JPS61497A - Utilization of high basicity steel making slug - Google Patents

Abstract

PURPOSE:To obtain a sludge hardener and a soil conditioning material from slug, by adding 5-30wt% of silicate to high basicity steel making sludge held under a molten state to generate melting reaction while adding gypsum or lime to the reaction mixture before crushing. CONSTITUTION:5-30wt% of one or more of silicate selected from rock, mineral, coal ash, waste brick and waste casting sand is added to high basicity steel making slug held under a molten state to generate melting reaction and the resulting mixture is subjected to water granulation treatment before drying. Subsequently, 3wt% of gypsum or lime is added to the treated sludge to crush the same. When a small amount of an alkali stimultaing agent such as CaO is added to this crushed materil and water is further added thereto to perform kneading, said crushed material becomes hydraulic and, therefore, can be used as a sludge hardener. As additives, Al2O3 or SiO2 may be used alone but it is pref. to add an additive in which a proper amount of SiO2, Al2O3, Fe2O3 or the like are contained because melting temp. is lowered.

Description

[Detailed Description of the Invention] This explanation explains that dusting (expansion and collapse) occurs during the cooling process and scatters as dust during handling, worsening the working environment.
Most of the projects are related to the effective use of high basicity steelmaking slag, which is disposed of in landfills.

There are various types of steelmaking slag, but in the present invention, among these, high basicity steelmaking slag, which is used in the reducing stage of ordinary steel, electric furnace, converter, and continuous casting (hereinafter referred to as CC) 2 of special steel, is used.
Targets slag.

Currently, these slags are cooled in a slag pot for about 3 to 12 hours before being discharged, but when the temperature reaches about 200 to 300℃,
Since G a O, S 10* is the main component, when it transitions from β to γ, it causes dusting and scatters, which worsens the working environment. In addition, an alkali stimulant (e.g. Ga
ps C; a (OHJhNa*GOa s NaO
After adding a small amount of H-, cement, etc., it hardly hardens even if water is added and kneaded (it has a latent hydraulic level of 9), so there is no way to use it, and most of it is discarded in landfills.

The present invention relates to a method for solving the above-mentioned drawbacks and effectively utilizing the problems.
α~β-20aO, Sto, mainly composed of glass, or 1 part α~β-2CaO,Sin, is made into a water slag and crushed after drying to give an alkaline stimulant (e.g. CaO,0a( OH), cement, NaO
It has been found that when a small amount of H etc. is added and kneaded with water, it has hydraulic properties.

In addition, the chemical composition of the above-mentioned high basicity steelmaking slag is generally 81
0m20~29wt%, AItos 3~8wt%, Ga040~50wt%, T-Fe0.4~0.8wt%.The range is quite wide, and the melting point is high due to the high basicity, so the scale ratio is low. may also decrease.

In addition, silicate rocks/minerals, etc. are added to
CaO-810. 2CaO-810, ~2Ga from the main body
When mainly modified to O-M90.2Sj, the melting point and viscosity decrease, the water slag ratio improves, and the glass becomes mainly glass. It was discovered that when a small amount of sludge is added and kneaded with water, it has hydraulic properties, and the sludge solidification strength was also discovered by adding silicate rocks, minerals, etc.

As additives, A40 and S10. Tameni can be used alone, but it has the drawback of having a high melting temperature and making it difficult for reactions to occur.
By adding a substance containing an appropriate amount of $1α, AJ-0-, Fe, On, etc., the melting temperature is reduced and the reaction occurs sufficiently.

The method of adding additives is t li[Fn′″″mo*? 9'I,
xo“02゛′4.

2. After tapping into the smelting furnace, put it into the smelting furnace.

3 Pour into contact with the slag flow discharged from the smelting furnace. (Simultaneous input) 4. Inject at a distance from the falling position of the slag flow from the smelting furnace to the slag ladle.

5. Use as a substitute for slag in a slag pot.

6 Pour the slag into the slag pan so that it forms a sandwich with the slag.

Z 3. A, 5, 6. Insert the lance pipe, and add bubbling gas (0, N1
, or Air)t=blow and diffuse.

8. Inject molten slag and additives, including partially hardened slag, into a slag heating furnace (1! air furnace method, alpha gas fuel furnace method 2).

There are methods etc.

Experiments conducted to confirm the effects of the method of the present invention and their effects will be shown below.

The disintegration rate (by weight) in Table 1, which shows chemical analysis values and properties of samples using experiments, is 100 only for reducing stage slag, electric furnace slag, and converter slag.

First, Table 2 shows several examples of the blending ratio (weight calculation) of each sample.

Table 2 Next, Table 3 shows the melting temperature (Seegelkornf according to JIS method) of the formulation of each sample.

Table 3 After drying the above samples in a constant temperature dryer (kept at 105 to 110°C for at least 24 hours), the samples were placed in an electro-fused magnesia pot.
Silicon Nyl) [air furnace (maintained at 1580°C, remelted at λ, taken out of the furnace, cooled in water, made granulated water,
After drying, crush it to less than about 200 mesh and add 3 layers of lime.
% and mixed, water was added, and after mixing, the mixture was placed in a plastic bag and sealed, and the curing status was examined, and the results are shown in Table 4.

The chemical analysis values, minerals formed, etc. of several examples were investigated and shown in Table 5.

Table 4 *The hardening status of blast furnace water (commercially available) is Δ after 1 day, Q after 3 days,
After 7 days ◎〇 In addition, ◎ indicates that it is very hard when pressed by hand, 0 indicates that it is the same hardness, △ indicates that it is slightly hard, and X indicates that it has not hardened. In addition, the prototype slag that has turned into water slag is It set almost immediately and began to harden after about 10 to 20 minutes.Table 5 Also, in the same way as mentioned above, for sludge with a moisture content of 305% (mainly kaolinite, montmorillonite, α-quartz), Each trial sample was crushed (less than 200 meth), mixed in a mortar kneading pot, and packed into a high-quality test mold in three layers with a rammer (according to the JIS method), after being cured in a humid air for one month, the compressive strength was examined. The results are shown in Table 6.

Table 6 Note that the unit of compressive strength is 9/ci.

*t: Reduction period slag (former mineral) *2. Blast furnace water slag (commercial product) As stated above, according to the method of the present invention, silicate rock and When pulverizing minerals, etc., the water slag ratio is high, the minerals produced change to mainly glass, and the hardening of sludge etc. is stronger than that of unadded water slag, and when blast furnace water slag powder is used, Similarly, it is possible to harden sludge, etc., and the strength is rather strong.

Claims (1)

[Claims] 1. Add 5 to 30 weight amounts of one or more of silicate rocks, minerals, coal ash, waste bricks, and foundry waste sand to high basicity steelmaking slag in a molten state to cause a melting reaction. A method for using high basicity steel slag, which is treated with water slag, dried, then crushed after adding 3% by weight of gypsum or lime, and used as a sludge hardening agent or soil conditioner.