JPS5831042A - Briquetting method of steel making sludge - Google Patents

Abstract

PURPOSE:To easily obtain a briquette having high strength, which is capable of using steel making sludge directly for a steel making furnace, by throwing the steel making sludge into a bittern solution, mixing them sufficiently, forming a briquette, and after that, leaving it as it is, and self-hardening it. CONSTITUTION:Sludge generated when making steel by a converter, or an electric furnace, etc. is thrown into a solution consisting of water of 10-25% of the sludge (dry quantity) and bittern of 1-8%, they are mixed sufficiently, a briquette is formed by the obtained mixture, and after that, it is left as it is more than 24 hours, and is self-hardened. The briqutte obtained in this way can be used directly for a steel making furnace, therefore, it is not required to convert it to pellets so as to be used for a blast furnace, and the expenses of equipment and the cost are curtailed. Also, when said briquetting method is applied to a dry sludge method and sludge collected from a hopper is cut directly to a bittern solution pool, and is converted to a breqette, a problem of generation of dust is eliminated, and a utilization range of the dry sludge collecting method can be expanded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for agglomerating sludge generated during steelmaking in a converter, electric furnace, or the like.

Traditionally, sludge generated in steel factories was mixed with rock powder and other effective iron raw materials to make pellets, and the finished product was used in a blast furnace. There was a problem with dust pollution during processing.

The present invention uses Nigari without using slag powder or other effective iron raw materials, so it can be used directly in a steel factory instead of being used in a blast furnace like pellet products, and it can be recovered by dry recovery. The purpose of this project is to provide a nodule process that can improve the dust environment in the process, and its characteristics are that steelmaking sludge is mixed with 10% to 25% water and 1% to 8% of the sludge (dry weight). # of bittern and mixed well to form a mass of wEd compound, and then
This is a method for producing steelmaking sludge that is allowed to self-harden by being left to stand for more than a period of time, and will be described with reference to embodiments as follows.

The materials used in this example consisted of the following components.

2. Gari Example 1゜ From the amount of adhesion (if the solution is less than 10% or more than 17%, the amount that will adhere to the baby boomer will increase), if it is more than 17%, it will be air dried to about 17%, and then molded with the baby boomer. It is a diagram showing the drop strength at each moisture content of the following persons D to D when left for 24 hours or more. - In addition, each content of A-D is as shown in the lower fertilizer ^: Moisture 17 to 25% is air-dried to about 17% and used after baby boom, strength is "for each moisture value from 0 to 17%" Average value.

B: Value of a baby boom product obtained by naturally drying the moisture content from 30% to about 17%.

C: Value of a baby boom product obtained by naturally drying the moisture content from 50% to about 17%.

D: Value of a baby boom product obtained by naturally drying the moisture content from 75% to about 17%.

According to the figure, the strength is the highest when the amount of bittern is added from 3% to 6%, and the strength tends to decrease before and after this peak. Therefore, in the present invention, the amount of Nigari is set in the range of 1 to 8%, and the preferable range is 3 to 6%.

In addition, if the moisture content is 25% or more (B, C, D), dry (
Perhaps because the time required for drying (naturally drying to 17% or less) was longer, the strength was significantly lower than that with the water content of 10 to 25% (A).

Example λ Figure 2 shows the same materials as above mixed in the proportion shown in the figure, except that the moisture content is 23%), 20@C.
C-capacity container K 18a CC-filled container after the water liquid runs out, the container is removed and the container is left as it is for 24 hours or more. Although the strength is slightly lower than that of the No. 1 baby boom machine product, which shows the drop strength when removed and left for 24 hours or more, the strength trends depending on the amount of Nigari added and the moisture content are the same as the baby boom product of Example 1.

Example 3゜1y3 shows the same steelmaking sludge as above, molded with a baby boom machine in the same manner as in Example 1 using water glass, sun extract, bentonite, cement, etc., which are generally used as binders, and then left for more than 24 hours. This is a diagram showing the drop strength when

As can be seen from the comparison with Figure 3, the strength of the product of the present invention is much higher than that of products using general binders. The reason for the high strength is thought to be that the former has a weak chemical reaction with the sludge and is due to physical bonding, while the latter is bitter or chlorinated! Gnesium (MgCJt-682
0) is a compound, but it is an ionic bonding substance made by attracting cations and anions by electrostatic force, and when it is placed in water, water molecules (
H2O) forms a hydration bond, and as a result, the bond between KMg+ and CJ- weakens, enters the liquid, and exists as hydration ions, which have various kinetic energies [moving around in the solution]. . Will this water ion react with the metallic iron in the sludge that is contained in the water ion and become chlorinated?
This is thought to be due to chemical bonds such as the production of iron (FeCJs) and the coagulation ability of this substance itself and the shrinkage ability due to water use. (In the case of baby boom-like use, physical pressure and compression heat are added to this chemical reaction, causing rapid condensation.)
As shown in the examples, the reason why the strength decreases when the concentration is higher or lower than a certain line is that when an ionic bond substance enters water, in the former case, the crystals do not collapse because there is less water.
This is thought to be because even if water crumbles, it immediately returns to recrystallization, making it difficult for reactions with sludge to occur.In the latter case, when there is a lot of water, the activity of ionic particles stops quickly and loses its activity.

Furthermore, the optimum amount of bittern added in 10% to 25% water of steelmaking sludge is 3% to 6% because of the iron content (M, Fe 5 Fe) and bitterness in steelmaking sludge. (
This shows that the balance between MgC) and t) was optimal, and that the range of bitterness is determined by the iron content of the sludge. When iron powder is added to the original sludge, the strength of the former decreases, and the strength of the latter decreases by 5%.
% to 3% [and still maintains the strength at 5%.

This indicates that it is desirable to determine the amount of EGARI to be added after carefully grasping the iron content in the sludge.

Furthermore, the present invention provides a method for rapidly agglomerating steelmaking sludge naturally or mechanically by placing it in a solution of water and bittern, but which method is used depends on the method of use, the amount of production, or The choice may be made depending on the type of transportation or urgency.

As described above, according to the present invention, steelmaking sludge can be easily made into agglomerates by bittering, and can be used directly in the steelmaking furnace. Since the inconvenience is eliminated, it has the effect of significantly reducing equipment costs and costs. In particular, the dry sludge method (which does not require a thickener or dewatering device in the wet method), which has been limited in its use due to the generation of dust, has been improved by the present invention. The sludge is cut out from the WJJ hopper via a dust prevention shield, mixed well in a kneading device, and a light pressure is applied to obtain a sludge mass, which eliminates the problem of dust generation. That is, according to the present invention, the dry recovery method, which is the most advantageous steelmaking sludge recovery method, can be utilized to the maximum, so the effects of the present invention are significant.

[Brief explanation of drawings]

Figure 11A is a diagram showing the relationship between the amount of bitterness and falling strength for each moisture content of horns produced using a baby boomer, and Figure IB is a diagram showing the amount of sludge adhering to the baby boomer.
Figure 2 shows the relationship between the amount of bitterness and the falling strength of products that are cured naturally without using a baby boom machine or by being lightly pressed by hand. Figure 4 shows the impact of iron content on strength. Representative Patent Attorney Masaaki Akizawa 2 Mitsugai/A 2 Ke Kuzu/B 7

Claims (1)

[Claims] (1) Steelmaking sludge is poured into a solution consisting of 10% to 25% of water and 1% to 8% of the sludge (dry weight), mixed well, and the mixture is made into agglomerates.・
A nodule method for steelmaking sludge, which is characterized by allowing it to self-harden by leaving it for 4 hours or more.