阅读说明：本技术 一种用于lf精炼的精炼渣及其使用方法 (Refining slag for LF refining and use method thereof ) 是由 王平 于 2021-09-14 设计创作，主要内容包括：本发明公开了一种用于LF精炼的精炼渣及其使用方法,属于精炼渣技术领域,该精炼渣由以下质量份的组分组成：35～45份CaO、29～33份Al-(2)O-(3)、5～7份MgO、7～11份碳酸盐、3～6份还原剂和0.5～1份CaCl-(2)。本发明可有效解决现有技术中存在的能耗高、钢产品夹杂物含量高、夹杂物形状不好、成渣速度慢和脱硫速度慢的问题。(The invention discloses refining slag for LF refining and a using method thereof, belonging to the technical field of refining slag, wherein the refining slag comprises the following components in parts by mass: 35-45 parts of CaO and 29-33 parts of Al 2 O 3 5-7 parts of MgO, 7-11 parts of carbonate, 3-6 parts of reducing agent and 0.5-1 part of CaCl 2 . The invention can effectively solve the problems of high energy consumption, high inclusion content of steel products, poor shape of inclusions, low slagging speed and low desulfurization speed in the prior art.)

1. The refining slag for LF refining is characterized by comprising the following components in parts by mass: 35-45 parts of CaO and 29-33 parts of Al₂O₃5-7 parts of MgO, 7-11 parts of carbonate, 3-6 parts of reducing agent and 0.5-E1 part of CaCl₂。

2. The refining slag for LF refining of claim 1, which is characterized by comprising the following components in parts by mass: 40 parts of CaO and 30 parts of Al₂O₃6 parts of MgO, 7-11 parts of carbonate, 3-6 parts of reducing agent and 0.5-1 part of CaCl₂。

3. The refining slag for LF refining as recited in claim 1 or 2, characterized by consisting of the following components in parts by mass: 40 parts of CaO and 30 parts of Al₂O₃6 parts of MgO, 9 parts of carbonate, 5 parts of reducing agent and 0.5-1 part of CaCl₂。

4. The refining slag for LF refining as defined in claim 3, wherein the carbonate is at least one of calcium carbonate and magnesium carbonate.

5. The refining slag for LF refining as recited in claim 4, wherein the carbonate is a combination of calcium carbonate and magnesium carbonate at a mass ratio of 1-2: 1-2.

6. The refining slag for LF refining of claim 3, wherein the reducing agent is at least one of SiC and CaSi.

7. The refining slag for LF refining as defined in claim 6, wherein the reducing agent is a composition of SiC and CaSi at a mass ratio of 1-2: 1-2.

8. The use of refining slag for LF refining according to any of claims 1-7, characterized by comprising the following steps:

step (1): adding the refined slag and the limestone fragments in a mass ratio of 1-2: 1-2 into a steel ladle for smelting before tapping of an electric furnace;

step (2): when LF refining is carried out, refining slag accounting for 1-2% of the mass of the molten steel is added once again.

9. The use of refining slag for LF refining according to claim 8, characterized in that the mass ratio of refining slag to limestone fragments in step (1) is 1: 1.

Technical Field

The invention relates to the technical field of refining slag, in particular to refining slag for LF refining and a using method thereof.

Background

At present, in the steel-making and refining processes, along with the pursuit of people for steel purification, the requirement of high purity is an inevitable trend, and meanwhile, the energy consumption is required to be reduced in the smelting process; in order to improve the use quality of steel products, the shape of inclusions in steel is modified from a strip shape to a spindle shape. In the LF (ladle furnace) refining technical process, slag materials with special proportion are added into a ladle and melted into liquid slag under the arc heating, and the slag materials achieving the purposes of refining molten steel, heat insulation and heat preservation and the like are collectively called as refining slag. The basic functions of the refining slag are to remove elements which adversely affect the quality of steel, such as inclusions and sulfur oxides in the molten steel, to purify the molten steel, to prevent the suction of molten steel, and to reduce heat loss. But the problems of high energy consumption, high inclusion content of steel products, poor shape of the inclusions, slow slagging speed and slow desulphurization speed exist in the smelting process by using the existing refining slag.

Disclosure of Invention

Aiming at the defects, the invention aims to provide refining slag for LF refining and a using method thereof, which can effectively solve the problems of high energy consumption, high inclusion content of steel products, poor inclusion shape, low slagging speed and low desulfurization speed in the prior art.

In order to achieve the purpose, the invention adopts the following technical scheme:

the invention provides refining slag for LF refining, which consists of the following components in parts by mass: 35-45 parts of CaO and 29-33 parts of Al₂O₃5-7 parts of MgO, 7-11 parts of carbonate, 3-6 parts of reducing agent and 0.5-1 part of CaCl₂。

Further, the refining slag for LF refining comprises the following components in parts by mass: 40 parts of CaO and 30 parts of Al₂O₃6 parts of MgO, 7-11 parts of carbonate, 3-6 parts of reducing agent and 0.5-1 part of CaCl₂。

Further, the refining slag for LF refining comprises the following components in parts by mass: 40 parts of CaO and 30 parts of Al₂O₃6 parts of MgO, 9 parts of carbonate, 5 parts of reducing agent and 0.5-1 part of CaCl₂。

Further, the carbonate is at least one of calcium carbonate and magnesium carbonate; preferably, the composition of calcium carbonate and magnesium carbonate has a mass ratio of 1-2: 1-2.

Further, the reducing agent is at least one of SiC and CaSi; preferably, the mass ratio of SiC to CaSi is 1-2: 1-2.

The invention also provides a use method of the refining slag for LF refining, which comprises the following steps:

step (1): adding the refined slag and the limestone fragments in a mass ratio of 1-2: 1-2 into a steel ladle for smelting before tapping of an electric furnace;

step (2): when LF refining is carried out, refining slag accounting for 1-2% of the mass of the molten steel is added once again.

Further, the electric furnace tapping in the step (1) adopts a reduction method to tap, and the tapping amount is 1-2% of the molten steel mass.

Further, the mass ratio of the refining slag to the limestone fragments in the step (1) is 1: 1.

Further, the particle size of the limestone fragments in the step (1) is below 80 mm.

Furthermore, the adding amount of the refining slag in the step (2) is 1 percent of the mass of the molten steel.

In summary, the invention has the following advantages:

1. the invention provides refining slag for LF refining, which has the advantages that the components are mutually cooperated, so that the problems of high energy consumption, high inclusion content of steel products, poor inclusion shape, low slagging speed and low desulfurization speed in the prior art are effectively solved; the specific process is as follows: CaO/Al₂O₃The components form the matrix binary slag with low melting point, the slagging speed is high, and the desulfurization capacity is strong; CaCl₂Not only can rapidly reduce the melting point of the refining slag, improve the fluidity of the slag and provide more sufficient dynamic conditions for metallurgical reaction, but also is matched with CaO/Al₂O₃The matrix is binary slag, so that the slag forming speed is further accelerated; the reducing agent such as SiC + CaSi can effectively reduce the oxygen potential in the steel, thereby reducing the content of inclusions in the steel; CaO/Al are simultaneously mixed₂O₃The binary slag of the matrix further improves the desulfurization efficiency, and the finally formed deoxidation product is calcareous and is mixed with Al in steel₂O₃The inclusion denaturation is low-melting-point aluminate inclusion, most of which floats out, and a small part of which exists in the steel in a spindle shape which has small influence on the service life of steel materials, so that the quality of the steel is improved; MgO can reduce the consumption of the magnesium refractory material in the whole system; carbonate provides CO for refining slag₂The electric efficiency is improved, the temperature rise is facilitated, and therefore the energy consumption is reduced, and the slagging speed is improved.

2. The refining slag of the invention adopts calcium production excess material, the cost is low; has the characteristics of high slagging speed, low energy consumption, steel-making slag charge saving, ladle service life prolonging, simple smelting operation and stable smelting quality, and simultaneously avoids CaF which is harmful to the operation of workers in the conventional refining slag₂The use of (1).

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is further described in detail with reference to the following embodiments. It should be understood that the detailed description and specific examples, while indicating the preferred embodiment of the invention, are intended for purposes of illustration only and are not intended to limit the scope of the invention.

Thus, the following detailed description of the embodiments of the present invention is not intended to limit the scope of the invention as claimed, but is merely representative of selected embodiments of the invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments of the present invention without making any creative effort, shall fall within the protection scope of the present invention.

Example 1

The embodiment provides refining slag for LF refining, which comprises the following components in parts by mass: 35 parts of CaO and 29 parts of Al₂O₃5 parts of MgO, 7 parts of carbonate, 3 parts of reducing agent and 0.5 part of CaCl₂(ii) a Wherein the carbonate is a composition of calcium carbonate and magnesium carbonate with the mass ratio of 1: 1; the reducing agent is a composition of SiC and CaSi with the mass ratio of 1: 1.

The use method of the refining slag for LF refining comprises the following steps:

step (1): adding the refining slag and the limestone fragments with the mass ratio of 1:1 into a ladle for smelting before tapping of an electric furnace; wherein, the electric furnace tapping adopts a reduction method to tap steel, and the tapping slag amount is 1 percent of the mass of molten steel; the particle size of the limestone fragments is below 80 mm;

step (2): when LF refining is carried out, refining slag accounting for 1 percent of the mass of the molten steel is added once again.

Example 2

The embodiment provides refining slag for LF refining, which comprises the following components in parts by mass: 40 parts of CaO and 30 parts of Al₂O₃6 parts of MgO, 9 parts of carbonate, 5 parts of reducing agent and 1 part of CaCl₂(ii) a Wherein the carbonate is a composition of calcium carbonate and magnesium carbonate with the mass ratio of 1: 1; the reducing agent is a composition of SiC and CaSi with the mass ratio of 1: 1.

The use method of the refining slag for LF refining comprises the following steps:

step (1): adding the refining slag and the limestone fragments with the mass ratio of 1:1 into a ladle for smelting before tapping of an electric furnace; wherein, the electric furnace tapping adopts a reduction method to tap steel, and the tapping slag amount is 1 percent of the mass of molten steel; the particle size of the limestone fragments is below 80 mm;

step (2): when LF refining is carried out, refining slag accounting for 1 percent of the mass of the molten steel is added once again.

Example 3

The embodiment provides refining slag for LF refining, which comprises the following components in parts by mass: 45 parts of CaO and 33 parts of Al₂O₃7 parts of MgO, 11 parts of carbonate, 6 parts of reducing agent and 1 part of CaCl₂(ii) a Wherein the carbonate is a composition of calcium carbonate and magnesium carbonate with the mass ratio of 1: 1; the reducing agent is a composition of SiC and CaSi with the mass ratio of 1: 1.

The use method of the refining slag for LF refining comprises the following steps:

step (1): adding the refining slag and the limestone fragments with the mass ratio of 1:1 into a ladle for smelting before tapping of an electric furnace; wherein, the electric furnace tapping adopts a reduction method to tap steel, and the tapping slag amount is 1 percent of the mass of molten steel; the particle size of the limestone fragments is below 80 mm;

step (2): when LF refining is carried out, refining slag accounting for 1 percent of the mass of the molten steel is added once again.

Example 4

The embodiment provides refining slag for LF refining, which comprises the following components in parts by mass: 45 parts of CaO and 33 parts of Al₂O₃7 parts of MgO, 11 parts of magnesium carbonate, 6 parts of reducing agent and 1 part of CaCl₂(ii) a Wherein the reducing agent is a composition of SiC and CaSi with the mass ratio of 1: 2.

The use method of the refining slag for LF refining comprises the following steps:

step (1): adding the refining slag and the limestone fragments with the mass ratio of 1:1 into a ladle for smelting before tapping of an electric furnace; wherein, the electric furnace tapping adopts a reduction method to tap steel, and the tapping slag amount is 1 percent of the mass of molten steel; the particle size of the limestone fragments is below 80 mm;

step (2): when LF refining is carried out, refining slag accounting for 1 percent of the mass of the molten steel is added once again.

Comparative example 1

The embodiment provides refining slag for LF refining, which comprises the following components in parts by mass: 40 parts of CaO and 30 parts of CaF₂6 parts of MgO, 9 parts of carbonate, 5 parts of reducing agent and 1 part of CaCl₂(ii) a Wherein the carbonate is a composition of calcium carbonate and magnesium carbonate with the mass ratio of 1: 1; the reducing agent is a composition of SiC and CaSi with the mass ratio of 1: 1.

The use method of the refining slag for LF refining comprises the following steps:

step (1): adding the refining slag and the limestone fragments with the mass ratio of 1:1 into a ladle for smelting before tapping of an electric furnace; wherein, the electric furnace tapping adopts a reduction method to tap steel, and the tapping slag amount is 1 percent of the mass of molten steel; the particle size of the limestone fragments is below 80 mm;

step (2): when LF refining is carried out, refining slag accounting for 1 percent of the mass of the molten steel is added once again.

Comparative example 2

The embodiment provides refining slag for LF refining, which comprises the following components in parts by mass: 40 parts of CaO and 30 parts of Al₂O₃30 parts of CaF₂6 parts of MgO, 9 parts of carbonate, 5 parts of reducing agent and 1 part of CaCl₂(ii) a Wherein the carbonate is a composition of calcium carbonate and magnesium carbonate with the mass ratio of 1: 1; the reducing agent is a composition of SiC and CaSi with the mass ratio of 1: 1.

The use method of the refining slag for LF refining comprises the following steps:

step (1): adding the refining slag and the limestone fragments with the mass ratio of 1:1 into a ladle for smelting before tapping of an electric furnace; wherein, the electric furnace tapping adopts a reduction method to tap steel, and the tapping slag amount is 1 percent of the mass of molten steel; the particle size of the limestone fragments is below 80 mm;

step (2): when LF refining is carried out, refining slag accounting for 1 percent of the mass of the molten steel is added once again.

Comparative example 3

The embodiment provides refining slag for LF refining, which comprises the following components in parts by mass: 55 parts of CaO and 30 parts of Al₂O₃6 parts of MgO and 9 parts of carbonate5 parts of reducing agent and 1 part of CaCl₂(ii) a Wherein the carbonate is a composition of calcium carbonate and magnesium carbonate with the mass ratio of 1: 1; the reducing agent is a composition of SiC and CaSi with the mass ratio of 1: 1.

The use method of the refining slag for LF refining comprises the following steps:

step (1): adding the refining slag and the limestone fragments with the mass ratio of 1:1 into a ladle for smelting before tapping of an electric furnace; wherein, the electric furnace tapping adopts a reduction method to tap steel, and the tapping slag amount is 1 percent of the mass of molten steel; the particle size of the limestone fragments is below 80 mm;

step (2): when LF refining is carried out, refining slag accounting for 1 percent of the mass of the molten steel is added once again.

Comparative example 4

The embodiment provides refining slag for LF refining, which comprises the following components in parts by mass: 40 parts of CaO and 50 parts of Al₂O₃6 parts of MgO, 9 parts of carbonate, 5 parts of reducing agent and 1 part of CaCl₂(ii) a Wherein the carbonate is a composition of calcium carbonate and magnesium carbonate with the mass ratio of 1: 1; the reducing agent is a composition of SiC and CaSi with the mass ratio of 1: 1.

The use method of the refining slag for LF refining comprises the following steps:

step (1): adding the refining slag and the limestone fragments with the mass ratio of 1:1 into a ladle for smelting before tapping of an electric furnace; wherein, the electric furnace tapping adopts a reduction method to tap steel, and the tapping slag amount is 1 percent of the mass of molten steel; the particle size of the limestone fragments is below 80 mm;

step (2): when LF refining is carried out, refining slag accounting for 1 percent of the mass of the molten steel is added once again.

Comparative example 5

The embodiment provides refining slag for LF refining, which comprises the following components in parts by mass: 40 parts of CaO, 6 parts of MgO, 9 parts of carbonate, 5 parts of reducing agent and 1 part of CaCl₂(ii) a Wherein the carbonate is a composition of calcium carbonate and magnesium carbonate with the mass ratio of 1: 1; the reducing agent is a composition of SiC and CaSi with the mass ratio of 1: 1.

The use method of the refining slag for LF refining comprises the following steps:

step (1): adding the refining slag and the limestone fragments with the mass ratio of 1:1 into a ladle for smelting before tapping of an electric furnace; wherein, the electric furnace tapping adopts a reduction method to tap steel, and the tapping slag amount is 1 percent of the mass of molten steel; the particle size of the limestone fragments is below 80 mm;

step (2): when LF refining is carried out, refining slag accounting for 1 percent of the mass of the molten steel is added once again.

Examples of the experiments

In this example, the refining slag of examples 1 to 4 and comparative examples 1 to 4 were subjected to viscosity measurement (measurement using a melt property measuring instrument), melting point measurement (measurement using a melt property measuring instrument), crystal phase precipitation temperature measurement (measurement using a differential thermal analyzer), slag formation time measurement, and shape measurement of inclusions in steel products, and the results are shown in Table 1 below.

TABLE 1

From the above table, the viscosity of the refining slag prepared by the technical scheme of the invention can reach 0.119Pa & s, the melting point is between 1420-1448 ℃, the precipitation temperature of the high-melting-point ore phase (namely, crystalline phase) is below 1580 ℃, the slagging speed is high, and the refining slag can be well applied to LF refining. Meanwhile, when the components (comparative examples 1 to 2 and comparative example 5) and the amount ratio (comparative examples 3 to 4) of the refining slag according to the present invention were changed, the synergistic effect of the components was weakened, so that the overall performance of the refining slag was lowered.

The foregoing is illustrative and explanatory only and is not intended to be exhaustive or to supplement or replace the specific embodiments described by those skilled in the art without inventive faculty.