阅读说明：本技术 回收氧化铬和形成铬合金钢的方法 (Method for recovering chromium oxide and forming chromium alloy steel ) 是由 曼苏尔·纳赛尔·阿尔哈比 萨米·穆泰布·阿尔穆泰里 马莱斯瓦拉·拉奥·塔迪博伊纳 于 2020-03-17 设计创作，主要内容包括：公开了回收氧化铬和生产铬合金钢的方法。氧化铬被还原成金属铬,金属铬与钢混合形成铬合金钢。(Methods of recovering chromium oxide and producing chromium alloy steels are disclosed. The chromium oxide is reduced to metallic chromium, which is mixed with steel to form chromium alloy steel.)

1. A method of recovering chromium oxide and forming a chromium alloy steel, the method comprising:

(a) adding an effective amount of a first composition comprising chromium oxide to a second composition comprising molten steel; and

(b) the chromium oxide is reduced under conditions suitable to form metallic chromium, wherein the metallic chromium is mixed with the molten steel to form a chromium alloy steel.

2. The method of claim 1, wherein the chromium oxide is chromium (III) oxide (Cr)₂O₃)。

3. The method of claim 2, wherein the first composition further comprises alumina.

4. The method of claim 3, wherein the first composition comprises 10 to 25 wt.% Cr₂O₃And 70 to 85 weight percent alumina.

5. The method of claim 4, wherein the first composition further comprises a total amount of 0 to 5 wt% SiO₂And K₂O。

6. The method of any one of claims 1 to 4, wherein the first composition is a spent catalyst.

7. The method of any one of claims 1 to 4, wherein in step (b) the chromium oxide is reduced by aluminium and the method comprises adding aluminium to the second composition.

8. The method of claim 7, wherein the aluminum is added to the second composition before, during, and/or after the first composition is added to the second composition.

9. The method of claim 7, wherein the at least a portion of the aluminum added reduces the added chromium oxide to form metallic chromium and aluminum oxide, and the at least a portion of the aluminum added reacts with dissolved oxygen in the molten steel to form aluminum oxide.

10. The method of claim 7, wherein the aluminum is added as aluminum dross and/or an aluminum wire.

11. The process of any one of claims 1 to 4, wherein the conditions of step (b) comprise a temperature of 1200 to 2000 ℃.

12. The method of any one of claims 1 to 4, wherein the second composition comprises slag on top of molten steel.

13. The process of claim 12, wherein the first composition is added to the slag in step (a).

14. The method of claim 12, further comprising adding lime to the slag.

15. The process of claim 12, wherein the slag absorbs at least a portion of the alumina formed and added in the process.

16. The method of any one of claims 1 to 4, wherein the method further comprises purging argon-containing gas from the bottom of the molten steel.

17. The method of any one of claims 1 to 4, wherein the method is performed during a secondary steelmaking process.

18. The method of claim 17, wherein the method is performed in a ladle furnace.

19. The method of any one of claims 1 to 4, further comprising adding one or more metals to the second composition, wherein the one or more metals are mixed with molten steel to form one or more metal-chromium-alloy steels.

20. The method of claim 19, wherein the one or more metals are selected from the group consisting of molybdenum, cobalt, copper, bismuth, titanium, tungsten, vanadium, manganese, and nickel.

Technical Field

The present invention generally relates to metal recovery and methods of producing metal alloys. In particular, the present invention relates to a method for recovering chromium oxide and producing chromium alloy steel.

Background

Chromium oxide-containing waste materials, such as chromium oxide-containing spent catalysts, are primarily disposed of as landfills and can pose an environmental hazard. There is a need for a cost effective recovery process for chromium oxide containing waste materials.

Disclosure of Invention

It has been found that a solution to the problem of providing a chromium oxide containing composition is provided. The solution is premised on recovering chromium from the chromium oxide to form a chromium alloy steel.

In aspects of the invention, methods of recovering chromium oxide and forming chromium alloy steels are described. The method may comprise steps (a) and (b). In step (a), an effective amount of a first composition comprising chromium oxide may be added to a second composition comprising molten steel. In step (b), the chromium oxide may be reduced to form metallic chromium, and the metallic chromium may be mixed with the molten steel to form chromium alloy steel. The method may be carried out in a ladle furnace during a secondary steelmaking process. The chromium oxide may be reduced at a temperature of 1400 ℃ to 1800 ℃, preferably 1500 ℃ to 1650 ℃, more preferably 1550 ℃ to 1600 ℃. In some aspects, the chromium oxide can be chromium (III) oxide (Cr)₂O₃). In some aspects, the first composition can further comprise alumina. In some aspects, the first composition may comprise 10 to 25 wt%, preferably 15 to 20 wt% Cr₂O₃And 70 to 85 wt%, preferably 75 to 80 wt% of alumina. In some particular aspects, the first composition may further comprise a total of 0 to 5 wt.% SiO₂And K₂And O. In some aspects, the first composition is a spent catalyst. In step (b), the chromium oxide may be reduced by aluminium (e.g. metallic aluminium) and the method may comprise adding aluminium to the second composition. The aluminum may be added to the second composition before, during, or after the first composition is added to the second composition. At least a portion of the added aluminum may reduce the chromium oxide to form aluminum oxide and metallic chromium, and at least a portion of the added aluminum may react with dissolved oxygen in the molten steel to form aluminum oxide. In some aspects, aluminum in the form of aluminum dross and/or aluminum wire can be added to the second composition. In some aspects, the second composition may comprise slag on top of the molten steel. In step (a), the first composition may be added to slag. The slag may absorb at least a portion of the alumina formed and/or added in the process and may remove the alumina from the molten steel. In some aspects, lime may be added to the slag. In some aspects, a slag modifier may be added to the slag. Argon-containing gas may be purged from the bottom of the molten steel. The argon-containing gas may be purged at a rate suitable to lift the alumina particles in the molten steel. In some aspects, the method may further include adding one or more metals to the second composition, and the one or more metals may be mixed with the molten steel to form one or more metal-chromium-alloy steels. In some particular aspects, the one or more metals may be selected from the group consisting of molybdenum, cobalt, copper, bismuth, titanium, tungsten, vanadium, manganese, and nickel.

The following includes definitions for various terms and phrases used throughout the specification.

Lime is a calcium-containing inorganic mineral composed primarily of oxides and hydroxides, usually calcium oxide and/or calcium hydroxide. The addition of lime discussed in this disclosure may include the addition of calcium oxide or calcium hydroxide or both.

The term "about" or "approximately" is defined as being close to as understood by one of ordinary skill in the art. In one non-limiting embodiment, these terms are defined as being within 10%, preferably within 5%, more preferably within 1%, and most preferably within 0.5%.

The terms "weight%", "volume%" or "mole%" refer to the weight, volume, or mole percent of a component, respectively, based on the total weight, volume, or total moles of materials comprising the component. In a non-limiting example, 10mol of the component in 100mol of the material is 10 mol% of the component.

The term "substantially" and variations thereof are defined as ranges that include within 10%, within 5%, within 1%, or within 0.5%.

The terms "inhibit" or "reduce" or "prevent" or "avoid" or any variation of these terms, as used in the claims and/or the specification, includes any measurable amount of reduction or complete inhibition to achieve a desired result.

The term "effective" as used in the specification and/or claims means sufficient to achieve a desired, expected, or intended result.

The use of the words "a" or "an" when used in the claims or the specification in conjunction with the terms "comprising," including, "" containing, "or" having "can mean" one, "but it also has the meaning of" one or more, "" at least one, "and" one or more than one.

The words "comprising" (and any form of comprising, such as "comprises" and "comprises"), "having" (and any form of having, such as "has" and "has"), "including" (and any form of including, such as "includes" and "includes") or "containing" (and any form of containing, such as "contains" and "contains") are inclusive or open-ended and do not exclude additional, unrecited elements or process steps.

The methods of the present invention can "comprise," "consist essentially of," or "consist of" the particular ingredients, components, compositions, etc. disclosed throughout the specification.

The term "predominantly", as that term is used in the specification and/or claims, means greater than any one of 50 weight percent, 50 mole percent, and 50 volume percent. For example, "predominantly" can include 50.1% to 100% by weight and all values and ranges therebetween, 50.1% to 100% by mole and all values and ranges therebetween, or 50.1% to 100% by volume and all values and ranges therebetween.

Other objects, features and advantages of the present invention will become apparent from the following drawings, detailed description and examples. It should be understood, however, that the drawings, detailed description and examples, while indicating specific embodiments of the present invention, are given by way of illustration only and are not intended to be limiting. In addition, it is contemplated that changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description. In other embodiments, features from specific embodiments may be combined with features from other embodiments. For example, features from one embodiment may be combined with features from any of the other embodiments. In further embodiments, additional features may be added to the specific embodiments described herein.

Drawings

For a more complete understanding, reference is now made to the following descriptions taken in conjunction with the accompanying drawings, in which:

FIG. 1: according to one embodiment of the present invention, chromium oxide is recovered in a ladle furnace during a secondary steelmaking process and a chromium alloy steel is formed.

Detailed Description

It has been found that a solution to the problem of disposing of chromium oxide containing waste material is provided. The premise of the scheme is to reduce the chromium oxide into metallic chromium and utilize the metallic chromium to produce the chromium alloy steel.

In aspects of the invention, methods of recovering chromium oxide and forming chromium alloy steels are described. The first composition comprising chromium oxide may be added to a second composition comprising molten steel. The chromium oxide may be reduced to form metallic chromium, and the metallic chromium may be mixed with molten steel to form chromium alloy steel. The amount of chromium oxide added may depend on the target chromium content of the chromium alloy steel being formed.

The first composition may be a waste material containing chromium oxide. In some aspects, the first composition is a spent chromium oxide-containing catalyst. In some aspects, the chromium may be chromium (III) oxide (Cr)₂O₃). In some aspects, the first composition may comprise alumina and Cr₂O₃. In some particular aspects, the first composition can comprise at least any one of 10 wt%, 11 wt%, 12 wt%, 13 wt%, 14 wt%, 15 wt%, 16 wt%, 17 wt%, 18 wt%, 19 wt%, 20 wt%, 21 wt%, 22 wt%, 23 wt%, 24 wt%, and 25 wt%, Cr equal to any one thereof, or between any two thereof₂O₃And at least any one of, equal to, or between any two of 70 wt%, 71 wt%, 72 wt%, 73 wt%, 74 wt%, 75 wt%, 76 wt%, 77 wt%, 78 wt%, 79 wt%, 80 wt%, 81 wt%, 82 wt%, 83 wt%, 84 wt%, and 85 wt% Al₂O₃. The first composition may optionally comprise SiO₂And K₂O, wherein SiO₂And K₂The total O content is at least any one of, equal to, or between any two of 0 wt%, 1 wt%, 2 wt%, 3 wt%, 4 wt%, and 5 wt%. The chromium may be reduced at a temperature of at least any one of, equal to, or between any two of 1400 ℃, 1450 ℃, 1500 ℃, 1550 ℃, 1600 ℃, 1650 ℃, 1700 ℃, 1750 ℃ and 1800 ℃.

The chromium oxide may be reduced by aluminum and the method may include adding aluminum to the second composition. The aluminum may be added to the second composition before, during, and/or after the first composition is added to the second composition. In some aspects, at least a portion of the aluminum added can reduce chromium oxide to form aluminum oxide and metallic chromium, and at least a portion of the aluminum added can remove dissolved oxygen present in the molten steel by reacting with the dissolved oxygen to form aluminum oxide. In some aspects, a minimum amount of aluminum may be added, where the minimum amount depends on the dissolved oxygen content of the molten steel and the amount of chromium oxide added to the second composition.

In some aspects, the second composition may comprise slag on top of the molten steel. In some aspects, the first composition may be added to slag. In certain aspects, the first composition may pass from the slag into the molten steel, the chromium oxide may be reduced in the molten steel to form metallic chromium, and the metallic chromium may be mixed with the molten steel. The slag can absorb alumina and can remove alumina from the molten steel. The alumina particles present in the molten steel can float up and be absorbed by the slag. The alumina particles in the molten steel can be at least a portion of the alumina added and/or formed in the method. The alumina added in the process may be alumina from the first composition added. The alumina formed in the process may be alumina formed by reducing chromium oxide with added aluminum and alumina formed by reacting dissolved oxygen in the molten steel with added aluminum. In some aspects, argon-containing gas may be purged from the bottom of the molten steel. The argon-containing gas can help to float the alumina particles in the molten steel. In certain aspects, lime may be added to the slag. The added lime can help the slag to absorb the alumina. The amount of lime added may depend on the alumina added and/or formed in the process. In some aspects, a slag modifier may be added to the slag. Slag modifiers may be used as needed to achieve target slag conditions to promote formation of the final steel alloy and to effectively remove alumina from the molten steel. In some aspects, the slag modifier can be limestone, dolomite, calcium aluminate, fluorite, or a combination thereof.

In some aspects, the slag may be an alkaline slag. In some aspects, the slag may include CaO, Al₂O₃、SiO₂And MgO.

In some aspects, one or more metals may be added to the second composition, and the one or more metals may be mixed with the molten steel to form one or more metal-chromium-alloy steels. The one or more metals may be selected from the group consisting of molybdenum, cobalt, copper, bismuth, titanium, tungsten, vanadium, manganese, and nickel.

In some aspects, the method may be performed in a ladle furnace during a secondary steelmaking process. The first composition may be added to the second composition in a ladle furnace. The chromium oxide may be reduced and the resulting metallic chromium may be mixed with the molten steel in the ladle furnace. The molten steel may be refined in a ladle furnace. In the ladle furnace, the molten steel can be desulfurized and impurities in the molten steel can be removed. FIG. 1 shows the recovery of chromium oxide and the formation of a chromium alloy steel in a ladle furnace during a secondary steelmaking process.

In the context of the present invention, at least the following 20 embodiments are described. Embodiment 1 is a method of recovering chromium oxide and forming a chromium alloy steel, the method comprising: (a) adding an effective amount of a first composition comprising chromium oxide to a second composition comprising molten steel; and (b) reducing the chromium oxide under conditions suitable to form metallic chromium, wherein the metallic chromium is mixed with the molten steel to form a chromium alloy steel. Embodiment 2 is the method of embodiment 1, wherein the chromium oxide is chromium (III) oxide (Cr)₂O₃). Embodiment 3 is the method of embodiment 2, wherein the first composition further comprises alumina. Embodiment 4 is the method of embodiment 3, wherein the first composition comprises 10 to 25 wt.% Cr₂O₃And 70 to 85 weight percent alumina. Embodiment 5 is the method of embodiment 4, wherein the first composition further comprises a total amount of 0 to 5 weight percent SiO₂And K₂And O. Embodiment 6 is the method of any one of embodiments 1 to 5, wherein the first composition is a spent catalyst. Embodiment 7 is the method of any one of embodiments 1 to 6, wherein in step (b), the chromium oxide is reduced by aluminum and the method comprises adding aluminum to the second composition. Embodiment 8 is the method of embodiment 7, wherein the adding the first composition to the second composition is preceded by adding the first composition to the second compositionAluminum is added to the second composition during and/or after. Embodiment 9 is the method of embodiment 7 or 8, wherein the at least a portion of the aluminum added reduces the added chromium oxide to form metallic chromium and aluminum oxide, and the at least a portion of the aluminum added reacts with dissolved oxygen in the molten steel to form aluminum oxide. Embodiment 10 is the method of any one of embodiments 7 to 9, wherein the aluminum is added as aluminum dross and/or an aluminum wire. Embodiment 11 is the method of any one of embodiments 1 to 10, wherein the conditions of step (b) include a temperature of 1200 to 2000 ℃. Embodiment 12 is the method of any one of embodiments 1 to 11, wherein the second composition includes slag on top of the molten steel. Embodiment 13 is the method of embodiment 12, wherein the first composition is added to slag in step (a). Embodiment 14 is the method of embodiment 12 or 13, wherein the method further comprises adding lime to the slag. Embodiment 15 is the method of any one of embodiments 12 to 14, wherein the slag absorbs at least a portion of the alumina formed and added in the method. Embodiment 16 is the method of any one of embodiments 1 to 15, wherein the method further comprises purging argon-containing gas from the bottom of the molten steel. Embodiment 17 is the method of any one of embodiments 1-16, wherein the method is performed during a secondary steelmaking process. Embodiment 18 is the method of embodiment 17, wherein the method is performed in a ladle furnace. Embodiment 19 is the method of any one of embodiments 1 to 18, further comprising adding one or more metals to the second composition, wherein the one or more metals are mixed with the molten steel to form one or more metal-chromium-alloy steels. Embodiment 20 is the method of embodiment 19, wherein the one or more metals are selected from the group consisting of molybdenum, cobalt, copper, bismuth, titanium, tungsten, vanadium, manganese, and nickel.

Although the embodiments of the present application and their advantages have been described in detail, it should be understood that various changes, substitutions and alterations can be made herein without departing from the spirit and scope of the embodiments as defined by the appended claims. Moreover, the scope of the present application is not intended to be limited to the particular embodiments of the process, machine, manufacture, composition of matter, means, methods and steps described in the specification. As one of ordinary skill in the art will readily appreciate from the disclosure set forth above, processes, machines, manufacture, compositions of matter, means, methods, or steps, presently existing or later to be developed that perform substantially the same function or achieve substantially the same result as the corresponding embodiments described herein may be utilized. Accordingly, the appended claims are intended to include within their scope such processes, machines, manufacture, compositions of matter, means, methods, or steps.