JPH11292659A - Surface treatment method for steelmaking slag - Google Patents

Abstract

(57) [Summary] [PROBLEMS] To increase the added value by improving the glossiness by performing surface treatment on steelmaking slag and to expand its use as a substitute for ornamental pebbles and decorative stones in gardens, for gardening, and the like. SOLUTION: A steelmaking slag having a residual expansion rate of 3.5% or less is put into a rotating drum and stirred for a predetermined time to rub the slags with each other, or by irradiating ultrasonic waves for a predetermined time to reduce the glossiness of the slag. improves.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a method for treating steelmaking slag generated in the refining process of the steel industry.

[0002]

2. Description of the Related Art Steelmaking slag generated during the refining process of a converter or the like is piled up in a mountain for a certain period of time until the expansion (CaO undergoes a hydration reaction and causes volume expansion) that occurs after solidification is called aging. It is common practice to leave it alone. However, this has a problem that much yard space is required. For this reason, for example, Japanese Patent Application Laid-Open No. Hei 5-17182 proposes a method of shortening the aging period by irradiating ultrasonic waves to slag immersed in water. However, in any case, the slag at the time of shipment has a gray color and can be used only for limited use such as crushed stone as a roadbed material or earth and sand as a landfill.

[0003]

SUMMARY OF THE INVENTION The present invention provides a steelmaking slag which has been subjected to a surface treatment to enhance its gloss and enhance its added value. For example, it is used as a substitute for ornamental pebbles and decorative stones in gardens, and for gardening. It is an object of the present invention to increase the size.

[0004]

The present inventors have conducted various experiments and studies to expand the use of steelmaking slag. As a result, Ca (OH) ₂ and Ca
It was found that a grayish particulate reactant, such as CO _3, adhered, and when this was peeled off, the steelmaking slag itself appeared black and became glossy. Further, it was found that when the steelmaking slag from which the reaction product of the fine particles was peeled was coated with a silica-based substance such as silica sol, silica fume, volcanic ash, and limestone, glossiness was further increased.

[0005] The present invention has been made based on the above-mentioned findings. Means 1 is to stir a steelmaking slag having a residual expansion rate of 3.5% or less and to rub the steelmaking slag with each other to rub the surface thereof. A surface treatment method for steelmaking slag characterized by improving the glossiness of the steelmaking slag. Means 2 is a method for producing a slag in which the steelmaking slag is stirred by a rotary drum mixer and the stirring time is equal to or longer than a time t [min] satisfying the above formula (1).

Means 3 comprises a steelmaking slag in which the steelmaking slag is stirred by a rotary drum mixer for a time t [min] or more which satisfies the above formula (2) and then water is poured into the rotary drum mixer to wash the steelmaking slag. This is a slag surface manufacturing method. Means 4 is to immerse steelmaking slag having a residual expansion rate of 3.5% or less in water and irradiate ultrasonic waves to the steelmaking slag for a time t [min] or more that satisfies the expression (3). This is a surface treatment method.

Means 5 comprises immersing steelmaking slag having a residual expansion rate of 3.5% or less in water and stirring the steelmaking slag with a rotary drum mixer for a time t [min] that satisfies the above formula (4) or more. This is a method for surface treatment of steelmaking slag in which slag is irradiated with ultrasonic waves. Further, the present invention is a surface treatment method for steelmaking slag in which a silica-based material such as silica sol, silica fume, volcanic ash, and limestone is coated on the surface of the steelmaking slag treated by the above means 1 to 5.

[0008]

DETAILED DESCRIPTION OF THE INVENTION The slag finished to some extent aging is mainly Ca (OH) ₂ and CaCO ₃ on the surface of the slag
Such a grayish fine particle reactant is attached.
Experiments have shown that when this is stirred vigorously or irradiated with ultrasonic waves, the grayish fine particle-like reactant is removed and the slag surface becomes black and glossy. This is because the surface of the slag is made black and glossy by taking the reaction fine particles by friction between the slags due to the stirring and the cleaning effect of the ultrasonic wave.

In the present invention, the target steelmaking slag has a residual expansion rate of 3.5% or less, and does not cause volume expansion of the steelmaking slag even after the above-mentioned treatment. If it is more than 0.5%, volume expansion occurs and collapses, making it unusable as a product. The residual expansion rate is a value determined by an expansion test method described in JIS 5015 appendix to road steel slag for measuring the residual expansion of slag.

Next, conditions for obtaining the effect will be described. In the case of stirring with a rotary drum mixer, a steelmaking slag having a good glossiness with a glossiness of 3 or more as shown by the solid line in FIG. It becomes something. Note that the glossiness is obtained by equally dividing the L value representing the chromaticity of black and white measured by the CANON colorimeter CR321 into five levels, and setting the levels 5, 0 to black and white, respectively.

The reason why the gloss is produced by the above-mentioned method is mainly that Ca (OH) adheres to the surface of steelmaking slag due to friction between the slag by stirring the slag in a rotary drum mixer.
_{This is because the} gray-grained particulate reactants such as ₂ and CaCO ₃ are peeled off by a physical impact, and a black color of the steelmaking slag itself appears and becomes glossy. Further, as shown by the dashed line in FIG. 1, after stirring for a time t [min] satisfying t * r = 50 or more and then immersing in water, a product having a glossiness of 3 or more can be obtained in a relatively short time. Was. It is considered that this is because, in addition to the abrasion caused by stirring, fine particles that are difficult to peel off by abrasion alone are dissolved and removed with water.

Further, as shown by the symbol △ in FIG. 1, when the slag that has undergone these treatments is coated by diluting silica sol in water, a Si film is formed on the surface of the slag, so that the glossiness is reduced. Improved. In addition, the same effect can be obtained by coating a substance such as silica fume, volcanic ash, or limestone, which is a substance that causes a pozzolanic reaction with slag.

Next, when the ultrasonic wave is irradiated, as shown in FIG. 2, there is a tendency that the longer the irradiation time, the better the glossiness, and the time t [min] at which t * W / V = 600 can be satisfied.
To obtain a glossiness of 3. This is considered to be because the fine particles are separated from the slag surface by the cavitation action of the ultrasonic waves. Furthermore, when the slag after these treatments is coated by diluting silica sol in water, a Si film is formed on the surface of the slag.
As shown by the dotted line, an increase in gloss was confirmed.

Further, when ultrasonic waves are irradiated while stirring with a rotary drum mixer, as shown in FIG.
When t * min or more satisfies r * W / V = 50,000, gloss level 3 or more was obtained. In addition, when the slag after these treatments is coated by diluting silica sol in water, a Si film is formed on the surface of the slag,
The improvement in glossiness was confirmed. As described above, the glossiness 3 is a value obtained by classifying a value measured by a commercially available measuring instrument according to a level, and is a value that can be visually judged to be not gray but black.

[0015]

An embodiment of the present invention will be described with reference to FIGS. 4 (a) and 4 (b). FIG. 4A shows a rotary drum mixer and FIG. 4B shows a coating tank, which is an apparatus configuration for improving the glossiness of converter slag by providing an ultrasonic generator in the rotary drum mixer. In the figure, 1 is an ultrasonic generator for irradiating an ultrasonic wave of 26 kHz, 2 is a rotary drum mixer provided so as to be able to control the number of rotations, 3 is a water supply nozzle for supplying water 4 into the rotary drum mixer 2, 5 is Converter slag 6 having a particle size shown in Table 1 is a coating tank for containing a coating agent 7 as a silica-based sol and covering the surface of the converter slag 5.

[0016]

[Table 1]

Tables 2 to 4 show the results of treating converter slag using the apparatus shown in FIG. Table 2 shows that the converter slag 5 having a residual expansion coefficient of 0.8 to 4 was supplied to the rotary drum mixer 2.
After the water is supplied as it is or until the converter slag 5 sinks from the water supply nozzle, the rotary drum mixer 2 is rotated at a predetermined rotation speed for a predetermined time and discharged. This is a result of immersing in a coating agent 7 in a coating tank 6 and drying it, or measuring the glossiness of a converter slag 5 discharged from the rotary drum mixer 2.

[0018]

[Table 2]

As can be seen from Examples 1 to 7, which satisfy the conditions of the present invention, converter slag having a good gloss was obtained. Above all, as shown in Example 5, it is preferable to supply water 4 into the rotary drum mixer 2 to stir the converter slag 5, and then immerse the converter slag 5 in a silica sol agent to obtain high glossiness. Further, in Comparative Example 1, since the residual expansion rate of the converter slag 5 was out of the range of the present invention, it was confirmed that the slag 5 collapsed one month after the completion of the gloss treatment. In Comparative Example 2, the agitation time in the rotary drum mixer 2, that is, the product of the agitation time and the number of rotations was out of the range of the present invention, and thus the glossiness was insufficient.

[0020]

[Table 3]

Table 3 shows that a converter slag 5 having a residual expansion rate of 1 to 4 was charged into a container by a predetermined weight, and water was supplied from a water supply nozzle until the converter slag 5 sank. The generator 1 irradiates it with a predetermined electric power and a predetermined time and discharges it. Then, it is immersed in the coating agent 7 in the coating tank 6 and dried, or the glossiness of the converter slag 5 discharged from the container is measured. It shows the results obtained. As can be seen, in Examples 8 to 11 satisfying the conditions of the present invention, converter slag having good gloss could be obtained. Above all, when compared with Example 9 which is considered to be almost the same condition as shown in Example 10, a high gloss can be obtained by immersing the converter slag 5 in the silica sol after stirring the ultrasonic wave in the converter slag 5 with the ultrasonic generator 1. Is preferred. Further, in Comparative Example 3, since the residual expansion rate of the converter slag 5 was out of the range of the present invention, it was confirmed that one month after the completion of the gloss treatment, the collapse occurred. In Comparative Examples 4 to 6, the gloss time was insufficient because the irradiation time and irradiation power in the ultrasonic generator 1, that is, the value obtained by dividing the product of the irradiation time and the power by the slag amount was out of the range of the present invention. .

[0022]

[Table 4]

Table 4 shows that the converter slag 5 having a residual expansion coefficient of 0.8 to 4 was charged into the rotary drum mixer 2 by a predetermined weight.
As it is or after water is supplied from a water supply nozzle until the converter slag 5 sinks, the rotary drum mixer 2
Is discharged at a predetermined number of rotations and for a predetermined time, and is further irradiated with a predetermined power and a predetermined time by the ultrasonic generator 1, and is immersed in the coating agent 7 in the coating tank 6 and dried. Or, it shows the result of measuring the glossiness of the converter slag 5 discharged from the container. As can be seen, in Examples 12 to 15 satisfying the conditions of the present invention, converter slag having good gloss could be obtained. Among them,
As shown in Example 14, water 4
Is supplied, the converter slag 5 is stirred, and then immersed in a silica sol.

In Comparative Example 7, since the residual expansion rate of the converter slag 5 was out of the range of the present invention, it was confirmed that one month after the completion of the gloss treatment, the slag 5 collapsed. Comparative Examples 8 to 1
0 indicates that the gloss time is insufficient because the irradiation time and irradiation power in the ultrasonic generator 1, that is, the product of the square of the irradiation time, the number of revolutions, and the power divided by the slag amount is out of the range of the present invention. did. Although the results of coating silica sols are shown as Examples and Comparative Examples in Tables 2 to 4, the same applies to coatings of slag with substances such as silica fume, volcanic ash, and limestone that cause a pozzolanic reaction, for example. The effect of is obtained.

[0025]

Industrial Applicability According to the present invention, it is possible to easily improve the glossiness of steelmaking slag. For example, it is possible to expand its use as a substitute for ornamental pebbles and decorative stones in gardens, for gardening, and the like. It has become possible.

[Brief description of the drawings]

FIG. 1 is a diagram showing the relationship between the product of the rotation time and the number of rotations of a rotary drum mixer and glossiness.

FIG. 2 is a diagram illustrating a relationship between ultrasonic irradiation and glossiness.

FIG. 3 is a diagram illustrating a relationship between a rotating drum, ultrasonic processing, and glossiness.

FIG. 4 illustrates an embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Ultrasonic generator 2 Rotary drum mixer 3 Water supply nozzle 4 Water 5 Steelmaking slag 6 Coating tank 7 Coating liquid

Claims (6)

[Claims] 1. A surface treatment method for steelmaking slag, wherein a steelmaking slag having a residual expansion rate of 3.5% or less is agitated, and the glossiness of the surface is improved by friction between the steelmaking slags. . 2. A method for producing a slag, wherein the stirring of the steelmaking slag is performed by a rotary drum mixer, and the stirring time is at least t [min] satisfying the following formula (1). t * r = 75 (1) where r is the rotation speed of the rotary drum mixer [rpm] 3. The following (2) in the rotary drum mixer:
The method for producing a surface of a steelmaking slag according to claim 1, wherein after the steelmaking slag is stirred for a time t [min] or more that satisfies the formula, water is poured into the rotary drum mixer to wash the steelmaking slag. t * r = 50 (2) where r is the rotation speed of the rotary drum mixer [rpm] 4. A steelmaking slag having a residual expansion rate of 3.5% or less is immersed in water, and a time t [min] satisfying the following equation (3) is satisfied.
As described above, a method for surface treatment of steelmaking slag, which comprises irradiating the steelmaking slag with ultrasonic waves. t * W / V = 600 (3) where, W: power consumption [W], V: slag weight [kg] 5. A steelmaking slag having a residual expansion rate of not more than 3.5% is immersed in water, and the steelmaking slag is stirred by a rotary drum mixer for a time t [min] or more satisfying the following formula (4) for at least t: min. A surface treatment method for steelmaking slag, which comprises irradiating slag with ultrasonic waves. t * r * W / V = 50000 (4) where, r: number of revolutions of the rotary drum mixer [rpm] W: power consumption [W], V: slag weight [kg] 6. A surface treatment of a steelmaking slag characterized by coating a silica-based material such as silica sol, silica fume, volcanic ash, limestone or the like on the surface of the steelmaking slag treated according to any one of claims 1 to 5. Method.