Aluminium based desulphurization reagent, process of preparation and applications thereof

Abstract

The present disclosure generally relates to the field of metallurgy and is particularly relevant to the process of steel making. Particularly, the present disclosure relates to partially or fully replacing the deoxidation capacity and hazardous effect of magnesium with aluminium. Consequently, the present disclosure provides a desulphurization reagent that reduces or replaces the need for employing magnesium along with conventional lime-based desulphurization reagents. The disclosure also relates to the process of preparing the desulphurization reagent or composition and its application in desulphurization of hot metal which is used steel making processes.

Description

[0001] “ALUMINIUM BASED DESULPHURIZATION REAGENT, PROCESS OF PREPARATION AND APPLICATIONS THEREOF”

[0002] FIELD OF THE DISCLOSURE

[0003] The present disclosure generally relates to the field of metallurgy and is particularly relevant to the process of steel making. Particularly, the present disclosure relates to inclusion of aluminium in a desulphurization (DS) reagent composition, wherein such aluminium partially or fully replaces the need for using magnesium along with conventional lime-based DS reagent. Further, the deoxidation capacity of magnesium in a desulphurization composition or reagent is also replicated by said inclusion of aluminium. Consequently, the present disclosure also relates to the process of preparing the aluminum based desulphurization reagent composition of the present disclosure and its applications in desulphurization of hot metal during steel making processes.

[0004] BACKGROUND ART

[0005] Molten steel is generally prepared in a steel refining furnace and is conventionally poured from the furnace into a ladle from which the molten steel is introduced into a casting mold for obtaining the desired form. Molten steel contains dissolved oxygen which is usually regarded as an undesirable impurity. As the molten steel cools, the solubility of oxygen in steel decreases, which results in excess oxygen causing blowholes or precipitate of FeO.

[0006] Since content of dissolved oxygen can interfere with the overall quality of the steel, it is highly desirable to lower the oxygen content of a melt since oxygen dissolved in a melt can precipitate as non-metallic inclusions which adversely affect the properties of the metal, such as tensile strength, ductility, toughness, weldability, polishability, and machinability.

[0007] 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:

[0008] - 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;

[0009] - sulphur forms undesirable sulphides which promote granular weakness and cracks in steel during solidification;

[0010] - sulphur has adverse effects on the mechanical properties of steel; and

[0011] - sulphur lowers the melting point, intergranular strength and cohesion of steel.

[0012] Hence, apart from oxygen as mentioned above, it is also essential to remove sulphur (desulphurize) from hot metal before primary steel making.

[0013] Commonly used desulphurization reagents for this process include quicklime and magnesium, that not only remove sulphur but also oxygen in the hot metal.

[0014] While magnesium present in such DS reagents acts as an oxidizer, it is expensive, and the means and manner of its storage are often hazardous. Further, magnesium is also volatile at 1091 °C, which results in its early loss due to gas formation.

[0015] Thus, there is a constant need to reduce use of magnesium along with such D S reagents and replace it with a suitable alternative, that is not only more economical, less volatile but also less hazardous to use and store.

[0016] OBJECTIVES OF THE DISCLOSURE

[0017] The primary objective of the present disclosure is to reduce the expense and hazardous effects of deoxidizers used in desulphurization reagents employed in the steel making process.

[0018] An objective of the present disclosure is to provide a desulphurization reagent or composition which reduces the oxygen potential in the hot metal desulphurization.

[0019] Another objective of the present disclosure is to facilitate the complete or partial removal of oxygen from hot metal during the process of steel making. Another objective of the preset disclosure is to provide a desulphurization reagent or composition that requires reduced content of magnesium to be employed alongside the reagent.

[0020] Still another objective of the present disclosure is to replace magnesium-based deoxidizing agent partially or fully in a desulphurization process that employs lime-based reagents for hot metal desulphurization (HMDS).

[0021] Thus, an objective of the present disclosure is to provide a desulphurization reagent having lower need of employing magnesium alongside the reagent, compared to existing or conventional limebased DS reagents.

[0022] Still another objective of the present disclosure is to reduce or replace content of magnesium alongside existing or conventional DS reagent to make the process more economical, safer and less hazardous.

[0023] Still another object of the present disclosure is to provide a process of preparing the desulphurization reagent or composition wherein the need for employing magnesium- based deoxidizer alongside the reagent, is partially or fully replaced.

[0024] Still another object of the present disclosure is to use the desulphurization reagent or composition of the present disclosure in desulphurization of hot metal.

[0025] Yet another object of the present disclosure is to provide method of reducing consumption of magnesium alongside a conventional lime-based desulphurization reagent, said method comprising including aluminium at a concentration of about 1% w / wto about 8% w / w in the said conventional reagent.

[0026] SUMMARY OF THE DISCLOSURE

[0027] The following summary is provided to facilitate an understanding of some of the innovative features unique to the disclosed embodiments and is not intended to the full description of the disclosure. A full appreciation of the various aspects of the preferred embodiments disclosed herein can be gained by taking the entire specification, claims, drawings, and abstract as a whole.

[0028] In an aspect, the present disclosure provides a desulphurization reagent or composition that partially or fully replaces the need of employing magnesium alongside the reagent, in existing or conventional lime-based DS reagent, with aluminium.

[0029] In another aspect, the present disclosure provides a desulphurization reagent composition comprising aluminium that allows for said reduction or replacement of the need of employing magnesium alongside the reagent in a DS process.

[0030] In another aspect, the present disclosure provides an inexpensive, safer and less hazardous desulphurization reagent or composition, compared to existing or conventional DS reagent having a deoxidizer.

[0031] In another aspect, the present disclosure provides a lime-based DS reagent or composition wherein aluminium acts as a deoxidizer.

[0032] In another aspect, the present disclosure provides a DS reagent or composition comprising raw lime, aluminium, slag fluidizer and reagent fluidizer.

[0033] In another aspect, the present disclosure provides a process of preparing a DS reagent or composition comprising partially or fully replacing the need of employing magnesium alongside the existing or conventional lime- based DS reagent, with aluminium.

[0034] In yet another aspect, the present disclosure also provides a method of reducing consumption of magnesium alongside a conventional lime-based desulphurization reagent, said method comprising including aluminium at a concentration of about 1% w / wto about 8% w / w in the said conventional reagent.

[0035] Further areas of applicability of the present disclosure will become apparent from the detailed description provided hereinafter. It should be understood that the detailed description and specific examples while indicating the preferred embodiment of the disclosure, are intended for purposes of illustration only and are not intended to limit the scope of the disclosure.

[0036] DETAILED DESCRIPTION OF THE DISCLOSURE

[0037] The details of one or more embodiments of the invention are set forth in the accompanying description below including specific details of the best mode contemplated by the inventors for carrying out the invention, by way of example. It will be apparent to one skilled in the art that the present invention may be practiced without limitation to these specific details.

[0038] Abbreviations Used:

[0039] DO- Deoxidizing or deoxidation

[0040] DS- Desulphurization

[0041] CaO- Lime

[0042] Al- Aluminium

[0043] The use of “comprise”, “comprises”, “comprising”, “contain”, “contains”, “containing”, “include”, “includes”, and “including” are not intended to be limiting. It is to be understood that both the foregoing general description and this detailed description are exemplary and explanatory only and are not restrictive.

[0044] Unless otherwise defined, scientific and technical terms used herein shall have the meanings that are commonly understood by those of ordinary skill in the art. Further, unless otherwise required by context, singular terms shall include pluralities and plural terms shall include the singular.

[0045] The foregoing broadly outlines the features and technical advantages of the present invention in order that the detailed description of the invention that follows may be better understood. It should be appreciated by those skilled in the art that the conception and specific embodiment disclosed may be readily utilized as a basis for modifying the disclosed methods or for carrying out the same purposes of the present invention. The present disclosure provides a desulphurization reagent or composition to be used in the desulphurization processes in the field of metallurgy. Particularly, the disclosure relates to inclusion of aluminium in a desulphurization reagent or composition. In other words, the present disclosure relates to partially or fully replacing the need of employing magnesium alongside an existing or conventional lime-based DS reagent, with aluminium. More particularly, the disclosure partially or fully replaces the need of employing magnesium which also acts as a deoxidizer when used alongside an existing or conventional lime-based DS reagent, with aluminium, which is a cheaper and safer alternative.

[0046] Accordingly, the present disclosure provides a desulphurization reagent or composition devoid of magnesium compared to existing or conventional DS reagent.

[0047] In an embodiment of the present disclosure, the desulphurization reagent or composition comprises aluminium that replaces the need of employing magnesium alongside an existing or conventional DS reagent.

[0048] In an embodiment of the present disclosure, the aluminium completely replaces the need of employing magnesium alongside an existing or conventional desulphurization reagent, wherein the aluminium also replicates the role of magnesium as a deoxidizer.

[0049] In an embodiment of the present disclosure, the DS reagent or composition comprises raw lime, aluminium, slag fluidizer and reagent fluidizer in defined quantities.

[0050] In another embodiment of the present disclosure, raw lime is present in the DS reagent or composition at a concentration range of about 81-97% and values and ranges therebetween for example 81%, 82%, 82%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96% and 97%.

[0051] In another embodiment of the present disclosure, raw lime is present in the DS reagent or composition at a concentration of about 91.92%. In another embodiment, the raw lime has a purity of about 90-92%. Accordingly, in an exemplary embodiment, the raw lime of 91.92% with 92% purity provides about 84.6% CaO in the finished product.

[0052] In another embodiment of the present disclosure, aluminium is present in the DS reagent or composition in the form of powder.

[0053] In another embodiment of the present disclosure, aluminium is present in the DS reagent or composition at a concentration range of about 1-8% and values and ranges therebetween for example 1.0%, 1.5%, 2.0%, 2.5%, 3.0%, 3.5%, 4.0%, 4.5%, 5.0%, 5.5%, 6.0%, 6.5%, 7.0%, 7.5% and 8%.

[0054] In another embodiment of the present disclosure, aluminium is present in the DS reagent or composition at a concentration of about 4%.

[0055] In another embodiment of the present disclosure, the slag fluidizer is present in the DS reagent or composition at a concentration range of about 2-6% and values and ranges therebetween for example 2.0%, 2.5%, 3.0%, 3.5%, 4.0%, 4.5%, 5.0%, 5.5%, and 6.0%.

[0056] In another embodiment of the present disclosure, slag fluidizer is present in the DS reagent or composition in the powdered form or in lumps.

[0057] In another embodiment of the present disclosure, slag fluidizer is selected from a group comprising cryolite, soda glass, spar, alumina powder, soda ash, fluorspar, borax and bauxite or any combination thereof.

[0058] In an embodiment of the present disclosure, the slag fluidizer is cryolite.

[0059] Accordingly, in another embodiment of the present disclosure, cryolite is present in the DS reagent or composition in the powdered form or in lumps. In another embodiment of the present disclosure, cryolite is present in the DS reagent or composition at a concentration range of about 2-6% and values and ranges therebetween for example 2.0%, 2.5%, 3.0%, 3.5%, 4.0%, 4.5%, 5.0%, 5.5%, and 6.0%.

[0060] In another embodiment of the present disclosure, cryolite is present in the DS reagent or composition at a concentration of about 4%.

[0061] In another embodiment of the present disclosure, reagent fluidizer is present in the DS reagent or composition at a concentration range of about 0.04-0.12% and values and ranges therebetween for example 0.04%, 0.05%, 0.06%, 0.07%, 0.08%, 0.09%, 0.10%, 0.11% and 0.12%.

[0062] In an embodiment of the present disclosure, the reagent fluidizer is selected from a group comprising silicon oil, and resil oil.

[0063] In an embodiment of the present disclosure, the reagent fluidizer is silicon oil.

[0064] Accordingly, in another embodiment of the present disclosure, silicon oil is present in the DS reagent or composition at a concentration range of about 0.04-0.12% and values and ranges therebetween for example 0.04%, 0.05%, 0.06%, 0.07%, 0.08%, 0.09%, 0.10%, 0.11% and 0.12%.

[0065] In another embodiment of the present disclosure, silicon oil is present in the DS reagent or composition at a concentration of about 0.08%.

[0066] The present disclosure accordingly provides a desulphurization reagent or composition comprising raw lime at a concentration range of about 81-97% and values and ranges therebetween for example 81%, 82%, 82%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96% and 97%; aluminium at a concentration range of about 1-8% and values and ranges therebetween for example 1.0%, 1.5%, 2.0%, 2.5%, 3.0%, 3.5%, 4.0%, 4.5%, 5.0%, 5.5%, 6.0%, 6.5%, 7.0%, 7.5% and 8%; along with slag fluidizer and reagent fluidizer. The present disclosure accordingly provides a desulphurization reagent or composition comprising raw lime at a concentration range of about 81-97% and values and ranges therebetween for example 81%, 82%, 82%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96% and 97%; aluminium at a concentration range of about 1-8% and values and ranges therebetween for example 1.0%, 1.5%, 2.0%, 2.5%, 3.0%, 3.5%, 4.0%, 4.5%, 5.0%, 5.5%, 6.0%, 6.5%, 7.0%, 7.5% and 8%; along with cryolite and silicon oil.

[0067] In an embodiment, the present disclosure provides a desulphurization reagent or composition comprising, raw lime at a concentration of about 91.92%; aluminium at a concentration of about 4%; along with slag fluidizer and silicon oil.

[0068] In an embodiment of the present disclosure, the slag fluidizer is selected from a group comprising cryolite, soda glass, spar, alumina powder, soda ash, fluorspar, borax and bauxite or any combination thereof.

[0069] The present disclosure accordingly provides a desulphurization reagent or composition comprising raw lime at a concentration range of about 81-97% and values and ranges therebetween for example 81%, 82%, 82%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96% and 97%; aluminium at a concentration range of about 1-8% and values and ranges therebetween for example 1.0%, 1.5%, 2.0%, 2.5%, 3.0%, 3.5%, 4.0%, 4.5%, 5.0%, 5.5%, 6.0%, 6.5%, 7.0%, 7.5% and 8%; slag fluidizer at a concentration range of about 2-6% and values and ranges therebetween for example 2.0%, 2.5%, 3.0%, 3.5%, 4.0%, 4.5%, 5.0%, 5.5%, and 6.0%; and reagent fluidizer at a concentration range of about 0.04-0.12% and values and ranges therebetween for example 0.04%, 0.05%, 0.06%, 0.07%, 0.08%, 0.09%, 0.10%, 0.11% and 0.12%.

[0070] In an embodiment, the present disclosure accordingly provides a desulphurization reagent or composition comprising raw lime at a concentration range of about 81-97% and values and ranges therebetween for example 81%, 82%, 82%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96% and 97%; aluminium at a concentration range of about 1-8% and values and ranges therebetween for example 1.0%, 1.5%, 2.0%, 2.5%, 3.0%, 3.5%, 4.0%, 4.5%, 5.0%, 5.5%, 6.0%, 6.5%, 7.0%, 7.5% and 8%; cryolite at a concentration range of about 2-6% and values and ranges therebetween for example 2.0%, 2.5%, 3.0%, 3.5%, 4.0%, 4.5%, 5.0%, 5.5%, and 6.0%; and silicon oil at a concentration range of about 0.04-0.12% and values and ranges therebetween for example 0.04%, 0.05%, 0.06%, 0.07%, 0.08%, 0.09%, 0.10%, 0.11% and 0.12%.

[0071] In an embodiment, the present disclosure provides a desulphurization reagent or composition comprising, raw lime at a concentration of about 91.92%; aluminium at a concentration of about 4%; slag fluidizer at a concentration of about 4%; and reagent fluidizer at a concentration of about 0.08%.

[0072] In another embodiment of the present disclosure, the slag fluidizer is selected from a group comprising cryolite, soda glass, spar, alumina powder, soda ash, fluorspar, borax and bauxite or any combination thereof.

[0073] In another embodiment of the present disclosure, the slag fluidizer is cryolite.

[0074] In another embodiment of the present disclosure, the reagent fluidizer is selected from a group comprising silicon oil and resil oil.

[0075] In another embodiment of the present disclosure, the reagent fluidizer is silicon oil.

[0076] Thus, in some embodiments, the present disclosure provides a desulphurization reagent or composition comprising, raw lime at a concentration of about 91.92%; aluminium at a concentration of about 4%; cryolite at a concentration of about 4%; and silicon oil at a concentration of about 0.08%.

[0077] In an embodiment of the present disclosure, the ingredients such as raw lime, aluminium, cryolite and silicon oil are mixed to prepare the composition.

[0078] The present disclosure thus also provides a process for preparing the desulphurization reagent composition as described above, the process comprising: a. mixing raw lime, aluminium, slag fluidizer, and reagent fluidizer to obtain a mixture; b. grinding the mixture for about 12-15 minutes to obtain the desulphurization reagent in a powder form.

[0079] In an embodiment of the present disclosure, the raw materials such as raw lime, aluminium, slag fluidizer such as cryolite and silicon oil are added in a grinding media and ground for about 12-15 minutes and pneumatically transported using the carrier gas. The final product is then stored appropriately.

[0080] In an embodiment of the present disclosure, the raw lime is at a concentration of about 81% w / w to about 97% w / w, the aluminium is at a concentration of about 1% w / w to about 8% w / w; the slag fluidizer is at a concentration of about 2% w / w to about 6% w / w; and the silicon oil is at a concentration range of about 0.04% w / w to about 0.12% w / w.

[0081] Thus, in an embodiment of the present disclosure, the raw materials such as raw lime at a concentration range of about 81-97% and values and ranges therebetween for example 81%, 82%, 82%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96% and 97%; aluminium at a concentration range of about 1-8% and values and ranges therebetween for example 1.0%, 1.5%, 2.0%, 2.5%, 3.0%, 3.5%, 4.0%, 4.5%, 5.0%, 5.5%, 6.0%, 6.5%, 7.0%, 7.5% and 8%; slag fluidizer such as cryolite at a concentration range of about 2-6% and values and ranges therebetween for example 2.0%, 2.5%, 3.0%, 3.5%, 4.0%, 4.5%, 5.0%, 5.5%, and 6.0%; and reagent fluidizer such as silicon oil at a concentration range of about 0.04-0.12% and values and ranges therebetween for example 0.04%, 0.05%, 0.06%, 0.07%, 0.08%, 0.09%, 0.10%, 0.11% and 0.12% are mixed and added in the grinding media.

[0082] In an embodiment of the present disclosure, the composition is prepared by considering the oxygen potential in the hot metal bath by stoichiometric calculations.

[0083] The present disclosure also provides a process for desulphurization of a hot metal, the process comprising pneumatically injecting the desulphurization reagent composition as prepared above, into the hot metal by applying a carrier gas to obtain desulphurized hot metal. In an embodiment of the present disclosure, the desulphurization reagent composition is injected into the hot metal for desulphurization through one or more of a mono-injection process or a coinjection process.

[0084] Thus, in some embodiments, the desulphurization reagent composition is injected into the hot metal for desulphurization through a co-inj ection process, along with magnesium, but where the use of the desulphurization reagent composition of the present disclosure reduces the need for magnesium alongside the reagent, when compared to a conventional setting where higher amount of magnesium would need to be accompanied alongside conventional lime-based reagent, devoid of aluminium.

[0085] Similarly, in some embodiments, the desulphurization reagent composition is injected into the hot metal for desulphurization through a mono-injection process, without magnesium, and where the use of the desulphurization reagent composition of the present disclosure eliminates the need for magnesium alongside the reagent, when compared to a conventional setting where magnesium would need to be mandatorily accompanied alongside conventional lime-based reagent, devoid of aluminium.

[0086] In an embodiment of the present disclosure, the desulphurization reagent composition is injected by the pneumatic injection via a refractory lance or dispensing vessel.

[0087] In an embodiment of the present disclosure, the carrier gas is selected from a group comprising nitrogen (N), helium (He), neon (Ne), argon (Ar), krypton (Kr), xenon (Xe) and radon (Rn), or any combination thereof.

[0088] In an embodiment of the present disclosure, the carrier gas is nitrogen (N).

[0089] In an embodiment of the present disclosure, the injecting of the desulphurization reagent composition to the hot metal is carried out at a temperature of about 1250°C to 1450°C.

[0090] In an embodiment of the present disclosure, the injecting of the desulphurization reagent composition to the hot metal is carried out at a temperature of about 1300°C to 1410°C. In an embodiment of the present disclosure, the process reduces the oxygen potential and sulphur content in hot metal desulphurization, when compared with a process employing a conventional lime-based reagent devoid of aluminium powder.

[0091] In an embodiment of the present disclosure, the process reduces magnesium consumption by at least about 14% to about 20% when compared with a process employing a conventional lime-based reagent devoid of aluminium powder.

[0092] In an embodiment of the present disclosure, the process reduces the desulphurization cycle time by about 2 minutes when compared with a process employing a conventional lime-based reagent devoid of aluminium powder.

[0093] In an embodiment of the present disclosure, the process reduces the desulphurization cost by about 3% when compared with the conventional lime-based reagents.

[0094] In an embodiment of the present disclosure, partially or fully replacing the need of employing magnesium alongside an existing or conventional lime-based DS reagent, with aluminium, and employing the said reagent for hot metal desulphurization reduces the oxygen potential in hot metal desulphurization.

[0095] In an embodiment of the present disclosure, the partial or full replacement of the need of using magnesium alongside an existing or conventional lime-based DS reagent, with aluminium, and employing the said reagent for hot metal desulphurization results in similar or identical deoxidation, while making the process safer and more economical.

[0096] In an embodiment of the present disclosure, the partial or full replacement of the need of using magnesium alongside an existing or conventional lime-based DS reagent, with aluminium, and employing the said reagent for hot metal desulphurization results in better deoxidation and increased efficiency of desulphurization. In another embodiment of the present disclosure, the partial or full replacement of the need of using magnesium alongside an existing or conventional lime-based DS reagent, with aluminium, and employing the said reagent for hot metal desulphurization reduces the oxygen potential in the hot metal and increases the desulphurization efficiency.

[0097] In another embodiment of the present disclosure, the partial or full replacement of the need of using magnesium alongside an existing or conventional lime-based DS reagent, with aluminium, helps in reducing the magnesium consumption and subsequently the cost of DS process.

[0098] In an embodiment of the present disclosure, boiling point of the aluminium is about 2470°C, thereby making it less volatile than magnesium, and aiding in enhancing the deoxidising efficiency of the DS reagent or composition.

[0099] In an embodiment of the present disclosure, the DS reagent or composition of the present disclosure is used in integrated steel plants wherein hot metal desulphurization is performed by injection process and other similar processes.

[0100] In some embodiment of the present disclosure, the desulphurization reagent or composition reduces the sulphur content in hot metal. For example, in some exemplary non-limiting embodiments, the desulphurization reagent reduces sulphur content in hot metal from about 0.060% w / w to about 0.009% w / w, from about 0.054% w / w to about 0.009% w / w, from about 0.060% w / w to about 0.010% w / w, and from about 0.054% w / w to about 0.010% w / w.

[0101] In some embodiment of the present disclosure, the desulphurization reagent or composition reduces cycle time by about 2 to 4 minutes, including values and ranges therebetween. For example, in some exemplary non-limiting embodiments, the desulphurization reagent reduces cycle time from about 32 minutes to about 30 minutes, including values and ranges therebetween.

[0102] In some embodiments of the present disclosure, the desulphurization reagent or composition reduces material consumption, contributing to cost savings and sustainability.. For example, in some exemplary non-limiting embodiments, the material consumption is reduced from about 3.25 kg / thm to about 3.00 kg / thm..

[0103] In some embodiments of the present disclosure, the desulphurization reagent or composition reduces the need for consumption of magnesium (MAG97 - reagent comprising about 97% magnesium) alongside conventional lime-based DS reagents. For example, in some exemplary non-limiting embodiments, the MAG97 consumption is reduced from about 0.45 kg / thm to about 0.362 kg / thm.

[0104] The present disclosure therefore also provides a method of reducing or eliminating consumption of magnesium alongside a conventional lime-based desulphurization reagent, said method comprising including aluminium at a concentration of about 1% w / w to about 8% w / w in the said conventional reagent.

[0105] In an embodiment of the present disclosure, the aluminium is included at a concentration of about 3% w / w to about 6% w / w in the reagent.

[0106] In an embodiment of the present disclosure, the aluminium is present in powder form, at a concentration of about 4% w / w.

[0107] In an embodiment of the present disclosure, wherein the method completely eliminates or reduces need for magnesium consumption alongside the reagent by at least about 14% to about 20% when compared with a process employing a conventional lime-based reagent devoid of aluminium powder.

[0108] In some embodiments of the present disclosure, the desulphurization reagent operates effectively across a defined range of hot metal temperatures, ensuring process stability. The hot metal temperature range is optimized between about 1250°C and 1450°C, including values and ranges therebetween. For example, in some exemplary non-limiting embodiments, the hot metal temperature range is from about 1330°C to about 1450°C and from about 1335°C to about 1450°C.

[0109] In some embodiments of the present disclosure, the desulphurization reagent or composition operates across a defined range of hot metal temperatures. The hot metal temperature range is optimized between about 1250°C and 1450°C, including values and ranges therebetween. For example, in some exemplary, non-limiting embodiments, the hot metal temperature range is from about 1250°C to 1450°C, from about 1250°C to 1400°C, from about 1250°C to 1350°C, from about 1250°C to 1300°C, and from about 1250°C to 1275°C. In some embodiments, the temperature range extends from about 1275°C to 1450°C, from about 1275°C to 1400°C, from about 1275°C to 1350°C, from about 1275°C to 1325°C, and from about 1275°C to 1300°C. In further embodiments, the hot metal temperature range is from about 1300°C to 1450°C, from about 1300°C to 1400°C, from about 1300°C to 1410°C, from about 1300°C to 1350°C, from about 1300°C to 1325°C, and from about 1300°C to 1310°C. In some embodiments, the range extends from about 1325°C to 1450°C, from about 1325°C to 1400°C, from about 1325°C to 1375°C, from about 1325°C to 1350°C, and from about 1325°C to 1335°C. In additional embodiments, the temperature range is from about 1350°C to 1450°C, from about 1350°C to 1425°C, from about 1350°C to 1400°C, from about 1350°C to 1375°C, from about 1350°C to 1355°C, and from about 1355°C to 1450°C.

[0110] In some embodiments of the present disclosure, the desulphurization reagent or composition leads to a significant reduction in the overall cost of the desulphurization process. The cost reduction ranges from about 3% to 5%, including values and ranges therebetween. For example, in some exemplary non-limiting embodiments, the cost reduction is from about 3% to about 5%, from about 3% to about 4.9%, from about 3% to about 4.8%, from about 3% to about 4.7%, from about 3% to about 4.6%, from about 3% to about 4.5%, from about 3% to about 4.4%, from about 3% to about 4.3%, from about 3% to about 4.2%, from about 3% to about 4.1%, from about 3% to about 4.0%, from about 3% to about 3.9%, from about 3% to about 3.8%, from about 3% to about 3.7%, from about 3% to about 3.6%, from about 3% to about 3.5%, from about 3% to about 3.4%, from about 3% to about 3.3%, from about 3% to about 3.2%, and from about 3% to about 3.1%. In some embodiments, the cost reduction is from about 3.1% to about 5%, from about 3.2% to about 5%, from about 3.3% to about 5%, from about 3.4% to about 5%, from about 3.5% to about 5%, from about 3.6% to about 5%, from about 3.7% to about 5%, from about 3.8% to about 5%, from about 3.9% to about 5%, from about 4.0% to about 5%, from about 4.1% to about 5%, from about 4.2% to about 5%, from about 4.3% to about 5%, from about 4.4% to about 5%, from about 4.5% to about 5%, from about 4.6% to about 5%, from about 4.7% to about 5%, from about 4.8% to about 5%, and from about 4.9% to about 5%. These values illustrate the various levels of cost reduction achievable using the desulphurization reagent, ensuring economic benefits and enhanced process efficiency. For example, in some exemplary non-limiting embodiments, the Desulphurization reagent or composition cost is reduced to about 0.97X of the conventional reagent cost, with a reduction of over 3% compared to conventional lime-based desulphurization reagents having cost X.

[0111] In some embodiments of the present disclosure, the conventional lime-based desulphurization reagent comprises Cao, cryolite, and silicon oil, and is devoid of aluminium.

[0112] In an exemplary non-limiting embodiment of the present disclosure, the conventional lime-based desulphurization reagent comprises about 95.92% Cao, about 4% cryolite, and about 0.08% silicon oil, and is devoid of aluminium.

[0113] In embodiments of the above-described process(s), the components of the desulphurization reagent and their concentrations or wt% are based on the embodiments of the product (desulphurization reagent) as described above. For the sake of brevity and to avoid repetition, each of those embodiments are not being reiterated in the context of the process(s). However, each of the said embodiments, completely fall within the purview of the process(s) for desulphurization of steel.

[0114] Without limiting the scope of the present disclosure as described above in any way, the present disclosure has been further explained through the example provided below.

[0115] It is to be noted that the present disclosure is susceptible to modifications, changes, and adaptations by those skilled in the art. Such modifications, changes adaptations are intended to be within the scope of the present disclosure.

[0116] Advantages

[0117] (1) The DS reagent or composition of the present disclosure provides an inexpensive alternative to existing DS reagent comprising a deoxidizer in the form of magnesium, because of the partial or full replacement of magnesium with aluminium.

[0118] (2) The DS reagent or composition of the present disclosure reduces the risk of hazards associated with storage and use of magnesium as a deoxidizer in steel making. EXAMPLES

[0119] Example 1: Composition of the desulphurization reagent or composition A DS reagent composition of the present disclosure is provided in table 1 below:

[0120] Table 1

[0121] The aforementioned composition of table 1 was prepared by mixing the raw materials as indicated in table 1. The raw materials were added in a grinding media and ground for about 12 to about 15 minutes and pneumatically transported using a carrier gas selected from a group comprising nitrogen (N), helium (He), neon (Ne), argon (Ar), krypton (Kr), xenon (Xe) and radon (Rn), or any combination thereof. The finished product was stored in finished goods storage silos. Subsequently, the said composition was employed for desulphurization of hot metal.

[0122] Example 2: Performance evaluation of the desulphurization reagent or composition

[0123] The desulphurization reagent of the present disclosure was tested against a conventional lime-based reagent in terms of desulphurization efficiency and process parameters.

[0124] Table 3

[0125] The performance of the desulphurization reagent or composition of the present disclosure was assessed in comparison with a conventional lime-based desulphurization reagent which is devoid of aluminium. The conventional lime-based desulphurization reagent comprises about 95.92% Cao, about 4% cryolite, and about 0.08% silicon oil. The evaluation focused on key parameters such as desulphurization efficiency, reagent consumption, cycle time, and cost-effectiveness. The results indicate the following key observations:

[0126] The desulphurization reagent was compared with a conventional lime-based reagent under similar conditions. Both reagents achieved the same final sulphur content of 0.009% from an initial sulphur content of 0.060%, with a target sulphur of 0.010%. However, the reagent of the present disclosure reduced the cycle time by 2 minutes from 32 minutes to 30 minutes, enhancing productivity. Material consumption decreased by about 7.7%, from 3.25 kg / thm with the conventional reagent to 3.00 kg / thm with the desulphurization reagent or composition of present disclosure. Magnesium consumption (MAG97) was reduced by about 20%, from 0.45 kg / thm to 0.362 kg / thm, further improving cost-efficiency. The hot metal temperature is aboutl300-1410°C, and the hazard level was lower for the reagent of present disclosure (medium vs. high for the conventional reagent). Lastly, the desulphurization reagent cost of the reagent of the present disclosure was also lower by over 3% when compared to the conventional reagent.

[0127] Throughout this specification, the word “comprise”, or variations such as “comprises” or “comprising” 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. Similarly, terms such as “include” or “have” or “contain” and all their variations are inclusive and 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.

[0128] The terms "about" or “approximately” are used herein to mean approximately, in the region of, roughly, or around. When the term "about" is used in conjunction with a numerical value / range, it modifies that value / range by extending the boundaries above and below the numerical value(s) set forth. In general, the term "about" is used herein to modify a numerical value(s) or a measurable value(s) such as a parameter, an amount, a temporal duration, and the like, above and below the stated value(s) by a variance of + / -20% or less, + / -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 in the disclosed disclosure, and achieves the desired results and / or advantages as disclosed in the present disclosure. It is to be understood that the value to which the modifier “about” or “approximately” refers is itself also specifically, and preferably, disclosed.

[0129] 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. As used in this specification and the appended claims, the singular forms “a,” “an” and “the” includes both singular and plural references unless the content clearly dictates otherwise. 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 invention to achieve one or more of the desired objects or results. As such, the terms “a” (or “an”), “one or more”, and “at least one” can be used interchangeably herein.

[0130] Numerical ranges stated in the form ‘from x to y’ include the values mentioned and those values that he 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. As regards 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.

[0131] Any discussion of documents, acts, materials, devices, articles and the like that has been included in this specification is solely for the purpose of providing a context for the invention. It is not to be taken as an admission that any or all of these matters form a part of the prior art base or were common general knowledge in the field relevant to the invention as it existed anywhere before the priority date of this application.

[0132] While considerable emphasis has been placed herein on the particular features of this invention, 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 invention. These and other modifications in the nature of the invention or the preferred embodiments will be apparent to those skilled in the art from the invention herein, whereby it is to be distinctly understood that the foregoing descriptive matter is to be interpreted merely as illustrative of the invention and not as a limitation.

[0133] All references, articles, publications, general inventions 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 composition comprising: a. raw lime at a concentration of about 81% w / w to about 97% w / w; b. aluminium at a concentration of about 1% w / w to about 8% w / w; c. slag fluidizer at a concentration of about 2% w / w to about 6% w / w; and d. reagent fluidizer at a concentration of about 0.04% to about 0.12%.

2. The desulphurization reagent composition as claimed in claim 1, comprising: a. raw lime at a concentration of about 87% w / w to about 92% w / w; b. aluminium at a concentration of about 3% w / w to about 6% w / w; c. slag fluidizer at a concentration of about 3% w / w to about 5% w / w; and d. reagent fluidizer at a concentration of about 0.06% to about 0.09%.

3. The desulphurization reagent composition as claimed in any of claims 1-2 comprising: a. raw lime at a concentration of about 91.92% w / w; b. aluminium at a concentration of about 4% w / w; c. slag fluidizer at a concentration of about 4% w / w; and d. reagent fluidizer at a concentration of about 0.08%.

4. The desulphurization reagent composition as claimed in any of claims 1 to 3, wherein the raw lime has a purity of about 90-92%.

5. The desulphurization reagent composition as claimed in any of claims 1 to 4, wherein the aluminium is present in powder form; wherein the slag fluidizer is selected from a group comprising cryolite, soda glass, spar, alumina powder, soda ash, fluorspar, borax and bauxite or any combination thereof; and wherein the reagent fluidizer is selected from a group comprising silicon oil and resil oil.

6. The desulphurization reagent composition as claimed in claim 5, wherein the slag fluidizer is cryolite; and wherein the cryolite is present in powder or lump form.

7. The desulphurization reagent composition as claimed in claim 5, wherein the reagent fluidizer is silicon oil.

8. A process for preparing the desulphurization reagent composition as claimed in claim 1, the process comprising: a. mixing raw lime, aluminium, slag fluidizer, and reagent fluidizer to obtain a mixture; b. grinding the mixture for about 12-15 minutes to obtain the desulphurization reagent in a powder form.

9. The process as claimed in claim 8, wherein the raw lime is at a concentration of about 81% w / w to about 97% w / w, the aluminium is at a concentration of about 1% w / w to about 8% w / w; the slag fluidizer is at a concentration of about 2% w / w to about 6% w / w; and the reagent fluidizer is at a concentration of about 0.04% w / w to about 0.12%.

10. The process as claimed in any of claims 8 to 9, wherein the slag fluidizer is cryolite and the reagent fluidizer is silicon oil.

11. A process for desulphurization of a hot metal, the process comprising pneumatically injecting the desulphurization reagent composition as claimed in any of claims 1 to 10, into the hot metal by applying a carrier gas to obtain desulphurized hot metal.

12. The process as claimed in claim 11, wherein the desulphurization reagent composition is injected into the hot metal for desulphurization through one or more of a mono-injection process or a co-inj ection process.

13. The process as claimed in any of claims 11 to 12, wherein the desulphurization reagent composition is injected by the pneumatic injection via a refractory lance or dispensing vessel; and wherein the carrier gas is selected from a group comprising nitrogen (N), helium (He), neon (Ne), argon (Ar), krypton (Kr), xenon (Xe) and radon (Rn), or any combination thereof.

14. The process as claimed in any of claims 11 to 13, wherein the injecting of the desulphurization reagent composition to the hot metal is carried out at a temperature of about 1250°C to 1450°C.

15. The process as claimed any of claims 11 to 14, wherein the process reduces the oxygen potential and sulphur content in hot metal desulphurization, when compared with a process employing a conventional lime-based reagent devoid of aluminium powder; wherein the process reduces magnesium consumption by at least about 14% to about 20% when compared with a process employing a conventional lime-based reagent devoid of aluminium powder; wherein the process reduces the desulphurization cycle time by about 2 minutes when compared with a process employing a conventional lime-based reagent devoid of aluminium powder; and wherein the process reduces the desulphurization cost by about 3% when compared with the conventional lime-based reagents.

16. A method of reducing or eliminating consumption of magnesium alongside a conventional lime-based desulphurization reagent, said method comprising including aluminium at a concentration of about 1% w / w to about 8% w / w in the said conventional reagent.

17. The method as claimed in claim 16, wherein the aluminium is included at a concentration of about 3% w / w to about 6% w / w in the reagent.

18. The method as claimed in any of claims 16 to 17, wherein the aluminium is present in powder form, at a concentration of about 4% w / w.

19. The method as claimed any of claims 16 to 18, wherein the method completely eliminates or reduces need for magnesium consumption alongside the reagent by at least about 14% to about 20% when compared with a process employing a conventional lime-based reagent devoid of aluminium powder.

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