DESC:TECHNICAL FIELD
The present disclosure is in the field of metallurgy and deoxidation reagents. The disclosure relates to a deoxidizing reagent, corresponding method of preparation, and process or use of said deoxidizing reagent in deoxidation of steel during steel making process.

BACKGROUND OF THE DISCLOSURE
Deoxidation of steel is a steel making technological operation in which concentration (activity) of oxygen dissolved in molten steel is reduced to a required level. Thus, deoxidized steel (or killed steel) has some or all of the oxygen removed from the melt during the steelmaking process. During steelmaking process, the aluminium consumption currently in steel plants, for aluminium killed and aluminium-silicon killed steel, using conventional deoxidation practices vary between 1.5 and 4.0 kg/tonne of crude steel. Such high addition of aluminium necessitates special treatment usually with calcium to produce clean steel. Further, slag conditioners such as synthetic slag and environmentally hazardous materials such as fluorspar are often added during the process for making the slag conducive to refining. Due to some of these significant drawbacks/challenges of conventional deoxidation practices, there is an immense need for an alternate deoxidation material which is more efficient, cost effective and environment friendly for production of clean steel. The present disclosure addresses this need.

STATEMENT OF THE DISCLOSURE
The present disclosure relates to a deoxidizing reagent comprising:
- calcium carbide (CaC2),
- aluminium (Al),
- an aluminium based compound selected from the group comprising alumina (Al2O3), aluminium nitride (AlN), aluminium carbide (Al4C3), and combinations thereof,
- calcium oxide (CaO), and
- a trace element selected from the group comprising manganese oxide (MnO), magnesium oxide (MgO), silicon dioxide (SiO2), and combinations thereof.

The present disclosure also relates to a method for preparing the deoxidizing reagent as defined above, the method comprising mixing calcium carbide, aluminium, aluminium based compound, calcium oxide and trace element, to obtain the deoxidizing reagent.

The present disclosure further relates to a process for deoxidation of liquid metal or liquid steel during production of steel, the process comprising reacting the deoxidizing reagent as described above with the liquid metal to obtain deoxidized metal.

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 “deoxidation reagent” refers to the product of the present disclosure which can be employed for liquid metal or liquid steel deoxidation process (removal of oxygen from liquid metal/liquid steel obtained during the process of steel making).

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

A primary objective of the present disclosure is to reduce or eliminate aluminium consumption in steel making.

Another objective of the present disclosure is to reduce lime consumption in steel making.

Yet another objective of the present disclosure is to reduce the alumina inclusion in steel.

Still another objective of the present disclosure is to reduce or eliminate the use of slag conditioners such as synthetic slag and fluorspar in steel making process.

Still another objective of the present disclosure is to eliminate the environmental hazards associated with the use of fluorspar during deoxidation of steel.

Still another objective of the present disclosure is to reduce or eliminate the requirement of special/additional treatment of steel with calcium.

Still another objective of the present disclosure is to reduce the total deoxidation process cost, thereby making the overall steelmaking process economical.

Still another objective is to achieve the above-mentioned objectives and perform the deoxidation process with better or at least equivalent process efficiency compared to conventional deoxidation reagents.

Thus, the present disclosure particularly relates to killing of oxygen in steel during tapping of liquid metal from the primary steelmaking furnace. In particular, the disclosure relates to the development of a deoxidation reagent which can partially or fully replace aluminium ingot or notch bar during tapping of liquid metal/steel and thereby reducing aluminium consumption significantly. The present disclosure also aims at making the slag more conducive to refining by reducing lime consumption. Additionally, as discussed above, the disclosure seeks to reduce or eliminate the use of slag conditioners such as synthetic slag and fluorspar.

In order to address the concerns mentioned above and to meet the aforesaid objectives, the present disclosure provides a deoxidation reagent for deoxidation of steel during tapping and processing in transfer ladle. Said deoxidation reagent comprises:
- calcium carbide (CaC2),
- aluminium (Al),
- an aluminium based compound selected from the group comprising alumina (Al2O3), aluminium nitride (AlN), aluminium carbide (Al4C3), and combinations thereof,
- calcium oxide (CaO), and
- a trace element selected from the group comprising manganese oxide (MnO), magnesium oxide (MgO), silicon dioxide (SiO2), and combinations thereof.

In some embodiments, the present disclosure provides a deoxidizing reagent comprising:
- calcium carbide (CaC2),
- aluminium (Al),
- aluminium based compounds comprising alumina (Al2O3), aluminium nitride (AlN) and aluminium carbide (Al4C3),
- calcium oxide (CaO), and
- trace elements comprising manganese oxide (MnO), magnesium oxide (MgO) and silicon dioxide (SiO2).

In some embodiments, the present disclosure provides a deoxidizing reagent comprising:
- CaC2,
- Al,
- Al2O3, AlN and Al4C3,
- CaO, and
- MnO, MgO and SiO2.

In some embodiments of the deoxidizing reagent, the calcium carbide (CaC2) is present in an amount of about 10 wt% to 70 wt% with respect to the weight of the deoxidizing reagent.

In some embodiments of the deoxidizing reagent, the aluminium (Al) is present in an amount of about 10 wt% to 30 wt% with respect to the weight of the deoxidizing reagent.

In some embodiments of the deoxidizing reagent, the aluminium based compound is present in an amount of about 20 wt% to 40 wt% with respect to the weight of the deoxidizing reagent.

In some embodiments of the deoxidizing reagent, the aluminium based compound is a mixture of Al2O3, AlN and Al4C3 in an amount of about 20 wt% to 40 wt% with respect to the weight of the deoxidizing reagent.

In some embodiments of the deoxidizing reagent, the aluminium based compound comprises about 80 wt% to 85 wt% of Al2O3 and about 15 wt% to 20 wt% of AlN and Al4C3 with respect to the total weight of the aluminium based compound.

In some embodiments of the deoxidizing reagent, the calcium oxide (CaO) is present in an amount of about 5 wt% to 15 wt% with respect to the weight of the deoxidizing reagent.

In some embodiments of the deoxidizing reagent, the trace element is present in an amount of about 5 wt% to 20 wt% with respect to the weight of the deoxidizing reagent.

In some embodiments of the deoxidizing reagent, the amount (wt% ranges) of the ingredients includes all values and sub-ranges therebetween.

In some embodiments, the deoxidizing reagent comprises:
- calcium carbide (CaC2) at about 10 wt% to 70 wt%;
- aluminium (Al) at about 10 wt% to 30 wt%;
- an aluminium based compound selected from the group comprising alumina (Al2O3), aluminium nitride (AlN), aluminium carbide (Al4C3), and combinations thereof, at about 20 wt% to 40 wt%;
- calcium oxide (CaO) at about 5 wt% to 15 wt%; and
- a trace element selected from the group comprising manganese oxide (MnO), magnesium oxide (MgO), silicon dioxide (SiO2), and combinations thereof, at about 5 wt% to 20 wt%.

In some embodiments, the deoxidizing reagent comprises:
- calcium carbide (CaC2) at about 20 wt% to 40 wt%;
- aluminium (Al) at about 20 wt% to 30 wt%;
- an aluminium based compound selected from the group comprising alumina (Al2O3), aluminium nitride (AlN), aluminium carbide (Al4C3), and combinations thereof, at about 20 wt% to 35 wt%;
- calcium oxide (CaO) at about 6 wt% to 13 wt%; and
- a trace element selected from the group comprising manganese oxide (MnO), magnesium oxide (MgO), silicon dioxide (SiO2), and combinations thereof, at about 7 wt% to 10 wt%.

In some embodiments, the deoxidizing reagent comprises:
- calcium carbide (CaC2) at about 10 wt% to 70 wt%;
- aluminium (Al) at about 10 wt% to 30 wt%;
- aluminium based compounds comprising alumina (Al2O3), aluminium nitride (AlN) and aluminium carbide (Al4C3), at about 20 wt% to 40 wt%;
- calcium oxide (CaO) at about 5 wt% to 15 wt%; and
- trace elements comprising manganese oxide (MnO), magnesium oxide (MgO) and silicon dioxide (SiO2), at about 5 wt% to 20 wt%.

In some embodiments, the deoxidizing reagent comprises:
- calcium carbide (CaC2) at about 20 wt% to 40 wt%;
- aluminium (Al) at about 20 wt% to 30 wt%;
- aluminium based compounds comprising alumina (Al2O3), aluminium nitride (AlN) and aluminium carbide (Al4C3), at about 20 wt% to 35 wt%;
- calcium oxide (CaO) at about 6 wt% to 13 wt%; and
- trace elements comprising manganese oxide (MnO), magnesium oxide (MgO) and silicon dioxide (SiO2), at about 7 wt% to 10 wt%.

In some embodiments, the deoxidizing reagent comprises:
- calcium carbide (CaC2) at about 23 wt%;
- aluminium (Al) at about 29 wt%;
- alumina (Al2O3), aluminium nitride (AlN) and aluminium carbide (Al4C3), at about 32 wt%;
- calcium oxide (CaO) at about 7 wt%; and
- manganese oxide (MnO), magnesium oxide (MgO) and silicon dioxide (SiO2), at about 9 wt%.

In some embodiments, the deoxidizing reagent comprises:
- calcium carbide (CaC2) at about 36 wt%;
- aluminium (Al) at about 21 wt%;
- alumina (Al2O3), aluminium nitride (AlN) and aluminium carbide (Al4C3), at about 23 wt%;
- calcium oxide (CaO) at about 12 wt%; and
- manganese oxide (MnO), magnesium oxide (MgO) and silicon dioxide (SiO2), at about 8 wt%.

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

In some embodiments, the deoxidizing reagent described above is employed for deoxidation of steel during tapping and processing in transfer ladle. Particularly, the deoxidizing reagent of the present disclosure is employed in deoxidizing the liquid metal during the process of tapping said liquid metal from the primary steel making furnace [such as basic oxygen furnace (BOF) or electric arc furnace (EAF)] to the ladle.

The present disclosure also relates to a method for preparing the deoxidizing reagent as defined above, the method comprising mixing or blending calcium carbide, aluminium, aluminium based compound, calcium oxide and trace element, to obtain the deoxidizing reagent.

In some embodiments of the above method, the mixing or blending is carried out by employing a blender, shovel, or a combination thereof.

In some embodiments of the above method, the mixing is carried out at room temperature.

In some embodiments of the above method, the mixing is carried out at a temperature of about 5? to 50?.

In some embodiments of the above method, calcium carbide (CaC2) is employed in an amount of about 10 wt% to 70 wt%, the aluminium (Al) is employed in an amount of about 10 wt% to 30 wt%, the aluminium based compound is employed in an amount of about 20 wt% to 40 wt%, the calcium oxide (CaO) is employed in an amount of about 5 wt% to 15 wt%, and the trace element is employed in an amount of about 5 wt% to 20 wt%.

In some embodiments of the above method, said method comprises blending calcium carbide, aluminium, aluminium based compound, calcium oxide and trace element in a mechanical blender, to obtain the deoxidizing reagent.

In some embodiments of the above method, said method comprises blending calcium carbide, aluminium, aluminium based compound, calcium oxide and trace element manually using a shovel, to obtain the deoxidizing reagent.

In embodiments of the above method, the concentrations or wt% of the components of the deoxidizing reagent including all values and sub-ranges are based on the embodiments of the product (deoxidizing 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 deoxidizing reagent.

The present disclosure further relates to a process for deoxidation of liquid metal during production of steel, the process comprising reacting the deoxidizing reagent as described above with the liquid metal to obtain deoxidized metal.

In some embodiments of the above described process of deoxidation of liquid metal, the deoxidation reagent comprises:
- calcium carbide (CaC2) at about 10 wt% to 70 wt%;
- aluminium (Al) at about 10 wt% to 30 wt%;
- an aluminium based compound selected from the group comprising alumina (Al2O3), aluminium nitride (AlN), aluminium carbide (Al4C3), and combinations thereof, at about 20 wt% to 40 wt%;
- calcium oxide (CaO) at about 5 wt% to 15 wt%; and
- a trace element selected from the group comprising manganese oxide (MnO), magnesium oxide (MgO), silicon dioxide (SiO2), and combinations thereof, at about 5 wt% to 20 wt%.

In some embodiments of the above described process of deoxidation of liquid metal, the deoxidation reagent comprises:
- calcium carbide (CaC2) at about 10 wt% to 70 wt%;
- aluminium (Al) at about 10 wt% to 30 wt%;
- aluminium based compounds comprising alumina (Al2O3), aluminium nitride (AlN) and aluminium carbide (Al4C3), at about 20 wt% to 40 wt%;
- calcium oxide (CaO) at about 5 wt% to 15 wt%; and
- trace elements comprising manganese oxide (MnO), magnesium oxide (MgO) and silicon dioxide (SiO2), at about 5 wt% to 20 wt%.

In some embodiments of the above described process of deoxidation of liquid metal, the deoxidation reagent comprises:
- calcium carbide (CaC2) at about 10 wt% to 70 wt%;
- aluminium (Al) at about 10 wt% to 30 wt%;
- aluminium based compounds comprising alumina (Al2O3), aluminium nitride (AlN) and aluminium carbide (Al4C3), at about 20 wt% to 40 wt%;
- calcium oxide (CaO) at about 5 wt% to 15 wt%; and
- trace elements comprising manganese oxide (MnO), magnesium oxide (MgO) and silicon dioxide (SiO2), at about 5 wt% to 20 wt%.

In some embodiments of the above described process of deoxidation of liquid metal, the deoxidation reagent comprises:
- calcium carbide (CaC2) at about 20 wt% to 40 wt%;
- aluminium (Al) at about 20 wt% to 30 wt%;
- aluminium based compounds comprising alumina (Al2O3), aluminium nitride (AlN) and aluminium carbide (Al4C3), at about 20 wt% to 35 wt%;
- calcium oxide (CaO) at about 6 wt% to 13 wt%; and
- trace elements comprising manganese oxide (MnO), magnesium oxide (MgO) and silicon dioxide (SiO2), at about 7 wt% to 10 wt%.

In some embodiments of the process described above, said process of deoxidation of liquid metal is performed during tapping and processing of said liquid metal in a transfer ladle.

In some embodiments of the process described above, the reaction of the deoxidizing reagent with the liquid metal comprises contacting the deoxidizing reagent with the liquid metal during tapping said liquid metal from a primary steel making furnace to the transfer ladle.

In some embodiments of the process described above, the primary steel making furnace is basic oxygen furnace (BOF) or electric arc furnace (EAF).

In some embodiments of the process described above, the process of deoxidation of liquid metal or liquid steel during production of steel comprises steps of:
a) adding deoxidizing reagent at bottom of the transfer ladle before tapping the liquid metal; and
b) adding deoxidizing reagent to a stream of liquid metal during tapping of said liquid metal from the primary steel making furnace to the transfer ladle.

In some embodiments of the process described above, the process of deoxidation of liquid metal during production of steel comprises steps of:
a) adding about 50% of the total deoxidizing reagent at bottom of the transfer ladle before tapping the liquid metal; and
b) adding the remaining about 50% of the total deoxidizing reagent to a stream of liquid metal during tapping from the primary steel making furnace to the transfer ladle.

In some embodiments of the process described above, the process results in a reduction in aluminium consumption of about 0.35 to 0.50 kilograms per tonne liquid steel (Kg/tls) when compared to a process which does not employ the present deoxidizing reagent.

In some embodiments of the process described above, the process results in a reduction in lime consumption of about 0.30 to 0.40 Kg/tls when compared to a process which does not employ the present deoxidizing reagent.

In embodiments of the above described process, the concentrations or wt% of the components of the deoxidizing reagent including all values and sub-ranges are based on the embodiments of the product (deoxidizing 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 process of deoxidation of liquid metal during production of steel.

The present disclosure also relates to use of the deoxidizing reagent as described above for deoxidizing liquid metal during production of steel.

In some embodiments of the use, the deoxidizing reagent removes oxygen from the liquid metal during the production of steel resulting in the manufacture of deoxidized or killed steel.

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 of Deoxidizing Reagent
All the ingredients/components of the deoxidizing reagent mixture were blended manually with the help of shovel to arrive at the following deoxidizing reagents/compositions:

Deoxidizing Reagent 1 (DO1)
- calcium carbide (CaC2) at about 23 wt%
- aluminium (Al) at about 29 wt%
- a mixture of alumina (Al2O3), aluminium nitride (AlN) and aluminium carbide (Al4C3) at about 32 wt%
- calcium oxide (CaO) at about 7 wt%, and
- combination of manganese oxide (MnO), magnesium oxide (MgO) and silicon dioxide (SiO2) at about 9 wt%.

Deoxidizing Reagent 2 (DO2)
- calcium carbide (CaC2) at about 36 wt%
- aluminium (Al) at about 21 wt%
- a mixture of alumina (Al2O3), aluminium nitride (AlN) and aluminium carbide (Al4C3) at about 23 wt%
- calcium oxide (CaO) at about 12 wt%, and
- combination of manganese oxide (MnO), magnesium oxide (MgO) and silicon dioxide (SiO2) at about 8 wt%.

The prepared deoxidizing reagents were taken for experimental trials to evaluate the efficiency in deoxidation of steel.

Example 2: Deoxidation of Liquid Metal
The process for deoxidation of liquid metal/liquid steel during steel making was performed as follows:
- about 50% quantity of deoxidizing reagent 1 or deoxidizing reagent 2 was added at the bottom of empty transfer ladle before tapping the liquid metal;
- the remaining 50% of deoxidizing reagent 1 or deoxidizing reagent 2 was added to the continuous liquid metal stream after about 25% of tapping of the liquid metal from the primary steel making furnace to the ladle;
- other ferroalloys, including aluminium, and lime as necessary were added after addition of the deoxidizing reagent 1 or deoxidizing reagent 2. The deoxidizing reagent reacts with the oxygen in liquid metal and performs deoxidation.

Results and Conclusions
The trial results are indicated in Table 1 below.

Table-1
Parameter Desired Target Without DO1 or DO2 addition With DO1 or DO2 addition
Al addition (Kg/tls) 2.4 2.9 2.5 to 2.4
DO1 or DO2 addition (Kg/tls) 1 - 0.4 to 1
Lime (CaO) addition (Kg/tls) 8.6 9 8.6
Results
Al reduction achieved (Kg/tls) 0.5 0 0.4 to 0.5
Lime reduction achieved (Kg/tls) 0.4 0 0.4

The above results demonstrate that:
a) employing the present deoxidizing reagent for deoxidation of liquid metal significantly reduces aluminium consumption during steel making. Particularly, as seen from Table 1, an Al reduction of about 0.4 to 0.5 kilogram per tonne liquid steel (Kg/tls) was achieved.
b) employing the present deoxidizing reagent for deoxidation of liquid metal significantly reduces lime consumption during steel making. Particularly, as seen from Table 1, lime reduction of about 0.4 Kg/tls was achieved.

Example 3: Comparative Examples
Apart from the present deoxidation reagents and corresponding results described above, the following prophetic examples and corresponding conclusions are provided based on alternate/comparative deoxidation reagents:

Comparative deoxidation reagent A (metallic Al absent and other components higher/lower than the present range)
- calcium carbide (CaC2): > 70 wt%
- aluminium based compounds (Al2O3, AlN and Al4C3): 8 wt%
- calcium oxide (CaO): 5 wt% to 15 wt%, and
- trace elements (MnO, MgO and SiO2): 5 wt% to 20 wt%

Employing the above reagent/composition for deoxidation will lead to the formation of high CaO in liquid steel slag which makes the slag crusty and also affects the basicity of slag by disturbing CaO/Al2O3 ratio which is not desirable with respect to quality of liquid steel.

Comparative deoxidation reagent B (CaC2 absent)
- aluminium (Al): 10 wt% to 30 wt%
- aluminium based compounds (Al2O3, AlN and Al4C3): 20 wt% to 40 wt%
- calcium oxide (CaO): 5 wt% to 15 wt%, and
- trace elements (MnO, MgO and SiO2): 5 wt% to 20 wt%

Employing the above reagent/composition for deoxidation will not lead to achieving the target Al reduction. The Al reduction with this reagent is up to a maximum of 0.3 kg/tls against the target of 0.5 kg/tls.

Comparative deoxidation reagent C (CaC2 wt% lower than the present range)
- calcium carbide (CaC2): 8 wt%
- aluminium (Al): 10 wt% to 30 wt%
- aluminium based compounds (Al2O3, AlN and Al4C3): 20 wt% to 40 wt%
- calcium oxide (CaO): 5 wt% to 15 wt%, and
- trace elements (MnO, MgO and SiO2): 5 wt% to 20 wt%

Employing the above comparative deoxidation reagent C vis-à-vis present deoxidizing reagent 2 (DO2) for deoxidation will lead to the following results:

Table-2
Parameter Desired Target Comparative deoxidation reagent C With DO2 addition
Al addition (Kg/tls) 2.4 2.7 to 2.9 2.5 to 2.4
Deoxidation reagent addition (Kg/tls) 1 0.4 to 1 0.4 to 1
Lime (CaO) addition (Kg/tls) 8.6 9 8.6
Results
Al reduction achieved (Kg/tls) 0.5 0 to 0.2 0.4 to 0.5
Lime reduction achieved (Kg/tls) 0.4 0 0.4

Thus, as seen from the results under Table 2, desired Al and lime reduction is not achieved when comparative deoxidation reagent C is employed i.e. when CaC2 is present at a wt% lower than the range of 10 wt% to 70 wt% (eg. 8 wt%).

Comparative deoxidation reagent D (CaC2 wt% higher than the present range)
- calcium carbide (CaC2): 75 wt%
- aluminium (Al): 10 wt% to 30 wt%
- aluminium based compounds (Al2O3, AlN and Al4C3): 20 wt% to 40 wt%
- calcium oxide (CaO): 5 wt% to 15 wt%, and
- trace elements (MnO, MgO and SiO2): 5 wt% to 20 wt%

Developing the above comparative deoxidation reagent D is not possible. This is because wt% of CaC2 cannot be increased beyond 70% as it will disturb the 100 wt% of composition. In other words, if greater than 70% CaC2 is used, the Al content is reduced significantly which makes the reagent/composition undesirable.

Comparative deoxidation reagent E (Al wt% lower than the present range)
- calcium carbide (CaC2): 10 wt% to 70 wt%
- aluminium (Al): 8 wt%
- aluminium based compounds (Al2O3, AlN and Al4C3): 20 wt% to 40 wt%
- calcium oxide (CaO): 5 wt% to 15 wt%, and
- trace elements (MnO, MgO and SiO2): 5 wt% to 20 wt%

Employing the above reagent/composition for deoxidation will lead to the formation of CaO in liquid steel slag which makes the slag crusty and also affects the basicity of slag by disturbing CaO/Al2O3 ratio which is not desirable with respect to quality of liquid steel.

Comparative deoxidation reagent F (Al wt% higher than the present range)
- calcium carbide (CaC2): 10 wt% to 70 wt%
- aluminium (Al): 35 wt%
- aluminium based compounds (Al2O3, AlN and Al4C3): 20 wt% to 40 wt%
- calcium oxide (CaO): 5 wt% to 15 wt%, and
- trace elements (MnO, MgO and SiO2): 5 wt% to 20 wt%

Employing the above comparative deoxidation reagent F vis-à-vis present deoxidizing reagent 2 (DO2) for deoxidation will lead to the following results:

Table-3
Parameter Desired Target Comparative deoxidation reagent F With DO2 addition
Al addition (Kg/tls) 2.4 2.6 to 2.9 2.5 to 2.4
Deoxidation reagent addition (Kg/tls) 1 0.4 to 1 0.4 to 1
Lime (CaO) addition (Kg/tls) 8.6 8.6 to 9 8.6
Results
Al reduction achieved (Kg/tls) 0.5 0 to 0.3 0.4 to 0.5
Lime reduction achieved (Kg/tls) 0.4 0 to 0.3 0.4

Thus, as seen from the results under Table 3, desired Al and lime reduction is not achieved when comparative deoxidation reagent F is employed i.e. when Al is present at a wt% higher than the range of 10 wt% to 30 wt% (eg. 35 wt%).

Overall, the deoxidation reagent of the present disclosure for deoxidation of steel was found to be effective in significantly reducing aluminium and lime consumption during steel making. Further, the above comparative examples (Example 3) demonstrate that all the components and the respective amounts (wt%) in the present deoxidation reagent are critical to achieve desired deoxidation efficiency and any deviation in with respect to ingredients and amounts will not yield desired results.

To summarize, the deoxidation reagent of the present disclosure has the following important advantages:
- reduces aluminium consumption in steel making.
- reduces lime consumption in steel making.
- reduces alumina inclusion in steel, reduces synthetic slag, fluorspar etc. in steel making.
- makes the slag more conducive to the treatment at ladle refining furnace.
- eliminates environmental hazards associated with the use of fluorspar in conventional deoxidation reagents.
- reduces the requirement of special treatment of steel with calcium during steel making.
- reduces the total deoxidation cost, thereby making the overall steel making cost effective.

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 deoxidizing reagent comprising:
- calcium carbide (CaC2),
- aluminium (Al),
- an aluminium based compound selected from the group comprising alumina (Al2O3), aluminium nitride (AlN), aluminium carbide (Al4C3), and combinations thereof,
- calcium oxide (CaO), and
- a trace element selected from the group comprising manganese oxide (MnO), magnesium oxide (MgO), silicon dioxide (SiO2), and combinations thereof.

2. The deoxidizing reagent as claimed in claim 1, wherein the reagent comprises:
- calcium carbide (CaC2),
- aluminium (Al),
- aluminium based compounds comprising alumina (Al2O3), aluminium nitride (AlN) and aluminium carbide (Al4C3),
- calcium oxide (CaO), and
- trace elements comprising manganese oxide (MnO), magnesium oxide (MgO) and silicon dioxide (SiO2).

3. The deoxidizing reagent as claimed in claim 1 or claim 2, wherein the calcium carbide (CaC2) is present in an amount of about 10 wt% to 70 wt%, the aluminium (Al) is present in an amount of about 10 wt% to 30 wt%, the aluminium based compound is present in an amount of about 20 wt% to 40 wt%, the calcium oxide (CaO) is present in an amount of about 5 wt% to 15 wt%, and the trace element is present in an amount of about 5 wt% to 20 wt%.

4. The deoxidizing reagent as claimed in any of the claims 1 to 3, wherein the reagent comprises:
- calcium carbide (CaC2) at about 10 wt% to 70 wt%;
- aluminium (Al) at about 10 wt% to 30 wt%;
- an aluminium based compound selected from the group comprising alumina (Al2O3), aluminium nitride (AlN), aluminium carbide (Al4C3), and combinations thereof, at about 20 wt% to 40 wt%;
- calcium oxide (CaO) at about 5 wt% to 15 wt%, and
- a trace element selected from the group comprising manganese oxide (MnO), magnesium oxide (MgO), silicon dioxide (SiO2), and combinations thereof, at about 5 wt% to 20 wt%.

5. The deoxidizing reagent as claimed in any of the claims 1 to 4, wherein the reagent comprises:
- calcium carbide (CaC2) at about 10 wt% to 70 wt%;
- aluminium (Al) at about 10 wt% to 30 wt%;
- aluminium based compounds comprising alumina (Al2O3), aluminium nitride (AlN) and aluminium carbide (Al4C3), at about 20 wt% to 40 wt%;
- calcium oxide (CaO) at about 5 wt% to 15 wt%, and
- trace elements comprising manganese oxide (MnO), magnesium oxide (MgO) and silicon dioxide (SiO2), at about 5 wt% to 20 wt%.

6. The deoxidizing reagent as claimed in any of the claims 1 to 5, wherein the reagent comprises:
- calcium carbide (CaC2) at about 23 wt%;
- aluminium (Al) at about 29 wt%;
- alumina (Al2O3), aluminium nitride (AlN) and aluminium carbide (Al4C3), at about 32 wt%;
- calcium oxide (CaO) at about 7 wt%, and
- manganese oxide (MnO), magnesium oxide (MgO) and silicon dioxide (SiO2), at about 9 wt%.

7. The deoxidizing reagent as claimed in any of the claims 1 to 5, wherein the reagent comprises:
- calcium carbide (CaC2) at about 36 wt%;
- aluminium (Al) at about 21 wt%;
- alumina (Al2O3), aluminium nitride (AlN) and aluminium carbide (Al4C3), at about 23 wt%;
- calcium oxide (CaO) at about 12 wt%, and
- manganese oxide (MnO), magnesium oxide (MgO) and silicon dioxide (SiO2), at about 8 wt%.

8. A method for preparing the deoxidizing reagent as claimed in any of the claims 1 to 7, the method comprising mixing calcium carbide, aluminium, aluminium based compound, calcium oxide and trace element, to obtain the deoxidizing reagent.

9. The method as claimed in claim 8, wherein the mixing is carried out by employing a blender, shovel, or a combination thereof.

10. The method as claimed in claim 8 or claim 9, wherein the mixing is carried out at a temperature of about 5? to 50?.

11. The method as claimed in any of the claims 8 to 10, wherein calcium carbide (CaC2) is present in an amount of about 10 wt% to 70 wt%, the aluminium (Al) is present in an amount of about 10 wt% to 30 wt%, the aluminium based compound is present in an amount of about 20 wt% to 40 wt%, the calcium oxide (CaO) is present in an amount of about 5 wt% to 15 wt%, and the trace element is present in an amount of about 5 wt% to 20 wt%.

12. A process for deoxidation of liquid metal during production of steel, the process comprising reacting the deoxidizing reagent as claimed in any of the claims 1 to 7 with the liquid metal to obtain deoxidized metal.

13. The process as claimed in claim 12, wherein said process is performed during tapping and processing the liquid metal in a transfer ladle;
and wherein the reacting comprises contacting the deoxidizing reagent with the liquid metal during tapping said liquid metal from a primary steel making furnace to the transfer ladle.

14. The process as claimed in claim 12 or claim 13, wherein the process of deoxidation of liquid metal during production of steel comprises steps of:
a) adding deoxidizing reagent at bottom of the transfer ladle before tapping the liquid metal; and
b) adding deoxidizing reagent to a stream of liquid metal during tapping of said liquid metal from the primary steel making furnace to the transfer ladle.

15. The process as claimed in any of the claims 12 to 14, wherein the process results in a reduction in aluminium consumption of about 0.35 to 0.5 kilograms per tonne liquid steel (Kg/tls) and a reduction in lime consumption of about 0.3 to 0.4 Kg/tls when compared to a process which does not employ the deoxidizing reagent defined in claims 1 to 7.

Dated this 26th day of November 2021

VIKAS J
IN/PA 2221
Of K&S Partners
Agent for the Applicant
To:
The Controller of Patents,
The Patent Office, at: Kolkata