JPH05279095A - Method of utilizing converter slug and preliminarily treated - Google Patents

Abstract

PURPOSE:To efficiently use a slug which is one of unused resources and also to increase efficiency of a concrete placing work by using a converter slug or a preliminarily treated slug of molten slug as a concrete filler and using sand, a water reducing agent and a thickener at that time. CONSTITUTION:The converter slug which is pulverized by air at <=5mm in the diameter and is formed at a spherical shape or the preliminarily treated slug of molten slug is used as a concrete filler and at that time the sand and the slug are compounded at a volume ratio of from 9:1 to 7:3 and besides the water reducing agent and the thickener are used together. By using the spherical slug, even though the ratio of water to cement in the concrete is small, the strength can be increased. Also the flowability is excellent, so that the unhardened concrete can sufficiently be filled in a mold frame without particlularily using a vibrator, thus the initial strength can be increased.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of utilizing converter slag and hot metal pretreatment slag, and more particularly to a method of effectively utilizing slag generated in steelmaking and hot metal pretreatment.

[0002]

2. Description of the Related Art A part of the above-mentioned slag is used for roadbed materials, etc., but most of it is of little use value and is disposed of as landfill as industrial waste.

[0003]

The landfill disposal of converter slag and hot metal pretreatment slag has many problems in terms of securing landfill site, landfill cost, and effective use of resources.

The present inventors have examined the use of converter slag and hot metal pretreatment slag as a part of concrete. Among conventional aggregates for concrete, coarse aggregate was mainly rounded river gravel, and fine aggregate was mainly similar river sand.The raw material ratio was good, and the flowability was fairly good. Since the collection of gravel and river sand is prohibited, crushed stone and crushed sand are mainly used, and the actual volume ratio and fluidity are poor.

Therefore, various efforts have been made such as increasing the water-cement ratio and increasing the cement content.
That is, concrete is cast by adding coarse aggregate, fine aggregate and water to cement (in some cases, adding water reducing agent, fly ash, granulated blast furnace slag powder, etc.), kneading with concrete mixer, etc. It is poured into and filled with a vibrator or the like.

However, if the mixing ratio of water in the concrete is increased in order to improve the filling property, in other words, the fluidity, the compressive strength of the concrete is lowered. Further, if the mixing ratio of water is reduced, the compressive strength of concrete rises to some extent, but the fluidity of concrete decreases, so that the filling becomes insufficient and the compressive strength decreases.

[0007] In recent years, while work related to civil engineering and construction has been increasing, there is a general tendency for these works to be shunned, and there is a shortage of workers. There is a problem that it causes trouble.

The present inventors effectively utilize the slag, which is an unused resource, by utilizing the converter slag and the hot metal pretreatment slag which have not been used so far, as the aggregate for concrete, and moreover It is to improve the efficiency of installation work.

[0009]

Means for Solving the Problems The present invention uses a converter slag that has been pulverized to a diameter of 5 mm or less and spheroidized, and a hot metal pretreatment slag as aggregate for concrete, in which case sand: converter slag or hot metal This is a method of using converter slag and hot metal pretreatment slag, which are prepared by mixing the volume ratio of the pretreatment slag in the ratio of 9: 1 to 7: 3, and further using the water reducing agent and the thickener together.

In addition, the converter slag is the slag generated from the converter during the steelmaking of the converter, and the hot metal pretreatment slag is the desiliconization and dephosphorization of the hot metal prior to the refining in the converter steelmaking method. ,
It is a slag that is generated during desulfurization treatment. In the present invention, two or more kinds of these slags may be mixed and used.

The spheroidized converter slag and hot metal pretreatment slag (hereinafter referred to as spheroidized slag) mean that the converter or pretreated molten slag is received in a ladle and crushed while tilting the ladle. It is a sphere with a diameter of 5 mm or less. Although those having a diameter of 2.5 mm or less are almost spherical, those having a diameter of 2.5 to 5.0 mm are formed as slightly distorted spherical shapes (subspherical shapes), and any of them can be used as the spherical slag. Further, the mixing ratio of the spheroidized slag is such that sand: spheroidized slag (volume ratio) is about 9: 1 to 7: 3.

[0012]

The present invention is constituted as described above, and by using the spheroidized slag, the strength can be increased even if the water-cement ratio of the concrete is reduced, and the fluidity is good, so a dare to use a vibrator. Even if it is not used, the ready-mixed concrete can be sufficiently filled into the form, and therefore the initial strength can be increased.

[0013]

EXAMPLES The present invention will be specifically described below with reference to examples. The converter slag or the hot metal pretreatment slag shown in Table 1 and Table 2 is received in separate ladles, discharged and cooled, and each slag after crushing and deironing (magnetic separation treatment) is put into an Elu-type electric furnace (300K
Each of them was melted at a temperature of about 1650 ℃ with VA and a dissolution capacity of 500 kg) and placed in a ladle, which was crushed while tilting the ladle to produce spherical slag with a diameter of 5 mm or less.

Table 1 shows the composition of the converter slag and the hot metal pretreatment slag, and Table 2 shows the physical properties.
In Tables 1 and 2, the discharged cooling material is the molten slag discharged into the slag yard and is gradually cooled, and the crushed material is
The molten slag is air-crushed, and the reforming converter slag or the modified hot metal pretreatment slag is a product obtained by adding a modifying material such as crushed stone ballas.

That is, there are converter slags and hot metal pretreatment slags having swelling / disintegrating properties, and such slags are known in the art (Japanese Patent Publication No. 55-51405 and 55-326).
No. 59 gazette), and the swelling / disintegrating property is prevented by adding a modifier such as crushed stone ballas described above.

[0016]

[Table 1]

[0017]

[Table 2]

Table 3 shows the properties of the sand and gravel compounded in the spheroidized slag of the present invention, Table 4 shows the particle size distribution of the unsieved prototype aggregate of the spheroidized slag, and Table 5 shows the particle size of 0.6 mm or less. It is a particle size distribution of the sieving prototype aggregate, and Table 6 shows a test result when spheroidized slag is mixed with concrete.

[0019]

[Table 3]

[0020]

[Table 4]

[0021]

[Table 5]

[0022]

[Table 6] As is clear from the results shown in Table 6, conventional sand as an aggregate,
Concrete such as crushed stone (silica powder) has low initial strength and poor filling. On the other hand, in the present invention, the initial strength is relatively high and the filling property is excellent. In particular, it is recognized that the modified converter slag in Table 1 or the modified hot metal pretreatment slag in combination with the water reducing agent and the thickener have excellent initial strength and filling properties.

[0023]

INDUSTRIAL APPLICABILITY As described above, according to the present invention, converter slag or hot metal pretreatment slag, which has little utility value and is mostly landfilled as industrial waste, is spheroidized and used as an aggregate for concrete. As a result, unused resources can be utilized, and it is not necessary to use a vibrator at the time of pouring concrete, so that the efficiency of pouring work can be improved and the initial strength of concrete can be increased.

Claims (1)

[Claims] 1. A converter slag or a hot metal pretreatment slag that is pulverized into a spherical shape having a diameter of 5 mm or less is used as an aggregate for concrete, and the volume ratio of sand: slag at that time is 9: 1 to 7: 3. A method for utilizing converter slag and hot metal pretreatment slag, characterized in that the water reducing agent and the thickening agent are used in combination.