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A method for recovering metal aluminum in pre-melted slag of vacuum circulation degassing furnace

A technology of vacuum circulation and recovery method, which is applied in the field of steelmaking technology, can solve the problems of increasing smelting costs, etc., and achieve the effect of reducing processing costs and reducing aluminum consumption

Active Publication Date: 2014-10-08
ANGANG STEEL CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

Due to the high price of metal aluminum, and aluminum is a strong deoxidizer, alumina is generally difficult to be reduced, and RH furnaces often use pre-melted slag rich in alumina for desulfurization, and the pre-melted slag after desulfurization is Discharged from the vacuum chamber into the top slag of the ladle can no longer be used, which increases the smelting cost. Therefore, it is necessary to develop an effective recovery method from the pre-melted slag for the metallurgical reaction environment of the vacuum circulation degassing of the RH furnace and the desulfurization of molten steel. Metal aluminum method to reduce the processing cost of RH furnace refining molten steel

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0017] A 180-ton RH furnace is used. Pre-slag containing Al 2 o 3 39.5wt%, CaO 46.1wt%. The carburant contains C95.4 wt%.

[0018] 1. Before the aluminum recycling operation in the RH furnace, deep deoxidation of molten steel is carried out with aluminum, and the mass percentage of Als in molten steel is controlled at 0.006%.

[0019] 2. The temperature of molten steel in the ladle is controlled at 1612°C.

[0020] 3. The vacuum pressure of the RH furnace vacuum chamber is controlled at 61Pa, and the lifting gas flow rate of the insertion tube is 75Nm 3 / h, the depth of the insertion tube immersed in molten steel is controlled at 450mm.

[0021] 4. After the molten steel is deoxidized, add 450 kg of pre-melted slag and 28 kg of recarburizer into the molten steel.

[0022] After 3 minutes of melting and reaction, the mixed slag is discharged to the vacuum chamber, and the molten steel circulates evenly after 2 minutes without adding any alloy or aluminum. After sampling...

Embodiment 2

[0024] A 180-ton RH furnace is used. Pre-slag containing Al 2 o 3 30wt%, CaO 58wt%. The carburant contains C93 wt%.

[0025] 1. Before the aluminum recovery operation in the RH furnace, the aluminum is used for deep deoxidation of the molten steel, and the mass percentage of Als in the molten steel is controlled at 0.011%.

[0026] 2. The temperature of molten steel in the ladle is controlled at 1644°C.

[0027] 3. The vacuum pressure of the RH furnace vacuum chamber is controlled at 42Pa, and the lifting gas flow rate of the insertion tube is 14Nm 3 / h, the depth of the insertion tube immersed in molten steel is controlled at 590mm.

[0028] 4. After the molten steel is deoxidized, add 1420 kg of pre-melted slag to the molten steel, and add 71 kg of recarburizer at the same time.

[0029] After 4 minutes of melting and reaction, the mixed slag is discharged to the vacuum chamber, and the molten steel circulates evenly after 2 minutes without adding any alloy or aluminu...

Embodiment 3

[0031] A 180-ton RH furnace is used. Pre-slag containing Al 2 o 3 45wt%, CaO 41wt%. The carburant contains C94.8wt%.

[0032] 1. Before the aluminum recycling operation in the RH furnace, deep deoxidation of molten steel is carried out with aluminum, and the mass percentage of Als in molten steel is controlled at 0.022%.

[0033] 2. The temperature of molten steel in the ladle is controlled at 1560°C.

[0034] 3. The vacuum pressure of the RH furnace vacuum chamber is controlled at 46Pa, and the lifting gas flow rate of the insertion tube is 130Nm 3 / h, the depth of the insertion tube immersed in molten steel is controlled at 490mm.

[0035] 4. After the molten steel is deoxidized, add 1100 kg of pre-melted slag to the molten steel and add 50 kg of recarburizer at the same time.

[0036] After 4 minutes of melting and reaction, the mixed slag is discharged to the vacuum chamber, and the molten steel circulates evenly after 2 minutes without adding any alloy or aluminum....

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PUM

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Abstract

The invention provides a method for recycling metallic aluminium in pre-melted slag of a vacuum circulation degassing furnace. Mass percent of Als in molten steel is controlled to be more than or equal to 0.005%; temperature of the molten steel in a steel ladle is controlled to be 1580-1650 DEG C; pressure of a vacuum chamber is controlled to be 40-67Pa, lift gas flow of an insert tube is controlled to be 70-150Nm<3> / h, depth of the insert tube which is immersed into the molten steel is controlled to be 400-600mm; and the pre-melted slag or bauxite is added into the molten steel in proportion of 1-8kg per ton of steel, a carburant is added into the molten steel in proportion of 0.1-0.4kg per ton of steel, and reduction-oxidation reaction of alumina and carbon under high vacuum degree in an RH furnace is utilized for reducing the metallic aluminium in alumina into the molten steel, thus the aim of recycling the metallic aluminium in the pre-melted slag is realized. Filed tests show that aluminium increase of the molten steel by adopting the recycling method disclosed by the invention is increased by more than 0.003-0.020%, consumption of aluminium can be greatly reduced, and treatment cost of the molten steel can be effectively reduced.

Description

technical field [0001] The invention belongs to the field of steelmaking technology, and in particular relates to a method for recycling metal aluminum in pre-slag of a vacuum circulation degassing furnace (RH furnace) into molten steel. Background technique [0002] Vacuum circulation degassing method (RH method) is an important method for refining molten steel outside the furnace. It has a series of advantages such as short processing cycle, large production capacity, good refining effect and easy operation, and has been widely used in steelmaking production. So far, the RH furnace has been transformed from a single degassing device into a multifunctional external refining device including vacuum decarburization, oxygen blowing decarburization, powder spraying and slag addition desulfurization, temperature compensation, uniform temperature and composition. Moreover, with the advancement of technology and the expansion of refining functions, it has shown significant advanta...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): C22B7/04C22B21/00C21C7/06
CPCY02P10/20
Inventor 林洋王晓峰张钟铮姚伟智袁皓马勇吴春杰臧绍双
Owner ANGANG STEEL CO LTD