阅读说明：本技术 一种废铁炼钢用精炼剂及精炼工艺 (Refining agent and refining process for scrap iron steelmaking ) 是由 不公告发明人 于 2019-11-20 设计创作，主要内容包括：本发明公开了一种废铁炼钢用精炼剂,所述精炼剂包括以下质量份的原料:氧化钙40～70份、氟化钙20～30份、金属铝40～60份、石墨粉5～30份、碳化硅10～30份、金属镁5～15份、二氧化钛5～10份、生物质1～3份、高岭土3～6份和磺化酚醛树脂1～3份。废铁炼钢的精炼工艺,包括以下步骤：①脱氧处理：在出钢的过程中,先在钢包中加入碳粉,随后加入脱氧剂和活性石灰进行脱氧处理,出钢完成后进行取样,取样后再在钢水的钢渣表面撒上一层碳化钙②精炼：钢包转入到精炼炉内后,分三次向钢包中加入精炼剂,精炼完毕后,进行浇铸工艺。本发明通过对整个精炼过程中的全流程控制,在能够提高钢水洁净度和质量的同时,还能够缩短精炼的时间。(The invention discloses a refining agent for scrap iron steelmaking, which comprises the following raw materials, by mass, 40-70 parts of calcium oxide, 20-30 parts of calcium fluoride, 40-60 parts of metal aluminum, 5-30 parts of graphite powder, 10-30 parts of silicon carbide, 5-15 parts of metal magnesium, 5-10 parts of titanium dioxide, 1-3 parts of biomass, 3-6 parts of kaolin and 1-3 parts of sulfonated phenolic resin.)

1. The refining agent for the steelmaking of the scrap iron is characterized by comprising, by mass, 40-70 parts of calcium oxide, 20-30 parts of calcium fluoride, 40-60 parts of metal aluminum, 5-30 parts of graphite powder, 10-30 parts of silicon carbide, 5-15 parts of metal magnesium, 5-10 parts of titanium dioxide, 1-3 parts of biomass, 3-6 parts of kaolin and 1-3 parts of sulfonated phenolic resin.

2. The refining agent for steelmaking from scrap according to claim 1, wherein: the refining agent also comprises 0-10 parts by mass of aluminum oxide, 0-5 parts by mass of rare earth oxide and 0-10 parts by mass of manganese dioxide.

3. The refining agent for steelmaking from scrap according to claim 1, wherein: the grain size of the refining agent is not more than 100 um.

4. The refining agent for steelmaking from scrap according to claim 1, wherein: the preparation method of the refining agent comprises the steps of weighing the required raw materials of the components according to the proportion of the refining agent, respectively putting the raw materials into an oven, baking the raw materials for 1-2 hours at the temperature of 100-120 ℃, cooling the baked raw materials to room temperature, uniformly mixing the raw materials, and crushing the raw materials into powder.

5. A refining process for scrap iron steelmaking is characterized in that: the method comprises the following steps:

① deoxidation treatment, namely, after the smelting of the scrap iron in an electric furnace is finished, tapping molten steel obtained by the electric furnace into a steel ladle, adding carbon powder into the steel ladle in the tapping process, then adding a deoxidizer and active lime for deoxidation treatment, sampling and detecting the components, the temperature and the oxygen content of the molten steel after the tapping is finished, scattering a layer of calcium carbide on the surface of steel slag of the molten steel after the sampling, wherein the adding amount of the calcium carbide is 0.1-0.2 kg/t of steel, then bottom blowing argon, the flow rate of the argon is 40-100 NL/min, and the time of the argon blowing is 5-10 min;

② refining, namely, firstly transferring a ladle into a refining furnace, adjusting the flow rate of bottom-blown argon to 200-250 NL/min before transferring the ladle into the refining furnace, wherein the argon blowing time is 2-5 min, firstly adding a refining agent into the ladle for the first time, the adding amount of the first refining agent is 5-10 kg/t of steel, adjusting the flow rate of the argon blowing to 150-200 NL/min, keeping the temperature of 1500-1520 ℃ for refining for 10-20 min, then adding a refining agent into the ladle for the second time, the adding amount of the second refining agent is 3-6 kg/t of steel, adjusting the flow rate of the argon blowing to 100-150 NL/min, keeping the temperature of 1520-1550 ℃ for refining for 10-15 min, then adding a refining agent into the ladle for the third time, the adding amount of the third refining agent is 3-5 kg/t of steel, continuing to heat, keeping the temperature of 1580-1590 ℃, adjusting the flow rate of the argon blowing to 50-100 NL/min, refining for 8-12 min, pouring the refined ladle into a continuous casting furnace, and then casting the slag in the ladle.

6. The refining process of scrap iron steelmaking according to claim 5, wherein in step ①, the addition of carbon powder is completed within one quarter of the tapping amount of molten steel, and the addition amount of carbon powder is 1-2 kg/t steel.

7. The refining process of steel-making from scrap iron according to claim 5, wherein in step ①, the addition time of said deoxidizer and active lime is completed within two-quarters to three-quarters of the steel tapping amount of the molten steel, the addition amount of said deoxidizer is 3-5 kg/t steel, and the addition amount of said active lime is 2-3 kg/t steel.

8. The refining process of scrap iron steelmaking according to claim 5, wherein in step ①, the deoxidizer comprises Si-Ca-Ba, Si-alloy and Mn-alloy, and the mass ratio of Si-Ca-Ba, Si-alloy and Mn-alloy is 1 (1-1.5) to (1-2).

Technical Field

The invention belongs to the technical field of steel smelting, and particularly relates to a refining agent for scrap iron steelmaking and a steel refining process using the refining agent.

Background

In China, the mainstream production process of steel can be divided into two flows, namely a long flow from iron ore and coke to pig iron and then to steel, and a short flow from iron-containing waste resources to steel. As is known to all, iron ore is an irrenewable resource, and at present, with the shortage of supply of common iron ore at home and abroad and the gradual rise of price, the use of a large amount of common iron ore will obviously increase the production cost of iron making, so that the adoption of iron-containing waste resources to smelt steel also becomes the preferred process in the current steel making industry. The existing steelmaking process of waste resources containing iron mainly comprises the working procedures of raw material sorting, raw material crushing, scrap steel preheating, electric furnace smelting, refining, casting and the like, wherein the circuit smelting is to carry out furnace charge melting, deslagging, dephosphorization and main alloying under an oxidizing atmosphere, the refining is to carry out deoxidation, desulfurization, impurity removal, inclusion denaturation, component fine adjustment, molten steel temperature control and the like under vacuum, inert gas or controllable atmosphere, in the steelmaking process of scrap iron, the refining is the essence and soul of the steelmaking process, and the reasonability or not of the refining process directly relates to the strength, toughness, fatigue strength, smoothness, corrosion resistance and the like of steel. At present, in order to realize the deoxidation and the desulphurization of molten steel and the removal of impurities in molten steel, two means are generally adopted for realizing the deoxidation and the desulphurization of molten steel, one means is a process control measure, the other means is that a refining agent is added into the molten steel for refining, so that the content of the impurities in the steel is reduced, the refining agent is favorable for the desulphurization and the deoxidation of the molten steel, the lining of a furnace body is protected, and the effects of the impurities in the molten steel are reduced, the quality of molten steel is affected, so that the purity of the molten steel is insufficient, and the surface quality and the performance of the cast steel are seriously affected. Therefore, it is an objective need to develop a refining agent for scrap iron steelmaking and a steel refining process using the refining agent, which have reasonable compatibility, simple treatment method, strong operability and strong impurity removal capability, can shorten refining time and ensure refining effect.

Disclosure of Invention

In order to solve the problems in the background art, the invention aims to provide a refining agent for scrap iron steelmaking and a steel refining process using the refining agent, which have the advantages of reasonable compatibility, simple treatment method, strong operability and strong impurity removal capability, can shorten the refining time and ensure the refining effect.

The refining agent for the steelmaking of the scrap iron comprises, by mass, 40-70 parts of calcium oxide, 20-30 parts of calcium fluoride, 40-60 parts of metal aluminum, 5-30 parts of graphite powder, 10-30 parts of silicon carbide, 5-15 parts of metal magnesium, 5-10 parts of titanium dioxide, 1-3 parts of biomass, 3-6 parts of kaolin and 1-3 parts of sulfonated phenolic resin.

Further, the grain size of the refining agent is not more than 100 um.

Further, the refining agent also comprises 0-10 parts by mass of aluminum oxide, 0-5 parts by mass of rare earth oxide and 0-10 parts by mass of manganese dioxide.

Further, the preparation method of the refining agent comprises the steps of weighing the raw materials of the required components according to the proportion of the refining agent, respectively putting the raw materials into an oven, baking the raw materials for 1-2 hours at the temperature of 100-120 ℃, cooling the baked raw materials to room temperature, uniformly mixing the raw materials, and crushing the raw materials into powder.

The invention relates to a scrap iron steelmaking refining process using a refining agent, which comprises the following steps:

① deoxidation treatment, namely, after the smelting of the scrap iron in an electric furnace is finished, tapping molten steel obtained by the electric furnace into a steel ladle, adding carbon powder into the steel ladle in the tapping process, then adding a deoxidizer and active lime for deoxidation treatment, sampling and detecting the components, the temperature and the oxygen content of the molten steel after the tapping is finished, scattering a layer of calcium carbide on the surface of steel slag of the molten steel after the sampling, wherein the adding amount of the calcium carbide is 0.1-0.2 kg/t of steel, then bottom blowing argon, the flow rate of the argon is 40-100 NL/min, and the time of the argon blowing is 5-10 min;

② refining, namely, firstly transferring a ladle into a refining furnace, adjusting the flow rate of bottom-blown argon to 200-250 NL/min before transferring the ladle into the refining furnace, wherein the argon blowing time is 2-5 min, firstly adding a refining agent into the ladle for the first time, the adding amount of the first refining agent is 5-10 kg/t of steel, adjusting the flow rate of the argon blowing to 150-200 NL/min, keeping the temperature of 1500-1520 ℃ for refining for 10-20 min, then adding a refining agent into the ladle for the second time, the adding amount of the second refining agent is 3-6 kg/t of steel, adjusting the flow rate of the argon blowing to 100-150 NL/min, keeping the temperature of 1520-1550 ℃ for refining for 10-15 min, then adding a refining agent into the ladle for the third time, the adding amount of the third refining agent is 3-5 kg/t of steel, continuing to heat, keeping the temperature of 1580-1590 ℃, adjusting the flow rate of the argon blowing to 50-100 NL/min, refining for 8-12 min, pouring the refined ladle into a continuous casting furnace, and then casting the slag in the ladle.

Further, in step ①, the adding time of the carbon powder is completed within one quarter of the molten steel tapping amount, the adding amount of the carbon powder is 1-2 kg/t steel, the adding time of the deoxidizer and the active lime is completed within two-quarters to three-quarters of the molten steel tapping amount, the adding amount of the deoxidizer is 3-5 kg/t steel, the adding amount of the active lime is 2-3 kg/t steel,

further, in step ①, the deoxidizer includes silicon-calcium-barium, a silicon alloy and a manganese alloy, and the mass ratio of the silicon-calcium-barium, the silicon alloy and the manganese alloy is 1 (1-1.5) to (1-2).

Compared with the prior art: the invention has the advantages that: firstly, carbon powder, deoxidizer, active lime and calcium carbide are added in the early stage of tapping, molten steel can be deoxidized, slag materials mixed in the molten steel are melted by utilizing impact energy of the molten steel and argon blowing stirring, excessive slag materials are prevented from entering a refining furnace to increase refining burden, secondly, in the refining process, refining agents are added in multiple batches, on one hand, the refining agents can adjust the temperature of the molten steel, heat balance in the furnace is guaranteed, refining time is shortened, on the other hand, the floating of impurities in the molten steel can be promoted, impurities in the molten steel are effectively removed, sulfur and phosphorus containing amount is reduced, quality and purity of the molten steel are improved, and good conditions are created for continuous casting; the refining agent adopted by the invention can promote the removal of inclusions in the molten steel, does not cause secondary pollution to the molten steel, has small size and uniform distribution of the residual inclusions in the molten steel after being treated by the refining agent, can greatly improve the refining effect of the molten steel, greatly improves the cleanliness of the molten steel, has the advantages of reasonable compatibility, simple treatment method, strong operability and strong impurity removal capability, and is easy to popularize and use.

Detailed Description

The present invention is further illustrated by the following examples, which are not intended to be limiting in any way, and any modifications or alterations based on the teachings of the present invention are intended to fall within the scope of the present invention.