JPS5839715A - Recovering method for steel making slag - Google Patents

Abstract

PURPOSE:To eliminate spraying of water, etc. and to recover the steel making slag in a slag pan by powdering and dropping the same without producing any powder dust by receiving the molten steel making slag in the slag pan, and solidifying the slag by cooling the same down to prescribed temp. then turning over the molten pan and placing the same on a slag recovering vessel in a hermetic chamber. CONSTITUTION:A slag pan 1 which receives the slag discharged from a steel making furnace is carried with a transporting carriage 2 to a slag treating shop or the like where the slag is solidified by cooling down to 140-400 deg.C. A wire rope 6 is set to the suspension handles 4 of the pan 1 in such a state and the pan is hoisted with a crane 3, whereby the pan is turned over. The hoisted pan 1 is placed on the stage 7 in a hermetic chamber 6 after a cover 8 is opened; thereafter, the cover 8 is closed. The pan 1 turned over and placed on said stage is air-cooled down to temp. below 140 deg.C, whereby the steel making slag is powdered and dropped into a slag recoverying vessel 9 placed below the pan 1. Thereafter the powdered and lumped steel making slag contained in the vessel 9 is fed to post stages for removal of base metal, etc.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for recovering steelmaking slag by water sprinkling, etc., without generating dust.

Conventionally, the method for treating steelmaking slag, which is produced as a by-product from steelmaking furnaces such as electric furnaces and converters, is to collect the slag from the furnace into a slag pan, and after solidification, the slag is extracted at a slag processing plant, sprinkled with water, and heavy objects are removed. It is common to crush the metal by barging it, recover the metal, and then use it in landfills as civil engineering materials.

However, with this type of disposal method, when first removing the slag from the pot, the slag pot is overturned, lifted, or hit against another object, and the vibrations force the slag to fall, resulting in an electric shock. .

In addition, steelmaking slag has the property of spontaneously collapsing when cooled to room temperature, which poses the problem that a large amount of dust is generated during processing, transportation, and storage, making the working environment sensitive.

Under these circumstances, the inventors conducted various studies on the pulverization and disintegration of steelmaking slag. Table 1 shows an example of the chemical analysis results of electric furnace slag in the reduction period.

Table 1 As is clear from Table 1, steelmaking slag has a basicity (cao
The amount of Zs o, ) is high and contains (most of a is Ca,
5104 (dicaleium smouth 1 cat). This CI, Sin, has several types of crystal modifications. In other words, when α1-C~5in4 remains at room temperature with an increase of 2 while it cools down to room temperature.

■β-C~810. When converting to

■T-CI, 510. When converting to

■β-C Town 510. Convert to γ-C town sio.

It may be converted to.

With such crystal transformation, the volume change is small in the cases (1) and (2) above. However, in the case of ■ and ■ above, r −C ~ SiO4
Since it has a relatively low density, a volume change occurs and a powdering collapse phenomenon occurs.

Further, the inventors conducted various experiments regarding the temperature at which the phenomenon of powder disintegration occurs and found that powderization occurs when the product is cooled to a temperature below 140°C.

This invention was made based on such knowledge, and after collecting steelmaking slag in a slag pot and cooling it to a temperature of 140 to 400°C, the steelmaking slag in a sealed chamber is pulverized and dropped from the slag pot. It is characterized in that it is processed by

That is, this invention cools and solidifies steelmaking slag in a slag pot, places it upside down at a temperature that does not cause pulverization, cools it to a temperature below that at which pulverization occurs, and causes it to fall down into powder due to the pulverization collapse phenomenon. It is something.

The present invention will be explained below based on the drawings. FIG. 1 is a diagram showing an embodiment of this invention. (1) is a slag pot;
St2) is a slag pot transport truck. The slag pot (1) that has received the slag discharged from the steelmaking furnace is transported by a transport truck (2) K, and is cooled and solidified at a temperature of 140 to 400 m at a slag processing plant or the like. The reason why the cooling solidification temperature is set to 140 to 400°C is that if the temperature is lower than 140°C, the slag will be powdered for the above-mentioned reason. In addition, the reason why the upper limit is set at 400°C is that it takes a long time to cool down during the next process of the present invention, which is overturning, so the upper limit was set at 400°C. ) Lifting sand and falling down (2), (Q, (2) beam V- in figure 0)
This shows the state of overturning due to the transport trolley (2).
), hang the slag pot (1) and hang it up by hooking the wire (5) to the hanging handle (4) for overturning provided at the bottom of the slag pot (1).

The lifted slag pot is placed in an airtight container. 0 In the figure, 3 in parentheses indicates the state in which it is placed? (6) A closed room military,
(7) is a mounting table. Sealed i! The device is placed in the container to prevent the generation of dust, and after opening the cover (8) and placing the container, the cover (8) is closed. aO is a hanging metal fitting. The slag pot placed upside down is air cooled to a temperature below 140°C. Steelmaking slag cooled to a temperature below 140°C is
A phenomenon of powdering and collapsing occurs, and the slag falls into powder into a slag collection container (9) placed below the overturning slag pot. The powdered steelmaking slag stored in the collection container (9) is taken out and sent to subsequent processes such as metal removal.

Example " Stainless steel was melted in an electric furnace with a capacity of 50T.

Approximately 2 T of the generated pufferfish during the reduction period was collected in a slag pot.

The slag pots that received the slag were left in the slag processing plant using a transport trolley, cooled to a temperature of 350°C, then hung by a crane for a few seconds, and then tipped over and placed on a mounting table in a closed room and covered. was closed and air cooled for 15 hours. The cooled steelmaking slag is powdered and falls into a collection container, the slag pot is lifted up and returned to its normal position on the transport trolley, and the steelmaking slag in the collection container is pulled out and the bare metal is removed to obtain steelmaking slag that does not contain water. It was done. The grain size of the obtained steelmaking slag is shown in Table 1, and the components are shown in Table 2.

Table 1 < 4 Table 2 (-K) This invention's collection method allows the slag to fall naturally inside a sealed container, so there is no generation of dust.Also, the slag falls out of the pot just by leaving it, so it is different from the conventional method. There is no need for manpower to extract the data from the AM4.

Furthermore, the obtained group ll11 nufugu does not require watering, etc.
It has many advantages, such as being dry and free of moisture, and can be reused as a slag material during steel manufacturing.

[Brief explanation of drawings]

FIG. 1 is a diagram showing an embodiment of this invention. In the figure, 1... slag pot, 2... transportation trolley, 3... crane, 4... hanging handle for overturning, 5... wire,
6... Sealed chamber, 7... Mounting table, 8... Cover, 9
...Slag collection container, 10...Hanging fittings. Applicant Sumitomo Metal Industries Co., Ltd. Agent 1) Yoshihisa:・1 layer□・
-1'

Claims (1)

[Claims] After receiving the molten steel slag in a slag pot and solidifying it by cooling it to a temperature of 140°C to 400°C, the slag pot is turned over,
A method for collecting steelmaking slag, which comprises placing the steelmaking slag in the slag pot on a puffer recovery container that has been placed in advance in a closed chamber, and then powdering and dropping the steelmaking slag in the slag pot.