阅读说明：本技术 一种炉渣改质剂及其制备方法 (Slag modifier and preparation method thereof ) 是由 杜金科 阎青 王忠刚 胡滨 高志滨 于亮涛 张伟 李四军 付常伟 李萍 邹春峰 于 2019-09-24 设计创作，主要内容包括：本发明公开了一种炉渣改质剂及其制备方法,按重量百分比计,该改质剂包括以下含量的物料：5～10％的石灰粉,40～60％的无烟煤粉,15～30％的白云石粉,5～20％的AD粉,2～6％的粘结剂。该改渣剂由于含有C和Al,因此能迅速降低渣中氧化铁含量并缩短溅渣时间,提高炉渣MgO含量、提高熔点和粘度,从而明显提高转炉溅渣护炉效果。本发明提供的炉渣改质剂在溅渣护炉使用后可降低补炉料、氮气、石灰多项消耗,经济效益显著。(The invention discloses a slag modifier and a preparation method thereof, wherein the modifier comprises the following materials in percentage by weight: 5-10% of lime powder, 40-60% of anthracite powder, 15-30% of dolomite powder, 5-20% of AD powder and 2-6% of binder. The slag modifier contains C and Al, so that the iron oxide content in the slag can be rapidly reduced, the slag splashing time is shortened, the MgO content of the slag is increased, the melting point and the viscosity are increased, and the slag splashing furnace protection effect of the converter is obviously improved. The slag modifier provided by the invention can reduce the consumption of repairing materials, nitrogen and lime after slag splashing and furnace protection, and has remarkable economic benefit.)

1. The slag modifier is characterized by comprising, by weight, 5-10% of lime powder, 40-60% of anthracite powder, 15-30% of dolomite powder, 5-20% of AD powder and 2-6% of a binder, and the raw materials are prepared and pressed into spherical particles.

2. The slag modifier according to claim 1, wherein the lime powder is active lime powder containing CaO not less than 80% and SiO₂Less than or equal to 5 percent, and the grain size less than 3mm is more than or equal to 90 percent.

3. The slag modifier according to claim 1, wherein the anthracite coal has a carbon content of not less than 90%, Sd of not more than 0.5%, and a particle size fraction of less than 2mm of not less than 90%.

4. The slag modifier according to claim 1, wherein the dolomite powder contains at least 18% of MgO and SiO₂Less than or equal to 3.5 percent, and the grain size less than 3mm is more than or equal to 90 percent.

5. The slag modifier according to claim 1, wherein the AD powder contains 15-30% of Al.

6. The slag modifier of claim 1, wherein the binder comprises one or more of a cellulose methyl, bentonite, a smectite-like silicate, a fine crystalline alumina and diatomaceous earth.

7. The slag modifier according to claim 1, wherein the slag modifier is in the form of spherical particles having a diameter of 10-30 mm.

8. A process for the preparation of the slag modifier of claims 1-7, comprising the steps of:

1) Putting raw materials of lime powder, AD powder, anthracite powder, dolomite powder and a binder into mixing equipment in proportion, and stirring and mixing uniformly;

2) Preparing the raw materials stirred and mixed in the step 1) into spherical particles with the diameter of 10-30 mm;

3) And (3) drying the pressed material obtained in the step 2) in a drying device, wherein the moisture content after drying is less than or equal to 2%, and obtaining a finished product material.

9. The method according to claim 8, wherein the apparatus for preparing spherical particles in step 2) comprises a pelletizing and/or pressing apparatus, and the pressure during the pressing process is 25-50 Mpa.

Technical Field

The invention belongs to the field of steelmaking, and particularly relates to a slag modifier and a preparation method thereof, which are used for reducing the oxidability of slag in a converter slag splashing protection stage and optimizing the slag splashing protection effect.

Background

Due to the smelting of part of low-carbon variety steel and low-phosphorus steel (C is less than or equal to 0.07 percent and P is less than or equal to 0.020 percent), the deep blowing at the smelting end point of the converter is serious, and the total iron content of the final slag of individual furnace is even more than 20 percent. On the one hand, the consumption of steel materials is increased due to too high TFe; on the other hand, the slag TFe is too high, so that the melting point and viscosity of the slag are reduced, the slag splashing furnace protection effect of the converter is seriously influenced, and great pressure is brought to the maintenance work of the converter body of the converter; meanwhile, slag splashing time is too long, and the time for repairing the furnace is too long, so that the production rhythm is seriously influenced; too high TFe can cause difficulty in stopping slag due to over-dilution of slag, increase consumption of alloy deoxidizer due to slagging heat, and even serious pollution to molten steel.

With the continuous progress of steel-making technology, the technology for modifying the converter steelmaking end-point slag is continuously popularized and applied in various large steel enterprises at present. The modifier is adopted to adjust the components of the converter final slag, the melting point and the viscosity of the slag are improved by reducing the FeO content of the slag, and the corrosion resistance and the anti-scouring performance of a slag splashing layer are improved, and the adhesion between the slag and a furnace lining is improved; the melting point and the viscosity of the slag are improved, and the modifier has the effect of quickly cooling the slag, so that the slag splashing and starting time can be shortened; the phosphorus content of the steel slag can be reduced by adding the reducing agent to carry out gasification dephosphorization reaction on the final slag, so that the steel slag can be further recycled. The gasified dephosphorization slag is left to the lower furnace to be used as a slagging raw material, so that the physical heat contained in the high-temperature steel slag can be utilized, and the consumption of slagging materials such as lime, dolomite and the like can be reduced, thereby further reducing the steel slag amount per ton of the converter.

Disclosure of Invention

In order to solve the problems that the low-carbon steel slag has strong oxidability and long slag splashing time and the slag is not easy to attach to a furnace lining, the invention provides a slag modifier for modifying the slag in the slag splashing stage of a converter and a preparation method thereof.

The invention provides a slag modifier which comprises, by weight, 5-10% of lime powder, 40-60% of anthracite powder, 15-30% of dolomite powder, 5-20% of AD powder and 2-6% of a binder, and the raw materials are prepared and pressed into spherical particles.

In order to achieve the purpose, the technical scheme adopted by the invention is as follows:

5-10% of lime powder, 40-60% of anthracite powder, 15-30% of dolomite powder, 5-20% of AD powder and 2-6% of binder are prepared and pressed into spherical particles, and the sum of the weight of the raw materials is 100%.

Preferably, the lime powder is active lime powder, the CaO content of the lime powder is more than or equal to 80 percent, and the SiO content of the lime powder is equal to or more than 80 percent₂Less than or equal to 5 percent, and the grain size less than 3mm is more than or equal to 90 percent.

preferably, the carbon content of the anthracite powder is more than or equal to 90 percent, the Sd is less than or equal to 0.5 percent, and the particle size fraction of less than 2mm is more than or equal to 90 percent.

Preferably, the dolomite powder contains more than or equal to 18 percent of MgO and SiO₂Less than or equal to 3.5 percent, and the grain size less than 3mm is more than or equal to 90 percent.

preferably, the AD powder contains 15-30% of Al.

Preferably, the shape of the slag modifier is granular, and the diameter of the slag modifier is 10-30 mm.

Preferably, the binder comprises one or more of carboxymethyl cellulose, bentonite, montmorillonite silicate, fine crystalline alumina and diatomite.

the invention provides a preparation method of a slag modifier, which comprises the following steps:

1) Putting raw materials of lime powder, AD powder, anthracite powder, dolomite powder and a binder into mixing equipment in proportion, and stirring and mixing uniformly;

2) Preparing the raw materials stirred and mixed in the step 1) into spherical particles with the diameter of 10-30 mm;

3) And (3) drying the pressed material obtained in the step 2) in a drying device, wherein the moisture content after drying is less than or equal to 2%, and obtaining a finished product material.

Preferably, the equipment for preparing the spherical particles in the step 2) comprises pelletizing and/or pressing equipment, and the pressure in the pressing forming process is 25-50 Mpa.

Compared with the prior art, the invention has the advantages that:

1. Because the anthracite powder is adopted, the main component is C, the C added into the furnace can react with the slag (FeO) to reduce the oxidability of the slag, and the reaction chemical equation is as follows: c + FeO ═ Fe + CO;

2. The invention contains AD powder, and the main components of the invention are Al and Al₂O₃Al added into the furnace reacts with the (FeO) in the slag to reduce the oxidizability of the slag, and the reaction chemical formula is as follows: 2Al +3FeO ═ 3Fe + Al₂O₃；

3. due to the reduction of FeO, the melting point and the viscosity of the slag are improved, the slag splashing time can be effectively shortened, the slag splashing furnace protection effect can be improved, the times of repairing the furnace can be further reduced, and the productivity of the converter can be effectively improved;

4. The dolomite powder is contained, and the main component of the dolomite powder is MgO, so that the MgO content in the slag can be increased, the melting point of the slag is further increased, and the slag splashing furnace protection effect is improved.

By using the slag modifier, the C added into the furnace can react with (FeO) in the slag to reduce the oxidability of the slag due to the C, Al deoxidizer, so that the melting point and the viscosity of the slag are improved due to the reduction of the FeO, the slag splashing time can be effectively shortened, the slag splashing furnace protection effect can be improved, the furnace repairing times can be further reduced, and the converter capacity can be effectively improved; because the dolomite powder is contained, the main component of the dolomite powder is MgO, the MgO content in the slag can be increased, the melting point of the slag is further improved, and the slag splashing furnace protection effect is improved; the modified furnace slag can be completely reserved for the next furnace for cyclic utilization, the consumption of converter steel materials, lime, dolomite, nitrogen and the like can be effectively reduced, the times of repairing the furnace can be greatly reduced, the operations of tiling, spray repair and the like are greatly reduced, the labor intensity of workers is effectively reduced, and various comprehensive social energy consumption is indirectly reduced.

Detailed Description

The present invention will be further described with reference to the following specific examples.