JPS63295458A - Process for recovering molten slag produced by electric steel making process fractionally and process for regenerating recovered molten slag - Google Patents

Abstract

PURPOSE:To treat slag timely and to enable its utilization for several uses by subdividing the slag discharged from an electric steel making furnace in small vessels to solidify the slag in early time, recovering iron contained in the slag by crushing the solidified slag, then screening the crushed slag with a revolving screen. CONSTITUTION:Slag X discharged from a tapping hole 1 of an electric steel making furnace is subsivided and poured into plural numbers of inverted truncated pyramidal slag ladle 3 having 1-1.3m length of one edge and about 1m depth, and the slag is allowed to solidify in early time by inserting a lifting hook 10 into the slag. The lifting hook 10 in the slag ladle 3 contg. the solidified slag is hung by a hook of a crane, and the solidified slag Y in the slag ladle 3 is discharged from the ladle 3 and mounted on many rails 12 on a crushing stand 11, where the slag is crushed to large pieces by injecting water using a breaker 16, and the crushed slag is dropped on a conveyor 17. While transporting the slag with the conveyor 17, iron contained in the slag is separated as ferrous foreign matters 2 magnetically with a conveyor 19 housing magnets therein and recovered, which is crushed then with a jaw crusher 20, and reutilized as fine particles A for a substitute of concrete sand, middle grins B as a material for roadbed, and coarse grains C as cobblestone after classifying with a rotary screen 23.

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention cools and solidifies molten slag generated in electric furnace steelmaking in front of the furnace, separates it and collects it, and pulverizes it to sort and collect it for reuse. The present invention relates to a method for dividing and recovering molten slag and a method for recycling the same.

(Prior art) Conventionally, when treating molten slag, especially oxidized slag, generated in electric furnace steelmaking, it is poured into a large slag pot that accommodates molten slag for one charge of steelmaking time, and then transported to a processing plant. After being transported to the slag pot and cooled, the slag is turned over and removed from the slag pot, then crushed and disposed of. Furthermore, in the case of a rotary kiln, molten metal is poured into the kiln and the process is carried out while rotating the drum.

(Problem to be solved by the invention) However, in these cases, a large slag pot (also called a slag bag) made of cast steel with a capacity of 10 tons has been used to solve the problem. Due to its large weight, it is difficult to handle, and since it is made of cast steel, it is also expensive to manufacture. In addition, the large volume of molten slag poured into a large slag pot requires a long time to cool down, so the processing of molten slag generated in electric furnace steelmaking requires 1 charge of steelmaking time, usually 1.5 hours. It cannot be efficiently and conveniently processed within about 2 hours.

However, the pulverized material that has been solidified in a slag pot and then pulverized is subjected to false disposal, and the recovered resources are not effectively utilized.

(Means for Solving the Problems) Therefore, in the present invention, in order to solve the above problems, firstly, the molten slag The present invention provides a method for dividing and recovering molten slag generated in electric furnace steelmaking by pouring the molten slag into small portions into a slag ladle 3 with a relatively short time and solidifying the molten slag in a relatively short time. The generated molten slag After transferring it to the crushing table 11, water injection 15 and breaker 16
, the crushed material is conveyed by falling onto the first conveyor 17 from the gap between the crushing tables 11 and subjected to magnetic selection, the selected crushed material is dropped into the Joe crusher 20 to be crushed again, and the crushed material is transported to the second conveyor 21. The present invention provides a method for recycling molten slag generated in electric furnace steelmaking, in which the molten slag is dropped onto a rotary sieve 23 for sorting and recovery.

(Example) First, molten slag X generated in electric furnace steelmaking shown in Fig. 1
In the split recovery equipment, 1 is the ore outlet formed on the front side of the electric furnace, and about 22 tons of oxidized slag Approximately 6 tons of oxidized slag Reference numeral 2 denotes a trolley rail disposed directly below the inclined ore outlet 1, on which a plurality of small-capacity slag pots 3 are lined up and loaded on the movable trolley 4. The size of this slag pot 3 is in the shape of an inverted truncated pyramid with a side length of about 1 to 1.3 meters and a depth of about 1 meter, and a thickness of 5 mm.
The pot structure is made by welding steel plates about centimeters in size.
Molten slag X for I charge generated in large electric furnace steelmaking
For this purpose, eight slag pots 3 each having a capacity of about 1i3) tons are arranged on a moving trolley 4, and for one chard of molten slag X generated in small electric furnace steelmaking, capacity is 2
Three slag pots 3 each weighing about a ton are arranged on a moving cart 4.

Reference numeral 5 denotes an angle-shaped guide extending over the upper casing of the slag pans 3, which guides the molten slag X from between adjacent slag pans 3.
prevent it from spilling out.

Reference numeral 6 denotes a traction fitting provided at the front and rear of the movable cart 4; 7 an electric winding machine for moving the movable cart 4 forward and backward; the tip of its wire lobe 8 is connected to the traction fitting 6 via a guide roller 9; are doing.

Therefore, when processing 1 charge of molten slag is scattered so that the solidified slag Y that has been cooled and solidified can be easily removed from the slag pot 3 later.

Then, the molten slag X is poured into the slag pan 3 loaded on the moving cart 4 by opening the door of the ore outlet 1 of the electric furnace and tilting the electric furnace.

When about 70 to 80% of the molten slag 4 is moved forward, etc., and the charged molten slag X is divided and collected into several slag pots 3.

After that, the hanging metal fitting 1o is placed approximately at the center of each slag pot 3.
In the case of molten slag The material naturally cools to 400-500 degrees Celsius and solidifies.

At that stage, the hook of the crane is hooked to the hanging fitting 10 of the solidified slag Y, and the solidified slag Y is lifted from the slag pot 3.
It is lifted up, taken out, and transferred to the next recycling process.

Next, in FIG. 2 showing a reprocessing device that crushes and sorts the solidified slag Y so that it can be reused, numeral 11 is a crushing table for the solidified slag Y, and on the table there are many l-shaped The rails 12 are arranged at coarse intervals with gaps of 20 to 30 centimeters in between. Reference numeral 13 denotes a scattering prevention panel for the crushed material surrounding the upper part of the crushing table 11, and 14 a guide for guiding the crushed material to fall, which surrounds the lower part of the crushing table 11. 1s is a water injection nozzle that sprays water on the solidified slag Y placed on the crushing table 11, and this
The solidified slag Y cooled to about 0 degrees causes shrinkage cracks. lli is a breaker or rock drill, which further divides the solidified slag Y that has caused shrinkage cracks. Reference numeral 17 denotes a first conveyor for conveying the crushed and fallen material to the upper part, and one side of the conveyor 17 is arranged so as to face the lower guide 14 directly below the crushing table 11. 18 is a drain groove formed below the first conveyor 17.

19 is a magnetic ore sorting conveyor equipped with a magnet, which is disposed directly above the first conveyor 17 in a crossed manner;
Iron foreign matter Z contained in the crushed material transported by the first conveyor 17 is removed by beneficiation. 20 is the first conveyor 1
The crusher 2 is disposed directly below the conveyor falling part of No.
It is further finely ground by ゜.

Reference numeral 21 denotes a second conveyor for conveying the finely divided and crushed fallen material to the upper part, and one of the conveyors 21 is disposed so as to face directly below the crusher 20.

Reference numeral 22 denotes a conveyance guide for crushed material disposed directly below the conveyance/falling part of the second conveyor 21, and 23 denotes a drum-shaped rotary sieve, with one entrance side of the rotary sieve 23 raised high and the other outlet side raised. It is rotatably supported in a low tilted state.

The size of the mesh of this rotary sieve 23 is formed in three stages from the entrance side to the exit side, and the cylindrical part 23A on the entrance side has a mesh size of about 4 mm for fine grains, and The cylindrical portion 23B has a mesh of about 25 mm for medium use, and the subsequent cylindrical portion 23G on the outlet side
These are for large grains and each has a mesh of 25 mm or more.

24 is a stockyard partition wall formed directly below the rotary sieve 23 (or at the end of the particle size sorting conveyor),
The recycled material passed through the rotary sieve 23 and stored separately is divided into sections to be collected according to particle size.

First, water is poured by the water injection nozzle 15 onto the solidified slag Y, which has been cooled and solidified to 400 to 500 degrees Celsius in the previous divided collection step and transferred onto the crushing table 11 by a crane or the like. Then, shrinkage cracks were generated in the solidified slag Y at 400 to 500 degrees Celsius, and the slag Y was further divided into intermediate pieces by a mechanical force such as a breaker 16 or a crusher, and crushed into relatively coarse crushed materials, which were arranged on a crushing table 11. The crushed material is caused to fall onto the first conveyor 17 through the gap between the L-shaped rails 12.

In the middle of being conveyed upward by this first conveyor 17, magnetic beneficiation conveyors 19 are arranged in a crossed manner.
The iron foreign matter Z contained in the crushed material is removed by the magnetic beneficiation conveyor 19 and then dropped downward from the conveying end of the first conveyor 17. There, a crusher 20 is disposed, which crushes the crushed material even more finely and drops it onto the second comparer 21.
1, and then conveyed upward again by the conveyance guide 22.
The liquid is fed into the rotary sieve 23 through the sieve 23. The pulverized materials are sorted into predetermined particle sizes and collected between the partition walls 24 of the stockyard below, or are reused as raw material aggregates that can be effectively reused as chemical fertilizers. (Effects of the Invention) As described above, the present invention, firstly, divides the molten slag Since we have provided a method for dividing and recovering molten slag generated in electric furnace steelmaking by pouring it into the furnace and cooling and solidifying it in a relatively short period of time, the slag ladle 3 can not only have a small capacity and be inexpensive, but also Since the molten slag X is poured into the small capacity slag pot 3, the cooling time is relatively short, and the solidified slag Y
It has excellent workability when transferring and pulverizing slag, and dramatically improves work efficiency in efficiently dividing and recovering molten slag X per 1 charge.

Second, the molten slag
The solidified slag Y is cooled and solidified in a relatively short time, and the solidified slag Y is transferred to the crushing table 11, and then water is poured into the slag 15 and the breaker 1
6, the crushed material is dropped and conveyed from the gap in the crushing table 11 onto the first conveyor 17, subjected to magnetic selection, the selected crushed material is dropped into the Joe crusher 20, crushed again, and transferred to the second conveyor 17. This is a recycling method for molten slag generated in electric furnace steelmaking, which is dropped onto a 21 and conveyed, then thrown into a rotary sieve 23 for sorting and recovery, so it is also effective from the viewpoint of effective resource reuse. Learn the various effects that can be taken care of.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram showing a division and recovery device for molten slag generated in electric furnace steelmaking, and FIG. 2 is a schematic diagram showing a regeneration processing device for crushing and sorting and recovering solidified slag. Code Table X Melted slag Y Solidified slag Z Iron foreign matter

Claims (4)

[Claims] (1) Molten slag X generated during one charge of steelmaking time is poured into multiple small-capacity slag pots 3, and then cooled and solidified in a relatively short time to produce molten slag generated in electric furnace steelmaking. Split collection method. (2) The size of the slag pot 3 should be determined so that the length of each side is 1 to 1.3.
The method for dividing and recovering molten slag generated in electric furnace steelmaking according to claim 1, wherein the pot structure is made of steel plate and has an inverted truncated pyramid shape with a depth of about 1 meter and a depth of about 1 meter. (3) Molten slag
The hanging fitting 10 is inserted into the slag to cool and solidify it in a relatively short time.The solidified slag Y is transferred to the crushing table 11 and crushed by the water injection 15 and the breaker 16, and the crushed material is The crushed materials are conveyed by falling onto the first conveyor 17 from the gap in the crushing table 11 for magnetic selection, and the selected crushed materials are dropped into the jaw crusher 20 and crushed again.
After dropping it onto the second conveyor 21 and conveying it,
A method for recycling molten slag generated in electric furnace steelmaking, which is input into a rotary sieve 23 and sorted and collected. (4) The size of the slag pot 3 is set so that the length of each side is 1 to 1.3.
4. The method for recycling molten slag generated in electric furnace steelmaking according to claim 3, wherein the ladle is made of steel plate and has an inverted truncated pyramid shape with a depth of about 1 meter and a depth of about 1 meter.