阅读说明：本技术 一种利用转炉炉渣铁氧化物生产海绵铁的方法 (Method for producing sponge iron by using iron oxide in converter slag ) 是由 李德军 廖相巍 于赋志 黄玉平 许孟春 康伟 吕春风 张维维 王丽娟 于 2020-07-08 设计创作，主要内容包括：本发明涉及一种利用转炉炉渣铁氧化物生产海绵铁的方法,将转炉炉渣中的铁氧化物粉分选出来与焦粉及沥青焦制成料球,在真空感应加热炉内均匀布置料球,每隔200-500mm料球料层布置一层块状当量直径在10-30mm的焦炭,焦炭层厚度50-100mm,真空感应加热炉内料层总厚度控制在1000-2000mm；在布料过程中,在物料当中插入侧壁带有小孔的刚玉通气管；在加热炉内熔炼成海绵铁。本发明提高转炉渣的回收利用率,提高对钢铁企业的环境改善,同时还能够进一步降低钢铁企业综合成本,有利于钢铁企业实现可持续发展。(The invention relates to a method for producing sponge iron by using iron oxide in converter slag, which comprises the steps of separating iron oxide powder in the converter slag, preparing the iron oxide powder, coke powder and pitch coke into material balls, uniformly arranging the material balls in a vacuum induction heating furnace, arranging a layer of coke with the block equivalent diameter of 10-30mm on a material ball layer every 200-500mm, controlling the thickness of a coke layer to be 50-100mm, and controlling the total thickness of the material layers in the vacuum induction heating furnace to be 1000-2000 mm; in the material distribution process, a corundum vent pipe with a small hole on the side wall is inserted into the material; smelting the mixture into sponge iron in a heating furnace. The invention improves the recycling rate of the converter slag, improves the environment improvement of the iron and steel enterprises, can further reduce the comprehensive cost of the iron and steel enterprises, and is beneficial to the realization of sustainable development of the iron and steel enterprises.)

1. A method for producing sponge iron by utilizing iron oxide in converter slag is characterized in that iron oxide powder in the converter slag, coke powder and pitch coke are made into material balls and are smelted into sponge iron in a heating furnace; the specific method comprises the following steps:

raw material treatment

1) Crushing the converter slag to ensure that the granularity is not more than 10mm, and separating and recycling iron elementary substances by magnetic separation;

2) grinding the residual slag particles, wherein the particle size of the ground slag powder is required to be 150-mesh and 300-mesh, carrying out secondary magnetic separation on the ground slag powder, and sorting iron oxide powder in the slag powder for later use;

3) crushing the lump coke, wherein the crushing granularity is required to be 0.5-5mm, and the asphalt coke is crushed into 0.05-2 mm;

mixing and pressing balls

1) Mixing 60-80% of iron oxide powder and 10-30% of coke powder according to weight percentage, adding 3-10% of asphalt coke, and mixing to prepare raw material powder;

2) pressing the raw material powder into material balls with the diameter of 20-50mm by using a ball press;

3) baking the pellets at a low temperature of 200 +/-10 ℃ for 2-3 hours, and then cooling to room temperature;

third, cloth

Uniformly arranging material balls in the vacuum induction heating furnace, arranging a layer of coke with the block equivalent diameter of 10-30mm on a material ball layer every 200-500mm, wherein the thickness of the coke layer is 50-100mm, and the total thickness of the material layer in the vacuum induction heating furnace is controlled to be 1000-2000 mm; in the material distribution process, a corundum air-permeable pipe with a small hole on the side wall is inserted into the material;

fourthly, heating reduction

1) After the material distribution is finished, carrying out vacuum-pumping treatment on the induction heating furnace, and keeping the pressure in the furnace at 0.2-0.5 atm;

2) heating the temperature in the furnace to 300 +/-10 ℃, and keeping the temperature for 10-20 min; then, the temperature in the furnace is raised to 1000 +/-10 ℃, and the temperature is kept constant for 30-80min to prepare sponge iron;

3) and introducing nitrogen or argon into the furnace for cooling treatment, cooling the furnace to the room temperature of 20 +/-10 ℃, taking out the sponge iron, carrying out high-pressure nitrogen purging on the sponge iron to remove surface impurities, and sealing, packaging and storing the sponge iron.

2. The method for producing sponge iron from iron oxide slag of converter according to claim 1, wherein corundum air-permeable tube is inserted in the thickness direction of the material layer in the third step in a cross shape.

Technical Field

The invention belongs to the field of metallurgy, and particularly relates to a method for producing sponge iron by using converter slag iron oxide.

Background

With the rapid development of the metallurgical industry in China, the steel yield is steadily increased, and the converter slag resource is increased along with the steady increase of the steel yield. The comprehensive utilization rate of the steel slag is low. Especially, the utilization rate of the converter steel slag is only 10 percent. The treatment and utilization level of the converter steel slag directly influences the overall utilization rate of the steel slag in China. The steel slag is used as a byproduct in steel making production, the comprehensive utilization of the steel slag can not only eliminate environmental pollution, but also create great economic benefit, and is an effective way for sustainable development. At present, the comprehensive recycling of the steel slag mainly comprises the steps of recycling simple substance iron (granular iron) in the steel slag by a magnetic separation method, and then returning the steel slag to a converter in the form of scrap steel for recycling. Most of the slag containing iron oxide is not recycled, which causes waste of resources.

Disclosure of Invention

The invention aims to solve the technical problem of providing a method for producing sponge iron by using converter slag iron oxide, and improving the recovery utilization rate of converter slag.

In order to achieve the purpose, the invention adopts the following technical scheme:

a method for producing sponge iron by utilizing iron oxide of converter slag comprises the steps of preparing iron oxide powder, coke powder and pitch coke in the converter slag into material balls, and smelting the material balls into sponge iron in a heating furnace; the specific method comprises the following steps:

raw material treatment

1) Crushing the converter slag to ensure that the granularity is not more than 10mm, and separating and recycling iron elementary substances by magnetic separation;

2) grinding the residual slag particles, wherein the particle size of the ground slag powder is required to be 150-mesh and 300-mesh, carrying out secondary magnetic separation on the ground slag powder, and sorting iron oxide powder in the slag powder for later use;

3) crushing the lump coke, wherein the crushing granularity is required to be 0.5-5mm, and the asphalt coke is crushed into 0.05-2 mm;

mixing and pressing balls

1) Mixing 60-80% of iron oxide powder and 10-30% of coke powder according to weight percentage, adding 3-10% of asphalt coke, and mixing to prepare raw material powder;

2) pressing the raw material powder into material balls with the diameter of 20-50mm by using a ball press;

3) baking the pellets at a low temperature of 200 +/-10 ℃ for 2-3 hours, and then cooling to room temperature;

third, cloth

Uniformly arranging material balls in the vacuum induction heating furnace, arranging a layer of coke with the block equivalent diameter of 10-30mm on a material ball layer every 200-500mm, wherein the thickness of the coke layer is 50-100mm, and the total thickness of the material layer in the vacuum induction heating furnace is controlled to be 1000-2000 mm; in the material distribution process, a corundum vent pipe with a small hole on the side wall is inserted into the material;

fourthly, heating reduction

1) After the material distribution is finished, carrying out vacuum-pumping treatment on the induction heating furnace, and keeping the pressure in the furnace at 0.2-0.5 atm;

2) heating the temperature in the furnace to 300 +/-10 ℃, and keeping the temperature for 10-20 min; then, the temperature in the furnace is raised to 1000 +/-10 ℃, and the temperature is kept constant for 30-80min to prepare sponge iron;

3) and introducing nitrogen or argon into the furnace for cooling treatment, cooling the furnace to the room temperature of 20 +/-10 ℃, taking out the sponge iron, carrying out high-pressure nitrogen purging on the sponge iron to remove surface impurities, and sealing, packaging and storing the sponge iron.

In the third step, a plurality of corundum air-permeable pipes are inserted in the thickness direction of the material layer in a cross shape.

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

the invention improves the recycling rate of the converter slag, improves the environment improvement of the iron and steel enterprises, can further reduce the comprehensive cost of the iron and steel enterprises, and is beneficial to the realization of sustainable development of the iron and steel enterprises.

Detailed Description

The invention is further illustrated by the following examples:

the following examples describe the invention in detail. These examples are merely illustrative of the best embodiments of the present invention and do not limit the scope of the invention.

A method for producing sponge iron by utilizing iron oxide of converter slag comprises the steps of preparing iron oxide powder, coke powder and pitch coke in the converter slag into material balls, and smelting the material balls into sponge iron in a heating furnace; the specific method comprises the following steps:

raw material treatment

1) Crushing the converter slag to ensure that the granularity is not more than 10mm, and separating and recycling iron elementary substances by magnetic separation;

2) grinding the residual slag particles, wherein the particle size of the ground slag powder is required to be 150-mesh and 300-mesh, carrying out secondary magnetic separation on the ground slag powder, and sorting iron oxide powder in the slag powder for later use;

3) crushing the lump coke, wherein the crushing granularity is required to be 0.5-5mm, and the asphalt coke is crushed into 0.05-2 mm;

mixing and pressing balls

1) Mixing 60-80% of iron oxide powder and 10-30% of coke powder according to weight percentage, adding 3-10% of asphalt coke, and mixing to prepare raw material powder;

2) pressing the raw material powder into material balls with the diameter of 20-50mm by using a ball press;

3) baking the pellets at a low temperature of 200 +/-10 ℃ for 2-3 hours, and then cooling to room temperature;

third, cloth

Uniformly arranging material balls in the vacuum induction heating furnace, arranging a layer of coke with the block equivalent diameter of 10-30mm on a material ball layer every 200-500mm, wherein the thickness of the coke layer is 50-100mm, and the total thickness of the material layer in the vacuum induction heating furnace is controlled to be 1000-2000 mm; in the material distribution process, a corundum air-permeable pipe with a small hole on the side wall is inserted into the material; a plurality of corundum vent pipes are inserted in the thickness direction of the material layer in a cross shape;

fourthly, heating reduction

1) After the material distribution is finished, carrying out vacuum-pumping treatment on the induction heating furnace, and keeping the pressure in the furnace at 0.2-0.5 atm;

2) heating the temperature in the furnace to 300 +/-10 ℃, and keeping the temperature for 10-20 min; then the temperature in the furnace is raised to 1000 +/-10 ℃, and the temperature is kept constant for 30-80min, at the temperature, the iron oxide and the carbon in the coke and the pitch coke are subjected to the following self-reduction reaction:

FeO+C＝Fe+CO₂

2Fe₂O₃+3C＝4Fe+3CO₂

Fe₃O₄+2C＝3Fe+2CO₂

finally preparing sponge iron;

3) and introducing nitrogen or argon into the furnace for cooling treatment, cooling the furnace to the room temperature of 20 +/-10 ℃, taking out the sponge iron, carrying out high-pressure nitrogen purging on the sponge iron to remove surface impurities, and sealing, packaging and storing the sponge iron.