DESC:TECHNICAL FIELD
The present disclosure is in the field of metallurgy and desulphurization materials. The disclosure relates to a desulphurization reagent comprising Gilsonite along with other components, corresponding method of preparation, and process or use of said desulphurization reagent for desulphurization of hot metal (HMDS) during production of steel.

BACKGROUND OF THE DISCLOSURE
During steel making process, removal of sulphur from hot metal is called desulphurization of hot metal (HMDS). Sulphur is a desirable element in steel when good machinability is required from the steel product. However, it is an unwanted element/impurity in most of the applications of steel due to the following reasons:
- sulphur affects both internal and surface quality of steel.
- sulphur contributes to the steel brittleness and when it exists in sulphide phase, it acts as a stress raiser in steel products.
- sulphur forms undesirable sulphides which promote granular weakness and cracks in steel during solidification.
- sulphur has adverse effect on the mechanical properties of steel.
- sulphur lowers the melting point, intergranular strength and cohesion of steel.

Hence, it is essential to remove sulphur (desulphurize) from hot metal before primary steel making. While a number of technologies have been developed for the external desulphurization of hot metal, a commonly used desulphurizing process is the deep injection of desulphurizing reagent in the hot metal. This is also known as dip lance process which is a reliable method for desulphurization of hot metal. Said method consists of pneumatic injection of desulphurization reagent into the hot metal with high dosing precision via a dispensing vessel and a refractory lined lance.

Commonly used desulphurization reagents for this process include lime, calcium carbide, magnesium etc. which remove the sulphur in the hot metal by chemical reaction and transfer it to slag that is usually removed immediately after completion of the injection process. One of the common methods of slag removal is to tilt the ladle and rake the slag off the ladle with the help of a slag raking machine.

However, there are some important issues with respect to the currently employed desulphurizing reagents. For instance, most of the currently employed desulphurization reagents are very expensive. Particularly, magnesium is both hazardous as well as expensive. In addition, its availability is restricted in limited number of countries. Further, while coal is used as a deoxidising reagent in the desulphurization process, typically coal has very low gasification potential.
Therefore, there is an immense need to develop an alternate, simple, and more importantly an economical/cost effective and environment friendly/less hazardous desulphurization reagent for effective removal of sulphur from hot metal during steel making process. The present disclosure addresses this need.

SUMMARY OF THE DISCLOSURE
The present disclosure provides a desulphurization reagent comprising:
- desulphurizing compound selected from calcium carbide (CaC2), lime (CaO), and a combination thereof,
- Gilsonite, and
- optionally, slag conditioner.

In some embodiments, the desulphurization reagent further comprises coal.

In some embodiments, the desulphurization reagent comprises the desulphurizing compound at an amount of about 10 wt% to about 97 wt%, the Gilsonite at an amount of about 1 wt% to about 20 wt%, the slag conditioner at an amount of about 0 wt% to about 10wt% and the coal at an amount of about 0 wt% to about 10wt%.

Further provided in the present disclosure is a method for preparing the desulphurization reagent as described above, the method comprising mixing the desulphurizing compound(s), the Gilsonite and optionally the slag conditioner and/or coal to obtain the desulphurization reagent.

Also provided herein is a process of desulphurization of hot metal during production of steel, the process comprising reacting the desulphurization reagent as described above with the hot metal to obtain desulphurized metal and sulphur rich slag.
BRIEF DESCRIPTION OF THE ACCOMPANYING FIGURES
In order that the disclosure may be readily understood and put into practical effect, reference will now be made to exemplary embodiments as illustrated with reference to the accompanying figures. The figures together with detailed description below, are incorporated in and form part of the specification, and serve to further illustrate the embodiments and explain various principles and advantages, in accordance with the present disclosure where:

Figure 1 depicts the results of flow index comparison between the Gilsonite containing desulphurization reagent of the present disclosure and a coal containing reagent at a concentration of 1 wt%.

Figure 2 depicts the results of flow index comparison between the Gilsonite containing desulphurization reagent of the present disclosure and a coal containing reagent at a concentration of 2 wt%.

DETAILED DESCRIPTION OF THE DISCLOSURE
In view of the limitations discussed above, and to remedy the need in the art for economical, safe and efficacious desulphurization reagent, the present disclosure provides a reagent comprising Gilsonite along with other ingredients, corresponding method of preparation, and process or use of said desulphurization reagent for desulphurization of hot metal (HMDS) during production of steel.

However, before describing the invention in greater detail, it is important to take note of the common terms and phrases that are employed throughout the present disclosure for better understanding of the technology provided herein.

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 “one embodiment” or “some embodiments” 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 one embodiment” or “in some embodiments” 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.

Regarding the embodiments characterized in this specification, it is intended that each embodiment be read independently as well as in combination with another embodiment. For example, in case of an embodiment 1 reciting 3 alternatives A, B and C, an embodiment 2 reciting 3 alternatives D, E and F and an embodiment 3 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; C, F, I, unless specifically mentioned otherwise.

Numerical ranges stated in the form ‘from x to y’ include the values mentioned and those values that lie within the range of the respective measurement accuracy as known to the skilled person. If several preferred numerical ranges are stated in this form, of course, all the ranges formed by a combination of the different end points are also included.

The term “about” as used herein is meant to encompass variations of and from the specified value, such as variations of +/-10% or less, +/-5% or less, +/-1% or less, and +/-0.1% or less of and from the specified value, insofar such variations are appropriate to perform the disclosed invention. These variations would be apparent to one of ordinary skill in the art in the context of the invention.
Throughout this specification, the term ‘a combination thereof’, ‘combinations thereof’ or ‘any combination thereof’ or ‘any combinations thereof’ are used interchangeably and are intended to have the same meaning, as regularly known in the field of patent disclosures.

As used herein, the term “desulphurization reagent” refers to the product of the present disclosure comprising Gilsonite which can be employed for hot metal desulphurization process (removal of sulphur from hot metal which is obtained during the process of steel making). The term “reagent” has also interchangeably been used in reference to the desulphurization reagent of the present disclosure.

As used herein, the term “desulphurization efficiency” refers to the fraction or percentage of sulphur removed from the sample subjected to the desulphurization process.

“Success Rate” as referred to in the present disclosure is the measure of desulphurization efficiency. It is defined as the ratio of the number of batches/lots/heats in which the desired sulphur is achieved (with a tolerance of +0.001% Sulphur) to the total number of batches/lots/heats attempted for that particular level of Sulphur.

An objective of the present disclosure is to provide an alternate, economical, and less hazardous desulphurization reagent showcasing improved efficiency of desulphurization.

Still another objective of the present disclosure is to develop an alternate desulphurization reagent which can reduce the overall costs and improve the overall efficiency of HMDS process.

Still another objective is to achieve the above-mentioned objectives and perform the HMDS process with high process efficiency by better interaction between the desulphurization reagent and the liquid hot metal.

Still another objective of the present disclosure is to ensure good flowability of the desulphurization reagent for smooth flow through the injection system.
A further objective is to devise a desulphurization reagent partially or completely devoid magnesium. This is achieved by the employment of Gilsonite as a bath agitator in the desulphurization reagent of the present disclosure.
Accordingly, the present disclosure provides a desulphurization reagent comprising:
- a desulphurizing compound,
- Gilsonite, and
- optionally, a slag conditioner.

In some embodiments, the desulphurization reagent comprises
- desulphurizing compound selected from calcium carbide (CaC2), lime (CaO), and a combination thereof,
- Gilsonite, and
- optionally, a slag conditioner.

In some embodiments, the desulphurization reagent comprises
- desulphurizing compound which is calcium carbide (CaC2),
- Gilsonite, and
- optionally, a slag conditioner.

In some embodiments, the desulphurization reagent comprises
- desulphurizing compound which is lime (CaO),
- Gilsonite, and
- optionally, a slag conditioner.

In some embodiments, the desulphurization reagent comprises
- calcium carbide (CaC2)
- lime (CaO),
- Gilsonite, and
- optionally, a slag conditioner.

In some embodiments, the desulphurization reagent comprises
- calcium carbide (CaC2)
- lime (CaO), and
- Gilsonite,

In some embodiments, the desulphurization reagent comprises
- calcium carbide (CaC2)
- lime (CaO),
- Gilsonite, and
- a slag conditioner.

In some embodiments, the slag conditioner is selected from a group comprising cryolite, alumina, fluorspar, bauxite, soda ash, borax, and any combination thereof.

Accordingly, in some embodiments, the desulphurization reagent comprises
- desulphurizing compound selected from calcium carbide (CaC2), lime (CaO), and a combination thereof,
- Gilsonite, and
- optionally, a slag conditioner selected from a group comprising cryolite, alumina, fluorspar, bauxite, soda ash, borax, and any combination thereof.

In some embodiments, the desulphurization reagent further comprises coal.

Accordingly, in some embodiments, the desulphurization reagent comprises
- desulphurizing compound selected from calcium carbide (CaC2), lime (CaO), and a combination thereof,
- Gilsonite,
- optionally, a slag conditioner selected from a group comprising cryolite, alumina, fluorspar, bauxite, soda ash, borax, and any combination thereof, and
- optionally, coal.

In some embodiments, the desulphurization reagent comprises
- desulphurizing compound selected from calcium carbide (CaC2), lime (CaO), and a combination thereof,
- Gilsonite,
- optionally, a slag conditioner selected from a group comprising cryolite, alumina, fluorspar, bauxite, soda ash, borax, and any combination thereof, and
- coal.

In some embodiments, the desulphurization reagent comprises
- desulphurizing compound selected from calcium carbide (CaC2), lime (CaO), and a combination thereof,
- Gilsonite, and
- coal.

In some embodiments, the desulphurization reagent comprises
- a desulphurizing compound selected from calcium carbide (CaC2), lime (CaO), and a combination thereof,
- Gilsonite,
- a slag conditioner selected from a group comprising cryolite, alumina, fluorspar, bauxite, soda ash, borax, and any combination thereof, and
- coal.

In some embodiments, the desulphurization reagent comprises the desulphurizing compound at a concentration ranging from about 10 wt% to about 97 wt%.

In some embodiments, the desulphurization reagent comprises the desulphurizing compound at a concentration of about 10 wt%, about 15 wt%, about 20 wt%, about 25 wt%, about 30 wt%, about 35 wt%, about 40 wt%, about 45 wt%, about 50 wt%, about 55 wt%, about 60 wt%, about 65 wt%, about 70 wt%, about 75 wt%, about 80 wt%, about 81 wt%, about 82 wt%, about 83 wt%, about 84 wt%, about 85 wt%, about 86 wt%, about 87 wt%, about 88 wt%, about 89 wt%, about 90 wt%, about 91 wt%, about 92 wt%, about 93 wt%, about 94 wt%, about 95 wt%, about 96 wt% or about 97 wt%.

In some embodiments, the desulphurization reagent comprises calcium carbide at a concentration ranging from about 10 wt% to about 60 wt%. In some embodiments, the desulphurization reagent comprises calcium carbide at a concentration of about 10 wt%, about 15 wt%, about 20 wt%, about 25 wt%, about 30 wt%, about 35 wt%, about 40 wt%, about 45 wt%, about 50 wt%, about 55 wt% or about 60 wt%.

In some embodiments, the desulphurization reagent comprises calcium oxide at a concentration ranging from about 20 wt% to about 97 wt%.

In some embodiments, the desulphurization reagent comprises calcium oxide at a concentration of about 20 wt%, about 25 wt%, about 30 wt%, about 35 wt%, about 40 wt%, about 45 wt%, about 50 wt%, about 55 wt%, about 60 wt%, about 65 wt%, about 70 wt%, about 75 wt%,about 80 wt%, about 81 wt%, about 82 wt%, about 83 wt%, about 84 wt%, about 85 wt%, about 86 wt%, about 87 wt%, about 88 wt%, about 89 wt%, about 90 wt%, about 91 wt%, about 92 wt%, about 93 wt%, about 94 wt%, about 95 wt%, about 96 wt% or about 97 wt%.

In some embodiments, the desulphurization reagent comprises Gilsonite at a concentration ranging from about 1 wt% to about 20 wt%.

In some embodiments, the desulphurization reagent comprises Gilsonite at a concentration ranging of about 1 wt%, about 2 wt%, about 3 wt%, about 4 wt%, about 5 wt%, about 6 wt%, about 7 wt%, about 8 wt%, about 9 wt%, about 10 wt%, about 11 wt%, about 12 wt%, about 13 wt%, about 14 wt%, about 15 wt%, about 16 wt%, about 17 wt%, about 18 wt%, about 19 wt% or about 20 wt%.

In some embodiments, the desulphurization reagent comprises the slag conditioner at a concentration ranging from about 0 wt% to about 10 wt %.

In some embodiments, the desulphurization reagent comprises the slag conditioner at a concentration of about 0 wt%, about 1 wt%, about 2 wt%, about 3 wt%, about 4 wt %, about 5 wt%, about 6 wt%, about 7 wt%, about 8 wt %, about 9 wt% or about 10 wt%.

In some embodiments, the desulphurization reagent comprises coal at a concentration ranging from about 0 wt% to about 10%.

In some embodiments, the ingredients/components of the desulphurization reagent defined in terms of absolute wt% values or wt% ranges are such that they make up the total percentage weight of the composition (desulphurization reagent) to 100%. In some embodiments, the reagent is prepared in a pre-blended form and stored for use in the hot metal desulphurization process. In some embodiments, the reagent is prepared as a combination of components stored separately, wherein said components are then directly added to the hot metal desulphurization process.

As mentioned above, one of the objectives of the present disclosure is to achieve enhanced interaction between the desulphurization reagent and the liquid hot metal. The efficiency of the desulphurization process, defined by the amount of Sulphur removed from hot metal, depends on the intensity of interaction between the desulphurization reagent and hot metal.

Enhanced interaction between the desulphurization reagent and the liquid hot metal is achieved by the present disclosure by creating in-situ explosion at or near the lance exits by adding components with high volatile content. In the present disclosure, such components are incorporated into the desulphurization reagent to generate significant amount of volatile matter as soon as it is released into liquid hot metal from the injection lance. Any high volatile content material which has lower impurity levels suits the purpose. A non-limiting example of such a material with high volatile content in the context of the present disclosure is Gilsonite. Gilsonite has higher volatile content (60-80%) compared to conventional additives like coal (~20%). Gilsonite functions as a bath agitator which aids the reaction and facilitates better utilization of desulphurizing reagent. The incorporation of Gilsonite in the reagent of the present invention also leads to reduction in specific consumption of the desulphurising reagent, thereby preserving raw materials used as reagents and reducing slag generation. Employing Gilsonitetherefore also addresses the issue of sustainability. In addition to the above, incorporation of Gilsonite in the desulphurization reagent reduces reliance on coal, without hampering flow properties and with improved efficiency of desulphurization.

In a non-limiting embodiment, the desulphurization reagent has desulphurization efficiency of about 10% to about 100%.

In some embodiments, the desulphurization reagent of the present disclosure shows at least about 30% to about 40% improvement in desulphurization success rate as compared to similar reagents lacking Gilsonite.

The present disclosure also provides a method for preparing the desulphurization reagent as described above, the method comprising:
mixing the desulphurizing compound(s), the Gilsonite and optionally the slag conditioner and/or coal to obtain the desulphurization reagent as described above.

In some embodiments of the above-described method, preparing the desulphurization reagent comprises mixing desulphurizing compound(s) and the Gilsonite.

In some embodiments of the above-described method, preparing the desulphurization reagent comprises mixing the desulphurizing compound(s), the Gilsonite and the slag conditioner.

In some embodiments of the above-described method, preparing the desulphurization reagent comprises mixing the desulphurizing compound(s), the Gilsonite and the coal.

In some embodiments of the above-described method, preparing the desulphurization reagent comprises mixing the desulphurizing compound(s), the Gilsonite, the slag conditioner and the coal.

In some embodiments, the aforesaid method is not restricted by the order of mixing of components. In some embodiments, the desulphurizing compound(s), the Gilsonite and optionally the slag conditioner and/or coal are contacted with each other and mixed sequentially to form the reagent, with no restriction on the order of contacting the respective components. In some embodiments, the desulphurizing compound(s), the Gilsonite and optionally the slag conditioner and/or coal are contacted with each other simultaneously and mixed.

In some embodiments of the above-described method, the contacting and mixing step described above comprises one or more of mixing the components, crushing, grinding, pulverising, or any combination thereof.

In some embodiments, the above-described method is carried out by employing a rod mill, ball mill, blender, crusher, grinder, pulverizer, or any combination thereof.

In some embodiments, the above-described method is carried out in a rod mill, ball mill or blender, or a combination thereof.

In some embodiments of the above-described method, the desulphurizing compound is employed in an amount of about 10 wt% to 97 wt%, the Gilsonite is employed in an amount of about 1 wt% to 20 wt%, the slag conditioner is employed in an amount of about 0 wt% to 10 wt% and the coal is employed in an amount of about 0 wt% to 10 wt%.
In some embodiments of the above-described method, the desulphurizing compound is employed in an amount of about 10 wt% to 97 wt%, the Gilsonite is employed in an amount of about 1 wt% to 20 wt%, the slag conditioner is employed in an amount of about 2 wt% to 10 wt% and the coal is employed in an amount of about 0 wt% to 10 wt%.

In embodiments of the above-described method, the concentrations or wt% of the components of the desulphurization reagent i.e. desulphurizing compound, Gilsonite and optionally, slag conditioner and/or coal are based on the embodiments of the product (desulphurizing reagent) as described above. For the sake of brevity and avoiding repetition, each of those embodiments are not being reiterated here again. However, each of the said embodiments, completely fall within the purview of the method of preparing the desulphurization reagent.

The present disclosure further relates to a process of desulphurization of hot metal during production of steel, the process comprising reacting the desulphurization reagent as described above with the hot metal to obtain desulphurized hot metal and sulfur rich slag.

In some embodiments, in the aforesaid process, the desulphurization reagent may be contacted with the hot metal for desulphurization through one or more of mono-injection process, co-injection process, multi-injection, pouring-over process, ladle top addition or ladle bottom addition. In some embodiments, the process of desulphurization is carried out in single or multiple iterations.

In the mono-injection variant, all the components of the reagent are pre-blended or mixed and stored in a single silo/ day-bin/ transfer dispenser/ injection dispenser and injected in hot metal ladle through a single injection/ single lance/ multi lance system.

In the co-injection and multi-injection variants, the components of the reagent are stored separately in more than one silo/ day-bin/ transfer dispenser/ injection dispenser and injected in hot metal ladle through a co-injection/ single lance system/multi lance system.

In the pouring-over variant of the process, the reagent is stored/dumped at the bottom inside a ladle or any other suitable container and hot metal is poured over it from a torpedo ladle or any other pouring ladle.

In the ladle top addition variant of the process, the reagent is added over the hot metal and the stirring is affected by a gas injection system through top lance or bottom/ side porous plugs or by a mechanical stirring system/impeller.

In the ladle bottom addition variant of the process, the reagent is added through porous plug/ plugs placed at the bottom of the ladle or at the side walls of the ladle with the help of a carrier gas.

In some embodiments, the desulphurization reagent is contacted with the hot metal at a ratio of about 2:1 to about 10:1.

In some embodiments, the desulphurization reagent is contacted with the hot metal at a ratio of about 2:1, about 3:1, about 4:1, about 5:1, about 6:1, about 7:1, about 8:1, about 9:1 or about 10:1.

In some embodiments, the desulphurization reagent is contacted with the hot metal at a temperature ranging from about 1250°C to about 1450°C.

In some embodiments, the desulphurization reagent is contacted with the hot metal at a temperature ranging from about 1250°C, about 1300°C, about 1350°C, about 1400°C or about 1450°C.

In embodiments of the above-described process, the concentrations or wt% of the ingredients/components of the desulphurization reagent i.e. desulphurizing compound, Gilsonite and optionally, slag conditioner and/or coal are based on the embodiments of the product (desulphurizing reagent) as described above. For the sake of brevity and in order to avoid repetition, each of those embodiments are not being reiterated here again. However, each of the said embodiments, completely fall within the purview of the process of desulphurization of hot metal during production of steel.

In some embodiments, the aforesaid method has desulphurization efficiency of about 10% to about 100%.

The present disclosure also relates to use of the desulphurization reagent as described above for desulphurizing hot metal before primary steelmaking.

In some embodiments of the use, the desulphurization reagent removes sulphur from the hot metal during the production of steel resulting in the manufacture of desulphurized or low sulphur steel.

In some embodiments, the desulphurization reagent may be used in different variants of the hot metal desulphurization process.

In some embodiments, the desulphurization reagent is used in a mono-injection process wherein all the components of the reagent are pre-blended or mixed and stored in a single silo/ day-bin/ transfer dispenser/ injection dispenser and injected in hot metal ladle through a single
injection/ single lance/ multi lance system.

In some embodiments, the desulphurization reagent is used in a co-injection process, wherein the components of the reagent are stored separately in more than one silo/ day-bin/ transfer dispenser/ injection dispenser and injected in hot metal ladle through a co-injection/ single lance system/multi lance system.

In some embodiments, the desulphurization reagent is used in pouring-over method in which the reagent is stored/dumped at the bottom inside a ladle or any other suitable container and hot metal is poured over it from a torpedo ladle or any other pouring ladle.

In some embodiments, the desulphurization reagent is used in ladle top addition wherein the reagent is added over the hot metal and the stirring is affected by a gas injection system through top lance or bottom/ side porous plugs or by a mechanical stirring system/impeller.

In some embodiments, the desulphurization reagent is used in ladle bottom addition wherein the reagent is added through porous plug/ plugs placed at the bottom of the ladle or at the side
walls of the ladle with the help of a carrier gas.

In embodiments of the above-described use, the concentrations or wt% of the ingredients/components of the desulphurization reagent i.e. desulphurizing compound, Gilsonite and optionally slag conditioner and/or coal are based on the embodiments of the product (desulphurizing reagent) as described above. For the sake of brevity and in order to avoid repetition, each of those embodiments are not being reiterated here again. However, each of the said embodiments, completely fall within the purview of the process of desulphurization of hot metal during production of steel.

In some embodiments of the use, the present reagent has desulphurization efficiency of about 10% to about 100%.

It is to be understood that the foregoing descriptive matter/embodiments are illustrative of the disclosure and not a limitation. While considerable emphasis has been placed herein on the particular/preferable 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 scope of the embodiments as described herein. Similarly, additional embodiments and features of the present disclosure will be apparent to one of ordinary skill in art based upon description provided herein.

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 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.

While the present disclosure is susceptible to various modifications and alternative forms, specific aspects thereof have been shown by way of examples and drawings and are described in detail below. However, it should be understood that it is not intended to limit the invention to the particular forms disclosed, but on the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the spirit and the scope of the invention as defined by the appended claims.

EXAMPLES
The present disclosure is further described with reference to the following examples, which are only illustrative in nature and should not be construed to limit the scope of the present disclosure in any manner.

Example 1: Preparation and Properties of Desulphurization Reagent
Different desulphurization reagents falling within the purview of the reagent as described above were prepared by adding varying concentrations of desulphurization compound, slag conditioner, coal and Gilsonite.

The prepared desulphurization reagent formulations were as follows:

Table 1:
COMPOSITION
DS1 DS2
DS3
DS4 DS5
COMPONENTS

Calcium carbide (wt%) 40 40 40 40 40
Lime
(wt%) 50 50 50 50 50
Gilsonite (wt%) 1 2 3 4 5
Slag conditioner – cryolite (wt%) 5 5 5 5 5
Coal (wt%) 4 3 2 1 0

Example 2: Desulphurization of Hot Metal (HMDS, lab scale)

Five laboratory scale experiments, with five different samples were executed with desulphurization reagents comprising Gilsonite or coal at different concentrations (about 1 wt% and about 2 wt%) in combination with about 30-40% of calcium carbide, about 54-64% of lime and about 4-5% of slag conditioner cryolite to check the effect on flow properties of the material. The observations are provided in the Table 2 below –

Table 2:
Lab scale trial Experiment 1 Experiment 2 Experiment 3 Experiment 4
Melt agitator employed Gilsonite Gilsonite Coal Coal
Wt % of melt agitator 2% 1% 2% 1%
Flow Index Value
Sample 1 0.27 0.28 0.29 0.35
Sample 2 0.27 0.29 0.31 0.31
Sample 3 0.29 0.28 0.29 0.31
Sample 4 0.27 0.26 0.30 0.32
Sample 5 0.28 0.27 0.30 0.32
Average 0.28 0.28 0.30 0.32

It was found through results of the experiments that better flow properties were achieved by desulphurization reagents employing Gilsonite as compared to coal (Figs.1 and 2).

Example 3: Desulphurization of Hot Metal (HMDS, plant scale)
The process for desulphurization of hot metal (HMDS) was performed as follows:

1. Desulphurization Reagent was stored in the injection dispenser;
2. The reagent was passed pneumatically through refractory lance;
3. Refractory lance was held by a metal rod;
4. Reagent passed through the bottom or side hole of the refractory lance into the hot metal ladle; and
5. The injected material reacts with sulphur and performs desulphurisation.

The trial conditions/parameters are further indicated in Table 3 below.

Table 3:
Flow rate 20-26 kg/min
Consumption pattern (kg/THM ) 5.32
Liquid metal Temperature range(degree Celsius) 1355-1377
In order to understand the effect of employment of Gilsonite in the Desulphurization Reagent of the present invention, desulphurization reactions were carried out using the desulphurization reagents of the present disclosure comprising Gilsonite and a variant thereof lacking Gilsonite. Observations from the said trials are provided in Table 4 below –

Table 4:
Parameters Desulphurization reagent of the present disclosure with Gilsonite (DS3) Desulphurization reagent
without Gilsonite
Count of Heat 95 84
Success rate +1, % 40 30
Av Sulphur after Desulphurisation treatment (%) 0.008 0.0085
Av Sulphur before Desulphurisation treatment (%) 0.056 0.0585
Initial Hot Metal-Temperature, °C 1337 1335

The above results demonstrate that the desulphurization efficiency of the present desulphurization reagents was better or at least at par compared to conventional reagent (i.e. desulphurization reagent lacking Gilsonite).

Additionally, apart from the desulphurization reagents described above which show desired/superior properties, any alternate desulphurization reagents developed with concentration of Gilsonite exceeding 20 wt% is not expected to be effective in achieving desired desulphurization efficiency during HMDS because greater amounts of Gilsonite means accommodating lesser amounts of desulphurizing compounds (CaC2 and/or CaO) which inherently leads to lower desulphurization efficiency during HMDS. Hence, the wt% of Gilsonite between 1 wt% to 20 wt% is desirable in the desulphurization reagent of the present disclosure.

Overall, the desulphurization reagent of the present disclosure comprising Gilsonite was found to be superior or at least at par when employed in HMDS process compared to conventional reagents lacking gilsonite.
All references, articles, publications, general disclosures etc. cited herein are incorporated by reference in their entireties for all purposes. However, mention of any reference, article, publication etc. 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.
,CLAIMS:We Claim:

1. A desulphurization reagent comprising:
- desulphurizing compound selected from calcium carbide (CaC2), lime (CaO), and a combination thereof,
- Gilsonite, and
- optionally, slag conditioner.

2. The desulphurization reagent as claimed in claim 1, wherein the slag conditioner is selected from cryolite, alumina, fluorspar, bauxite, soda ash, borax, and any combination thereof.

3. The desulphurization reagent as claimed in claim 1, wherein the reagent further comprises coal.

4. The desulphurization reagent as claimed in any of claims 1-3, wherein said desulphurization reagent is selected from:

i) a) desulphurizing compound which is calcium carbide (CaC2), and
b) Gilsonite,

ii) a) desulphurizing compound which is calcium carbide (CaC2),
b) Gilsonite, and
c) slag conditioner;

iii) a) desulphurizing compound which is lime (CaO), and
b) Gilsonite;

iv) a) desulphurizing compound which is lime (CaO),
b) Gilsonite, and
c) slag conditioner;

v) a) desulphurizing compound which is a combination of calcium carbide (CaC2) and lime (CaO), and
b) Gilsonite;
vi) a) desulphurizing compound which is a combination of calcium carbide (CaC2) and lime (CaO),
b) Gilsonite, and
c) slag conditioner;

vii) a) desulphurizing compound which is calcium carbide (CaC2),
b) Gilsonite, and
c) coal;

viii) a) desulphurizing compound which is calcium carbide (CaC2),
b) Gilsonite,
c) slag conditioner; and
d) coal;

ix) a) desulphurizing compound which is lime (CaO),
b) Gilsonite; and
c) coal;

x) a) desulphurizing compound which is lime (CaO),
b) Gilsonite,
c) slag conditioner; and
d) coal;

xi) a) desulphurizing compound which is a combination of calcium carbide (CaC2) and lime (CaO),
b) Gilsonite, and
c) coal;
or
xii) a) desulphurizing compound which is a combination of calcium carbide (CaC2) and lime (CaO),
b) Gilsonite,
c) slag conditioner, and
d) coal.
5. The desulphurization reagent as claimed in any of the claims 1 to 4, wherein the desulphurizing compound is present in an amount of about 10 wt% to 97 wt%, Gilsonite is present in an amount of about 1 wt% to 20 wt%, the slag conditioner is present in an amount of about 0 wt% to 10wt% and the coal is present in an amount of about 0 wt% to 10wt%.

6. The desulphurization reagent as claimed in claim 1, wherein the reagent comprises:
- calcium carbide (CaC2) at 10 wt% to 60 wt%,
- lime (CaO) at 20 wt% to 97 wt%,
- Gilsonite at 1 wt% to 20 wt%,
- optionally, a slag conditioner at 0 wt% to 20 wt%, and
- optionally, coal at 0 wt% to 10 wt%.

7. A method for preparing the desulphurization reagent as claimed in any of the claims 1 to 6, the method comprising
mixing the desulphurizing compound(s), the Gilsonite and optionally the slag conditioner and/or coal to obtain the desulphurization reagent

8. The method as claimed in claim 7, wherein the mixing step comprises mixing the components, crushing, grinding, pulverising, or any combination of said techniques; and wherein said mixing is carried out by employing a ball mill, blender, crusher, grinder, pulverizer, or any combination thereof.

9. The method as claimed in claim 7, wherein the desulphurizing compound is employed at an amount of about 10 wt% to 97 wt%, Gilsonite is employed at an amount of about 1 wt% to 20 wt%, the slag conditioner is employed at an amount of about 0 wt% to 10wt% and the coal is employed at an amount of about 0 wt% to 10wt%.

10. A process of desulphurization of hot metal during production of steel, the process comprising reacting the desulphurization reagent as claimed in any of the claims 1 to 6 with the hot metal to obtain desulphurized metal and sulphur rich slag.

11. The process as claimed in claim 10, wherein the desulphurization reagent is contacted with the hot metal for desulphurization through one or more of mono-injection process, co-injection process, multi-injection, pouring-over process, ladle top addition or ladle bottom addition.

12. The process as claimed in claim 10, wherein the desulphurization reagent is contacted with the hot metal at a ratio of about 2:1 to about 10:1.

13. The process as claimed in claim 10, wherein the presence of Gilsonite in the desulphurization reagent increases the desulphurization efficiency compared to a desulphurization reagent lacking Gilsonite; and wherein the desulphurization efficiency of the process is about 10% to 100%.

14. The process as claimed in claim 13, wherein the presence of Gilsonite in the desulphurization reagent increases the desulphurization efficiency by at least about 30% to about 40% as compared to a desulphurization reagent lacking Gilsonite.

Dated this 22nd day of October 2020