Double-slag and full-slag-remaining semi-steel steelmaking method

Abstract

The invention belongs to the technical field of metallurgy, particularly relates to a double-slag and full-slag-remaining semi-steel steelmaking method and provides the double-slag and full-slag-remaining semi-steel steelmaking method so as to solve the problems of late initial smelting slag forming time, poor dephosphorization effect, high auxiliary material consumption and the like for existing semi-steel steelmaking. The method comprises the steps as follows: a, the first furnace: after semi-steel is mixed, active lime, high-magnesium lime and an acidic compound slag former are added to the furnace while top blowing of oxygen is performed, then silicon iron is added, the oxygen is blown continuously, and molten steel and slag are obtained; b, the second furnace: the slag obtained in the previous furnace is completely left in the furnace, and the acidic compound slag former is added; the oxygen is blown continuously after the semi-steel is mixed, and when the temperature of the semi-steel ranges from 1,350 DEG C to 1,400 DEG C, part of the slag is discarded; and then secondary slag forming is performed, and molten steel and slag are obtained. According to the method, 4-5 furnaces form a cycle, the auxiliary material consumption is low, early-stage dephosphorization is fast, and the dephosphorization effect is good. The method is simple to operate, low in production cost and suitable for popularization and use.

Description

technical field

[0001] The invention belongs to the technical field of metallurgy, and in particular relates to a semi-steel steelmaking method with double slag and all slag remaining. Background technique

[0002] my country is rich in vanadium-titanium magnetite resources. Domestic iron and steel enterprises such as Panzhihua Iron and Steel, Chenggang, Kunming Iron and Steel, and Weiyang Iron and Steel all use vanadium-titanium magnetite for smelting. The main raw material for converter steelmaking is after vanadium is extracted by a special converter. The semi-steel, the semi-steel obtained after desulfurization and vanadium-containing molten iron has a carbon mass percentage of 3.4-4.0%, silicon and manganese elements as traces, a sulfur mass percentage of ≤0.015%, and a phosphorus mass percentage 0.060-0.080%. Therefore, semi-steel smelting has the characteristics of less acidic slag-forming substances, single slag system components, and insufficient heat in the blowing ...

Examples

Embodiment 1

[0031] Embodiment 1 adopts the method of the present invention to carry out semi-steel steelmaking

[0032] A 120t converter in a factory uses semi-steel for steelmaking, and the phosphorus content of the semi-steel entering the furnace is 0.070%. When the first furnace is smelted, semi-steel is mixed into the converter, and at the same time as the blowing is started, 10kg / t of active lime, 15kg of high magnesium lime and slagging agent are added to the furnace, and 1kg / t of ferrosilicon is added to the steel, and the progress of oxygen blowing When it is 0-40%, the oxygen supply intensity of the oxygen lance is 2.5m 3 Between / t·min, the oxygen blowing progress is 40% to the end of the blowing and the oxygen supply intensity is 3.5, the slag basicity at the control end is 3, until the end of the blowing, and all slag is left for the early dephosphorization of the next furnace . The second furnace smelting uses the slag with all the slag remaining in the first furnace for ea...

Embodiment 2

[0039] Embodiment 2 adopts the method of the present invention to carry out semi-steel steelmaking

[0040] A 120t converter in a factory uses semi-steel for steelmaking, and the phosphorus content of the semi-steel entering the furnace is 0.080%. When the first furnace is smelted, semi-steel is mixed into the converter, and at the same time as the blowing is started, 15kg / t of active lime, 10kg of high magnesium lime and acidic composite slagging agent are added to the furnace, and 1.5kg / t of ferrosilicon is added to the furnace. When the oxygen blowing progress is 0-40%, the oxygen supply intensity of the oxygen lance is between 2.8, and the oxygen supply intensity is between 40% and 4 at the end of blowing, and the slag alkalinity at the control end is 3.5 until the end of blowing. And leave all the slag for dephosphorization in the early stage of the next furnace. The second furnace smelting uses the slag with all the slag remaining in the first furnace to carry out depho...

Embodiment 3

[0050] Embodiment 3 adopts the method of the present invention to carry out semi-steel steelmaking

[0051] A 120t converter in a factory uses semi-steel for steelmaking, and the phosphorus content of the semi-steel entering the furnace is 0.075%. When the first furnace is smelted, semi-steel is mixed into the converter, and at the same time as the blowing is started, 12kg / t of active lime, 12kg of high-magnesium lime and acidic composite slagging agent are added to the furnace, and 2kg / t of ferrosilicon is added to the furnace. When the oxygen progress is 0% to 40%, the oxygen supply intensity of the oxygen lance is between 3.0, the oxygen supply intensity is between 40% and 4.5 at the end of the blowing, and the slag alkalinity at the end is controlled at 4 until the end of blowing, and All remaining slag is used for dephosphorization in the early stage of the next furnace. The second furnace smelting uses the slag with all the slag remaining in the first furnace for early ...

technical field

[0001] The invention belongs to the technical field of metallurgy, and in particular relates to a semi-steel steelmaking method with double slag and all slag remaining. Background technique

[0002] my country is rich in vanadium-titanium magnetite resources. Domestic iron and steel enterprises such as Panzhihua Iron and Steel, Chenggang, Kunming Iron and Steel, and Weiyang Iron and Steel all use vanadium-titanium magnetite for smelting. The main raw material for converter steelmaking is after vanadium is extracted by a special converter. The semi-steel, the semi-steel obtained after desulfurization and vanadium-containing molten iron has a carbon mass percentage of 3.4-4.0%, silicon and manganese elements as traces, a sulfur mass percentage of ≤0.015%, and a phosphorus mass percentage 0.060-0.080%. Therefore, semi-steel smelting has the characteristics of less acidic slag-forming substances, single slag system components, and insufficient heat in the blowing ...

Examples

Embodiment 1

[0031] Embodiment 1 adopts the method of the present invention to carry out semi-steel steelmaking

[0032] A 120t converter in a factory uses semi-steel for steelmaking, and the phosphorus content of the semi-steel entering the furnace is 0.070%. When the first furnace is smelted, semi-steel is mixed into the converter, and at the same time as the blowing is started, 10kg / t of active lime, 15kg of high magnesium lime and slagging agent are added to the furnace, and 1kg / t of ferrosilicon is added to the steel, and the progress of oxygen blowing When it is 0-40%, the oxygen supply intensity of the oxygen lance is 2.5m 3 Between / t·min, the oxygen blowing progress is 40% to the end of the blowing and the oxygen supply intensity is 3.5, the slag basicity at the control end is 3, until the end of the blowing, and all slag is left for the early dephosphorization of the next furnace . The second furnace smelting uses the slag with all the slag remaining in the first furnace for ea...

Embodiment 2

[0039] Embodiment 2 adopts the method of the present invention to carry out semi-steel steelmaking

[0040] A 120t converter in a factory uses semi-steel for steelmaking, and the phosphorus content of the semi-steel entering the furnace is 0.080%. When the first furnace is smelted, semi-steel is mixed into the converter, and at the same time as the blowing is started, 15kg / t of active lime, 10kg of high magnesium lime and acidic composite slagging agent are added to the furnace, and 1.5kg / t of ferrosilicon is added to the furnace. When the oxygen blowing progress is 0-40%, the oxygen supply intensity of the oxygen lance is between 2.8, and the oxygen supply intensity is between 40% and 4 at the end of blowing, and the slag alkalinity at the control end is 3.5 until the end of blowing. And leave all the slag for dephosphorization in the early stage of the next furnace. The second furnace smelting uses the slag with all the slag remaining in the first furnace to carry out depho...

Embodiment 3

[0050] Embodiment 3 adopts the method of the present invention to carry out semi-steel steelmaking

[0051] A 120t converter in a factory uses semi-steel for steelmaking, and the phosphorus content of the semi-steel entering the furnace is 0.075%. When the first furnace is smelted, semi-steel is mixed into the converter, and at the same time as the blowing is started, 12kg / t of active lime, 12kg of high-magnesium lime and acidic composite slagging agent are added to the furnace, and 2kg / t of ferrosilicon is added to the furnace. When the oxygen progress is 0% to 40%, the oxygen supply intensity of the oxygen lance is between 3.0, the oxygen supply intensity is between 40% and 4.5 at the end of the blowing, and the slag alkalinity at the end is controlled at 4 until the end of blowing, and All remaining slag is used for dephosphorization in the early stage of the next furnace. The second furnace smelting uses the slag with all the slag remaining in the first furnace for early ...