by any
claims that issue on an application based here on. Accordingly, the embodiments of the
present invention are intended to be illustrative, but not limiting, of the scope of the
invention, which is set forth in the following claims.

WE CLAIM
1. An ionic polymeric flocculant having a general formula of St-g-(pAAm-co-
pSS) for settling of iron ore fines and ultra-fines for enabling effective solid-liquid
separation, said flocculant comprises of starch, polyacrylamide and polystyrene
sulphonate.
2. The polymeric flocculant as claimed in claim 1, wherein quantity of all
ingredients are as follows:
Starch – ...0.5 to 2.eq
Acrylamide – 4 to 8....eq
polystyrene sulphonate – 0.75 to 3.75 eq.
3. The polymeric flocculant as claimed in claim 1, having structure of

4. A method for preparing polymeric flocculant for solid liquid separation
comprising:
- dissolving of starch in distilled water at a temperature of 65°C-75°C along
with constant stirring and aqueous potassium persulphate being added to in an inert
atmosphere;
- adding aqueous mixture of acrylamide (AAm) and TEMED
(Tetramethylethylenediamine), followed by mixing of sodium p-styrenesulfonate (SS);
- continuing with the reaction for 2.5-3.5 hour with continuous nitrogen
purging followed by cooling;

- precipitation of reaction mixture into acetone for removal of uncontrolled
formed homopolymer and unreacted monomer to form a product.
5. The method as claimed in claim 4, wherein 0.5 to 2eq. starch is dissolved
in 40 to 100eq distilled water and 0.01 to 0.05 eq potassium persulphate was added to
it.
6. The method as claimed in claim 4, wherein 4 to 8 eq acrylamide and 0.05
to 0.25eq TEMED were utilized.
7. The method as claimed in claim 4, wherein the starch is dissolved for a
duration of 11-13 hour.
8 The method as claimed in claim 4, wherein the inert atmosphere has created
through nitrogen bubbling for a duration of 15mins.
9. The method as claimed in claim 4, wherein the reaction is continued with
continuous nitrogen purging.
10. The method as claimed in claim 4, wherein final product is dried at a
temperature of 60°C in vacuum oven.
11. The method as claimed in claim 4, wherein drying of the product in an oven,
which then subjected to characterization tests.