Method of producing SLAG conditioner from electric arc furnace slag

Abstract

A slag conditioner is produced by a process including the steps of, mixing a pre-fused slag base component, an alumina brick component having 0% to 25% magnesium oxide, separated ladle shrouds formed of aluminum graphite including 0% to 15% carbon, and a magnesia brick material including 75% to 100% MgO. During the mixing step moisture content of the slag conditioner mixture is maintained below 2%, a lime to alumina ratio in the slag conditioner mixture is maintained at approximately 1:1, and a content of magnesium oxide in the slag conditioner mixture is maintained at 6% to 20% by weight.

Description

METHOD OF PRODUCING SLAG CONDITIONER FROM ELECTRIC ARCFURNACE SLAGCROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This patent claims priority to U.S. Provisional Application 63 / 656,639, filed on June 6, 2024. The disclosure of this prior application is considered part of the disclosure of this application and is hereby incorporated by reference in its entirety.FIELD

[0002] The present disclosure relates generally to a method of producing slag conditioner products using byproducts from refining and other manufacturing processes.BACKGROUND

[0003] This section provides background information related to the present disclosure and is not necessarily prior art.

[0004] The steelmaking industry is continuously seeking more sustainable practices, particularly concerning the management of its material waste streams. A primary challenge lies in the environmentally responsible and economically viable utilization of these byproducts, moving away from traditional disposal methods towards circular economy approaches. This imperative is driven by both the need to conserve natural resources and to minimize the environmental footprint associated with large-scale industrial operations.

[0005] A notable byproduct generated in substantial quantities during steelmaking processes, such as in electric arc furnaces (EAF) and basic oxygen furnaces (BOF), is slag. Historically, the disposal of slag has presented challenges, and there is a persistent need to develop methods that can transform this material from a waste product into a valuable input for other processes or products. Efficiently utilizing slag not only addresses waste reduction but also offers the potential to create new materials that can enhance industrial processes.

[0006] The present disclosure addresses these challenges by providing methods for producing slag conditioners, which are crucial for optimizing the steelmaking process. These new slag conditioners aim to be more sustainable by incorporating recycled materials, such as EAF slag and other industrial byproducts like waste fiberglass. Furthermore, specific formulations are designedto improve operational efficiencies and reduce negative impacts, for example, by creating slag conditioners that quickly melt at furnace tapping temperatures or by eliminating the need for aggressive fluidizers like Spar, which can cause damage to equipment.SUMMARY

[0007] An aspect of the disclosure provides a 50-50 ladle calcium aluminate slag conditioner. The slag conditioner is produced by a process including the steps of, providing a pre-fused slag base component, providing an alumina brick component having 0% to 25% MgO, providing separated ladle shrouds formed of aluminum graphite including 0% to 15% carbon, providing a magnesia brick material including 75% to 100% MgO, and mixing the slag base component, the alumina brick component, the separated ladle shrouds, and the magnesia brick material to form a slag conditioner mixture, wherein during the mixing step: moisture content of the slag conditioner mixture is maintained below 2%, a lime to alumina ratio in the slag conditioner mixture is maintained at approximately 1 : 1, and a content of magnesium oxide in the slag conditioner mixture is maintained at 6% to 20% by weight.

[0008] Aspects of the disclosure may include one or more of the following optional features. In some examples, the pre-fused slag base component is Furnastone™. In some implementations, the step of mixing the slag base component includes mixing approximately 77% by weight of the pre-fused slag base component, approximately 10% by weight of the alumina brick component, approximately 9% by weight of the separated ladle shrouds, and approximately 3% by weight of the magnesia brick material.

[0009] In some configurations, the step of mixing the slag base component includes mixing 55- 85% by weight of the pre-fused slag base component, 5-25% by weight of the alumina brick component, 5-15% by weight of the separated ladle shrouds, and 0-10% by weight of the magnesia brick material, the process further includes pre-fusing one or more of the alumina brick component, the separated ladle shrouds component, or the magnesia brick material prior to mixing step.

[0010] In some examples, the slag conditioner product formed by the process is a pre-fused slag conditioner. In some implementations, the pre-fused slag conditioner product is configured to melt at a temperature of approximately 1565° Celsius. In some examples, the slag conditioner is produced by a process including the steps of providing waste fiberglass having a silica (SiCh) content of 85% to 100%, providing separated ladle shrouds formed of aluminum graphite including0% to 15% carbon, providing calcined soda ash including 35% to 65% sodium oxide (Na2O), providing a magnesia brick material including 75% to 100% magnesium oxide (MgO), and mixing the waste fiberglass, the separated ladle shrouds, the calcined soda ash, and the magnesia brick to form a slag conditioner mixture, wherein during the mixing step: moisture content of the slag conditioner mixture is maintained below 2%, a lime to silica ratio in the slag conditioner mixture is maintained at approximately 1 : 1, a content of magnesium oxide in the slag conditioner mixture is maintained at 6% to 20% by weight.

[0011] In some examples, the mixing step includes mixing approximately 63% by weight of the waste fiberglass, approximately 19% by weight of the separated ladle shrouds, approximately 9% by weight of the calcined soda ash, and approximately 9% by weight of the magnesia brick material. 10. In some implementations, the mixing step includes mixing 50-85% by weight of the waste fiberglass, 5-25% by weight of the separated ladle shrouds, 5-25% by weight of the calcined soda ash, and 0-15% by weight of the magnesia brick material.

[0012] In some implementations, the ladle silicate flux slag conditioner produced is a pre-fused slag conditioner. In some configurations, the pre-fused slag conditioner is configured to melting at a basic oxygen furnace or electric arc furnace tapping temperature of approximately 1371° Celsius. In some examples, the waste fiberglass, the separated ladle shrouds, the calcined soda ash, and the magnesia brick material provided in the process each have a particle size of less than or equal to approximately % inch.

[0013] Another aspect of the disclosure provides a tundish calcium aluminate basic tundish flux slag conditioner. The slag conditioner is produced by a process including providing a blast furnace slag, providing lime, providing Furnastone™, providing waste fiberglass, providing a magnesia brick material, providing sawdust, and mixing the provided components to form a slag conditioner mixture, wherein during the mixing: moisture content of the slag conditioner mixture is maintained below 2%, a lime to alumina ratio in the slag conditioner mixture is maintained at approximately 1 : 1, and a content of magnesium oxide in the slag conditioner mixture is maintained at 8% to 10% by weight.

[0014] Aspects of the disclosure may include one or more of the following optional features. In some examples, the mixing step includes mixing approximately 42% by weight of the blast furnace slag, approximately 38% by weight of lime, approximately 8% by weight of Furnastone™,approximately 8% by weight of waste fiberglass, approximately 4% by weight of the magnesia brick material, and approximately 2% by weight of sawdust.

[0015] In some examples, the mixing includes mixing, 35-50% by weight of the blast furnace slag, 25-45% by weight of lime, 0-15% by weight of Furnastone1M, 0-15% by weight of waste fiberglass, 0-10% by weight of the magnesia brick material, and 0-10% by weight of sawdust.

[0016] In some implementations, the provided blast furnace slag is 30A blast furnace slag produced by Edw. C. Levy Co ™.

[0017] The details of one or more implementations of the disclosure are set forth in the accompanying drawings and the description below. Other aspects, features, and advantages will be apparent from the description, the drawings, and the claims.DRAWINGS

[0018] The drawings described herein are for illustrative purposes only of selected configurations and not all possible implementations, and are not intended to limit the scope of the present disclosure.

[0019] FIG. l is a flow chart illustrating an example set of steps for producing a slag conditioner according to the present disclosure.

[0020] FIG. 2 is a flow chart illustrating an example set of steps for producing a slag conditioner according to the present disclosure.

[0021] FIG. 3 is a flow chart illustrating an example set of steps for producing a slag conditioner according to the present disclosure.

[0022] Corresponding reference numerals indicate corresponding parts throughout the drawings.DETAILED DESCRIPTION

[0023] Example configurations will now be described more fully with reference to the accompanying drawings. Example configurations are provided so that this disclosure will be thorough, and will fully convey the scope of the disclosure to those of ordinary skill in the art. Specific details are set forth such as examples of specific components, devices, and methods, to provide a thorough understanding of configurations of the present disclosure. It will be apparent to those of ordinary skill in the art that specific details need not be employed, that exampleconfigurations may be embodied in many different forms, and that the specific details and the example configurations should not be construed to limit the scope of the disclosure.Slag Conditioner Example 1: 50-50 Ladle Calcium Aluminate

[0024] One example of a slag conditioner according to the present disclosure includes a 50-50 ladle calcium aluminate. This slag conditioner is pre-fused (i.e., pre-melted) so that it quickly melts at BOF / EAF tapping temperature (1565° Celsius / 2850° Fahrenheit). By pre-fusing the slag conditioner, the overall melting temperature of the slag conditioner is reduced relative to conditioners that are not pre-fused. The pre-fused slag conditioner further allows the immediate addition and fusing of Lime without arcing to start desulfurization during tapping. In turn, this protects the steel and alloys like aluminum from reoxidation and poor yield. Further, this composition is perfectly compatible with refractory systems typical for these steelmaking operations to prevent excessive bottom and sidewall wear.

[0025] Referring to FIG. 1, the method 200 of forming the first example of the slag conditioner 205 is shown. In an initial step 202, four components 20 la-20 Id of the slag conditioner 204 are provided and mixed to form a slag conditioner mixture 203, as shown in Table 1 below. The first component includes a slag base component 201a, such as Fumastone™ provided by Butler Mill Service™. In this example, the slag base is a pre-fused base material that allows for a lower overall melting temperature relative to slag base components that are not pre-fused.

[0026] A second component 201b of the slag conditioner includes an alumina brick component in a range including 0% to 25% MgO. Providing the alumina brick component in a range exceeding 25% may increase the melting temperature of the final slag conditioner product above acceptable ranges for use in the steelmaking process.

[0027] A third component 201c of the slag conditioner includes separated ladle shrouds formed of aluminum graphite including 0% to 15% carbon. Utilizing these separated ladle shrouds, which are understood to be a recycled refractory component from steelmaking operations, offers an advantage over using virgin aluminum graphite by contributing to the sustainable utilization of materials waste streams. This approach helps in reducing the reliance on virgin raw materials and repurposes materials recovered from spent refractory components (e.g., ladle shrouds).

[0028] A fourth component 20 Id of the slag conditioner includes a magnesia brick material including 75% to 100% magnesium oxide (MgO). Magnesia bricks are often used to linesteelmaking furnaces and ladles. Over time and due to harsh operating conditions (extreme temperatures, chemical attack by molten metal and slag), these refractory linings wear out and degrade. Thus, steelmaking vessels often require relining, which involves tearing out the old, worn-out refractory material. These discarded refractory materials, including spent magnesia bricks, generally become a significant solid waste stream or industrial byproduct of the steelmaking operations. By incorporating the magnesia brick byproduct, this method eliminates the need for producing (i.e., separating) raw magnesium oxide from dolostone. An example of a suitable magnesia brick material includes Magnesia Brick % x 0 produced by SDI Butler™. The magnesium oxide provided by this component is integral to the overall composition of the slag conditioner 205, which is designed to be compatible with refractory systems typical for steelmaking operations, thereby helping to prevent excessive bottom and sidewall wear.

[0029] Optionally, one or more of the second component 201b, the third component 201c, and / or the fourth component 201d (collectively, the “additives”) may be pre-fused, which would further lower the overall melting temperature of the slag conditioner 205. Pre-fusing the additives 201b-201d is not necessary in conventional steelmaking process as a composition including 77% of the slag base is sufficient to add in non-pre-fused components. During the mixing process, moisture content of the slag conditioner mixture 203 is maintained below 2%, a lime to alumina ratio is maintained at approximately 1 : 1, and a content of magnesium oxide is maintained at 6% to 20% by weight. The blended slag conditioner 205 is introduced directly into the steelmaking process at step 206.Table 1: Formulation for 50-50 Ladle Calcium AluminateMaterial % Weight RangeSDI Butler Furnastone %” x 0 77% 55-85%SDI Butler Alumina Brick % x 0 10% 5-25%SDI Butler Separated Ladle Shrouds (Alumina Graphite) % x 0 9% 5-15%SDI Butler Magnesia Brick % x 0 3% 0-10%Slag Conditioner Example 2: Ladle Silicate Flux

[0030] Another example of a slag conditioner 305 provides a ladle silicate flux, which is designed to eliminate a need for Spar (CaF2) or Potash Feldspar. This slag conditioner 305 is pre-fused so that it quickly melts at basic oxygen furnace (BOF) and electric arc furnace (EAF) tapping temperature (1371° Celsius / 2500° Fahrenheit). The slag conditioner 305 may be added with lime additions to dilute the fluidizer and prevent damage to dolomitic ladles. This composition allows the immediate addition and fusing of lime additions without arcing to start desulfurization during tapping. Advantageously, this composition eliminates the need for Spar, which is a relatively aggressive form of fluidizer that can damage ladles.

[0031] Referring to FIG. 2, the method 300 of forming another example of the slag conditioner 305 is shown. In an initial step 302, four components 301a-301d of the slag conditioner are provided and mixed to form a slag conditioner mixture 303, as shown in Table 2 below.

[0032] The first component 301a includes waste fiberglass having a silica (SiCh) content of 85% to 100%. Waste fiberglass may be obtained as a byproduct of manufacturing processes that utilize fiberglass components (e.g., boat hulls, aircraft components, bathtubs, etc ). By utilizing waste fiberglass as a component within the slag conditioner 305, the fiberglass is removed from conventional waste streams (e.g., landfills).

[0033] A second component 301b of the slag conditioner mixture 303 includes separated ladle shrouds formed of aluminum graphite including 0% to 15% carbon, as discussed previously A third component 301c of the slag conditioner mixture 303 includes a calcined soda ash 35% to 65% Na2O. A fourth component 301 d of the slag conditioner includes a magnesia brick material including 75% to 100% MgO, as discussed previously.

[0034] During the mixing process, moisture content of the slag conditioner is maintained below 2%, a lime to silica ratio is maintained at approximately 1 : 1, and a content of magnesium oxide is maintained at 6% to 20% by weight. The blended slag conditioner 304 is introduced directly into the steelmaking process at step 306.Table 2: Formulation for Ladle Silicate FluxMaterial % Weight RangeWaste Fiberglass %” x 0 63% 50-85%SDI Butler™ Separated Ladle Shrouds (Alumina Graphite) % x 0 19% 5-25%Calcined Soda Ash % x 0 9% 5-25%SDI Butler™ Magnesia Brick % x 0 9% 0- 15%Slag Conditioner Example 3: Tundish Calcium Aluminate - Basic Tundish Flux

[0035] In yet another example, a slag conditioner 405 is provided as a basic tundish flux including tundish calcium aluminate. This example of the slag conditioner 405 is a direct replacement for Performix SD-021Mand is designed to be very low density and very low melting temperature, which allows the slag to act as an insulator in the steelmaking process. Lower moisture content minimizes free hydrogen that can dissolve into the steel.

[0036] Referring to FIG. 3, the method 400 of forming the third example of the slag conditioner 405 is shown. In an initial step 402, components 401a-401f of the slag conditioner 405 are provided and mixed to form a slag conditioner mixture 403, as shown in Table 3 below. The first component includes a blast furnace slag, such as 30A blast furnace slag produced by Edw. C. Levy Co.™. A second component 401b of the slag conditioner mixture 403 includes Lime. A third component 401c of the slag conditioner mixture 403 includes Fumastone™ provided by Edw. C. Levy Co ™. A fourth component 401d of the slag conditioner mixture 403 includes waste fiberglass. A fifth component 40 le of the slag conditioner mixture 403 includes a magnesia brick material. A sixth component 40 If of the slag conditioner mixture 403 includes sawdust. During the mixing process, moisture content of the slag conditioner is maintained below 2%, a lime to alumina ratio is maintained at approximately 1 : 1, and a content of magnesium oxide is maintained at 8% to 10% by weight. The blended slag conditioner 405 is introduced directly into the steelmaking process at step 406.Table 3: Formulation for Tundish Calcium Aluminate - Basic Tundish FluxMaterial % Weight RangeEdw. C. Levy Co. 30A BF Slag3 / / ’ x O 42% 35-50%Lime 38% 25-45%Edw. C. Levy Co. Furnastone %” x 0 8% 0-15%Waste Fiberglass %” x 0 8% 0-15%SDI Butler™ Magnesia Brick %” x 0 4% 0-10%Sawdust A” x 0 2% 0-10%

[0037] The terminology used herein is for the purpose of describing particular example configurations only and is not intended to be limiting. As used herein, the singular articles “a,” “an,” and “the” may be intended to include the plural forms as well, unless the context clearly indicates otherwise. The terms “comprises,” “comprising,” “including,” and “having,” are inclusive and therefore specify the presence of features, steps, operations, elements, and / or components, but do not preclude the presence or addition of one or more other features, steps, operations, elements, components, and / or groups thereof. The method steps, processes, and operations described herein are not to be construed as necessarily requiring their performance in the particular order discussed or illustrated, unless specifically identified as an order of performance. Additional or alternative steps may be employed.

[0038] When an element or layer is referred to as being “on,” “engaged to,” “connected to,” “attached to,” or “coupled to” another element or layer, it may be directly on, engaged, connected, attached, or coupled to the other element or layer, or intervening elements or layers may be present. In contrast, when an element is referred to as being “directly on,” “directly engaged to,” “directly connected to,” “directly attached to,” or “directly coupled to” another element or layer, there may be no intervening elements or layers present. Other words used to describe the relationship between elements should be interpreted in a like fashion (e.g., “between” versus “directly between,” “adjacent” versus “directly adjacent,” etc.). As used herein, the term “and / or” includes any and all combinations of one or more of the associated listed items.

[0039] The terms first, second, third, etc. may be used herein to describe various elements, components, regions, layers and / or sections. These elements, components, regions, layers and / or sections should not be limited by these terms. These terms may be only used to distinguish one element, component, region, layer or section from another region, layer or section. Terms such as “first,” “second,” and other numerical terms do not imply a sequence or order unless clearly indicated by the context. Thus, a first element, component, region, layer or section discussed below could be termed a second element, component, region, layer or section without departing from the teachings of the example configurations.

[0040] The foregoing description has been provided for purposes of illustration and description. It is not intended to be exhaustive or to limit the disclosure. Individual elements or features of a particular configuration are generally not limited to that particular configuration, but, where applicable, are interchangeable and can be used in a selected configuration, even if not specificallyshown or described. The same may also be varied in many ways. Such variations are not to be regarded as a departure from the disclosure, and all such modifications are intended to be included within the scope of the disclosure.

Claims

CLAIMSWhat is claimed is:

1. A 50-50 ladle calcium aluminate slag conditioner, the slag conditioner being produced by a process comprising the steps of: providing a pre-fused slag base component; providing an alumina brick component having 0% to 25% MgO; providing separated ladle shrouds formed of aluminum graphite including 0% to 15% carbon; providing a magnesia brick material including 75% to 100% MgO; and mixing the slag base component, the alumina brick component, the separated ladle shrouds, and the magnesia brick material to form a slag conditioner mixture, wherein during the mixing step: moisture content of the slag conditioner mixture is maintained below 2%; a lime to alumina ratio in the slag conditioner mixture is maintained at approximately 1 :1; and a content of magnesium oxide in the slag conditioner mixture is maintained at 6% to 20% by weight.

2. The slag conditioner of claim 1, wherein the pre-fused slag base component is Furnastone™.

3. The slag conditioner of claim 1, wherein the step of mixing the slag base component comprises mixing: approximately 77% by weight of the pre-fused slag base component; approximately 10% by weight of the alumina brick component; approximately 9% by weight of the separated ladle shrouds; and approximately 3% by weight of the magnesia brick material.

4. The slag conditioner of claim 1, wherein the step of mixing the slag base component comprises mixing:55-85% by weight of the pre-fused slag base component;5-25% by weight of the alumina brick component;5-15% by weight of the separated ladle shrouds; and0-10% by weight of the magnesia brick material.

5. The slag conditioner of claim 1, wherein the process further comprises pre-fusing one or more of the alumina brick component, the separated ladle shrouds component, or the magnesia brick material prior to mixing step.

6. The slag conditioner of claim 1, wherein the slag conditioner product formed by the process is a pre-fused slag conditioner.

7. The slag conditioner of claim 6, wherein the pre-fused slag conditioner product is configured to melt at a temperature of approximately 1565° Celsius.

8. A ladle silicate flux slag conditioner, the slag conditioner being produced by a process comprising the steps of providing waste fiberglass having a silica (SiO2) content of 85% to 100%; providing separated ladle shrouds formed of aluminum graphite including 0% to 15% carbon; providing calcined soda ash including 35% to 65% Na2O; providing a magnesia brick material including 75% to 100% MgO; and mixing the waste fiberglass, the separated ladle shrouds, the calcined soda ash, and the magnesia brick to form a slag conditioner mixture, wherein during the mixing step: moisture content of the slag conditioner mixture is maintained below 2%; a lime to silica ratio in the slag conditioner mixture is maintained at approximately 1 : 1; and a content of magnesium oxide in the slag conditioner mixture is maintained at 6% to 20% by weight.

9. The slag conditioner of claim 8, wherein the mixing step comprises mixing:approximately 63% by weight of the waste fiberglass; approximately 19% by weight of the separated ladle shrouds; approximately 9% by weight of the calcined soda ash; and approximately 9% by weight of the magnesia brick material.

10. The slag conditioner of claim 8, wherein the mixing step comprises mixing:50-85% by weight of the waste fiberglass;5-25% by weight of the separated ladle shrouds;5-25% by weight of the calcined soda ash; and0-15% by weight of the magnesia brick material.

11. The slag conditioner of claim 8, wherein the ladle silicate flux slag conditioner produced is a pre-fused slag conditioner.

12. The slag conditioner of claim 8, wherein the pre-fused slag conditioner is configured to melting at a basic oxygen furnace or electric arc furnace tapping temperature of approximately 1371° Celsius.

13. The slag conditioner of claim 8, wherein the waste fiberglass, the separated ladle shrouds, the calcined soda ash, and the magnesia brick material provided in the process each have a particle size of less than or equal to approximately % inch.

14. A tundish calcium aluminate basic tundish flux slag conditioner, the slag conditioner being produced by a process comprising: providing a blast furnace slag; providing lime; providing Furnastone™; providing waste fiberglass; providing a magnesia brick material; providing sawdust; andmixing the provided components to form a slag conditioner mixture, wherein during the mixing: moisture content of the slag conditioner mixture is maintained below 2%; a lime to alumina ratio in the slag conditioner mixture is maintained at approximately 1 : 1; and a content of magnesium oxide in the slag conditioner mixture is maintained at 8% to 10% by weight.

15. The slag conditioner of claim 14, wherein the mixing comprises mixing: approximately 42% by weight of the blast furnace slag; approximately 38% by weight of lime; approximately 8% by weight of Furnastone™; approximately 8% by weight of waste fiberglass; approximately 4% by weight of the magnesia brick material; and approximately 2% by weight of sawdust.

16. The slag conditioner of claim 14, wherein the mixing comprises mixing:35-50% by weight of the blast furnace slag;25-45% by weight of lime;0-15% by weight of Furnastone™;0-15% by weight of waste fiberglass;0-10% by weight of the magnesia brick material; and0-10% by weight of sawdust.

17. The slag conditioner of claim 14, wherein the provided blast furnace slag is 30A blast furnace slag produced by Edw. C. Levy Co.TM.

18. The slag conditioner of claim 14, wherein the provided blast furnace slag, Furnastone™, waste fiberglass, and magnesia brick material each have a particle size of less than or equal to approximately % inch.

19. The slag conditioner of claim 14, wherein the provided sawdust has a particle size of less than or equal to approximately 14 inch.

20. The slag conditioner of claim 14, wherein the provided waste fiberglass has a silica content of 85% to 100% and the provided magnesia brick material includes 75% to 100% magnesium oxide.

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