CN113293254A

CN113293254A - High-efficiency utilization process of high-grade iron-containing raw material

Info

Publication number: CN113293254A
Application number: CN202110526835.0A
Authority: CN
Inventors: 曾四宝; 赵滨; 田新喜; 张利武; 陈焕建; 闫栋; 楚士进
Original assignee: Shandong Shiheng Special Steel Group Co Ltd
Current assignee: Shandong Shiheng Special Steel Group Co Ltd
Priority date: 2021-05-14
Filing date: 2021-05-14
Publication date: 2021-08-24

Abstract

A high-efficiency utilization process of high-grade iron-containing raw materials is characterized in that different adding amounts are defined according to molten iron components: the process directly puts iron-containing materials such as furnace slag, iron scale, slag basin slag steel, ladle casting residue, finishing cutting slag and the like generated in the steelmaking process into the furnace, and reduces secondary pollution. The steel-making converter is technically optimized in the aspects of a charging system, a temperature system, an oxygen supply system, a slagging system and the like, and the iron-containing raw material can be fully utilized after the operation technology is optimized, so that the metal material consumption of the converter can be reduced, and the production cost of a steel-making workshop can be reduced.

Description

High-efficiency utilization process of high-grade iron-containing raw material

Technical Field

The invention belongs to the field of steelmaking, and relates to a high-efficiency utilization process of a high-grade iron-containing raw material.

Background

At present, high-grade internal circulation iron-containing raw materials in a steelmaking workshop mainly comprise furnace slag, iron scales, slag basin slag steel, ladle casting residues, finishing cutting slag and the like. The raw materials are not effectively recycled, so that the resources are wasted and the environment is polluted. How to efficiently utilize the part of the internally-circulated iron-containing raw material and reduce the metal material consumption is a key measure for optimizing technical indexes of a workshop and reducing the production cost. By carrying out technical optimization on the aspects of a charging system, a temperature system, an oxygen supply system, a slagging system and the like, the method can efficiently utilize the furnace slag, the iron scale and other iron-containing raw materials, solve the problem of recycling of solid wastes and reduce the production cost.

Disclosure of Invention

The invention defines different adding amounts according to the components of molten iron: 0.20-0.50% of molten iron silicon, 0.5-1.0 t of furnace slag, 0.5t of iron scale and 0.2-0.5 t of other internally-circulated iron-containing raw materials; the height of molten iron silicon is more than 0.50 percent, the slag is 1.0-1.5 t/furnace, the scale is 0-0.5 t/furnace, and other internally circulating iron-containing raw materials are 0.5-0.8 t/furnace; the silicon content of molten iron is less than 0.20 percent, the slag is 0-0.5 t/furnace, and the iron scale is 0.5-1.0 t/furnace.

1. According to the heat balance principle of converter smelting, after the internal circulation iron-containing raw material is fed into the converter, the feeding amount of slagging materials such as lime, raw dolomite and the like is reduced in the early stage, the early-stage heat expenditure is reduced, and the heat balance and stable rising are ensured.

2. Because a large amount of raw materials with high content of internally circulated FeO are used, the control of splashing is the primary target of smelting, and the stability of converter smelting is greatly influenced by over-high or over-low position of a gun, improper gun pressing time and the like. The oxygen flow is dynamically controlled, so that the earlier-stage reaction of the converter can be slowed down, and the splashing can be reduced. The specific method comprises the following steps: and controlling the oxygen flow at the highest flow in the early stage of converting, adjusting the oxygen flow to be low flow 2-3 min after slagging, gradually recovering to be normal after 4min, and timely changing the position of a gun according to the condition in the furnace. Because the oxygen amount entering the converter molten pool is reduced, the violent degree of carbon-oxygen reaction is reduced, the temperature rise of the converter molten pool is more uniform and stable, the accumulation speed of FeO is reduced, explosive low-temperature metal splashing in the early stage of blowing can be effectively avoided, and the utilization rate of oxygen can be improved.

3. The slagging and slagging operation of the converter with low alkalinity and less slag amount for rapid dephosphorization. By implementing low-alkalinity and less-slag-amount smelting, the early dephosphorization rate is firstly ensured, after blowing, Si and Mn in molten iron are quickly oxidized into slag, the content of (CaO) in the slag is very low, and then iron is oxidized, FeO gradually permeates into (CaO), the (CaO) is dissolved along with the FeO, and the content is gradually increased. The reaction of (SiO 2) and (CaO) in the initial slag easily generates a high melting point substance (2 CaO. SiO2) with a melting point of about 2130 ℃, the substance has a dense structure, and if the substance reaches a certain thickness, the lime is slowly dissolved, and the dephosphorization rate of the converter is reduced. Therefore, it is necessary to control the slag composition in the early stage and reduce the formation of (2 cao. sio2).

4. The invention has the advantages that:

the process directly puts iron-containing materials such as furnace slag, iron scale, slag basin slag steel, ladle casting residue, finishing cutting slag and the like generated in the steelmaking process into the furnace, reduces secondary pollution, can fully utilize iron-containing raw materials after optimization of the operation technology, and reduces the production cost of a steelmaking workshop. After the project is implemented, the metal material consumption can be reduced, and the production cost can be reduced.

Detailed Description

1. And (4) repeatedly carrying out magnetic separation on the slag discharged from the furnace by using a crown block sucker, and feeding the high-grade magnetic separation slag into the furnace for consumption.

2. And after being dug out by the finishing cyclone well, the iron oxide scale is placed at a specified position for drying and then is consumed in the furnace.

3. Slag steel in a slag basin, residual slag in a steel ladle, finishing cutting slag and the like are sorted and stored by hot ladle repair and finishing selection, and then transferred to a slag yard to be charged into a furnace for consumption.

4. The converter operation satisfies the smelting heat balance principle, the oxygen lance is robbed the position, the process operation control of flow does not have the splash and overflow sediment phenomenon, and reasonable slagging operation ensures earlier stage dephosphorization effect, improves the dephosphorization rate.

The invention has been described in an illustrative manner, and it is to be understood that the invention is not limited to the precise form disclosed, and that various insubstantial modifications of the inventive concepts and solutions, or their direct application to other applications without such modifications, are intended to be covered by the scope of the invention.

Claims

1. The high-efficiency utilization process of the high-grade iron-containing raw material is characterized in that different adding amounts are defined according to molten iron components:

(1) 0.20-0.50% of molten iron silicon, 0.5-1.0 t of furnace slag, 0.5t of iron scale and 0.2-0.5 t of other internally-circulated iron-containing raw materials;

(2) more than or equal to 0.50 percent of molten iron silicon, 1.0 to 1.5t of furnace slag, 0 to 0.5t of iron scale and 0.5 to 0.8t of other internally-circulated iron-containing raw materials;

(3) the molten iron silicon is less than or equal to 0.20 percent, the furnace slag is 0 to 0.5 t/furnace, and the iron scale is 0.5 to 1.0 t/furnace.

2. The process for efficiently utilizing the high-grade iron-containing raw material according to claim 1, wherein the flow of the oxygen supply intensity is controlled to prevent the slag from splashing and overflowing after the addition amount of the high-grade iron-containing raw material is increased.