阅读说明：本技术 提高电炉炉龄的冶炼方法 (Smelting method for improving service life of electric furnace ) 是由 陈路 王建 于 2020-06-15 设计创作，主要内容包括：本发明属于冶金技术领域,具体涉及一种提高电炉炉龄的冶炼方法。针对电炉冶炼中对炉衬侵蚀,导致电炉炉龄低的问题,本发明提供了一种提高电炉炉龄的冶炼方法,包括以下步骤：a、上一炉冶炼留钢10t,向炉内加入石灰和废钢物料,使废钢物料融化,融化过程中加入碳粉,同时向炉内吹氧气,冶炼2/3～出钢前,向炉内加入白云石；b、冶炼过程中底吹气体,吹炼开始至1/3阶段采用N<Sub>2</Sub>,吹炼1/3～2/3阶段采用CO<Sub>2</Sub>；吹炼2/3～出钢前,采用CO<Sub>2</Sub>与Ar混合气体；c、冶炼终点温度控制为1650～1720℃。本发明通过控制底吹气体的种类及流量,以及后期加入白云石等措施的配合使用,共同提高了电炉的使用寿命,降低生产成本,经济效益显著。(The invention belongs to the technical field of metallurgy, and particularly relates to a smelting method for prolonging the service life of an electric furnace. Aiming at the problem of low furnace life of the electric furnace caused by erosion of a furnace lining in electric furnace smelting, the invention provides a smelting method for improving the furnace life of the electric furnace, which comprises the following steps: a. smelting 10t of steel left in the previous furnace, adding lime and waste steel materials into the furnace to melt the waste steel materials, adding carbon powder in the melting process, simultaneously blowing oxygen into the furnace, and adding dolomite into the furnace before smelting 2/3-steel tapping; b. in the smelting process, N is adopted from the beginning of blowing to 1/3 stage of bottom blowing gas 2 CO is adopted in the blowing 1/3-2/3 stage 2 (ii) a Blowing 2/3-before tapping, CO is adopted 2 Mixed gas with Ar; c. the smelting end point temperature is controlled to be 1650-1720 ℃. The invention controls the type and flow of bottom blowing gas, and adds dolomite in the later period, thereby improving the service life of the electric furnace, reducing the production cost and having obvious economic benefit.)

1. The smelting method for improving the service life of the electric furnace is characterized by comprising the following steps of:

a. smelting 10t of steel left in the previous furnace, adding 18-25 kg/t of lime and 40-50 t of waste steel materials into the furnace to melt the waste steel materials, adding carbon powder in the melting process, wherein the adding amount of the carbon powder is 40-60 kg/t of steel, simultaneously blowing oxygen into the furnace, and adding dolomite in an amount of 25-35 kg/t of steel into the furnace before smelting 2/3-steel tapping;

b. in the smelting process, N is adopted from the beginning of blowing to 1/3 stage of bottom blowing gas₂The flow rate is 0.06-0.25 Nm³T.min; CO is adopted in the blowing 1/3-2/3 stage₂The flow rate is 0.10-0.35 Nm³T.min; blowing 2/3-before tapping, CO is adopted₂Mixed with Ar, CO₂The mixing ratio of the mixed solution and Ar is 3:1, and the flow rate is 0.2-0.45 Nm³/t·min；

c. The smelting end point temperature is controlled to be 1650-1720 ℃.

2. The smelting method for improving the campaign of the electric furnace according to claim 1, wherein: the scrap steel material in the step a is scrap steel with iron content more than 80 percent.

3. The smelting method for improving the campaign of the electric furnace according to claim 1, wherein: step a, adding a slagging auxiliary material during smelting, comprising the following steps: active lime, dolomite and ferrosilicon.

4. The smelting method for improving the campaign of the electric furnace according to claim 1, wherein: the active lime is active lime containing 85-90% of CaO; the dolomite is CaO: 28-31%, MgO: 20 to 22% of CO₂: 45-49% of dolomite.

5. The smelting method for improving the campaign of the electric furnace according to claim 1, wherein: the carbon powder in the step a is carbon powder with the C content being more than or equal to 95 percent.

6. The smelting method for improving the campaign of the electric furnace according to claim 1, wherein: the oxygen blowing amount in the oxygen blowing in the step a is 10-30 m³The oxygen pressure is 0.8-1.2 MPa.

Technical Field

The invention belongs to the technical field of metallurgy, and particularly relates to a smelting method for prolonging the service life of an electric furnace.

Background

The smelting process of the electric furnace is always in an oxidizing atmosphere, a large amount of oxygen is contained in the molten steel and mainly exists in the form of FeO, particularly when low-carbon steel is smelted, the oxygen content in the molten steel is higher, and the oxygen in the molten steel reacts with carbon in the magnesia carbon brick body at high temperature, so that a loose decarburized layer is formed on the surface of the gas supply brick, and the service life of the electric furnace is shortened.

At present, a great deal of research is being conducted by those skilled in the art in order to increase the life of electric furnaces.

Patent CN101216251A discloses a method for maintaining bricks on the working layer of the furnace wall of an electric furnace, which is to spray different parts at different furnace ages according to the maintenance method determined by whether the electric furnace is a double furnace or a single furnace. The method can be used for maintaining the furnace wall working layer bricks of the electric furnace for steelmaking, and by implementing the method, the furnace life of the intermediate repair and the overhaul interval is improved, the time of the intermediate repair and the overhaul is shortened, the actual service time of the electric furnace is prolonged, and the consumption of refractory per ton steel is reduced on the basis of unchanging unit consumption of the unshaped refractory. The method mainly aims at repairing the damaged electric furnace so as to improve the furnace life, does not fundamentally improve the service life of the furnace life, and has no precautionary effect.

Disclosure of Invention

The technical problem to be solved by the invention is as follows: the problem of low furnace life of the electric furnace caused by erosion to the furnace lining in electric furnace smelting.

The technical scheme for solving the technical problems comprises the following steps: provides a smelting method for improving the service life of an electric furnace. The method comprises the following steps:

a. smelting 10t of steel left in the previous furnace, adding 18-25 kg/t of lime and 40-50 t of waste steel materials into the furnace to melt the waste steel materials, adding carbon powder in the melting process, wherein the adding amount of the carbon powder is 40-60 kg/t of steel, simultaneously blowing oxygen into the furnace, and adding dolomite in an amount of 25-35 kg/t of steel into the furnace before smelting 2/3-steel tapping;

b. in the smelting process, N is adopted from the beginning of blowing to 1/3 stage of bottom blowing gas₂The flow rate is 0.06-0.25 Nm³T.min; CO is adopted in the blowing 1/3-2/3 stage₂The flow rate is 0.10-0.35 Nm³T.min; blowing 2/3-before tapping, CO is adopted₂Mixed with Ar, CO₂The mixing ratio of the mixed solution and Ar is 3:1, and the flow rate is 0.2-0.45 Nm³/t·min；

c. The smelting end point temperature is controlled to be 1650-1720 ℃.

In the smelting method for improving the service life of the electric furnace, the scrap steel material in the step a is scrap steel with the iron content of more than 80 percent.

In the smelting method for prolonging the service life of the electric furnace, a slagging auxiliary material is added in the smelting process in the step a, and the smelting method comprises the following steps: active lime, dolomite and ferrosilicon.

Further, the furnace life of the electric furnace is improvedIn the smelting method, the active lime is active lime containing 85-90% of CaO; the dolomite is CaO: 28-31%, MgO: 20 to 22% of CO₂: 45-49% of dolomite.

In the smelting method for improving the service life of the electric furnace, the carbon powder in the step a is carbon powder with the C content of more than or equal to 95 percent.

In the smelting method for improving the service life of the electric furnace, the oxygen blowing amount in the oxygen blowing in the step a is 10-30 m³The oxygen pressure is 0.8-1.2 MPa.

Compared with the prior art, the invention has the beneficial effects that:

the invention provides a smelting method for prolonging the service life of an electric furnace, which jointly prolongs the service life of the electric furnace by controlling the type and flow of bottom blowing gas and matching the measures of adding dolomite and the like at the later stage. The production cost is reduced, and the economic benefit is remarkable. The TFe content of the end-point steel slag obtained by adopting the measures is below 25 percent.

Detailed Description

The invention provides a smelting method for prolonging the service life of an electric furnace, which comprises the following steps:

a. smelting 10t of steel left in the previous furnace, adding 18-25 kg/t of lime and 40-50 t of waste steel materials into the furnace to melt the waste steel materials, adding carbon powder in the melting process, wherein the adding amount of the carbon powder is 40-60 kg/t of steel, simultaneously blowing oxygen into the furnace, and adding dolomite in an amount of 25-35 kg/t of steel into the furnace before smelting 2/3-steel tapping;

b. in the smelting process, N is adopted from the beginning of blowing to 1/3 stage of bottom blowing gas₂The flow rate is 0.06-0.25 Nm³T.min; CO is adopted in the blowing 1/3-2/3 stage₂The flow rate is 0.10-0.35 Nm³T.min; blowing 2/3-before tapping, CO is adopted₂Mixed with Ar, CO₂The mixing ratio of the mixed solution and Ar is 3:1, and the flow rate is 0.2-0.45 Nm³/t·min；

c. The smelting end point temperature is controlled to be 1650-1720 ℃.

In order to save production cost, in the smelting method for prolonging the service life of the electric furnace, the scrap steel material in the step a is scrap steel with the iron content of more than 80 percent.

In order to improve the smelting slagging effect and control the oxygen content in steel components, in the smelting method for improving the service life of the electric furnace, slagging auxiliary materials are added in the step a during smelting, and the method comprises the following steps: active lime, dolomite and ferrosilicon.

Furthermore, in order to improve the slagging effect, in the smelting method for improving the service life of the electric furnace, the active lime is active lime containing 85-90% of CaO; the dolomite is CaO: 28-31%, MgO: 20 to 22% of CO₂: 45-49% of dolomite.

In the smelting method for improving the service life of the electric furnace, the carbon powder in the step a is carbon powder with the C content of more than or equal to 95 percent.

In the smelting method for improving the service life of the electric furnace, the oxygen blowing amount in the oxygen blowing in the step a is 10-30 m³The oxygen pressure is 0.8-1.2 MPa.

The invention particularly changes the method of bottom blowing gas in the smelting process, the bottom blowing gas is divided into three stages, and N is blown in the first stage₂The flow rate is 0.06-0.25 Nm³The/t.min can blow off most impurities in the molten steel; second stage using CO₂The flow rate is 0.10-0.35 Nm³T.min; removing redundant oxygen in the molten steel; blowing CO in the third stage₂Mixed gas of Ar and the mixed gas in a mixing ratio of 3:1 and a flow rate of 0.2-0.45 Nm³/t·min。

By adopting the method, the oxygen content in the smelting process can be reduced, thereby fundamentally reducing the erosion to the furnace lining and improving the furnace life.

The following examples are given to further illustrate the embodiments of the present invention, but are not intended to limit the scope of the present invention to the examples.