CN102399917A

CN102399917A - Method for recycling residual hot steel slag in continuous casted steel ladle

Info

Publication number: CN102399917A
Application number: CN2010102764524A
Authority: CN
Inventors: 许刚; 廖相巍; 雷洪波; 李惊鸿; 叶印鹏
Original assignee: Angang Steel Co Ltd
Current assignee: Angang Steel Co Ltd
Priority date: 2010-09-07
Filing date: 2010-09-07
Publication date: 2012-04-04

Abstract

The invention discloses a method for recycling residual hot steel slag in a continuous casted steel ladle. The method is characterized in that in continuous casting production, after steel ladle molten steel is injected into a tundish, molten residual hot steel slag in a steel ladle is poured into a heavy molten iron pot and then are put into a converter with molten iron for steel making. The method enables heat energy, residual steel and residues of residual hot steel slag in a continuous casted steel ladle to be fully used, and reduces steel-making accessory consumption and a steel-making production cost.

Description

A kind of continuous casting ladle is annotated the method for afterheat-state slag recycling

Technical field

The present invention relates to a kind of continuous casting ladle and annotate the method for the residual steel residue of afterheat-state recycling, belong to the steel-making continuous casting production technical field.

Background technology

In the steel-making continuous casting production process, after liquid steel refining finished, ladle was transported to continuous caster and is poured into a mould; When the basic emptying of molten steel in the ladle; Close ladle nozzle, get into the continuous casting tundish to stop ladle slag, and then influence the quality of the cleanliness factor and the steel of molten steel; At this moment, the residual hot steel slag that some amount is arranged in the ladle.Conventional at present treatment process is to pour these slags into slag ladle, transports slag treatment plant to, through after a series of processing, could obtain again utilizing.There is following shortcoming in the surplus slag treatment technology of conventional notes:

1) transport the slag of slag treatment plant to, must be through after a series of processing, could obtain again utilizing or discarded, not only waste time and energy, and cost is very high;

2) ladle is annotated surplus residual steel and residue, and temperature is up to about 1550 ℃, and its heat is underutilized;

3) ladle is annotated in the surplus slag, contains the metal of have an appointment 5～10% (volumes), is not directly recycled;

4) ladle is annotated surplus residue, and basicity and CaO content are higher, and its remaining sweetening power does not obtain fully effectively utilizing.

In addition, recently some new technology are appearring aspect the recycling of ladle notes afterheat-state slag:

1) CSP annotates the empty bag of afterheat-state slag recovery of heat cycling and reutilization technology, China, application number: 200610012345.1;

2) ladle refining slag recoverying and utilizing method, Japan, special permission is open, and the spy opens flat 11-92817 (1999);

3) exploitation and the application (Tang Gang) of LF hot steel slag cycling and reutilization technology, steel-making, in August, 2006;

4) application (Ma Gang) of LF stove hot steel slag recycle utilization, China is metallurgical, in July, 2008;

5) LF hot steel slag cycling and reutilization is put into practice (peace steel), and Henan is metallurgical, in June, 2007;

6) LF refining furnace hot steel slag recycle (wide steel), metallurgical collection, in August, 2009.

Above-mentioned first method is that notes waste heat slag is poured in another sky ladle, when tapping, utilizes notes waste heat slag that molten steel is carried out wash heat, realizes annotating surplus slag recycle, has practiced thrift wash heat with synthetic slag charge, and the while has been reclaimed filling remaining liquid steel again; Second method is that notes waste heat slag is stayed in the former ladle, when tapping, utilizes notes waste heat slag that molten steel is carried out wash heat next time, realizes annotating surplus slag recycle, practicing thrift wash heat with when synthesizing slag charge, reclaims filling remaining liquid steel; Four kinds of methods in back and first method are similar; Also be to pour notes waste heat slag into next the preparation to carry out in the empty ladle of refining operation; Realize annotating surplus slag recycle; The characteristic of the high basicity of afterheat-state slag, strong reducing property is annotated in performance, thereby reduces the consumption of slag charge such as lime when realizing refining, reclaims filling remaining liquid steel simultaneously.

There is following shortcoming in above new technology:

1) will annotate the waste heat slag and pour into and maybe will annotate the waste heat slag in another sky ladle and stay in the former ladle, steel situation with fixed attention all possibly occur, may weld the stagnant water mouth when serious;

2) when the surplus slag recycle of notes surpassed more than 3 times, the quantity of slag was too much, and slag blanket is blocked up, can influence normal running, stirred, was adjusted to and grades like Argon, must carry out the waste operation this moment;

3) along with the slag cycle index increases, CaO content progressively descends in the slag, and sulfur capacity reduces, and can influence desulfurization rate, also must carry out the waste operation this moment;

4) recovery of the surplus slag of notes receives the influence of steel grade, generally is used for same steel grade, or the recyclable high-carbon steel grade that is used for of the surplus slag of the notes of low-carbon (LC) steel grade.

Summary of the invention

The object of the present invention is to provide a kind of continuous casting ladle to annotate the method for afterheat-state slag recycling, the continuous casting ladle is annotated the afterheat-state slag pour in the heavy iron ladle (molten iron is housed), be blended into converter, be used for steel-making with molten iron; Ladle is annotated the recycling of afterheat-state slag, and heat energy, residual steel, the residue that can make the continuous casting ladle annotate the afterheat-state slag are fully used, and reduces the consumption of steelmaking ingredient, reduces the STEELMAKING PRODUCTION cost.

The objective of the invention is to realize like this; A kind of continuous casting ladle is annotated the method for afterheat-state slag recycling; It is characterized in that: during continuous casting is produced, after ladle molten steel injects the end of processing of tundish, fused in the ladle is annotated the afterheat-state slag pour in the heavy iron ladle; To annotate subsequently the afterheat-state slag with molten iron be blended into converter be used for steel-making.

Above-mentioned continuous casting ladle is annotated the method for afterheat-state slag recycling, in the heavy iron ladle enough headroom will be arranged, and overhead clearance is greater than 15% usually; Occur when unusual when annotating surplus slag, can not reclaim and annotate the yield that surplus slag is annotated in surplus slag or control; At steelshop, the surplus slag of notes in the heavy iron ladle is blended into converter with molten iron; During steel-making, reduce steelmaking ingredient lime consumption 10%～20%, fusing assistant consumption 20%～50%.

This technology is annotated surplus slag, reduction supplementary product onsumption, shortening smelting time except having to reclaim; Boost productivity, simplify the slag treatment process, reduce production costs, outside the advantage of remarkable in economical benefits, also have annotate surplus slag be arranged in be difficult on the molten iron solidifying, the recovery of slag seldom receives the influence of steel grade and slag composition, annotates surplus slag CaF ₂Advantages such as the less environmental protection influence to converter steelmaking of content is little.

Embodiment

A kind of continuous casting ladle is annotated the method for afterheat-state slag recycling, and the operation of its preferred forms is following:

1) deslagging: during continuous casting is produced, after ladle molten steel injects the end of processing of tundish, in 10 minutes, fused is annotated the afterheat-state slag pour in the heavy iron ladle (molten iron is housed) into;

2) shove charge: will annotate the afterheat-state slag and be blended into converter with molten iron;

3) steel-making: lime consumption reduces by 10%～20% (wt), and the fusing assistant consumption reduces by 20%～50% (wt), the pushing off the slag tapping;

4) refining:, when refining finishes, measure thickness of slag layer in the bag by conventional processing;

5) continuous casting:, carry out the next one and annotate surplus slag recovery process by conventional processing.

Above-mentioned continuous casting ladle is annotated the method for afterheat-state slag recycling, in 10 minutes after ladle molten steel injects the end of processing of tundish, fused is annotated the afterheat-state slag pour in the heavy iron ladle; Headroom in the heavy iron ladle is 15% of an iron ladle height; Annotating surplus slag yield is 3%～7% of steel melting furnace capacity; Annotate that residual steel accounts for 10% (volume) in the surplus slag; Steelmaking ingredient lime consumption minimizing 10%～20%, fusing assistant consumption reduce 20%～50%, and smelting time shortens 1～5min, and productivity improves 1%～5%; Recovery rate of iron improves 1%～5%, and production cost reduces by 10～20 yuan/t steel.

Claims

1. a continuous casting ladle is annotated the method for afterheat-state slag recycling, it is characterized in that: during continuous casting is produced, after ladle molten steel injects the end of processing of tundish, fused in the ladle is annotated the afterheat-state slag pour in the heavy iron ladle; To annotate subsequently the afterheat-state slag with molten iron be blended into converter be used for steel-making.

2. a kind of continuous casting ladle according to claim 1 is annotated the method for afterheat-state slag recycling, it is characterized in that: in the heavy iron ladle enough headroom will be arranged; Occur when unusual when annotating surplus slag, must control annotate the pouring volume of surplus slag.

3. a kind of continuous casting ladle according to claim 2 is annotated the method for afterheat-state slag recycling, it is characterized in that: the overhead clearance in the heavy iron ladle is greater than 15%.

4. a kind of continuous casting ladle according to claim 2 is annotated the method for afterheat-state slag recycling, it is characterized in that: when abnormal conditions appear in the surplus slag of notes in the ladle, can not reclaim and annotate the afterheat-state slag, or the yield of surplus slag is annotated in control.