JPS6121939A - Use of steel slag - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] Since the present invention has the ability to expand and disintegrate after cooling, it is used for roadbed materials etc. after aging treatment, but currently most of it is disposed of in landfills. This relates to the effective use of steelmaking slag.

Although there are various types of steelmaking slag, the present invention focuses on converter slag and electric furnace slag (oxidation stage).

Generally, steelmaking slag is 2CaO1S! 02, F-CaO,
F'MgO,2CaO-FeJ3.4CaC1・^fa
O1?・Fe1a03, Faa03, Fe, o, ,F
Since it contains eO, etc., it has no latent hydraulic properties, and when blast furnace slag is slowly cooled, it becomes melilite (2CaO・Aja
(intermediate component of 13-5i02~2CaO・Mg0・2CiO>) and CaS, and when rapidly cooled, it becomes mainly glass and has latent hydraulic properties, and is used as a blast furnace cement admixture.

Currently, these steelmaking slags are placed in a simmering pot and heated for about 20 minutes.
Although it is discharged after 12 hours, when the temperature reaches about 200 to 300°C, it expands and collapses when 2CaO-SjO transitions from β to γ, and because it contains F-Can and F・M2O, it expands and collapses. As mentioned above, most of the waste is disposed of in landfills.

The present invention solves the above-mentioned drawbacks and relates to a method of effectively utilizing the water slag so that a'~β-2C80/5iOa is mainly composed of glass or a'~β-2C80/5iOa is mainly composed of glass. After drying in
:0.3, CaC7!2, etc. was added in a small amount, and water was added and kneaded to obtain hydraulic properties.

It has also been found that the greater the powderiness, the more rapidly it hardens.

The gist is a method of utilizing steelmaking slag, which is characterized by turning molten steelmaking slag into slag, drying it, and then mixing and pulverizing it with Boltland cement clinker and/or gypsum to obtain a raw material for producing mixed cement.

Hereinafter, experiments conducted to confirm the effects of the present invention and the effects will be shown.

Table 1 shows the chemical analysis values and properties of the samples used in the experiment.

Table 1 Main minerals contained 1 Decay rate 1 Notes 1 (by X-ray diffraction) 1 (χ) Rice I + Glass 10
．． Shown for comparison with 21 I*1 steelmaking slag.

Since 2 ASTM method (all in 20, 200'e,
(Retained for 3 hours) The size of the sample was 10~25#l#I, and less than 10 parts were considered to be disintegrated.

Next, Table 2 shows the melting temperature (in a Seegel cone according to the JIS method) of each sample.

After drying the sample in a constant temperature dryer (maintained at 105-110°C) for more than 24 hours, it was placed in an electro-fused magnesia crucible.
It is then melted again in a siliconite electric furnace (maintained at 1580°C), taken out of the furnace, and cooled in water to create granulated water.
After drying, the mixture was pulverized to about 200 meshes or less, 3% by weight of lime was added and mixed, water was added, and after kneading, the mixture was placed in a plastic bag and sealed, and the hardening status was examined as shown in Table 3.

Table 2 ■ Sample 1 Steelmaking slag (^) 1 Steelmaking slag (B)
1 melting temperature 'el 1520 1 1505
Table 3 7 - □ --- Left 0 Same 1 Blast furnace slag 1 Water slag 1 (Commercial product) 1 In particular, water slag from steelmaking slag (A, B) is mixed within about 10 minutes after adding water and mixing. harden.

Note that 0 indicates that it is very hard even when pressed by hand, O indicates that it is the same hardness, Δ indicates that it is slightly hard, and X indicates that it is not hardened.

The chemical analysis values, minerals formed, etc. of several examples were investigated and are shown in Table 4.

Table 4 1 Prototype 1 1 Analysis value 3x*82 11 items 1
Sample l lN0 l l Sin, I AF, % l
T・Fa I CaO Pi 90 "... 11 11-W-1 Main containing minerals ('INa by X-ray diffraction,
OI KxOl lO
, 2, 10, 01 glass-based a' and β-2Ca01
−111 engineering−−−L−−−−−−−−−−−−111 ÷
Furthermore, the main content of slag that has turned into water slag is glass a.
' and β-2C@0.5101, autoclaved (ASTM) 1. , the decay rate is approximately 0.
It was less than 5%.

Next, 5.10.20% by weight of the ordinary Portland cement clinker was replaced with the above-mentioned slag, and then 3% by weight of gypsum was added to 100% of this mixture. 5700
Grind to CIIlo/9 etc. and JIS method NiJ-1:
A rutal test, a paste test, etc. were conducted. Some examples are shown in Table 5.

Table 5 (JIS/Mortar) I Sample and 1 Mixing ratio of clinker, etc. (weight X) Gypsum l Ordinary cement M days 17 days 128 days 1 (3) l
I 55 13151sso l(3) l
l 36 1205'
1375 1(3) I l
53 12951sso l+3) l
l 39 122513951(3) l
l 34 1195136511 10
0 l 57 134715721 notes
Blaine value: 3100-3200cm 7g (paste) As described above, according to the method of the present invention, molten slag is rapidly cooled in water to form a slag, and after drying, it is mixed with cement clinker and ground or When mixed with individually crushed products, it has hydraulic properties and the product has high strength, so it can be used as a major replacement material for reactor water slag.

In addition, in the paste test, the effect starts at about 10 min, so it can be used as a binder for briquettes and pellets.

Claims (1)

[Claims] 1. A method for utilizing steelmaking slag, which comprises turning molten steelmaking slag into slag, drying it, and then mixing and pulverizing it with Portland cement clinker and/or gypsum to obtain a raw material for producing mixed cement.