JPH06329449A - Method for recovering metal in slag - Google Patents

Abstract

(57) [Abstract] [Objective] The present invention is a method for recovering the metal in the slag by treating the metal-containing slag generated in the refining process of molten metal, particularly in the molten and semi-molten state. I will provide a. [Structure] Slag containing molten or semi-molten metal is discharged into a pit or yard, and immediately after that, the molten metal is dispersed and solidified in the slag while being inverted or stirred and mixed by a cultivator. It is characterized by recovering the iron content in the slag by cooling at least and then crushing, sieving and magnetic separation. Furthermore, it is a method of spreading a slag mass in advance and discharging the slag on it.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for recovering slag ingots by treating ingots containing slag generated in the refining process of molten metal, particularly in a molten and semi-molten state.

[0002]

2. Description of the Related Art The slag generated in the refining process of molten metal contains molten metal and is of various types depending on the refining method and the composition of the slag. Conventionally, this slag has been cooled, solidified and crushed to collect and recycle the effective metal components, and the slag has been separately adjusted and supplied for roadbed materials and landfills. For example, in the process of treating steelmaking slag, as shown in FIG. 2, the slag containing the metal discharged from the converter to the converter ladle car is first tilted and discharged into the pit or yard. Here, it is forcibly cooled by sprinkling water,
After that, the slag is naturally cooled to a predetermined temperature by being left for a certain time.

Next, the slag that has been cooled and solidified in the pit and the yard is excavated to an appropriate size by a heavy machine or a bulldozer, and is carried into a separate yard by a truck or the like. Here too, it is left outdoors for a predetermined period,
During this time, the slag is partly atomized due to natural collapse,
Then, it was carried into the final processing plant, further crushed and separated by a crusher, etc., and adjusted to a size suitable for roadbed materials and landfill.

The conventional method of recovering metal in the above-mentioned slag treatment process is mainly a method of removing large metal in the excavation stage as shown in FIG. As another method, as shown in FIG. 3, when slag is discharged, only the ingot is separately released to solidify the molten ingot, and then the ingot is excavated and divided by fusing, and further divided by pyrene. The method of collection was adopted.

The above-described conventional slag ingot recovery processing involves complicated work steps, and in particular, melting and slag work of slag ingots deteriorates the work environment, and there are problems such as pollution, and improvements are desired. Was there. Furthermore, the entire slag process requires a considerable amount of time until it is cooled and solidified, cut or melted, and further subdivided, and the processing equipment requires a considerable area to install a wide variety of machines, and its cost is a problem. It was. For this reason, a drastic review of the treatment process has been demanded.

As this known technique, for example, Japanese Patent Laid-Open No. 3-2
In the No. 02406 publication, the ingot and the slag in the slag are separated at the early stage of the treatment, and pretreatment for rough cracking is performed, all the slag containing the ingot is discharged, and the semi-molten or solidified slag is continuously processed collectively. However, there is no mention of the recovery of bullion.

However, these conventional techniques are still not sufficient in terms of efficiency of slag treatment and environmental problems,
Further, it has been desired to develop a slag treatment technology that achieves high efficiency of treatment, makes the recovery of metal ingot more efficient, uses slag more effectively, and reduces the treatment cost.

[0008]

DISCLOSURE OF THE INVENTION The present invention solves the problems of the prior art, in which the slag containing the metal generated during the refining of molten metal is discharged into a pit or yard and immediately after that, it is melted or semi-finished. By stirring in the molten state, it is aimed to promote the fine-grained solidification and to achieve the conventional level of Grizzly passage. That is, normally, in the stage of the liquid slag, it is possible to give a sufficient stirring motion even if the stirring force is not so large,
This agitation makes it possible to simply increase the cooling area of the slag, and to solidify the slag without causing them to come into close contact with each other during solidification. Furthermore, in this slag that has been subdivided after plowing, the metal in the slag is dispersed and solidified when it solidifies, and this can be used to easily and quickly collect the metal ingots. I will provide a.

[0009]

The present invention is to solve the above-mentioned problems, and the gist thereof is to discharge slag containing molten or semi-molten metal into a pit or a yard. Immediately after that, the molten metal is dispersed and solidified in the slag while being inverted or stirred and mixed by a cultivator, and then cooled, and then crushed, sieved and magnetically selected to recover the iron content in the slag. It is a method of collecting metal in slag, which is characterized in that

When discharging a slag containing a larger amount of metal, the slag particles are spread in advance in the pit or yard, and then the slag containing the molten or semi-molten metal is discharged into the pit or yard. Immediately after that, the molten metal is dispersed and solidified in the slag while being inverted or stirred and mixed by a cultivator, and then cooled, and then crushed, sieved and magnetically selected to recover the iron content in the slag. It is a method of collecting metal in slag, which is characterized in that

[0011]

The operation of the present invention will be described below. The present invention performs a treatment of discharging a slag containing a molten or semi-molten metal ingot and stirring and mixing with a cultivator, and by dispersing and solidifying the molten metal in the slag, that is, atomizing the metal. The first requirement is to modify the distribution and its distribution to be almost uniform.

As a result, unlike the prior art, a method for recovering the metal in a state where the metal is most easily recovered and the metal is quickly and efficiently recovered is realized. The state of the metal in the slag of the present invention is shown in FIG. 4 in comparison with the conventional method. FIG. 4A shows the existing state of the ingot in the conventional slag, and shows that the ingot is solidified as a large lump surrounded by the slag. Figure 4
(B) is a state where the metal of the present invention exists, and shows a state where the metal is finely dispersed in the slag. Moreover, although it depends on the amount of metal in Fig. 4 (a), it is 500-2000mm.
4 (b), most of the small lumps around 250 mm are large.

That is, in the present invention, the metal is finely and uniformly distributed, which is the most preferable form for collecting the metal. This is due to the cultivating action of the present invention, in which the slag is sufficiently agitated, so that a fairly large thermal stress occurs in the slag, and this stress causes the slag to spontaneously collapse and It is dispersed and solidified by a mechanism similar to this. further,
It can be considered that the pressing force and the rotary motion of the plowing process described above act as a driving force for crushing the slag, and the motion of the slag causes fragmentation and uniform distribution of the metal.

Further, in the second invention of the present invention, in order to promote the dispersion and solidification of the metal, a slag mass is spread in advance over the entire surface of the slag discharge field, and the same amount as the discharge slag is spread over the slag mass. Is a method of releasing. This is because the spread slag mass acts as a core during solidification of the slag and further promotes dispersion of the metal during cooling in the tilling process. The slag mass laid in advance is an example, and other substances may be used as long as it is solid and acts as a solidification nucleus of the slag.

It can be expected that the state of FIG. 4 (b) is realized by combining the nucleation action and the plowing action of the solidification described above. In this state, after crushing, sieving and magnetic separation can be carried out efficiently to collect the metal. In the slag processing method of the present invention, the state of the metal that is evenly distributed in the finely divided slag is obtained by a relatively simple processing method, and the conventional metal recovery process that requires a long time is It is simplified or omitted, and the particle size distribution and composition of the recovered metal are stable. Therefore, recycling of bullion becomes easy.

That is, the second requirement of the present invention is that the slag after plowing according to the present invention is directly conveyed by a hot conveyer, and a cooling drum for cooling adjustment and further subdividing is provided in the middle. . In this cooling drum, the slag temperature at the time of charging was about 700 ° C, the slag was cooled to about 150 ° C, and the cooling drum was further rotated to impart collision energy to the slag for fragmentation. The feature is that it can proceed.

For this reason, the cooling drum of the present invention is generally cylindrical, but any method may be used as long as the slag is cooled and a contact force is applied by mechanical stirring such as rotation.
Any shape may be used as long as it is a vertical rotary container. In the present invention, since the temperature of the slag after plowing is about 700 ° C., the charging temperature to the cooling drum is to supply the slag using a hot conveyor.

Furthermore, if necessary, it is possible to supply water and / or mist to the inside of the cooling drum of the present invention to adjust the cooling rate of the slag inside. Further, the supplied slag is sequentially moved to the discharge port by the rotation of the cooling drum, and the discharged slag is discharged to enable continuous operation.

[0019]

EXAMPLES The present invention will be described in more detail based on examples. FIG. 1 shows a diagram of the steelmaking slag treatment process of the present invention.
The slag discharged from the converter is poured into the converter pan and transferred to the slag treatment site by the converter pan truck. Before the slag is discharged, if the surface of the slag inside the pot car is in a state where the river is stretched, skin puncture is performed as an operation to break this and make it easier to discharge.

Thereafter, the discharged slag is cultivated and solidified by a cultivator. Thereafter, a step of sieving and adjusting the particle size by a vibrating grizzly may be provided if necessary. At this stage, the metal is dispersed in the solidified slag with a grain size almost equal to that of the finely divided state, usually 700 to 800 ° C.
Since it has a temperature of, it is charged into the cooling drum by the hot conveyor. As described above, while the slag is cooled from about 1200 ° C. at the time of discharge to 700 to 800 ° C. at the end of the tillage, the molten metal is uniformly dispersed as fine particles in the crushed slag by the tilling step of the present invention. It solidifies, and its size becomes about 90% or more after about 250 mm or less after the cultivating and coagulating treatment of the present invention, and becomes about 30 mm or less of the usual subdivided state after the cooling drum treatment.

The cooling drum rotates moderately to add mutual collision and / or striking action to the internal slag, so that the subdivision effect is further developed. Further, if necessary, it is possible to promote cooling to the cooling drum by sprinkling water and / or mist, etc. Normally, the processing capacity of this cooling drum is to cool about 300 tons of slag to about 150 ° C. in about 40 minutes. It is possible.

In the second invention of the present invention, a slag mass having a size of about 50 mm or less and an amount equal to the amount of the discharged slag is spread over the entire surface of the slag discharge pit in advance, and then the slag is discharged. However, when the method of the present invention was carried out, the result was that the slag particle size distribution after the plowing treatment was further improved, and the dispersion state of the metal was more uniform.

According to the above-mentioned treatment method of the present invention, the slag containing the uniformly dispersed ingot is conveyed to the ingot recovery step, and the ingot is almost entirely recovered by crushing, sieving and magnetic separation. The processing time until the magnetic separation is shortened to about 30 to 40 minutes in the tilling step, and it takes about one week before the conventional processing plant is shortened to about 40 minutes by the cooling drum of the present invention. To be done. As described above, in the treatment process of the present invention, fine particles of the slag having the metal in a uniformly dispersed state up to the conventional state of being finely divided can be obtained by a short-time treatment.

According to the above examples, the converter slag was actually mixed and stirred, and the dispersion-solidified slag was put on a cooling drum, and then sieved and magnetic separation was performed. Nevertheless, it was found that the collection efficiency of metal is significantly improved.

[0025]

As is apparent from the examples of the present invention, in the present invention, molten metal slag containing metal is mixed and stirred in a molten or semi-molten state to promote dispersion and solidification of the metal and to subdivide the slag. By adding a cooling drum, it is possible to obtain a slag with uniformly dispersed metal up to the conventional subdivision stage in a very short time. It is possible to simply omit the slag treatment step, and to reduce the treatment area extremely, thereby significantly reducing the treatment cost.

[Brief description of drawings]

FIG. 1 is a schematic diagram of a converter slag processing step according to the present invention.

FIG. 2 is a schematic diagram of a conventional converter slag treatment process, particularly a metal recovery process in a slag discharge process.

FIG. 3 is a schematic diagram of a conventional converter slag treatment process, particularly a metal recovery process in a slag excavation process.

FIG. 4 is a diagram showing the distribution of metal in the solidified slag of the present invention and the conventional method, showing (a) the conventional method and (b) the present invention.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Yoshimi Watanabe, 370 Sakata, Kimitsu, Chiba Prefecture, within Kimitsu Branch, Hamada Heavy Industries Ltd. (72) Inventor, Michio Shigeraki, 370, Sakata, Kimitsu, Chiba Prefecture, within Kimitsu Branch, Hamada Heavy Industries Ltd. (72) Inventor Hirotaka Murakami, 370 Sakata, Kimitsu-shi, Chiba Hamada Heavy Industries Ltd. Kimitsu Branch

Claims (2)

[Claims] 1. A slag containing molten or semi-molten metal is discharged into a pit or a yard, and immediately after that, the slag is poured into the slag while being inverted or stirred and mixed by a cultivator. A method of recovering metal in slag, which comprises recovering iron content in slag by dispersing and solidifying and cooling, followed by crushing, sieving and magnetic separation. 2. When discharging slag containing a large amount of metal, slag particles are spread in advance in a pit or yard, and then slag containing molten or semi-molten metal is discharged into the pit or yard. Immediately after that, the molten slag is dispersed and solidified in the slag while being inverted or stirred and mixed by a cultivator, and the slag is cooled and then crushed, sieved and magnetically separated to recover the iron content in the slag. A method of collecting bullion in slag, characterized by: