阅读说明：本技术 一种转炉两吹两倒一次出渣法处理高硅中钒铁水提钒方法 (Method for extracting vanadium from high-silicon medium-vanadium molten iron by converter two-blowing two-pouring one-time slag tapping method ) 是由 文玉兵 张卫强 邹荣 欧阳晨曦 杨春雷 潘杨勇 付仕猛 陈大双 李金柱 刘林刚 于 2020-07-10 设计创作，主要内容包括：本发明涉及一种转炉两吹两倒一次出渣法处理高硅中钒铁水提钒方法,属于冶金技术领域。该方法包括铁水废钢配比、一次供氧去硅倒渣、二次供氧提钒、后期控温降FeO保钒渣品位、出渣几大步骤。本发明方法具有处理高硅含钒铁水提钒、降低半钢残钒、提高钒渣品位品质等优点,使得转炉在使用高硅铁水(＞0.55wt%[Si])提钒冶炼过程中,钒渣品位从平均7.8%提高到10.1%,铁水中钒得到充分回收,钒渣中[SiO<Sub>2</Sub>]控制在9.91～11.3%,易于推广应用。(The invention relates to a method for extracting vanadium from high-silicon medium-vanadium molten iron by a converter two-blowing two-pouring one-time slag tapping method, belonging to the technical field of metallurgy. The method comprises the steps of proportioning molten iron and scrap steel, carrying out primary oxygen supply, removing silicon and deslagging, carrying out secondary oxygen supply and vanadium extraction, controlling temperature and reducing the grade of FeO vanadium-retaining slag in the later period, and carrying out slag tapping. The method has the advantages of treating high-silicon vanadium-containing molten iron to extract vanadium, reducing residual vanadium in semisteel, improving the grade quality of vanadium slag and the like, so that the converter uses the high-silicon molten iron (more than 0.55wt% [ Si ] to improve the quality of vanadium slag]) In the vanadium extraction smelting process, the grade of the vanadium slag is improved from 7.8 percent to 10.1 percent on average, vanadium in molten iron is fully recovered, and [ SiO ] in the vanadium slag 2 ]The control is 9.91-11.3%, and the method is easy to popularize and apply.)

1. A method for extracting vanadium from high-silicon medium-vanadium molten iron by a converter two-blowing two-pouring one-time slag tapping method is characterized by comprising the following steps:

A. proportioning molten iron and scrap steel: adding molten iron and scrap steel into an LD converter, controlling the temperature of the molten iron to be 1200-1250 ℃, and adjusting the charging proportion of the scrap steel in the converter to be less than 8%;

B. primary oxygen supply, silicon removal and slag removal: the oxygen supply flow is 6800-7500 m during 2.9-3.1 minutes before oxygen blowing smelting of the converter³Controlling the lance position to 1350-1500 mm, blowing oxygen for smelting for 2.4-2.6 minutes, then reducing the lance position to 400-500 mm, continuing blowing for the rest time, and then lifting the lance to pour out the initial-stage high-silicon slag;

C. secondary oxygen supply and vanadium extraction: after pouring out the initial high silicon slag, the converter is shaken up, the lance position is controlled to be 900-1200 mm, and the oxygen supply flow is controlled to be 6500-7000 m³Continuously supplying oxygen for blowing for 2.0-2.5 minutes to ensure that the furnace slag contains more than 70wt% of FeO, and adding 0-5 t of cooling vanadium-titanium balls to control the temperature in the furnace to be 1300-1350 ℃;

D. and (3) controlling the temperature and reducing the grade of the FeO vanadium-retaining slag in the later period: after vanadium is extracted by secondary oxygen supply, the lance position is reduced to 400-600 mm for blowing for 10-60 seconds, and the blowing end point temperature is controlled to be less than 1390 ℃;

E. deslagging: and pouring the vanadium slag into a slag basin in the semisteel discharging process.

2. The method for extracting vanadium from high-silicon molten vanadium iron by using a converter two-blowing two-dumping slag tapping method according to claim 1, wherein in the step A, the molten iron comprises the following chemical components: 3.8 to 4.5 weight percent of C, 0.55 to 0.73 weight percent of Si, 0.20 to 0.25 weight percent of V, 0.23 to 0.49 weight percent of Mn, 0.063 to 0.149 weight percent of P, less than or equal to 0.035 weight percent of S, and the balance of Fe and inevitable impurities.

3. The method for extracting vanadium from high-silicon medium-vanadium molten iron by using a converter two-blowing two-pouring one-time slag tapping method according to claim 1, wherein in the step A, the chemical components of the scrap steel are as follows: 0.12 to 0.30wt% of C, 0.20 to 0.50wt% of Si, 0.45 to 1.15wt% of Mn, 0.025 to 0.055wt% of P, 0.020 to 0.045wt% of S, and the balance of Fe and inevitable impurities.

4. The method for extracting vanadium from high-silicon medium-vanadium molten iron by using a converter two-blowing two-pouring one-time slag tapping method according to claim 1, wherein in the step C, the lance position is controlled in a high-medium-low mode at 1200-900 mm.

5. The method for extracting vanadium from high-silicon molten vanadium iron by using a converter two-blowing two-pouring one-time slag tapping method according to claim 1, characterized in that in the step E, a hot slag sample is taken from the rear of the converter for analysis during semisteel tapping, and then vanadium slag is poured into a special slag basin.

Technical Field

The invention belongs to the technical field of metallurgy, and particularly relates to a method for extracting vanadium from high-silicon medium-vanadium molten iron by a converter two-blowing two-pouring one-time slag tapping method.

Background

The method is influenced by the continuous increase of the international iron ore price, inland iron and steel enterprises increase the use proportion of peripheral lean and impure ores, the resources of the peripheral vanadium-titanium magnetite in Yunnan are rich, and the development of blast furnace vanadium-titanium magnetite smelting and vanadium extraction and steel making become the optimal selection of steel enterprises. When the blast furnace adopts vanadium titano-magnetite which is difficult to smelt, the molten iron with the silicon content of more than 5 percent is high (Si) due to the influence of the structure of the ore, raw materials and the fluctuation of the furnace conditions]Greater than 0.55%) and vanadium extraction and steel making are not possible. In the conventional process of vanadium extraction and steel making by a converter, the oxidation of vanadium can be inhibited by the high silicon content of molten iron, and vanadium Slag (SiO) is contained in the molten iron₂) The high content of the vanadium causes the problems of partial rare slag state, reduced quality grade of vanadium slag, high residual vanadium in semisteel, low slag yield and the like. Therefore, how to overcome the defects of the prior art is a problem which needs to be solved urgently in the technical field of metallurgy at present.

Disclosure of Invention

The invention aims to solve the defects of the prior art and provides a method for extracting vanadium from high-silicon medium-vanadium molten iron by a converter two-blowing two-dumping one-time deslagging method, which enables the converter to use high-silicon molten iron (> 0.55wt% [ Si ] to extract vanadium]) In the vanadium extraction smelting process, the grade of the vanadium slag is improved from 7.8 percent to 10.1 percent on average, and the vanadium Slag (SiO) is contained in the vanadium slag₂) The control is carried out at 9.91-11.3%, vanadium in the molten iron is fully recovered, and the grade and quality of the vanadium slag are improved.

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

a method for extracting vanadium from high-silicon medium-vanadium molten iron by a converter two-blowing two-pouring one-time slag tapping method comprises the following steps:

A. proportioning molten iron and scrap steel: adding molten iron and scrap steel into an LD converter, controlling the temperature of the molten iron to be 1200-1250 ℃, and adjusting the charging proportion of the scrap steel in the converter to be less than 8%;

B. primary oxygen supply, silicon removal and slag removal: the oxygen supply flow is 6800-7500 m during 2.9-3.1 minutes before oxygen blowing smelting of the converter³Controlling the lance position to 1350-1500 mm, blowing oxygen for smelting for 2.4-2.6 minutes, then reducing the lance position to 400-500 mm, continuing blowing for the rest time, and then lifting the lance to pour out the initial-stage high-silicon slag;

C. secondary oxygen supply and vanadium extraction: after pouring out the initial high silicon slag, the converter is shaken up, the lance position is controlled to be 900-1200 mm, and the oxygen supply flow is controlled to be 6500-7000 m³Continuously supplying oxygen for blowing for 2.0-2.5 minutes to ensure that the furnace slag contains more than 70wt% of FeO, and adding 0-5 t of cooling vanadium-titanium balls to control the temperature in the furnace to be 1300-1350 ℃;

D. and (3) controlling the temperature and reducing the grade of the FeO vanadium-retaining slag in the later period: after vanadium is extracted by secondary oxygen supply, the lance position is reduced to 400-600 mm for blowing for 10-60 seconds, and the blowing end point temperature is controlled to be less than 1390 ℃;

E. deslagging: and pouring the vanadium slag into a slag basin in the semisteel discharging process.

Further, preferably, in the step a, the molten iron has the following chemical components: 3.8 to 4.5 weight percent of C, 0.55 to 0.73 weight percent of Si, 0.20 to 0.25 weight percent of V, 0.23 to 0.49 weight percent of Mn, 0.063 to 0.149 weight percent of P, less than or equal to 0.035 weight percent of S, and the balance of Fe and inevitable impurities.

Further, in the step A, the chemical composition of the scrap steel is preferably as follows: 0.12 to 0.30wt% of C, 0.20 to 0.50wt% of Si, 0.45 to 1.15wt% of Mn, 0.025 to 0.055wt% of P, 0.020 to 0.045wt% of S, and the balance of Fe and inevitable impurities.

Further, in the step C, the gun position is controlled in a high-medium-low mode at 1200-900 mm.

Further, preferably, in the step E, in the semisteel tapping process, a hot slag sample is taken after the furnace for analysis, and then the vanadium slag is poured into a special slag basin.

In the step A of the invention, the charging proportion of the scrap steel is less than 8 percent, and can be 0 percent.

In the step B, the remaining time is 2.9-3.1 minutes minus 2.4-2.6 minutes.

In the step C of the invention, when the gun position is controlled in a high-medium-low mode at 1200-900 mm, the operation is carried out according to the existing operation method, and the specific operation control mode is not limited by the invention.

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

when the blast furnace adopts vanadium titano-magnetite which is difficult to smelt, the molten iron with the silicon content of more than 5 percent is high (Si) due to the influence of the structure of the ore, raw materials and the fluctuation of the furnace conditions]More than 0.55 percent), the problems of the conventional vanadium slag for vanadium extraction and steel making that the grade quality is reduced, the slag state is more dilute, the slag yield is low and the like can be caused, and about more than 5 percent of molten iron can not be subjected to vanadium extraction due to high silicon content. The method of the invention ensures that the converter uses high-silicon molten iron (more than 0.55wt% [ Si ]]) In the vanadium extraction smelting process, the grade of the vanadium slag is improved from 7.8 percent to 10.1 percent on average, vanadium in molten iron is fully recovered, and [ SiO ] in the vanadium slag₂]Controlling the temperature to be 9.91-11.3%;

the method has the advantages of treating high-silicon vanadium-containing molten iron to extract vanadium, reducing residual vanadium in semisteel, improving the grade and quality of vanadium slag and the like, and is easy to popularize and apply.

Detailed Description

The present invention will be described in further detail with reference to examples.

It will be appreciated by those skilled in the art that the following examples are illustrative of the invention only and should not be taken as limiting the scope of the invention. The examples do not specify particular techniques or conditions, and are performed according to the techniques or conditions described in the literature in the art or according to the product specifications. The materials or equipment used are not indicated by manufacturers, and all are conventional products available by purchase.