Claims:We Claim:
1) An organic polymer represented by Formula I:

(A-CH2 )n
Formula I
wherein:
‘A’ is lignin sulfonate or a salt of lignin sulfonate; and
‘n’ is an integer ranging from 10 to 1000.

2) The polymer as claimed in claim 1, wherein the polymer is composed of lignin sulfonate or a salt of lignin sulfonate, and formaldehyde.

3) The polymer as claimed in claim 1, wherein ‘A’ is sodium lignosulfonate, calcium lignosulfonate, potassium lignosulphonate, or any combination thereof.

4) The polymer as claimed in claim 1, wherein ‘A’ is sodium lignosulphonate and is represented by:

5) The polymer as claimed in claim 1, wherein the lignin sulfonate or a salt thereof comprises phenol moiety, phenolic derivative moiety, sulfonate moiety or combinations thereof which polymerize in presence of formaldehyde to form the organic polymer.

6) The polymer as claimed in any of the preceding claims, wherein the phenol, the phenolic derivative, sulfonate or combinations thereof of the lignin sulphonate or the salt thereof is connected to the formaldehyde by covalent linkage, cross linking bonds or a combination of both covalent and cross links.

7) A process of synthesizing the polymer as claimed in any of the claims 1 to 6, comprising:
a) preparing a mixture of lignosulfonate or salt thereof and formaldehyde, and heating the mixture at a temperature up to about 40? to 45°C; and
b) adding alkali to the mixture and rising the temperature in a controller manner up to about 85? to 90°C followed by further heating for a time-period of about 1.5 hours to 2 hours.

8) The process as claimed in claim 7, wherein heating of step a) is carried out up to 45°C;
and wherein the heating of step b) is carried out for a time-period of about 2 hours.

9) The process as claimed in claim 7, wherein the alkali is sodium hydroxide, potassium hydroxide, or a mixture thereof;
and wherein the alkali is added as an aqueous solution and the temperature rise is controlled by adding said alkali in a controller manner.

10) The process as claimed in claim 7, wherein the lignosulfonate or salt thereof is at a concentration of about 70 wt% to 75 wt%, the formaldehyde is at a concentration of about 14 wt% to 18 wt%, and alkali is at a concentration of about 8 wt% to 10 wt%.

11) The process as claimed in claim 7, wherein the lignosulfonate is sodium lignosulfonate and the alkali is sodium hydroxide.

12) A blend for preparing metallurgical coke comprising coal and the polymer as claimed in any of the claims 1 to 6.

13) A method for improving coking potential of coal, comprising preparing a blend by contacting the polymer of Formula I as claimed in any of the claims 1 to 6 with the coal, to obtain the coal with improved coking potential.

14) The blend as claimed in claim 12 or the method as claimed in claim 13, wherein the polymer is at a concentration of about 0.5 to 2 wt% of the blend.

15) The blend as claimed in claim 12 or the method as claimed in claim 13, wherein the coal comprises non-coking coal (NCC) at a concentration of about 5 wt% to 20 wt% of the blend and coking coal (CC) at a concentration of about 95 wt% to 80 wt% of the blend.

16) The blend or the method as claimed in claim 15, wherein the coking coal (CC) comprises hard coking coal (HCC) at a concentration of about 25 wt% to 40 wt% and medium coking coal (MCC) at a concentration of about 50 wt% to 55 wt%.

17) The blend as claimed in claim 12 or the method as claimed in claim 13, wherein the polymer improves crucible swelling number (CSN) and fluidity of the blend;
and wherein the CSN of the blend increases at least by 2 points to 3 points and the fluidity of the blend increases by at least 50 ddpm to 100 ddpm.

18) The blend as claimed in claim 12 or the method as claimed in claim 13, wherein the polymer improves coking potential of the coal by enabling accommodation of about 10 wt% to 12 wt% of non-coking coal (NCC) when compared to less than 5 wt% of non-coking coal in the absence of the polymer.
, Description:TECHNICAL FIELD
The present disclosure relates to the field of metallurgy and polymer chemistry. The disclosure particularly relates to an organic polymer for enhancing coking potential of coal for use in production of metallurgical coke.

BACKGROUND OF THE DISCLOSURE
In blast furnace for production of pig iron, metallurgical coke plays a crucial role. Coke acts as a fuel, reducing agent and is also responsible for the permeability of the charge. Because of the numerous functions of coke in blast furnace, stringent quality parameters of its physical and chemical properties are required to ensure smooth operation and high productivity in modern blast furnaces. Since the price of prime coking coal is high and the worldwide reserve of prime coking coal is low, continuous efforts/research is going on to develop alternate carbonaceous material or enhancing quality of inferior/non-coking coal in coal blends to improve the coke quality. In other words, a technology without compromising the coke quality and employing higher ratio/amounts of non-coking coal is highly desirable. The present disclosure tries to address said need.

STATEMENT OF THE DISCLOSURE
The present disclosure relates to an organic polymer represented by Formula I:

(A-CH2 )n
Formula I
wherein:
‘A’ is lignin sulfonate or a salt of lignin sulfonate; and
‘n’ is an integer ranging from 10 to 1000.

In some embodiments of the disclosure, ‘A’ is sodium lignosulfonate, calcium lignosulfonate, potassium lignosulphonate, or any combination thereof.

The present disclosure further relates to a process of synthesizing the polymer as described above, comprising:
a) preparing a mixture of lignosulfonate or salt thereof and formaldehyde, and heating the mixture at a temperature up to about 40? to 45°C; and
b) adding alkali to the mixture and rising the temperature in a controller manner up to about 85? to 90°C followed by further heating for a time-period of about 1.5 hours to 2 hours.

The present disclosure also provides a blend for preparing metallurgical coke, said blend comprising coal and the polymer of Formula I as described above.

The present disclosure further relates to a method for improving coking potential of coal, comprising preparing a blend by contacting the polymer of Formula I as described above with the coal, to obtain the coal with improved coking potential.

BRIEF DESCRIPTION OF THE ACCOMPANYING FIGURES
Figure 1 represents Fourier-transform infrared spectroscopy (FTIR) spectra of the present lignosulphonate-formaldehyde based polymer.

DETAILED DESCRIPTION OF THE DISCLOSURE
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” or “containing” or “has” or “having”, or “including but not limited to” 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.

Reference throughout this specification to “some embodiments”, “one embodiment” or “an embodiment” means that a particular feature, structure or characteristic described in connection with the embodiment may be included in at least one embodiment of the present disclosure. Thus, the appearances of the phrases “in some embodiments”, “in one embodiment” or “in an embodiment” in various places throughout this specification may not necessarily all refer to the same embodiment. It is appreciated that certain features of the disclosure, which are, for clarity, described in the context of separate embodiments, may also be provided in combination in a single embodiment. Conversely, various features of the disclosure, which are, for brevity, described in the context of a single embodiment, may also be provided separately or in any suitable sub-combination.

The term “about” as used herein encompasses variations of +/- 10% and more preferably +/- 5%, as such variations are appropriate for practicing the present invention.

A primary objective of the present disclosure is to synthesize polymeric additive to address the need of improving coking potential of non-coking coals, thereby enhancing the overall efficiency of metallurgical coke production.

Another objective of the present disclosure is to maximize the utilization of low grade/non-coking coals in a coal blend for economical and efficient production of metallurgical coke. Particularly, the objective is to utilize maximum amount of non-coking coal in coal blend without deterioration of metallurgical coke properties.

Yet another objective of the present disclosure is to improve the swelling and fluidity of coal matrix by employing a polymeric additive during carbonization.

Still another objective of the present disclosure is to synthesize a polymer from sulphur salt of lignin. Particularly, the objective is to provide an organic polymer based on lignin sulphonate and aldehyde for incorporation/maximizing the amount of non-coking coal in coal blend.

Accordingly, to meet the above objectives, an organic polymer derived from lignin sulphonate and formaldehyde is provided by the present disclosure.

Lignin is a class of complex organic polymers comprising cross-linked phenolic precursors. Lignin sulphonate or lignosulfonate or sulfonated lignin is water-soluble anionic polyelectrolyte polymer and is a by-product from the production of wood pulp using sulfite pulping process.

Particularly, the present disclosure provides an organic polymer represented by Formula I:

(A-CH2 )n
Formula I
wherein:
‘A’ is lignin sulfonate or a salt of lignin sulfonate; and
‘n’ is an integer ranging from 10 to 1000.

In some embodiments of the polymer, the polymer is composed of lignin sulfonate or a salt of lignin sulfonate, and formaldehyde.

In some embodiments, the methylene moiety (-CH2) in the polymer is derived from formaldehyde.

In some embodiments of the polymer, ‘A’ is a salt of lignin sulfonate.

In some embodiments of the polymer, the salt of lignin sulfonate is selected from sodium lignosulfonate, calcium lignosulfonate, potassium lignosulphonate, or any combination thereof.

In some embodiments of the polymer, ‘A’ is sodium lignosulfonate.

In some embodiments of the polymer, ‘A’ is sodium lignosulphonate and is represented by:

In some embodiments of the polymer, ‘A’ is calcium lignosulfonate.

In some embodiments of the polymer, ‘A’ is calcium lignosulphonate and possesses the same structure as that of sodium lignosulfonate represented above except for sodium being replaced by calcium.

In some embodiments of the polymer, ‘A’ is potassium lignosulfonate.

In some embodiments of the polymer, ‘A’ is potassium lignosulphonate and possesses the same structure as that of sodium lignosulfonate represented above except for sodium being replaced by potassium.

In some embodiments, the lignin sulphonate comprises phenol moiety, phenolic derivative moiety, sulfonate moiety or combinations thereof which polymerize in presence of formaldehyde to form the organic polymer of Formula I as described above.

In some embodiments, sodium lignosulphonate comprises phenol moiety, phenolic derivative moiety, sulfonate moiety or combinations thereof which polymerize in presence of formaldehyde to form the organic polymer of Formula I as described above.

In some embodiments of the polymer, the phenol, the phenolic derivative, sulfonate or combinations thereof of the lignin sulphonate or the salt thereof is connected to the formaldehyde or methylene moiety by covalent linkage.

In some embodiments of the polymer, the phenol, the phenolic derivative, sulfonate or combinations thereof of the lignin sulphonate or the salt thereof is connected to the formaldehyde or methylene moiety by cross linking bonds.

In some embodiments of the polymer, the phenol, the phenolic derivative, sulfonate or combinations thereof of the lignin sulphonate or the salt thereof is connected to the formaldehyde or methylene moiety by a combination of both covalent and cross links.

In some embodiments, the above described organic polymer of Formula I is represented by:
(A-CH2 )n
wherein ‘n’ ranges from 10 to 500, including all values and ranges therefrom.

In some embodiments, the above described organic polymer of Formula I is represented by:
(A-CH2 )n
wherein ‘n’ ranges from 300 to 500, including all values and ranges therefrom.

In some embodiments, the above described organic polymer of Formula I is represented by:
(A-CH2 )n
wherein ‘n’ ranges from 200 to 800, including all values and ranges therefrom.

In some embodiments, the above described organic polymer of Formula I is represented by:
(A-CH2 )n
wherein ‘n’ ranges from 500 to 800, including all values and ranges therefrom.

In some embodiments, the above described organic polymer of Formula I is represented by:
(A-CH2 )n
wherein ‘n’ ranges from 500 to 1000, including all values and ranges therefrom.

In some embodiments, the polymer comprises solid content of about 30% to 40%, fixed carbon of about 50% to 60% and has a viscosity of about 20 cP to 30 cP.

In some embodiments, the present polymer is a hybrid compound consisting of lignin sulfonate and formaldehyde. The hydrophobic segment of the polymer primarily comprises single aromatic based crosslinked polymer of lignin sulphonate. The hydrophilic segment (carbonaceous material) is composed of -OH, C=O group of acid derivative and -OCH2R linkage.

The present disclosure further relates to a process of synthesizing the polymer of Formula I as described above, comprising:
a) preparing a mixture of lignosulfonate or salt thereof and formaldehyde, and heating the mixture at a temperature up to about 40? to 45°C; and
b) adding alkali to the mixture and rising the temperature in a controller manner up to about 85? to 90°C followed by further heating for a time-period of about 1.5 hours to 2 hours.

In some embodiments of the above described process, the heating of step a) is carried out up to 45°C.

In some embodiments of the above described process, the heating of step b) is carried out for a time-period of about 2 hours.

In some embodiments of the above described process, the alkali is sodium hydroxide, potassium hydroxide, or a mixture thereof.

In some embodiments of the above described process, the alkali is sodium hydroxide.

In some embodiments of the above described process, the alkali is added as an aqueous solution and the temperature rise is controlled by adding said alkali in a controller manner.

In some embodiments of the above described process, the sodium hydroxide is added as an aqueous solution and the temperature rise is controlled by adding the sodium hydroxide in a controller manner.

In some embodiments of the above described process, the lignosulfonate or its salt is at a concentration of about 70 wt% to 75 wt%.

In some embodiments of the above described process, the formaldehyde is at a concentration of about 14 wt% to 18 wt%.

In some embodiments of the above described process, the alkali is at a concentration of about 8 wt% to 10 wt%.

In some embodiments of the above described process, the lignosulfonate is sodium lignosulfonate and the alkali is sodium hydroxide.

In some embodiments, the process of synthesizing the polymer of Formula I as described above comprises:
a) preparing a mixture of sodium lignosulfonate and formaldehyde, and heating the mixture at a temperature up to 45°C; and
b) adding sodium hydroxide to the mixture and rising the temperature in a controller manner until temperature reached 85? to 90°C followed by further heating for a time-period of 2 hours.

The present disclosure also provides a blend for preparing metallurgical coke, said blend comprising coal and the polymer of Formula I as described above.

In some embodiments of the blend, the polymer is at a concentration of about 0.5 to 2 wt% of the blend.

In some embodiments of the blend, the polymer is at a concentration of about 1 to 1.5 wt% of the blend.

In some embodiments of the blend, the coal comprises non-coking coal (NCC) at a concentration of about 5 wt% to 20 wt% of the blend and coking coal (CC) at a concentration of about 95 wt% to 80 wt% of the blend.

In some embodiments of the blend, the coking coal (CC) comprises hard coking coal (HCC) at a concentration of about 25 wt% to 40 wt% and medium coking coal (MCC) at a concentration of about 50 wt% to 55 wt%.

In some embodiments of the blend, the polymer increases/improves crucible swelling number (CSN) and fluidity of the coal blend.

In some embodiments of the blend, the CSN of the blend is increased at least by 2 points to 3 points and the fluidity of the blend is increased by at least 50 ddpm to 100 ddpm.

In some embodiments of the blend, the polymer improves coking potential of the coal by enabling accommodation of about 10 wt% to 12 wt% of non-coking coal (NCC) when compared to less than 5 wt% of non-coking coal in the absence of the polymer.

The present disclosure also relates to a method for improving coking potential of coal, comprising preparing a blend by contacting the polymer of Formula I as described above with the coal, to obtain the coal with improved coking potential.

In some embodiments of the above described method for improving coking potential of coal, the polymer is at a concentration of about 0.5 to 2 wt% of the blend.

In some embodiments of the above described method for improving coking potential of coal, the polymer is at a concentration of about 1 to 1.5 wt% of the blend.

In some embodiments of the above described method for improving coking potential of coal, the coal comprises non-coking coal (NCC) at a concentration of about 5 wt% to 20 wt% of the blend and coking coal (CC) at a concentration of about 95 wt% to 80 wt% of the blend.

In some embodiments of the above described method for improving coking potential of coal, the coking coal (CC) comprises hard coking coal (HCC) at a concentration of about 25 wt% to 40 wt% and medium coking coal (MCC) at a concentration of about 50 wt% to 55 wt%.

In some embodiments of the above described method for improving coking potential of coal, the polymer increases/improves crucible swelling number (CSN) and fluidity of the coal blend.

In some embodiments of the above described method for improving coking potential of coal, the CSN of the blend is increased at least by 2 points to 3 points and the fluidity of the blend is increased by at least 50 ddpm to 100 ddpm.

In some embodiments of the above described method for improving coking potential of coal, the polymer improves coking potential of the coal by enabling accommodation of about 10 wt% to 12 wt% of non-coking coal (NCC) when compared to less than 5 wt% of non-coking coal in the absence of the polymer.

The present disclosure further provides use of the polymer of Formula I as described above for improving coking potential of non-coking or inferior grade coal.

In some embodiments, use of the present polymer increases the efficiency of metallurgical coke making process.

In some embodiments, using the present polymer of Formula I for metallurgical coke making comprises:
(i) synthesizing the lignin sulfonate or its salt, and formaldehyde based organic polymer as described above;
(ii) mixing the polymer with coal blend; and
(iii) employing the coal blend in metallurgical coke making process.

Without wishing to be bound by any theory, the lignin sulfonate or its salt, and formaldehyde based polymer of Formula I of the present disclosure acts as an additive to improve coking potential of coal by generating hydrogen at the fluidic range of coal (about 350-550?) which helps to enhance the fluidity of the coal matrix and thereby enabling accommodation of higher amount of coal (non-coking coal) in the matrix.

Thus, the present disclosure focusses on developing an organic polymeric additive which can create new window in coke making industry through maximum utilization of inferior grade coal/non-coking coals as an alternative to prime coking coals. The present organic polymer improves the coking potential of non-coking coal thereby maximizing the use of non-coking coal amounts in metallurgical coke making. The presently synthesized polymer can be added as an additive at lower amounts to enhance fluidity and swelling property of coal matrix. Particularly, the presently synthesized polymeric additive is effective at lower dosages (eg. 0.5% - 2%) to accommodate higher percentage (eg. 10-12%) of inferior/non-coking coal in the coal blend without deterioration of coke properties and thereby improves the Coke Strength after Reaction (CSR) as further observed from the carbonization study described in the forthcoming examples.

It is to be understood that the foregoing descriptive matter is illustrative of the disclosure and not a limitation. Although preferred embodiments have been depicted and described in detail herein, it will be apparent to those skilled in the relevant art that various modifications, additions, substitutions, and the like can be made without departing from the spirit of the invention and these are therefore considered to be within the scope of the invention as defined in the claims which follow. Further, to the extent not already indicated, it will be understood by those of ordinary skill in the art that any one of the various embodiments herein described and illustrated can be further modified to incorporate features shown in any of the other embodiments disclosed herein. In other words, 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.

Further, it should be understood that this invention is not limited to the particular methodology, protocols, and reagents, etc., described herein and as such may vary. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the scope of the present invention, which is defined solely by the claims.

As regards all the embodiments/examples characterized in this specification, in particular in the claims, it is intended that each embodiment mentioned in a dependent claim is combined with each embodiment of each claim (independent or dependent) said dependent claim depends from. As an example, in case of an independent claim 1 reciting 3 alternatives A, B and C, a dependent claim 2 reciting 3 alternatives D, E and F and a claim 3 depending from claims 1 and 2 and reciting 3 alternatives G, H and I, it is to be understood that the specification unambiguously discloses embodiments corresponding to combinations: A, D, G; A, D, H; A, D, I; A, E, G; A, E, H; A, E, I; A, F, G; A, F, H; A, F, I; B, D, G; B, D, H; B, D, I; B, E, G; B, E, H; B, E, I; B, F, G; B, F, H; B, F, I; C, D, G; C, D, H; C, D, I; C, E, G; C, E, H; C, E, I; C, F, G; C, F, H; and C, F, I, unless specifically mentioned otherwise.

Similarly, and also in those cases where independent and/or dependent claims do not recite alternatives, it is understood that if dependent claims refer back to a plurality of preceding claims or plurality of embodiments, any combination of subject-matter covered thereby is considered to be explicitly disclosed. For example, in case of an independent claim 1, a dependent claim 2 referring back to claim 1, and a dependent claim 3 referring back to both claims 2 and 1, it follows that the combination of the subject-matter of claims 3 and 1 is clearly and unambiguously disclosed as is the combination of the subject-matter of claims 3, 2 and 1. In case a further dependent claim 4 is present which refers to anyone of claims 1 to 3, it follows that the combination of the subject-matter of claims 4 and 1, of claims 4, 2 and 1, of claims 4, 3 and 1, as well as of claims 4, 3, 2 and 1 is clearly and unambiguously disclosed.

The above considerations apply mutatis mutandis to all claims and embodiments of the present specification. To give a few examples, the combination of claims 4, 7 and 1 is clearly and unambiguously envisaged in view of the claim structure/claimed subject-matter. The same applies for the combinations of claims 12, 13, 7 and 1, and, to give a few further examples which are not limiting, the combination of claims 8, 7, 12 and 13 etc.

Descriptions of well-known/conventional methods/steps and techniques are omitted so as to not unnecessarily obscure the embodiments herein. Further, the disclosure herein provides for below examples illustrating the above described embodiments, and in order to illustrate the embodiments of the present disclosure certain aspects have been employed. The examples used herein for such illustration are intended merely to facilitate an understanding of ways in which the embodiments herein may be practiced and to further enable those of skill in the art to practice the embodiments herein. Accordingly, the following examples should not be construed as limiting the scope of the embodiments herein.

INCORPORATION BY REFERENCE
All references, articles, publications, patents, patent publications, and patent applications (if any) cited herein are incorporated by reference in their entireties for all purposes. However, mention of any reference, article, publication, patent, patent publication, and patent application cited herein is not, and should not be taken as, an acknowledgment or any form of suggestion that they constitute valid prior art or form part of the common general knowledge in any country in the world.

EXAMPLES

Example 1: Synthesis of organic polymer according to present disclosure
The components 0.03-0.05 moles (about 73 wt%) of sodium lignosulphonate, 3-4 moles (about 16 wt%) of formaldehyde and 1-2 moles (about 11 wt%) of sodium hydroxide, all in an aqueous solution are taken. Initially, a mixture is prepared with sodium lignosulfonate and formaldehyde. The mixed components are then heated up to 45?. An aqueous solution of sodium hydroxide is thereafter prepared and is slowly mixed with the reaction mixture. The temperature rise is controlled by adding sodium hydroxide in a controlled manner. After the temperature reaches around 85-90?, heating is continued for another 2 hours till viscosity become constant, to obtain the polymer of Formula 1.

Example 2: Characterization of the synthesized organic polymer
Physical and chemical characteristics of the polymer
Physical and chemical properties of the synthesized lignin sulfonate and formaldehyde based polymer (Formula I) is described below:
(a) Appearance: Black solution
(b) Viscosity: 15-25 cps
(c) pH: 7.0 ± 1.0
(d) Specific Gravity: 1.2
(d) Solubility: completely soluble in water

The synthesized material is a polymeric hybrid compound consisting of lignin sulfonate and formaldehyde. The hydrophobic segment of the polymer mainly consists of single aromatic based crosslinked polymer of lignin sulphonate. The hydrophilic carbonaceous material is composed of -OH, C=O group of acid derivative and -OCH2R linkage.

Structural characterization of the polymer (FTIR spectra):
Figure 1 represents the FTIR spectrum of the polymer. The FTIR spectrum of the polymer shows single bond C-O stretching vibrations of -CH2OH group at 1125 cm-1. The peaks at 1343 cm-1 are associated with the C–H bending vibration. The emerging peaks at 1445 cm-1 are attributed to -CH2 deformation vibration. An aromatic C=C stretching peak is observed at around 1600 cm-1. The peak at 2925 cm-1 is due to the aliphatic -CH modes. The peaks at 3330 cm-1 is associated with the O–H stretching vibration.

Example 3: Coking Potential Tests - Crucible swelling number (CSN) and Fluidity study
For testing, two inferior coals (Coal A1 and Coal A2) are considered. These coals are subjected to crucible swelling number test and fluidity. Details of the tests are as follows:

Crucible swelling number (CSN): Crucible swelling number test is done by following ASTM D720-91 (2010). 1 gm of sample (-0.212 mm size) is taken in a translucent squat shaped silica crucible and the sample is levelled by tapping the crucible 12 times. The crucible is covered with a lid and heated under standard conditions, either by a special type of gas burner or muffle furnace. After the test, the shape of coke button is compared with a standard chart and accordingly, the crucible swelling number (0 to 9) is assigned to the coal sample.

Fluidity: In fluidity measurement, fine coal (not pulverised) is heated slowly and as it melts and passes through its plastic range, its fluidity is noted. Results are expressed as maximum fluidity in dial divisions per minute (ddpm). Characteristic temperatures recorded are initial softening temperature, maximum fluidity temperature and re-solidification temperature. The plastic range, which is the temperature range during which the coal is in its plastic state, is also important. All coking and caking tests are sensitive to oxidation, but the fluidity test is by far the most sensitive. The instrument used for fluidity determination is known as Geiseler Plastometer. Plastometer measures the plastic properties of coal by using of a constantly applied torque on a stirrer, placed on a crucible into which the coal is charged. The ASTM standard (D2639-Plastometer) is followed for this test. 5 gm sample of -0.425 mm particle size is packed around a stirrer in a cylindrical steel crucible (21.5mm ID x 35 mm length). As the coal is heated under prescribed conditions of 3?, it begins to soften, and the torque weight causes the stirrer to rotate in the sample. As the coal begins to soften and attain fluid state at higher temperature, the stirrer rotates more rapidly up to a maximum. As the temperature continues to raise, the fluidity of coal starts to fall because of re-solidification of coal and subsequently the stirrer moves slowly until the coal is resolidified into coke and the stirrer stops. The speed of rotation of the stirrer in terms of dial divisions per minute (ddpm) and the corresponding temperatures is recorded every minute. The temperature at 1 ddpm is taken as initial softening temperature. The temperature at the maximum ddpm is taken as maximum fluid temperature. The solidification temperature is the temperature at which the stirrer movement stops. Maximum fluidity corresponds to the maximum ddpm which is reported.
Following Table 1a shows the CSN and fluidity results of Coal A1 and A2. Table 1b shows said results after addition of 1% percent of presently synthesized polymer (Formula I).

Table 1: CSN and Fluidity results
(a)
Sample CSN Maximum Fluidity (ddpm)
Coal A1 1 Nil
Coal A2 4.5 1497
(b)
Coal A1+1% Polymer 2 Nil
Coal A2+1% Polymer 5.5 1513

From Table 1, it is evident that with the addition of polymer, fluidity and crucible swelling number has been substantially improved. After characterization of these rheological properties, carbonization study was conducted.

Example 4: Carbonization study
Characterization of coal:
Particularly, two types of hard coking coal or good coking coal (HCC), two types of medium coking coal (MCC) and one type of inferior coal or non-coking coal (IC) were used for blending. Before blending, the coals were characterized in terms of ash, volatile matter (VM), crucible swelling number (CSN) and fluidity. The details of are as follows:

Ash determination: Ash is determined by following ASTM standard D 3174-11. 1 gm of 250 mm size sample is taken to a weighed capsule. The sample is placed in a cold muffle furnace and heated gradually at such a rate that the temperature reached about 450? to 500? by about 1 hour. At the end of 2 hour, it reached about 950?. After cooling, the weight of the sample is measured and ash is calculated by weight difference.

VM determination: VM is determined by following ASTM standard D 3175-11. In this test, 1 gm of 250 mm size sample is taken in a covered platinum crucible and heated in a furnace of about 950? for about 7 minutes. The VM is calculated by weight difference.
Determination of CSN is already described in earlier section. Table 2 presents properties of different coal.

Table 2: Coal properties
Coal Ash, % db VM, % db Crucible Swelling number
HCC 9 - 16 20 - 24 7 - 8
MCC 10 - 18 21 - 24 4 - 5.5
IC 9 - 10 15 - 17 1 - 3

After complete characterization of the polymer and coal, a series of carbonization tests were designed and conducted in 7 kg carbolite oven under stamp charging conditions. Said series of carbonization tests were carried out to study the influence of the polymer on coke properties. Water was added to the coal blend to obtain the desired value of moisture content. The coal cake was made inside a cardboard box keeping the bulk density 1150 kg/m3. Tests were done with different blends. Initially, test was carried out with base blend (blend no 1). Thereafter, the hard coking coal (HCC) from the base blend was replaced by inferior coal or non-coking coal (IC). Optimized quantity of polymer was added to maintain the coke quality. Before charging the coal cake into the oven, it was ensured that the empty oven temperature was 900±5°C. After 5 hours of carbonization time, the hot coke was pushed out and quenched with water. The coke samples were tested for coke strength after reaction (CSR) and CRI (coke reactivity indices). Coke strength after reaction was done by following the NSC method. 200 g coke of 19-21 mm size was heated in a reaction tube (78 mm diameter X 210 mm length) at about 1100? for about 2 hours during which CO2 was passed at 5 L/min. The percentage loss in weight of coke during the above reaction is reported as the coke reactivity test (CRI). This reacted coke was further tested by rotating in a I drum (127 mm diameter X725 mm length) for about 30 minutes at a speed of about 20 rpm. The coke was then screened on a 10 mm sieve and the % of + 10 mm fraction is reported as the coke strength after reaction (CSR).

Carbonization results:
Different coals were used for blend preparation/designing. Based on the properties of different coal, a series of blends were designed wherein the percentage of present polymer of Formula I (designated as LS0) was varied from 0.5% to 1.5 %. The results of coke strength after reaction (CSR) in provided in Table 3.

Table 3: Different blend compositions and coke strength after reaction (CSR)
Blend 1 2 3 4 5 6
Component, % HCC-37
MCC-55
IC-8
HCC-27
MCC-55
IC-18
HCC-27
MCC-55
IC-18
LS0-0.5 HCC-27
MCC-55
IC-18
LS0-0.7 HCC-27
MCC-55
IC-18
LS0-1 HCC-27
MCC-55
IC-18
LS0-1.5
CSR 48 41.8 43.7 43.2 45.6 50.2

Blend 1 is the base blend of coke plant containing around 37 % HCC, 55% MCC and 8% IC. The CSR (Coke strength after reaction) of said blend is around 48. In the 2nd blend, 10% HCC is replaced by additional 10% IC. The CSR comes down to 41 due to the increased addition of inferior/non-coking coal (IC). This is expected since a good coal (HCC) was replaced with a poor/inferior coal. In blends 3 to 6, blend 2 was repeated with the addition of 0.5%, 0.7%, 1% and 1.5% of polymer LS0. The results clearly show that CSR gradually increases. Further, with addition of 1.5% polymer, CSR more than base blend was achieved.

The above results indicate that addition of polymer in coal blends having high amounts of inferior/non-coking coal has a positive effect in improving the coking potential of the coal blend. Further, about 1.3-1.5% polymer addition enables accommodation of at least 10% more inferior/non-coking coal instead of the expensive/hard coking coal.

Researchers have been trying various methods on how to increase the coke strength of coal and there has been continuous focus on how to increase efficiency and overall energy savings in coke manufacturing. Thus, the present disclosure tries to address this need wherein the formation of metallurgical coke from inferior/non-coking coal is carried out by addition of polymeric additive of Formula I as described above. More particularly, the disclosure synthesizes an organic polymer based on lignin sulfonate and formaldehyde for application as an additive in metallurgical coke production. The above results clearly evidences the technical effects of the present polymer (Formula I) in enhancing the coking potential of non-coking/inferior coal grades by accommodating higher amounts of said non-coking coal and thereby lowering the need of expensive/high grade coals. This further improves the overall economics and efficiency of coke manufacturing.