DESC:TECHNICAL FIELD
The present disclosure is in the field of metallurgy and desulphurization materials. The disclosure relates to desulphurization reagent comprising soda glass 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.

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) 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 are 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 reagent reaction. 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, some of which are described below:
a) the current desulphurization reagents contain elements or compounds which create health and environmental hazards. Particularly, the current desulphurization reagents contain fluorine-based compounds as slag fluidizers (eg. cryolite which contains about 50% fluorine). Such conventional slag fluidizers containing fluorine when used in desulphurizing reagent and subsequently injected through the lance in the hot metal ladle during desulphurization process generate fumes containing the harmful fluorine gas. This fluorine gas is harmful to human health and also poses safety risks to environment.

Following are the health hazards related to fluorine gas exposure:
- fluorine is an extremely strong irritant to all tissues it comes in contact with.
- fluorine can cause injury ranging from mild irritation to caustic burns depending on the concentration of the gas at the time of exposure.
- fluorine is a very severe irritant of the lungs, mucous membranes, skin and eyes.
- fluorine can also cause death when exposed at high concentrations.

Following are the environment hazards related to fluorine gas exposure:
- plants that are sensitive to fluorine exposure even low concentrations of fluorine can cause damage and a decline in its growth.
- too much fluoride whether taken in the form of soil by roots or adsorbed from the atmosphere by the leaves, retards the growth of plants and reduces crop yields. The plants more affected are corns and apricots.
- needless to say, high fluorine presence can cause severe long-term pollution/environmental effects.

b) most of the currently employed desulphurization reagents are very expensive.

c) all the desulphurizing reagents are not equally effective in their ability to remove sulphur. For instance, calcium carbide has more potential to remove sulphur than lime. However, it cannot be injected into hot metal on its own and must be blended with volatiles in order to increase the agitation of the bath. On the other hand, pre-blending of different desulphurizing reagents such as magnesium-lime or magnesium-calcium carbide is less effective since blended reagents are prone to segregation during transport and storage besides individual injection rates of desulphurizing reagents get sacrificed.

d) the removal of slag is difficult due to its viscous nature and lot of iron particles are thus carried away or lost during slag off.

e) the efficiency of desulphurization process is limited due to inadequate removal of reaction product from the reaction site due to lack of fluidity of the slag.

f) the efficiency of the desulphurization process also gets affected due to inadequate removal of silicate layers formed on the lime particle.

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.

STATEMENT OF THE DISCLOSURE
The present disclosure relates to a desulphurization reagent comprising:
- a desulphurizing compound selected from calcium carbide (CaC2), lime (CaO), and a combination thereof,
- soda glass, and
- optionally, a slag fluidizer, a bath agitator, or a combination thereof.

The present disclosure also relates to a method for preparing the desulphurization reagent as defined above, the method comprising:
a) mixing desulphurizing compound, soda glass, and optionally slag fluidizer and/or bath agitator; or
b) adding soda glass to: i) desulphurizing compound, or ii) a mixture comprising desulphurizing compound and at least one compound selected from slag fluidizer and bath agitator, to obtain the desulphurization reagent as defined above.

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 defined above with the hot metal to obtain desulphurized metal and sulphur rich slag.

BRIEF DESCRIPTION OF THE ACCOMPANYING FIGURE
Figure 1 depicts the results of granulometry and flow property test (Flow Index) of the desulphurization reagents of present disclosure and conventional reagents.

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 “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 soda glass which can be employed for hot metal desulphurization process (removal of sulphur from hot metal which is obtained during the process of steel making).

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

Another objective of the present disclosure is to reduce or eliminate the use of expensive conventional slag fluidisers currently used in desulphurization of hot metal (HMDS).

Another object of the present disclosure is to reduce or eliminate the risk of environmental hazards associated with the currently used/conventional slag fluidisers.

Yet another objective of the present disclosure is to employ an alternate material which can perform the function of slag fluidiser, thereby reducing the need or use of conventional slag fluidisers in HMDS.

Still another objective of the present disclosure is to develop an alternate material for slag fluidizing function to partially or fully replace the currently used/conventional slag fluidizers.

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 better or at least equivalent process efficiency compared to conventional desulphurization reagent.

In order to address the concerns mentioned above and to meet the aforesaid objectives, the present disclosure provides soda glass as a partial replacement of conventional/currently used slag fluidizers in desulphurisation reagent.

Accordingly, the present disclosure provides a desulphurization reagent comprising:
- a desulphurizing compound,
- soda glass, and
- optionally, a conventional slag fluidizer, a bath agitator, or a combination thereof.

In some embodiments, the present disclosure provides a desulphurization reagent comprising:
- a desulphurizing compound selected from calcium carbide (CaC2), lime (CaO), and a combination thereof,
- soda glass, and
- optionally, a slag fluidizer, a bath agitator, or a combination thereof.

In some embodiments, the present disclosure provides a desulphurization reagent comprising:
- a desulphurizing compound which is calcium carbide (CaC2), lime (CaO), and a combination thereof,
- soda glass, and
- optionally, a slag fluidizer, a bath agitator, or a combination thereof,
wherein the slag fluidizer is selected from cryolite, alumina, fluorspar, bauxite, soda ash, borax, and any combination thereof; and the bath agitator is selected from coal, magnesium, coke, gilsonite, and any combination thereof.

In some embodiments, the present disclosure provides a desulphurization reagent comprising:
- a desulphurizing compound which is calcium carbide (CaC2) and lime (CaO),
- soda glass,
- a bath agitator which is coal, magnesium, coke, gilsonite, or any combination thereof,
- optionally, a slag fluidizer, selected from cryolite, alumina, fluorspar, bauxite, soda ash, borax, and any combination thereof.

In some embodiments, the present disclosure provides a desulphurization reagent comprising:
- a desulphurizing compound which is lime (CaO),
- soda glass, and
- optionally, a slag fluidizer, a bath agitator, or a combination thereof,
wherein the slag fluidizer is selected from cryolite, alumina, fluorspar, bauxite, soda ash, borax, and any combination thereof; and the bath agitator is selected from coal, magnesium, coke, gilsonite, and any combination thereof.

In some embodiments, the present disclosure provides a desulphurization reagent comprising:
- a desulphurizing compound which is lime (CaO),
- soda glass, and
- optionally a slag fluidizer selected from cryolite, alumina, fluorspar, bauxite, soda ash, borax, or any combination thereof.

In some embodiments, the present disclosure provides a desulphurization reagent selected from:
i) a) desulphurizing compound which is calcium carbide (CaC2) and lime (CaO),
b) soda glass,
c) slag fluidizer which is cryolite, and
d) bath agitator which is coal;

ii) a) desulphurizing compound which is calcium carbide (CaC2) and lime (CaO),
b) soda glass, and
c) bath agitator which is coal;

iii) a) desulphurizing compound which is calcium carbide (CaC2) and lime (CaO), and
b) soda glass;

iv) a) desulphurizing compound which is calcium carbide (CaC2), and
b) soda glass;

v) a) desulphurizing compound which is lime (CaO),
b) soda glass, and
c) slag fluidizer which is cryolite;

vi) a) desulphurizing compound which is lime (CaO), and
b) soda glass;

and

vii) a) desulphurizing compound which is lime (CaO),
b) soda glass,
c) slag fluidizer which is cryolite, and
d) bath agitator which is coal.

In some embodiments of the desulphurization reagent of the present disclosure, the desulphurizing compound and soda glass are mandatory components/ingredients, and the slag fluidizer and/or the bath agitator are optionally present. In other words, the desulphurization reagent of the present disclosure comprises desulphurizing compound and soda glass with slag fluidizer and/or the bath agitator being optionally present.

In some embodiments, the desulphurizing compound is present in an amount of about 5 wt% to 96 wt%, soda glass is present in an amount of about 0.1 wt% to 15 wt%, the slag fluidizer is present in an amount of about 0.1 wt% to 15 wt%, and the bath agitator is present in an amount of about 0.1 wt% to 10 wt%, including all values and sub-ranges therebetween.

In some embodiments, the desulphurizing compound is present in an amount of about 20 wt% to 96 wt%, soda glass is present in an amount of about 1 wt% to 4 wt%, the slag fluidizer is present in an amount of about 1 wt% to 8 wt%, and the bath agitator is present in an amount of about 2 wt% to 8 wt%, including all values and sub-ranges therebetween.

In some embodiments, the desulphurization reagent comprises:
- calcium carbide (CaC2) at 5 wt% to 55 wt%,
- lime (CaO) at 45 wt% to 85 wt%,
- soda glass at 0.1 wt% to 15 wt%, and
- optionally, a slag fluidizer at 0.1 wt% to 15 wt%, or a bath agitator at 0.1 wt% to 10 wt%, or a combination of slag fluidizer and bath agitator thereof, including all values and sub-ranges therebetween.

In some embodiments, the desulphurization reagent comprises:
- calcium carbide (CaC2) at 5 wt% to 55 wt%,
- lime (CaO) at 45 wt% to 85 wt%,
- soda glass at 0.1 wt% to 15 wt%,
- slag fluidizer at 0.1 wt% to 15 wt%, and
- bath agitator at 0.1 wt% to 10 wt%, including all values and sub-ranges therebetween.

In some embodiments, the desulphurization reagent comprises:
- calcium carbide (CaC2) at 5 wt% to 55 wt%,
- lime (CaO) at 45 wt% to 85 wt%,
- soda glass at 0.1 wt% to 15 wt%, and
- bath agitator at 0.1 wt% to 10 wt%, including all values and sub-ranges therebetween.

In some embodiments, the desulphurization reagent comprises:
- calcium carbide (CaC2) at about 20 wt%,
- lime (CaO) at about 70 wt%,
- soda glass at 1 to 4 wt%,
- cryolite at 1 to 4 wt%, and
- coal at 5 wt%.

In some embodiments, the desulphurization reagent comprises:
- calcium carbide (CaC2) at about 20 wt%,
- lime (CaO) at about 70 wt%,
- soda glass at 1 wt%,
- cryolite at 4 wt%, and
- coal at 5 wt%.

In some embodiments, the desulphurization reagent comprises:
- calcium carbide (CaC2) at about 20 wt%,
- lime (CaO) at about 70 wt%,
- soda glass at 2 wt%,
- cryolite at 3 wt%, and
- coal at 5 wt%.

In some embodiments, the desulphurization reagent comprises:
- calcium carbide (CaC2) at about 20 wt%,
- lime (CaO) at about 70 wt%,
- soda glass at 3 wt%,
- cryolite at 2 wt%, and
- coal at 5 wt%.

In some embodiments, the desulphurization reagent comprises:
- calcium carbide (CaC2) at about 20 wt%,
- lime (CaO) at about 70 wt%,
- soda glass at 4 wt%, and
- coal at 5 wt%.

In some embodiments, the desulphurization reagent comprises:
- lime (CaO) at 65 wt% to 95 wt%,
- soda glass at 0.1 wt% to 15 wt%, and
- optionally a slag fluidizer at 0.1 wt% to 15 wt%, including all values and sub-ranges therebetween.

In some embodiments, the desulphurization reagent comprises:
- lime (CaO) at about 95 wt%,
- soda glass at 1 to 4 wt%, and
- cryolite at 1 to 4 wt%.

In some embodiments, the desulphurization reagent comprises:
- lime (CaO) at about 95 wt%,
- soda glass at 2 wt%, and
- cryolite at 3 wt%.

In some embodiments, the desulphurization reagent comprises:
- lime (CaO) at about 95 wt%,
- soda glass at 3 wt%, and
- cryolite at 2 wt%.

In some embodiments, the desulphurization reagent comprises:
- lime (CaO) at about 95 wt%,
- soda glass at 4 wt%, and
- cryolite at 1 wt%.

In some embodiments, the desulphurization reagent comprises:
- lime (CaO) at about 96 wt%, and
- soda glass at 4 wt%.

In some embodiments, the desulphurization reagent comprises soda glass in an amount of about 0.1 wt%, 0.5 wt%, 1 wt%, 1.5 wt%, 2 wt%, 2.5 wt%, 3 wt%, 3.5 wt%, 4 wt%, 4.5 wt%, 5 wt%, 5.5 wt%, 6 wt%, 6.5 wt%, 7 wt%, 7.5 wt%, 8 wt%, 8.5 wt%, 9 wt%, 9.5 wt%, 10 wt%, 10.5 wt%, 11 wt%, 11.5 wt%, 12 wt%, 12.5 wt%, 13 wt%, 13.5 wt%, 14 wt%, 14.5 wt% or 15 wt%, including values therebetween.

In embodiments of the present disclosure, 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 of the desulphurization reagent, the soda glass has a composition comprising:
- silica (SiO2) at about 50 wt% to 80 wt%,
- sodium oxide (Na2O) at about 5 wt% to 20 wt%,
- calcium oxide (CaO) at about 5 wt% to 15 wt%,
- magnesium oxide (MgO) at about 2 wt% to 10 wt %, and
- trace elements/compounds comprising aluminum oxide (Al2O3), ferric oxide (Fe2O3), titanium dioxide (TiO2) and potassium oxide (K2O) at about 0.01 wt% to 2 wt%, including all values and sub-ranges therebetween.

In embodiments of the present disclosure, the ingredients/components of the soda glass defined in terms of absolute wt% values or wt% ranges are such that they make up the total percentage weight of the composition (soda glass) to 100%.

In some embodiments of the desulphurization reagent, the soda glass has a composition comprising:
- silica (SiO2) at about 73 wt%,
- sodium oxide (Na2O) at about 14 wt%,
- calcium oxide (CaO) at about 8 wt%,
- magnesium oxide (MgO) at about 4 wt%, and
- trace compounds comprising aluminum oxide (Al2O3), ferric oxide (Fe2O3), titanium dioxide (TiO2) and potassium oxide (K2O) at about 1 wt%.

In some embodiments, the desulphurization reagent comprises:
- calcium carbide (CaC2) at 5 wt% to 55 wt%,
- lime (CaO) at 45 wt% to 85 wt%,
- soda glass at 0.1 wt% to 15 wt%,
- slag fluidizer at 0.1 wt% to 15 wt%, and
- bath agitator at 0.1 wt% to 10 wt%;
wherein the soda glass has a composition comprising:
- silica (SiO2) at about 50 wt% to 80 wt%,
- sodium oxide (Na2O) at about 5 wt% to 20 wt%,
- calcium oxide (CaO) at about 5 wt% to 15 wt%,
- magnesium oxide (MgO) at about 2 wt% to 10 wt %, and
- trace elements/compounds comprising aluminum oxide (Al2O3), ferric oxide (Fe2O3), titanium dioxide (TiO2) and potassium oxide (K2O) at about 0.01 wt% to 2 wt%.

In some embodiments, the desulphurization reagent comprises:
- calcium carbide (CaC2) at 5 wt% to 55 wt%,
- lime (CaO) at 45 wt% to 85 wt%,
- soda glass at 0.1 wt% to 15 wt%, and
- bath agitator at 0.1 wt% to 10 wt%;
wherein the soda glass has a composition comprising:
- silica (SiO2) at about 50 wt% to 80 wt%,
- sodium oxide (Na2O) at about 5 wt% to 20 wt%,
- calcium oxide (CaO) at about 5 wt% to 15 wt%,
- magnesium oxide (MgO) at about 2 wt% to 10 wt %, and
- trace elements/compounds comprising aluminum oxide (Al2O3), ferric oxide (Fe2O3), titanium dioxide (TiO2) and potassium oxide (K2O) at about 0.01 wt% to 2 wt%.

In some embodiments, the desulphurization reagent comprises:
- lime (CaO) at 65 wt% to 96 wt%,
- soda glass at 0.1 wt% to 15 wt%, and
- slag fluidizer at 0.1 wt% to 15 wt%;
wherein the soda glass has a composition comprising:
- silica (SiO2) at about 50 wt% to 80 wt%,
- sodium oxide (Na2O) at about 5 wt% to 20 wt%,
- calcium oxide (CaO) at about 5 wt% to 15 wt%,
- magnesium oxide (MgO) at about 2 wt% to 10 wt %, and
- trace elements/compounds comprising aluminum oxide (Al2O3), ferric oxide (Fe2O3), titanium dioxide (TiO2) and potassium oxide (K2O) at about 0.01 wt% to 2 wt%.

In some embodiments, the desulphurization reagent comprises:
- lime (CaO) at 65 wt% to 96 wt%, and
- soda glass at 0.1 wt% to 15 wt%,
wherein the soda glass has a composition comprising:
- silica (SiO2) at about 50 wt% to 80 wt%,
- sodium oxide (Na2O) at about 5 wt% to 20 wt%,
- calcium oxide (CaO) at about 5 wt% to 15 wt%,
- magnesium oxide (MgO) at about 2 wt% to 10 wt %, and
- trace elements/compounds comprising aluminum oxide (Al2O3), ferric oxide (Fe2O3), titanium dioxide (TiO2) and potassium oxide (K2O) at about 0.01 wt% to 2 wt%.

The present disclosure also provides a method for preparing the desulphurization reagent as described above, the method comprising:
a) mixing desulphurizing compound, soda glass, and optionally slag fluidizer and/or bath agitator; or
b) adding soda glass to: i) desulphurizing compound, or ii) a mixture comprising desulphurizing compound and at least one compound selected from slag fluidizer and bath agitator, to obtain the desulphurization reagent as described above.

In some embodiments of the above described method, preparing the desulphurization reagent comprises mixing desulphurizing compound, soda glass, and optionally slag fluidizer and/or bath agitator.

In some embodiments of the above described method, preparing the desulphurization reagent comprises adding soda glass to the desulphurizing compound.

In some embodiments of the above described method, preparing the desulphurization reagent comprises adding soda glass to a mixture comprising desulphurizing compound and at least one compound selected from slag fluidizer and bath agitator.

In some embodiments of the above described method, the mixing or adding step comprises mixing the ingredients, crushing, grinding, pulverising, or any combination of techniques thereof.

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

In some embodiments of the above described method, the mixing or adding is carried out in a 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 5 wt% to 96 wt%, soda glass is employed in an amount of about 0.1 wt% to 15 wt%, the slag fluidizer is employed in an amount of about 0.1 wt% to 15 wt%, and bath agitator is employed in an amount of about 0.1 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, soda glass, slag fluidizer and bath agitator are based on the embodiments of the product (desulphurization 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 metal and sulfur rich slag.

In some embodiments of the above described process of desulphurization of hot metal, the desulphurizing compound is employed in an amount of about 5 wt% to 96 wt%, soda glass is employed in an amount of about 0.1 wt% to 15 wt%, the slag fluidizer is employed in an amount of about 0.1 wt% to 15 wt%, and bath agitator is employed in an amount of about 0.1 wt% to 10 wt%.

In some embodiments of the above described process of desulphurization of hot metal, the desulphurization reagent comprises:
- calcium carbide (CaC2) at 5 wt% to 55 wt%,
- lime (CaO) at 45 wt% to 85 wt%,
- soda glass at 0.1 wt% to 15 wt%,
- slag fluidizer at 0.1 wt% to 15 wt%, and
- bath agitator at 0.1 wt% to 10 wt%;
wherein the soda glass has a composition comprising:
- silica (SiO2) at about 50 wt% to 80 wt%,
- sodium oxide (Na2O) at about 5 wt% to 20 wt%,
- calcium oxide (CaO) at about 5 wt% to 15 wt%,
- magnesium oxide (MgO) at about 2 wt% to 10 wt %, and
- trace elements/compounds comprising aluminum oxide (Al2O3), ferric oxide (Fe2O3), titanium dioxide (TiO2) and potassium oxide (K2O) at about 0.01 wt% to 2 wt%.

In some embodiments of the above described process of desulphurization of hot metal, the desulphurization reagent comprises:
- calcium carbide (CaC2) at 5 wt% to 55 wt%,
- lime (CaO) at 45 wt% to 85 wt%,
- soda glass at 0.1 wt% to 15 wt%, and
- bath agitator at 0.1 wt% to 10 wt%;
wherein the soda glass has a composition comprising:
- silica (SiO2) at about 50 wt% to 80 wt%,
- sodium oxide (Na2O) at about 5 wt% to 20 wt%,
- calcium oxide (CaO) at about 5 wt% to 15 wt%,
- magnesium oxide (MgO) at about 2 wt% to 10 wt %, and
- trace elements/compounds comprising aluminum oxide (Al2O3), ferric oxide (Fe2O3), titanium dioxide (TiO2) and potassium oxide (K2O) at about 0.01 wt% to 2 wt%.

In some embodiments of the above described process of desulphurization of hot metal, the desulphurization reagent comprises:
- lime (CaO) at 65 wt% to 96 wt%,
- soda glass at 0.1 wt% to 15 wt%, and
- slag fluidizer at 0.1 wt% to 15 wt%;
wherein the soda glass has a composition comprising:
- silica (SiO2) at about 50 wt% to 80 wt%,
- sodium oxide (Na2O) at about 5 wt% to 20 wt%,
- calcium oxide (CaO) at about 5 wt% to 15 wt%,
- magnesium oxide (MgO) at about 2 wt% to 10 wt %, and
- trace elements/compounds comprising aluminum oxide (Al2O3), ferric oxide (Fe2O3), titanium dioxide (TiO2) and potassium oxide (K2O) at about 0.01 wt% to 2 wt%.

In some embodiments of the above described process of desulphurization of hot metal, the desulphurization reagent comprises:
- lime (CaO) at 65 wt% to 96 wt%, and
- slag fluidizer at 0.1 wt% to 15 wt%;
wherein the soda glass has a composition comprising:
- silica (SiO2) at about 50 wt% to 80 wt%,
- sodium oxide (Na2O) at about 5 wt% to 20 wt%,
- calcium oxide (CaO) at about 5 wt% to 15 wt%,
- magnesium oxide (MgO) at about 2 wt% to 10 wt %, and
- trace elements/compounds comprising aluminum oxide (Al2O3), ferric oxide (Fe2O3), titanium dioxide (TiO2) and potassium oxide (K2O) at about 0.01 wt% to 2 wt%.

In embodiments of the above described process, the concentrations or wt% of the ingredients/components of the desulphurization reagent i.e. desulphurizing compound, soda glass, slag fluidizer and bath agitator are based on the embodiments of the product (desulphurizing compound) 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 process of desulphurization of hot metal during production of steel.

In some embodiments of the above described process, the presence of soda glass in the desulphurization reagent increases the desulphurization efficiency compared to a desulphurization reagent lacking soda glass.

In some embodiments of the above described process, the desulphurization efficiency of the process is about 95% to 100%.

In some embodiments of the above described process, the process results in a pot loss of about 7 kg/thm to 15 kg/thm.

Without wishing to be bound by any theory, the present inventors hypothesize that the presence of soda glass in the desulphurization reagent improves the slag fluidizing function of the reagent based on the following:
1. Soda glass contains sodium oxide (Na2O) which is an effective silicate network breaker. Sodium oxide provides O2- free ions, causing depolymerization of highly crystalline network, thereby lowers slag viscosity and fluidizes the slag.
2. Soda glass addition leads to no fume generation as it doesn’t contain any fume generating agent like fluorine or CO2, when compared to addition of conventional slag fluidizer compounds such as soda ash or fluoride-based compounds.
3. Soda glass addition does not create any endothermic reaction unlike addition of conventional slag fluidizer compounds such as soda ash. Endothermic reactions are undesirable during desulphurization process.
4. By employing soda glass, vaporisation loss is minimal as all Na2O is a part of slag structure.
5. Soda glass further helps in desulphurisation as it contains Na2O.
6. Soda glass is free from fluorine. Therefore, it is non-hazardous and more environment friendly.

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 of the use, the present reagent has desulphurization efficiency of about 95% to 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.

EXAMPLES
Example 1: Preparation and Properties of Desulphurization Reagent
9 different desulphurization reagent recipes were prepared by adding different percentages of soda glass (1%, 2%, 3% and 4%) by using lab scale ball mill and blender. The soda glass had composition comprising: silica (SiO2) at about 50 wt% to 80 wt%, sodium oxide (Na2O) at about 5 wt% to 20 wt%, calcium oxide (CaO) at about 5 wt% to 15 wt%, magnesium oxide (MgO) at about 2 wt% to 10 wt%, and trace compounds comprising aluminum oxide (Al2O3), ferric oxide (Fe2O3), titanium dioxide (TiO2) and potassium oxide (K2O) at about 0.01 wt% to 2 wt%. Preferably, the soda glass had the composition comprising: silica at about 73 wt%, sodium oxide at about 14 wt%, calcium oxide at about 8 wt%, magnesium oxide at about 4 wt%, and trace compounds comprising aluminum oxide, ferric oxide, titanium dioxide and potassium oxide at about 1 wt%.

The prepared desulphurization reagent formulations were as follows:

Desulphurization Reagent 1 (DS1)
- calcium carbide (CaC2) at about 20 wt%,
- lime (CaO) at about 70 wt%,
- soda glass at 1 wt%,
- cryolite_at 4 wt%, and
- coal at 5 wt%.

Desulphurization Reagent 2 (DS2)
- calcium carbide (CaC2) at about 20 wt%,
- lime (CaO) at about 70 wt%,
- soda glass at 2 wt%,
- cryolite at 3 wt%, and
- coal at 5 wt%.

Desulphurization Reagent 3 (DS3)
- calcium carbide (CaC2) at about 20 wt%,
- lime (CaO) at about 70 wt%,
- soda glass at 3 wt%,
- cryolite at 2 wt%, and
- coal at 5 wt%.

Desulphurization Reagent 4 (DS4)
- calcium carbide (CaC2) at about 20 wt%,
- lime (CaO) at about 70 wt%,
- soda glass at 4 wt%,
- cryolite at 1 wt%, and
- coal at 5 wt%.

Desulphurization Reagent 5 (DS5)
- calcium carbide (CaC2) at about 20 wt%,
- lime (CaO) at about 71 wt%,
- soda glass at 4 wt%, and
- coal at 5 wt%.

Desulphurization Reagent 6 (DS6)
- lime (CaO) at about 95 wt%,
- soda glass at 2 wt%, and
- cryolite at 3 wt%

Desulphurization Reagent 7 (DS7)
- lime (CaO) at about 95 wt%,
- soda glass at 3 wt%, and
- cryolite at 2 wt%

Desulphurization Reagent 8 (DS8)
- lime (CaO) at about 95 wt%,
- soda glass at 4 wt%, and
- cryolite at 4 wt%

Desulphurization Reagent 9 (DS9)
- lime (CaO) at about 96 wt%, and
- soda glass at 4 wt%,

All the 9 desulphurization reagents of the present disclosure were tested for properties such as granulometry, flow property test (Flow Index) and the results were compared with a desulphurization reagent lacking soda glass (referred as ‘conventional desulphurization reagent’ or ‘conventional reagent’). Said conventional reagents which lack soda glass had the following compositions:

Conventional Reagent 1:
- calcium carbide (CaC2) at about 20 wt%,
- lime (CaO) at about 71 wt%,
- cryolite at 4 wt%, and
- coal at 5 wt%.

Conventional Reagent 2:
- lime (CaO) at about 96 wt%, and
- cryolite at 4 wt%,

The results of the different recipes are represented by graphs as shown in Figures 1A, 1B, 1C and 1D, respectively. As observed from these figures, there was no significant difference in both flow index and granulometry of conventional reagent (lacking soda glass) and the present desulphurization reagent (DS1 to DS9) which contains soda glass as a partial or complete replacement of conventional slag fluidiser. In other words, the present desulphurization reagent showed desired properties making it suitable for further assessment, especially in HMDS. Hence, the present desulphurization reagents were taken for small scale industrial trials to further evaluate other properties such as efficiency in HMDS.

Example 2: Desulphurization of Hot Metal (HMDS)
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 bar;
4. Reagent passed through the bottom 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 1 below.

Table-1
Consideration Present Desulphurization Reagent

DS1 DS2 DS3 DS6
Replacement of conventional slag fluidizer
(cryolite) 0% 25% 50% 25%
Soda glass 1% 2% 3% 2%

Flow rate 35-40 kg/min 30-35 kg/min
Consumption pattern (kg/THM PPSD) 0.086 0.053
Liquid metal Temperature range 1350-1420 1350-1420

The above described reagents were tested at different stages under two different industrial conditions. The efficiency of the present desulphurization reagents were measured and compared with the conventional reagent in terms of desulphurization (DS) success rate, pot loss and FeO content in slag. The consumption pattern was measured in kg/thm PPSD. It is calculated based on the amount of reagent added to remove per point sulphur in 1MT during desulphurisation.

DS success rate has been calculated based on the percentage of heats achieving the target sulphur level (with a positive tolerance of 0.004% S) out of total heats treated. Pot loss has been calculated based on the amount of slag and metal removed during slag raking after desulphurisation.

Results and Conclusions
Stage wise results of industrial trials are presented in Table 2 below.

Table 2
Consideration Measurement Unit Industrial Trial 1 Industrial Trial 2
Conventional
Reagent 1 Test-1
(DS1) Test-2
(DS2) Test-3
(DS3) Conventional
Reagent 2 Test-1
(DS6)
Replacement of conventional slag fluidizer
(cryolite) % 0 0 25 50 0 25
Soda glass % 0 1 2 3 0 2
Parameters
Pot loss Kg/thm 11 to 15 11.31 10.28 14.08 7.28 7.12
Desulphurization Success rate % 97 100 98 95 100 100
FeO in Slag % 47.80 38.80 38.79 35.89 42.81 43.39
Average Liquid metal Temperature 0C 1385 1386 1394 1383 1379 1384

The above results demonstrate that:
a) the desulphurization efficiency of the present desulphurization reagents was better or at least at par compared to conventional reagent (i.e. desulphurization reagent lacking soda glass). In other words, the desulphurization reagent of the present disclosure is highly efficient in sulphur removal and desulphurization success rate up to 100% can be achieved.
b) Pot loss when present desulphurization reagents were employed was lower (i.e. better in DS1, DS2 and DS6) or at par (DS3) compared to conventional reagent.
c) FeO content of the obtained slag when present desulphurization reagents were employed was lower (i.e. better in DS1, DS2 and DS3) or at par (DS6) compared to conventional reagent.

Additionally, apart from the present desulphurization reagents (DS1 to DS9) described above which show desired/superior properties, any alternate desulphurization reagents developed with soda glass having amounts of greater than 15 wt% is not expected to be effective in achieving desired desulphurization efficiency during HMDS because greater amounts of soda glass (i.e. > 15 wt%) means accommodating lesser amounts of desulphurizing compounds (CaC2 and/or CaO) which inherently leads to lower desulphurization efficiency during HMDS. Hence, the wt% of soda glass between 0.1 wt% to 15 wt% is desirable in the desulphurization reagent of the present disclosure.

Overall, the desulphurization reagent of the present disclosure comprising soda glass was found to be superior or at least at par when employed in HMDS process compared to conventional reagents. The results also indicate that conventional slag fluidizers can be successfully replaced with soda glass by way of employing the desulphurization reagent of the present disclosure. More importantly, said soda glass is highly beneficial for being environment friendly and highly cost effective.

To summarize, the desulphurization reagent of the present disclosure comprising soda glass has the following important advantages:
- reduces the risk of hazards associated with the use of conventional slag fluidizers, and is therefore less hazardous and more environment friendly. Particularly, as there is no fluoride containing slag due to the use of soda glass in the desulphurization reagent, slag dumping will be easy/less hazardous.
- slag raking problem during desulphurization process (HMDS) is reduced since the slag formed is less viscous and therefore rakability is easy and less time consuming.
- there is reduced ladle jamming problem.
- the present reagent is cost effective when compared to using conventional slag fluidizers such as cryolite, alumina and fluorspar. For instance, soda glass is cheaper by around 70% compared to cryolite.
- the present reagent achieves superior or desired desulphurization efficiency when compared with current reagents containing conventional slag fluidizers.

INCORPORATION BY REFERENCE
Any discussion on references, articles, publications, patents, patent publications, and patent applications 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.
,CLAIMS:We Claim:

1. A desulphurization reagent comprising:
- a desulphurizing compound selected from calcium carbide (CaC2), lime (CaO), and a combination thereof,
- soda glass, and
- optionally, a slag fluidizer, a bath agitator, or a combination thereof.

2. The desulphurization reagent as claimed in claim 1, wherein the slag fluidizer is selected from cryolite, alumina, fluorspar, bauxite, soda ash, borax, and any combination thereof; and the bath agitator is selected from coal, magnesium, coke, gilsonite, and any combination thereof.

3. The desulphurization reagent as claimed in claim 1, wherein said desulphurization reagent is selected from:
i) a) desulphurizing compound which is calcium carbide (CaC2) and lime (CaO),
b) soda glass,
c) slag fluidizer which is cryolite, and
d) bath agitator which is coal;

ii) a) desulphurizing compound which is calcium carbide (CaC2) and lime (CaO),
b) soda glass, and
c) bath agitator which is coal;

iii) a) desulphurizing compound which is calcium carbide (CaC2) and lime (CaO), and
b) soda glass;

iv) a) desulphurizing compound which is calcium carbide (CaC2), and
b) soda glass;

v) a) desulphurizing compound which is lime (CaO),
b) soda glass, and
c) slag fluidizer which is cryolite;

vi) a) desulphurizing compound which is lime (CaO), and
b) soda glass;

and

vii) a) desulphurizing compound which is lime (CaO),
b) soda glass,
c) slag fluidizer which is cryolite, and
d) bath agitator which is coal.

4. The desulphurization reagent as claimed in any of the claims 1 to 3, wherein the desulphurizing compound is present in an amount of about 5 wt% to 96 wt%, soda glass is present in an amount of about 0.1 wt% to 15 wt%, the slag fluidizer is present in an amount of about 0.1 wt% to 15 wt%, and the bath agitator is present in an amount of about 0.1 wt% to 10 wt%.

5. The desulphurization reagent as claimed in claim 1, wherein the desulphurizing compound is present in an amount of about 20 wt% to 96 wt%, soda glass is present in an amount of about 1 wt% to 4 wt%, the slag fluidizer is present in an amount of about 1 wt% to 8 wt%, and the bath agitator is present in an amount of about 2 wt% to 8 wt%.

6. The desulphurization reagent as claimed in claim 1, wherein the reagent comprises:
- calcium carbide (CaC2) at 5 wt% to 55 wt%,
- lime (CaO) at 45 wt% to 85 wt%,
- soda glass at 0.1 wt% to 15 wt%, and
- optionally, a slag fluidizer at 0.1 wt% to 15 wt%, or a bath agitator at 0.1 wt% to 10 wt%, or a combination of slag fluidizer and bath agitator thereof.

7. The desulphurization reagent as claimed in claim 1, wherein the reagent comprises:
i):
- calcium carbide (CaC2) at 20 wt%,
- lime (CaO) at 70 wt%,
- soda glass at 1 to 4 wt%,
- cryolite at 1 to 4 wt%, and
- coal at 5 wt%;

or

ii):
- calcium carbide (CaC2) at 20 wt%,
- lime (CaO) at 70 wt%,
- soda glass at 1 to 4 wt%, and
- coal at 5 wt%.

8. The desulphurization reagent as claimed in claim 1, wherein the reagent comprises:
- lime (CaO) at 65 wt% to 96 wt%,
- soda glass at 0.1 wt% to 15 wt%, and
- optionally, a slag fluidizer at 0.1 wt% to 15 wt%.

9. The desulphurization reagent as claimed in claim 1, wherein the reagent comprises:
i):
- lime (CaO) at 95 wt%,
- soda glass at 1 to 4 wt%, and
- cryolite at 1 to 4 wt%,

or

ii):
- lime (CaO) at 96 wt%, and
- soda glass at 4 wt%.

10. The desulphurization reagent as claimed in claim 1, wherein the soda glass has a composition comprising silica (SiO2) at about 50 wt% to 80 wt%, sodium oxide (Na2O) at about 5 wt% to 20 wt%, calcium oxide (CaO) at about 5 wt% to 15 wt%, magnesium oxide (MgO) at about 2 wt% to 10 wt%, and trace compounds comprising aluminum oxide (Al2O3), ferric oxide (Fe2O3), titanium dioxide (TiO2) and potassium oxide (K2O) at about 0.01 wt% to 2 wt%.

11. The desulphurization reagent as claimed in claim 1, wherein the soda glass has a composition comprising silica (SiO2) at about 73 wt%, sodium oxide (Na2O) at about 14 wt%, calcium oxide (CaO) at about 9 wt%, magnesium oxide (MgO) at about 4 wt%, and trace compounds comprising aluminum oxide (Al2O3), ferric oxide (Fe2O3), titanium dioxide (TiO2) and potassium oxide (K2O) at about 1 wt%.

12. A method for preparing the desulphurization reagent as claimed in any of the claims 1 to 11, the method comprising:
a) mixing desulphurizing compound, soda glass, and optionally slag fluidizer and/or bath agitator; or
b) adding soda glass to: i) desulphurizing compound, or ii) a mixture comprising desulphurizing compound and at least one compound selected from slag fluidizer and bath agitator, to obtain the desulphurization reagent as claimed in any of the claims 1 to 11.

13. The method as claimed in claim 12, wherein the mixing or adding step comprises mixing the ingredients, crushing, grinding, pulverising, or any combination of said techniques thereof;
and wherein said mixing or adding is carried out by employing a ball mill, blender, crusher, grinder, pulverizer, or any combination thereof.

14. The method as claimed in claim 12, wherein the desulphurizing compound is employed in an amount of about 5 wt% to 96 wt%, soda glass is employed in an amount of about 0.1 wt% to 15 wt%, the slag fluidizer is employed in an amount of about 0.1 wt% to 15 wt%, and bath agitator is employed in an amount of about 0.1 wt% to 10 wt%.

15. 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 11 with the hot metal to obtain desulphurized metal and sulphur rich slag.

16. The process as claimed in claim 15, wherein the presence of soda glass in the desulphurization reagent increases the desulphurization efficiency compared to a desulphurization reagent lacking soda glass;
and wherein the desulphurization efficiency of the process is about 95% to 100%.
17. The process as claimed in claim 15, wherein the process results in a pot loss of about 7 Kg/thm to 14 Kg/thm, and FeO in sulphur rich slag is about 35% to 44%.