JPS61243132A - Binder for sintering raw materials - 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 (Field of Industrial Application) The present invention relates to a binder used for granulating raw materials in producing sintered ore to be charged into a blast furnace in the steel industry.

(Prior art) The current sintering method involves mixing iron ore powder of approximately 10 or less with coke of an appropriate particle size and limestone powder as necessary, and charging the mixture into a sintering nozzle and then removing the coke from the surface layer. The coke is ignited and the coke is combusted while sucking air downward, and the combustion heat sinteres the fine ore.

As described above, since sintering progresses through the combustion of coke, the supply of air to the sintered layer, that is, the degree of ventilation of the sintered layer, is a very important operational factor.

Measures to improve the ventilation of the sintered layer up to the keratin level generally include improving the granulation conditions by increasing the granulator, extending the granulation time, or adding a binder such as quicklime to reduce the amount of pseudo particles (hereinafter referred to as granulation) after humidity control granulation. A method of coarsening the O raw material (referred to as pseudo particles) after wet granulation has been developed.

As a binder, one of the inventors of the present invention has also
-148913 proposes a rapid cement component.

(Problems to be Solved by the Invention) However, there is a limit to the above-mentioned reinforcement of the granulator, and quicklime or quick-setting cement components as a binder can be expected to be effective, but are expensive and costly. However, there remain serious problems.

The present invention was made to solve these conventional problems, and its purpose is to provide an inexpensive binder that requires special pre-treatment when granulating the sintering raw material. It's about measuring down. Another purpose is to perform granulation using an inexpensive binder and to improve sinterability without impeding the air permeability of the imitation particle packed bed in the armpit.

(Means and effects for solving the problem) The present inventors have made various studies to solve the above problem, and the water slag-formed steelmaking slag obtained by rapidly cooling molten slag is It was discovered that it is inexpensive and can be used as a binder for sintering raw materials. A method of using this rapidly cooled steelmaking slag as a soil improvement material has been proposed in Japanese Patent Application No. 59-143943 or No. 59-143941, but the present invention utilizes the hydraulic properties of this steelmaking slag to perform sintering. It is characterized by its use in the raw material zbinder.

That is, the present invention is a binder used in the ore granulation process, which is obtained by rapidly cooling molten steelmaking slag.
Or at least silicate rocks, minerals, weathered products, karami, glass scraps, foundry waste sand, coal ash, waste bricks, red mud, volcanic ejecta, blast furnace slag, desiliconization slag, and iron oxide are added to molten steelmaking slag. The feature is that one or more types of stimulants are added to cause a melting reaction and then rapidly cooled, and each stimulant is combined with the stimulant. Stimulants include stone, lime, and NaOH.

0aOOhOaO2, etc. are used.

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

Generally, steelmaking slag is 20aO, 8i0, F −0”O
@F @MgO@2 QatQ, palOs %
40aO, person 1. sOs * Fetus, Fes
04, Few Os, F2O, etc.1. Tail temperature % IF ice-hydraulic property is not present, and when blast furnace slag is slowly cooled, it becomes melilite (20aO, human tsos, S10
Mushroom ~ 20aO, :M:gO) = 28IOs intermediate component)
It has Os8, and when rapidly cooled, it becomes glass-based, has latent hydraulic properties, and is used as a blast furnace cement admixture.

Currently, these steelmaking slags are collected in a slag ladle, and are heated to about 20 to 12
Although it is discharged after some time, when the temperature reaches about 200 to 300℃, it expands and collapses when 2oao and sio move from β to r, and it has expansion and collapse properties because it contains %F, OaO%F, and MgO. Therefore, most of it is disposed of in landfills.゛The present invention relates to a technique for eliminating the above-mentioned drawbacks and effectively utilizing them.
By rapidly cooling this steelmaking slag, for example, with water, α
'~β-20a0810g main body or glass main body, or 1 part α'~β-2oao 5ioz and glass main body, and add a stimulant (for example, stone bone 1 ash, 0aO1Qa (O
H)s, NaOH1Na200a, OaO & Semey)
This is based on the discovery that it has hydraulic properties when a small amount of water is added and kneaded.

In addition, some converter slags have a small amount of iron due to their chemical composition, and there is also a method of producing electric furnace slabs in which both the oxidation period and the reduction period are produced at once (one slag method). When slowly cooled, 20aO, FegO
s % 40aO, At*Os, and Fezes are formed into a water slag after a modification treatment, resulting in stronger strength. In addition, the range of chemical components is quite wide, and the melting point is high due to the high basicity, so the scale ratio may be reduced. Therefore, preferably, silicate rocks, minerals, etc. are further added to the molten steelmaking slag, and α′ to β-2010,81
0 from the main body to 20a□, 5tcb to 20M0. Mg0.
28 When mainly modified with jOs, the melting point and viscosity decrease,
By rapidly cooling this, the ratio of water slag improves, and the product becomes mainly glass. After drying, this product is also ground to remove stimulants (such as gypsum, lime, 0aO1()a(OHh, cement, etc.)
Na Mayuzumi 00B, 0a01hNaOH.

oaoo, etc.), and when water is added and kneaded, it has hydraulic properties.

Additives can be added as follows: 1. Inserted into the smelting furnace at the beginning or during smelting. 2. Injected into the H smelting furnace after tapping. 3. 4. Inject at a distance from the falling position of the slag flow from the smelting furnace to the slag ladle. 5. Used 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.

There are other methods.

The present invention was completed based on these considerations, and is
L These hydraulic slags or slag-based products are inexpensive, and when a stimulant is added and used as a binder for sintering raw materials, granulation properties are improved, and during sintering, a sintered layer is formed. This improves ventilation and improves sinterability.

(Example) Examples of the present invention will be shown below.

Sintering was performed using a current sintering machine. Table 1 shows the binders used in the present invention. When additives were added to the molten slag in Examples BF, they were added as a substitute for the soft slag at the bottom of the slag pan.

These molten slags are melted, the molten modified slag is dropped,
This was sprayed with water and rapidly cooled to form a water slag. After further drying,
It was ground to a Blaine value of 3800 cfA/f and combined with a stimulant to form a binder.

Also, for comparison, a conventional example (H) that does not use a binder
, and a conventional example using quicklime as a binder (G
) was carried out.

The sintering raw materials are commonly used ones, and their blending ratios are shown in Table 2, the sintering conditions in Table 3, and the results in Table 4. The amount of binder added was constant at 1% as a ratio of the outer frame to the sintering raw material.

Table 4 Φ ? The results of the examples will be explained according to Table 4.

The productivity and product yield in A to Ft using the binder according to the present invention are higher than the conventional example H of sintering without a binder, and are almost equivalent to the level of the conventional example G with OaQ added as a binder. ing. Also, the strength of 1 is maintained.

As shown in the example, is there a method for rapidly cooling slag? In addition to the water cooling method, air cooling methods, air-water cooling methods, etc. can be used. However, the water cooling method is preferable due to its cooling effect and equipment simplification.

(Effect of the invention) As described above, according to the present invention, the conventional OaO can be
The binder according to the present invention can be used as a binder in place of OaO, and can be used as a binder in place of OaO.Since the binder according to the present invention is made from steelmaking slag, which is generally discarded, the C is significantly lower than that of OaO. The price will be lower. Therefore, the manufacturing cost of sintered ore is reduced, and sintered ore of good quality can be obtained, which is a great effect.

Agent Patent Attorney Masaaki Akizawa 2 others

Claims (2)

[Claims] (1) A binder for sintering raw materials comprising steelmaking slag obtained by rapid cooling from a molten state and a stimulant for hardening the slag. (2) Silicate rocks and minerals are added to molten steelmaking slag.
The product is obtained by melting and reacting with at least one of weathered materials, karami, glass scraps, foundry waste sand, coal ash, waste bricks, red mud, volcanic ejecta, blast furnace slag, desiliconization slag, and iron oxide, followed by rapid cooling. 1. A binder for sintering raw materials, comprising a sintered product and a stimulant for curing the product.