阅读说明：本技术 转炉炼钢用生白云石代替轻烧白云石 (Light-burned dolomite replaced by raw dolomite for converter steelmaking ) 是由 李刚 唐民生 杨庆利 陈丰健 李兆琳 黄永红 于 2021-09-08 设计创作，主要内容包括：本发明申请公开了一种转炉炼钢用生白云石代替轻烧白云石方法,其配料由主材铁水、辅材氧化铁皮和生白云石组成,生白云石的主要成分是CaCO-(3)和MgO-(3),是生产加工轻烧白云石的原料,其在1000℃左右高温时能够分解除CaO和MgO,吸收热量同时产生大量的CO-(2)。在转炉内加入生白云石,可以充分利用转炉富余热量,实现转炉冶炼冶炼过程热平衡,同时降低溶剂消耗成本,废气通过OG系统全部回收利用或净化处理,由于加入生白云石分解吸热,降低了前期升温速度,有利于泡沫渣的形成,同时生成大量的CO-(2)气体弥散在前期渣内,有利于泡沫渣层的增高,提高了去磷效果。(The invention discloses a method for replacing light-burned dolomite with raw dolomite for converter steelmaking, which comprises the following ingredients of main material molten iron, auxiliary material iron scale and raw dolomite, wherein the main component of the raw dolomite is CaCO 3 And MgO 3 Is a raw material for producing and processing light-burned dolomite, can remove CaO and MgO at a high temperature of about 1000 ℃, absorbs heat and simultaneously generates a large amount of CO 2 . The raw dolomite is added into the converter, the surplus heat of the converter can be fully utilized, the heat balance in the smelting process of the converter is realized, the solvent consumption cost is reduced, the waste gas is completely recycled or purified through an OG (oxygen gas decarburization) system, the earlier-stage heating speed is reduced due to the decomposition and heat absorption of the raw dolomite, the foam slag is favorably formed, and a large amount of CO is generated simultaneously 2 The gas is dispersed in the early-stage slag, which is beneficial to the increase of the foam slag layer and improves the dephosphorization effect.)

1. A method for replacing light-burned dolomite with raw dolomite for converter steelmaking comprises the following ingredients of main materials of molten iron, auxiliary materials of iron scale and raw dolomite, and is characterized in that: 930Kg of molten iron, 3-4t of raw dolomite and 1400Kg of iron scale according to the weight; firstly, raw dolomite accounting for 2/3 and 200Kg of iron scale are added into a converter, then all molten iron is added, the lance head of an oxygen lance is adjusted to be 1400mm away from the liquid level of the molten iron to start blowing, and the oxygen flow is controlled to be 38000m for carrying out the year/h at 35000-; adding the rest 1/3 raw dolomite into the converter in 5-6 batches in 8 minutes after the start of blowing, wherein each batch of dolomite is 200Kg by weight, and each batch of dolomite is added with the oxide scale which is 100-200Kg by weight at the same time;

wherein after blowing for 4 minutes, when the distance between the lance head of the oxygen lance and the lance position of the liquid level of the molten steel is 15000-.

2. The method for replacing light-burned dolomite with raw dolomite for converter steelmaking as claimed in claim 1, wherein: the silicon content of the molten iron is less than 0.40 percent.

Technical Field

The invention belongs to the field of steelmaking process, relates to a converter steelmaking process, and particularly relates to a converter steelmaking raw dolomite for replacing light-burned dolomite.

Background

The traditional converter steelmaking process needs to use lime and calcined dolomite, wherein the calcined dolomite is used as a steelmaking flux to improve the content of magnesium oxide in slag, the calcined dolomite is also called light-burned dolomite, however, besides consuming a large amount of energy in the calcining process of the dolomite, no matter a shaft kiln process or a sleeve kiln process is adopted, a large amount of carbon dioxide can be generated in the calcining process, positive contribution is made to the global greenhouse effect, the consumption of resources is saved by reducing the use of the calcined dolomite, and the low-carbon emission reduction is facilitated.

The light-burned dolomite used in the traditional converter steelmaking process is one of important slagging materials, the main components are CaO and MgO, and the light-burned dolomite added in the converter steelmaking process can improve the MgO content in slag, reduce the corrosion of slag on a furnace lining, protect the furnace lining and greatly improve the service life of the converter. The main component of the raw dolomite is CaCO₃And MgO₃Is a raw material for producing and processing light-burned dolomite, can remove CaO and MgO at a high temperature of about 1000 ℃, absorbs heat and simultaneously generates a large amount of CO₂. Because scrap steel resources are in shortage relative to blast furnace molten iron in a short time, the heat balance in the converter smelting process is influenced by using a large amount of high-temperature molten iron, the temperature in the process of adjusting by a coolant needs to be increased, the solvent consumption is increased, through technical analysis, raw dolomite is added into the converter, the surplus heat of the converter can be fully utilized, the heat balance in the converter smelting process is realized, the solvent consumption cost is reduced, and the waste gas is completely recycled or purified by an OG system.

Disclosure of Invention

The invention discloses a raw dolomite for converter steelmaking to replace light-burned dolomite, which comprises the following ingredients of main material molten iron, auxiliary material iron scale and raw dolomite, and is characterized in that: 930Kg of molten iron, 3-4t of raw dolomite and 1400Kg of iron scale according to the weight; firstly, raw dolomite accounting for 2/3 and 200Kg of iron scale are added into a converter, then all molten iron is added, the lance head of an oxygen lance is adjusted to be 1400mm away from the liquid level of the molten iron to start blowing, and the oxygen flow is controlled to be 38000m for carrying out the year/h at 35000-; adding the rest 1/3 raw dolomite into the converter in 5-6 batches in 8 minutes after the start of blowing, wherein each batch of dolomite is 200Kg by weight, and each batch of dolomite is added with the oxide scale which is 100-200Kg by weight at the same time;

the silicon content of the molten iron is less than 0.40 percent.

Drawings

The invention is described in further detail below with reference to the following figures and detailed description:

FIG. 1 is a graph showing the lance position and dolomite addition time according to the present invention.

Detailed Description

The invention discloses a method for replacing light-burned dolomite with raw dolomite for converter steelmaking, which comprises the following ingredients of main material molten iron, auxiliary material iron scale and raw dolomite, and is characterized in that: 930Kg of molten iron, 3-4t of raw dolomite and 1400Kg of iron scale according to the weight; firstly, raw dolomite accounting for 2/3 and 200Kg of iron scale are added into a converter, then all molten iron is added, the lance head of an oxygen lance is adjusted to be 1400mm away from the liquid level of the molten iron to start blowing, and the oxygen flow is controlled to be 38000m for carrying out the year/h at 35000-; adding the rest 1/3 raw dolomite into the converter in 5-6 batches in 8 minutes after the start of blowing, wherein each batch of dolomite is 200Kg by weight, and each batch of dolomite is added with the oxide scale which is 100-200Kg by weight at the same time;

wherein after blowing for 4 minutes, when the distance between the lance head of the oxygen lance and the lance position of the liquid level of the molten steel is 15000-;

the silicon content of the molten iron is less than 0.40 percent.

By adopting the method, the cost is reduced, the efficiency is improved, the environmental protection is facilitated, and through practical application, the raw dolomite can be immediately decomposed and react to generate CO when being added into the converter₂The surface temperature of molten iron in the smelting process of the converter is up to 1100 ℃, the temperature of a fire point area is up to 3000 ℃, and CO generated by decomposition is high₂The gas expands more than 4000 times instantly to push the generated CaO and MgO to fly into the slag, and simultaneously, CO is used₂The newly generated light-burned dolomite is in a porous fine crystal shape by escaping, and the slagging speed is improved. The main purpose of converter slagging isDecarbonizing, heating and dephosphorizing, because of adding raw dolomite for decomposition and heat absorption, the earlier-stage heating speed is reduced, the foam slag is favorably formed, and simultaneously a large amount of CO is generated₂The gas is dispersed in the early-stage slag, which is beneficial to the increase of the foam slag layer and improves the dephosphorization effect.