CN105018675B - Stainless steel EAF foaming slag and its application method - Google Patents

Abstract

The invention discloses a kind of stainless steel EAF foaming slag and its application method, stainless steel EAF foaming slag includes CaCO₃, CaO, SiO₂, silica flour, Al₂O₃, Na₂CO₃（Soda ash）, MgO and CaF₂（Fluorite）；Stainless steel EAF foaming slag is compressed into solid mass form, is launched by high hopper into molten bath；The present invention reduces Cr in slag₂O₃Content improves the metal recovery rate in stainless steel, and foaming effect is more preferable, alleviates noise, due to the foaming submerged arc of electrode, greatly reduces power consumption, extends the service life of electrode, bell, furnace lining；Improve the working environment of stokehold, overcome powdered granule foaming agent quality kick the beam dispensing when the problem of being siphoned away by the dust exhaust apparatus on stove.

Description

Stainless steel EAF foaming slag and its application method

Technical field

The present invention relates to stainless steel electric furnace smelting technical fields, relate in particular to a kind of real in electric arc furnace smelting processing Stainless steel EAF foaming slag and its application method.

Background technology

At present, in the smelting process of domestic and international electric-arc furnace steelmaking, making foamed slag is a kind of widely used technology, passes through system Making foamed slag can realize that improving electric arc heat transfer condition improves the thermal efficiency, reduces electric arc and the furnace wall of electric furnace and the radiant heat of bell are invaded Electric arc is stablized in erosion, reduces noise and arc light irradiation, improves the technique effects such as stokehold working environment.

In the prior art, the mode of injecting oxygen and carbon dust is real in the smelting process of electric-arc furnace steelmaking simultaneously for generally use The process of existing foam slag making, because technique needs, melting the oxygen stage must be to bath lancing, and the iron under oxygen-enriched environment in mother liquor can occur Oxidation reaction generation iron oxide can reduce metal recovery rate, and be blown carbon dust by the molten steel into molten bath, can be by the oxygen of generation Change iron reduction, so as to improve the metal recovery rate in foamed slag, and reduce the quantity of slag.Meanwhile carbon dust generates in reduction reaction CO gases, make slag foam to form foamed slag.

There are some defects for this technology：When using electric arc furnace smelting stainless steel, containing substantial amounts of in mother liquor of stainless steel Chromium, the chemical property of chromium is more active than iron, and Cr is generated under oxygen-enriched environment₂O₃If not reducing spray oxygen amount, if being difficult to ensure not Chromium content in rust steel；If reducing spray oxygen amount, the production rate for causing CO is reduced, promotes foaming difficulty.In addition, merely with carbon dust As foaming agent, carbon content in molten steel is necessarily caused to increase, so as to cause decarburization program must be increased in subsequent handling.

In traditional stainless steel-making process, the carbon dust of injection is powdered, it is necessary to be added in from stokehold, so as to influence to make The industry time；Powder is easily raised and drifted in launch process, influences the working environment of stokehold；The lighter in weight of carbon dust powder, The 10%-15% of total amount can be siphoned away by the dust exhaust apparatus on stove in launch process, meaningless loss is excessive.

The content of the invention

The object of the present invention is to provide a kind of stainless steel EAF foaming slag and its application methods, it is intended to make up above-mentioned each technology Defect.

The specific technical solution that the present invention uses is as follows：

A kind of stainless steel EAF foaming slag, including CaCO₃, SiO₂, silica flour, Al₂O₃, C, soda ash, MgO, the quality of each component Percentage is：

CaCO₃18%-55%；

SiO₂5%-25%；

Silica flour10%-15%；

Al₂O₃5%-20%；

C 3%-7%；

Soda ash1%-5%；

MgO 5%-15%；

CaF₂ 3%-8%。

A kind of preferred formula is that the mass percent of each component is：

CaCO₃47%；

SiO₂5%；

Silica flour 12%；

Al₂O₃5%；

C 7%；

Soda ash 4%；

MgO 12%；

CaF₂8%。

By adding CaCO₃And soda ash, when adding in molten bath, CaCO₃It is decomposed into CaO and CO₂, Na₂CO₃It is decomposed into Na₂O and CO₂, the blistering of slag charge is caused as source of the gas, reaction principle is：

CaCO₃=CaO+CO₂

Na₂CO₃=Na₂O+CO₂

CO₂+C=2CO

In this way, change and blistering is only realized by the mode of injecting oxygen and carbon dust generation CO in the prior art. Improve the speed of slag making blistering.

By adding silica flour, silica flour is as the Cr in reducing agent reducing slag₂O₃, reaction principle is：

3Si+2Cr₂O₃=3SiO₂+4Cr

It solves as a result, in stainless steel fusion process, chromium generates Cr under oxygen-enriched environment₂O₃The problem of.Reduction need not be passed through The chromium content in oxygen amount guarantee stainless steel is sprayed, and improves recovery rate of iron.

MgO and the CaO, Na of bubbling process generation₂O forms the slag making materials in steelmaking process, saves slag making raw material, together When ensure that the basicity of slag.Reduce the input amount of C, so as to avoid carbon content in molten steel excessively high.

By the SiO for adding acidic oxide₂, the pH value of clinker is balanced, avoids the basicity of clinker is excessively high from causing slag knot Block.

By adding aluminium oxide, Al₂O₃It can be with the CaO, Na of alkalescence₂O, MgO reaction generation calcium aluminate, Lv Suan Magnesium, aluminic acid Sodium, also can be with acid SiO₂Manosil AS is generated, reduces slag fusing point, adjusts the viscosity and surface tension of slag, extends furnace wall, Furnace lining, the service life of bell.

By adding CaF₂, the fusing point of infusibility substance is reduced, promotes clinker flowing, slag and metal is made to separate well.

A kind of application method to above-mentioned stainless steel EAF foaming slag：In smelting process, by the stainless steel electric furnace Foaming agent is compressed into solid mass form, and the mode launched into molten bath feeds intake.

In fusion process, the foaming agent of solid mass form can sink to slag bottom, not disturb the foam performance of slag, together When, bubble promotes slag foaming from slag blanket bottom, reaches better foaming effect.The foaming agent of solid forms will not exist because Quality kicks the beam the problem of being siphoned away by the dust exhaust apparatus on stove.

Preferably：The stainless steel EAF foaming slag volume for being compressed into solid mass form reduces 20%-30%.

It is further to be preferably：In smelting process, the stainless steel EAF foaming slag is compressed into sphere dispensing and is arrived Mode in molten bath feeds intake.

Thus obtained effect is：Evenly, foaming effect is more preferable for bubble during foaming in all directions.

Compared with prior art, the solution have the advantages that：Reduce Cr in slag₂O₃Content is improved in stainless steel Metal recovery rate, foaming effect is more preferable, due to the foaming submerged arc of electrode, reduces power consumption, extends electrode, bell, furnace lining Service life；The working environment of stokehold is improved, foaming agent quality is overcome and kicks the beam when launching by the dust exhaust apparatus on stove The problem of siphoning away.

Specific embodiment

The present invention will be further described with reference to embodiments.

Embodiment 1：A kind of stainless steel EAF foaming slag, the mass percent of each component are：

CaCO₃47%；

SiO₂5%；

Silica flour 12%；

Al₂O₃5%；

C 7%；

Soda ash 4%；

MgO 12%；

CaF₂8%。

Embodiment 2：A kind of stainless steel EAF foaming slag, the mass percent of each component are：

CaCO₃18%；

SiO₂25%；

Silica flour 15%；

Al₂O₃20%；

C 3%；

Soda ash 1%；

MgO 15%；

CaF₂3%。

Embodiment 3：A kind of stainless steel EAF foaming slag, the mass percent of each component are：

CaCO₃ 55%；

SiO₂7%；

Silica flour 10%；

Al₂O₃10%；

C 3%；

Soda ash 5%；

MgO 5%；

CaF₂5%。

A kind of application method to above-mentioned stainless steel EAF foaming slag：In smelting process, the stainless steel electric furnace is sent out Infusion is compressed into spherical morphology, and the mode launched into molten bath feeds intake.It is compressed into the stainless steel EAF foaming slag body of sphere Product reduces 20%.

	First time injected volume	Second of injected volume	Foaming height	Foamed time
					Embodiment 1	500kg	800kg	500mm	25min
Embodiment 2	500kg	800kg	470mm	23min
					Embodiment 3	500kg	800kg	450mm	22min

Table 1

Table 1 is given produced by EAF foaming slag of the dispensing using embodiment 1-3 during 90t electric furnace smelting stainless steels Foaming effect.

The above, is only a few embodiments of the present invention, and the present invention is not only restricted to the limitation of above-described embodiment, it is all according to According to similar modification, variation and replacement that the technical spirit of the present invention makees above-described embodiment, technical solution of the present invention is still fallen within In the range of.Protection scope of the present invention is only defined by tbe claims.

Claims (1)

1. a kind of application method of stainless steel EAF foaming slag, it is characterised in that：Stainless steel EAF foaming slag includes CaCO₃, SiO₂, silica flour, Al₂O₃, C, soda ash, MgO, CaF₂；The mass percent of each component is：

CaCO₃18%-55%；

SiO₂5%-25%；

Silica flour10%-15%；

Al₂O₃5%-20%；

C 3%-7%；

Soda ash1%-5%；

MgO 5%-15%；

CaF₂3%-8%；

In smelting process, thrown in a manner that the stainless steel EAF foaming slag is compressed into sphere launch into molten bath Material.