JPS5850302B2 - How to generate slag that does not disintegrate - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing non-collapsing slag by changing the mineralogical composition of collapsible converter slag.

Generally, converter slag mainly contains gamma and beta-2CaO-8iO2 and contains gehlenite, akermanite, free lime, magnetite, wustite, and the like.

Because slag disintegrates and expands, there are few ways to use it, and currently it is used for landfilling, etc., but for pollution prevention purposes,
It is becoming difficult to secure a landfill site, and disposal is becoming a problem.

When we investigate the cause of the collapse of these slags, we find that Ca(0H)2
, free lime (hereinafter referred to as F-CaO), CaO3 and γ-2CaO-8iO□, so Ca
(OH) 2, CaCO3 is caused by F-CaO, which absorbs moisture in the air and sprinkled during cooling of the slag, and
a(OH)2 further absorbs CO2 from the air and produces CaC
You can see that it has changed to O5.

Therefore, in this application, F-CaO1 and γ-2CaO-8iO2, which are the causes of these collapses, are replaced by stable mineral compositions, namely 3CaO-Ag2O3, 2CaO-Ag2O3・5iO
(Gehlenite), 2CaO-Mg0.2SiO2 (Akermanite), etc., thereby providing a method for producing slag that does not disintegrate even without rapid cooling.

In this application, one or more of red mud, slate, shale, sand, and various types of calamari are added to converter slag in a molten state, and the final composition is Ag2O34.1 to 11.9% by weight, St021.
1-34.8% by weight, CaO21.4-38.4% by weight
This relates to a method of producing slag that does not disintegrate by doing so.

The reason for adding various additives as mentioned above while the slag is in a molten state is to effectively utilize the sensible heat of the molten slag. The method is such that an amount of external heat sufficient to cause the above mixture to undergo a melting reaction is supplied from the outside by the necessary means.

Also, adding the above additives to converter slag changes the mineral composition to 3CaO・Ag2O3, 2CaO-Ag2O.
The purpose is to change it to 3゜2CaO-Mg0.2SiO2, and for this purpose, as revealed by its mineral composition, Ag2O3 alone is sufficient as an additive, but it is said that Ag2O3 alone has a high melting temperature and is difficult to cause a reaction. Because of this drawback, an appropriate amount of S s 02 t A 1 203 was added at the same time to reduce the melting temperature and ensure that the reaction occurred sufficiently.

The above additives, red mud, are Fe2O3, Ag2O3, Na2
Since it is rich in O, it has a low melting temperature (approximately 1220°C).

Slate and shale are found in relatively large quantities throughout Japan and can be obtained at relatively low prices.

Since it is rich in F e 203 etc., it is also a low melting material (approximately 1250° C.).

Table 1 below shows typical compositions of red mud and slate.

In addition, in the method of the present invention, in principle, the melting point of the molten reactant must be kept at a relatively low temperature in order to allow the melting reaction to proceed only by the sensible heat of the molten slag without supplying external heat. In addition to the sensible heat possessed by molten slag, if a method is adopted to supply the required heat source from the outside, a relatively large amount of red mud, slate, etc. can be added, and by adding external heat in this way, the slag that has been completely cooled can be The method of the present invention is also applicable to the following.

Next, tests for determining the composition of each mixture of the present application and their results will be shown.

First, Table 2 shows samples (% by weight) with various compositions.

Next, Table 3 shows the blending ratios (% by weight) of various composition samples.

Next, Table 4 shows melting temperatures (■) of various composition sample formulations.

Next, Table 5 shows the minerals produced in slag from various composition sample formulations.

Next, Table 7 shows the autoclave test results of slags from various composition sample formulations.

Note that the autoclave test refers to the JIS test method for concrete and aggregate (200℃, 20kg/i, heating for 3 hours)
This was carried out for slag particle sizes of 10 to 15 mrn, and the pulverization rate was calculated by considering slag particles of 10 mrn or less as pulverized products.

As a result of the above, when a low melting material containing an appropriate amount of Ag2O, 5102, etc., such as red mud or slate, is added to converter slag, 3CaO・Aeρ3゜2CaO
-Mg0.2SiO2,2CaO-Ag2O3.SiO
2 etc. are mainly produced, and 2CaO-8iO2 and F-CaO are eliminated.

If a larger amount is added, it becomes glass, and 2Ca0.8102
and F-CaO completely disappear and turn into slag that hardly disintegrates.

Its chemical composition is SiO□11~34.8°A in the converter slag.
g20s 4.1~11.9, CaO21,4~3
If the content is 8.4% by weight, disintegration can be prevented.

The temperature of the slag discharged from the converter is approximately 1500 to 1550℃ in the slag pot.Assuming that the temperature is 1500℃, the sensible heat is 450,000 Km/1 (1500X0.3=450cat).
/fj).

The heat of dissolution of clay (assuming 5% adhered water and 10% crystallized water) is as follows.

Heat of vaporization of water 88,000 Kcat/l (0.15xss
s-87,・m/,! iJ) Heat required for melting viscosity 31.9 months 0Vt ((1-0,5) (1250X0
．． 3)-318, fine Vg]1500-12so=25
o25oXo, 3=75a1!7', p 7s75K
As a result of mVt or higher, approximately 18.4% by weight can be dissolved (
In reality, there are differences in the capacity of the pot, such as the size of the pot, the size of the pot, and the heat dissipation, but if you use a pot with a size of 20 to 251, it is possible to melt up to 20% by weight.)

As mentioned above, according to the method of the present application, current collapse,
There is no need to rapidly cool converter slag, which is unused and difficult to dispose of due to expansion, and it can be easily and quickly turned into slag that does not collapse and expand, and the large sensible heat of molten slag can be effectively utilized. It is possible to use it.

Furthermore, since the slag produced by the method of the present invention does not disintegrate or expand, it can be effectively used as ballast, sand, etc., and is easy to transport and handle.

Claims (1)

[Claims] 1 The final composition of the converter slag in a molten state is A/20341-11.9% by weight, S 10211-3.
A method of producing slag that does not disintegrate by adding one or more of red mud, slate, shale, sand, and various types of karami in an amount to be 4.8% by weight and 1.4 to 38.4% by weight of CaO2.