Process for washing, pre-desulfurizing and refining tapping steel slag of converter

A technology of tapping slag and pre-desulfurization, applied in the direction of manufacturing converters, etc., can solve the problems of non-desulfurization process research, heavy refining tasks, and reducing the sulfur content of the LF furnace to the station, so as to achieve simple operation, convenient large-scale production, and relieve pressure. Effect

Active Publication Date: 2010-08-11
SHOUGANG CORPORATION
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  • Summary
  • Abstract
  • Description
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  • Application Information

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Problems solved by technology

[0003] Chinese patent 200710158648.1 discloses a non-refining steel slag washing process. The invention adopts continuous feeding of slag washing material into the molten steel, and then sends the molten steel to the line feeding station for calcium treatment. It does not need to go through the refining equipment and then send it to the variety production line. This method deoxidizes the molten steel, removes the inclusions in the steel, and improves the quality of the slab. The characteristic of this method is that only the deoxidation and inclusion removal analysis of the slag washing process is carried out, and the desulfurization process of the slag washing process is not studied.
[0004] Chinese patent 200810054589.8 discloses a rapid desulfurization method of converter tapping slag washing and refining furnace. The invention includes two steps of tapping slag washing and LF refining. Tapping adopts weak deoxi

Method used

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Examples

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Example Embodiment

[0017] Implementation example 1:

[0018] The steel grade is resistant to HIC X65, and the converter tapping slag washing and pre-desulfurization is carried out by the process of the present invention: 100 tons converter tapping, tapping temperature 1700°C, strong aluminum-iron deoxidation when tapping 1.5min, aluminum-iron addition amount is 4.5kg / t Steel; before tapping, add synthetic slag at the bottom of the steel ladle with an amount of 8kg / t steel; use an alloy chute for 2 minutes of tapping, and add white ash continuously and evenly with the steel flow, the total amount added is 6kg / t steel, before the end of tapping The addition is complete; the bottom blowing effect of the ladle is maintained during the tapping process, and the bottom blowing argon flow is controlled at 3NL / (min·t); after the tapping is completed, aluminum particles are added to the ladle slag surface to deoxidize the slag surface, and the addition amount is 0.8kg / t Steel; after slag washing, steel slag ...

Example Embodiment

[0019] Implementation example 2:

[0020] Steel grade X70, the converter tapping slag washing and pre-desulfurization is carried out using the process of the present invention: 100 tons converter tapping, tapping temperature 1720℃, strong aluminum-iron deoxidation at 1.5min tapping, aluminum-iron addition is 5kg / t steel; Add synthetic slag at the bottom of the ladle before steel, the addition amount is 5kg / t steel; when the steel is tapped 2min, the alloy chute is used, and the white ash is continuously and uniformly added with the steel flow. The total addition amount is 4kg / t steel, and the addition is completed before the end of the tapping; During the tapping process, the bottom blowing effect of the ladle is maintained, and the bottom blowing argon flow is controlled at 4NL / (min·t); after tapping, aluminum particles are added to the ladle slag surface to deoxidize the slag surface, and the addition amount is 0.6kg / t steel; Slag oxidation after washing: (FeO+MnO)≤3.1%, the sl...

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PUM

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Abstract

The invention relates to a process for washing, pre-desulfurizing and refining tapping steel slag of a converter, which belongs to the technical field of steel making. The process is characterized in that the steel-tapping temperature of the converter is 1,650-1,720DEG C; strongly deoxidizing by adopting ferro-aluminium the addition of which is 3-5kg/t of steel when the steel is tapped for 1.5min; adding synthetic slag the addition of which is 5-8kg/t of steel at the bottom of a steel ladle before tapping steel; lime the addition of which is 4-6kg/t of steel is continuously added along steel stream when the steel is tapped for 2 min; the flow rate of argon gas bottom blowing from the ladle in the steel tapping process is controlled to be 3-5NL/(min.t); aluminum particles the addition of which is 0.5-0.8kg/t of steel are added into a slag surface after finishing tapping for deoxidizing the slag surface; and after finishing slag washing, the oxidability of steel slag is expressed by the following relationship: the total contents of FeO and MnO is les than or equal to 3.5 percent and the performance index of converter slag (in percentage by weight) is the weight ratio of CaO to (SiO2.Al2O3) being 0.4-0.5. The invention has the advantages that the sulfur content in the steel is desorbed from 90ppm-110ppm to within 60ppm by using a slag-washing control process, the desulfurization rate for slag washing can reach 30-45.45 percent and the sulfur content of end steel in an LF converter is reduced; the invention creates favorable preconditions for rapid deep desulfurization and relieves the pressure of the refining station; and in addition, the method has simple operation and is convenient to achieve the requirement of scale production.

Description

technical field [0001] The invention belongs to the technical field of steelmaking, and in particular relates to a refining process for washing and pre-desulfurization of slag from a converter, especially when smelting low-sulfur steel, creating a good precondition for rapid and deep desulfurization in LF furnace refining, so as to realize the stability of sulfur content in steel control. Background technique [0002] In high-quality steel, sulfur is a harmful element except for special steel types. In addition to causing hot embrittlement of steel, it can also affect the mechanical properties of steel by forming sulfide inclusions; when the sulfur content in steel is controlled to be high, The ductility and toughness of steel are reduced, especially the impact toughness of steel; sulfur has a great influence on the hot deformation processability and weldability of steel; when the sulfur content is high, it will damage the corrosion resistance of steel and cause corrosion on...

Claims

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Application Information

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IPC IPC(8): C21C5/36C21C7/072C21C7/06
Inventor 李战军王文军朱志远刘金刚郝宁姜中行蒋海涛刘洋吕延春王彦锋王东柱史志强石树东麻庆申孙硕猛危尚好刘建明陈霞张建师李广双万潇谢翠红杨国伟韦耀环关春阳刘成
Owner SHOUGANG CORPORATION
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