JPS6081294A - Coke aggregates and manufacture thereof - Google Patents

Abstract

PURPOSE:To obtain coke aggregates capable of raising iron-melting temperature in refining in converter, for charging in converter, by blending strongly caking coal coke powder, steelmaking slag powder and organic binder followed by compression forming. CONSTITUTION:The objective coke aggregates can be obtained by blending (A) strongly caking coal coke powder containing water which has been so adjusted that the size falls below 10mm. with <=3mm. powder accounting for >=80wt% and has been so conditioned that the water content falls <=12wt% (pref. 6-12wt%), (B) 5-20wt% of steelmaking slag powder and (C) <=4wt% of organic binder such as molasses, PVA followed by compression forming. EFFECT:Contributing to higher yield in iron manufacture and economically increase iron production.

Description

Detailed Description of the Invention (72, 7-Field of application on the upper right) The invention is directed to a coke mass for charging into a converter fi'', which aims to increase the temperature of iron during mixing. This book is all about minerals and their preparation methods.

(Illllllllllllllllllllllllllllllllllllllllllllllll. Oxygen gas is blown into the hot metal to remove impurities such as silicon, phosphorus, and carbon from the hot metal to make steel, but during such scouring, the temperature inside the furnace rises due to oxidative exothermic reactions such as during sand removal, and the temperature inside the furnace rises. Scrap iron such as iron ore or steel cutting scraps generated in the post-process of steelmaking is charged in advance, and the optimum temperature is maintained by utilizing the heat absorbed by the melting or reaction. Therefore, the yield of iron was good, and it was also possible to increase the amount of steel produced in the converter when there was a shortage of bath iron.

However, in recent optimal ironmaking methods, a method has been implemented in which the desanding and phosphorization in the converter are carried out outside the converter by blowing ferrous oxide, lime, etc. together with an inert gas. In such cases, the temperature of the hot metal drops by about 100°C due to heat absorption during blowing or sensible heat carried away by the inert gas, and therefore, during smelting in the converter, the iron ore or scrap iron is There have been disadvantages such as a reduction in iron production yield, an increase in scrap iron inventory within the steelworks, and the inability to cope with a shortage of hot metal.

On the other hand, strongly coking coal coke, which is referred to as uninvented, is a hard coke made by completely dry distilling strongly coking coal mainly for use in blast furnaces, and since lumps are required for blast furnaces, it is crushed and sieved. The top of the sieve is supplied to the blast furnace, and the coke powder under the sieve has few uses compared to the amount generated and has a small bulk specific gravity, so the amount of inventory will gradually increase, so it is necessary to have a large storage area and prevent environmental issues such as preventing it from scattering due to wind. They were having trouble managing their storage facilities. Although the above-mentioned coke powder was used to raise the temperature inside the converter, there were problems with the equipment, such as clogging of pots due to shelving in the hopper before charging into the converter, and Thermal efficiency is around 50 coefficients, resulting in a large amount of energy loss due to scattering loss due to flow, etc., and therefore there has been a demand for agglomeration of coke powder.

In addition, recently, the steelmaking slag generated in converter smelting has been subjected to crushing, sieving, magnetic separation, etc. in order to make effective use of it, and it has been used for the recovery of iron and the production of roadbed refining, etc. Since dust is generated in each process, a dust collector is installed to collect the dust as an environmental measure. This collected dust is in the form of fine powder, so there is currently no use for it.
All measures are taken to prevent dust from scattering before being dumped.

(Structure of the Invention) The present invention aims to provide a coke briquette and a method for producing coke briquette mainly intended for use in raising the temperature in a converter in order to meet the above-mentioned problems and demands. The gist is that the coke powder generated in the sizing process of coke briquettes and coke briquettes, which are made by compression molding strong coking coal and coke powder with the addition of steelmaking slag powder and an organic binder, are ,
Furthermore, the particle size structure of coke powder is 10 mm or less and 3 m
The granules are sized so that the granules are on an 80 weight plate with a moisture content of 12 weight M% or less, preferably within a range of 6 to 12 weight percent, and 5 to 20 weight percent of steelmaking slag powder is With the weight clerk,
This is a method for producing coke briquettes in which all organic binders are mixed and compression molded.

The present invention will be explained in more detail with reference to the drawings.

FIG. 1 is a process diagram showing the manufacturing method of the present invention.

The coking coal coke powder, whose moisture content has been detected in advance, is cut into a fixed amount by a receiving hopper 1 and a feeder 2 at the bottom, and then transferred to a drying device M (Ij) by a belt conveyor 3.
It is sent to a vibrating conveyor 4 to have a moisture content of about 8%, and is sieved through an rruπ-th sieve screen.The upper part of the sieve is sent to a sieved souvenir box 5, and the lower part is sent to a sub-hot spring 7 via a route conveyor 6. Temporarily placed in the container, and supplied to the mixing container 8 intermittently and quantitatively. On the other hand, steelmaking slag powder and organic binder are transported to hopper 7.
, feeder 10 and tank 11. The amount of coking coal coke is cut from the meter 12 into the mixer 8 according to the amount, and the mixture in the mixing and punching 8 is continuously turned into coke briquettes in the roll compression molding 13, and the net condenser in the lower part is made into coke briquette. The finished products are stored in a finished product box 16 by a conveyor 14 and a belt conveyor 15.

Below the sieve of the net conveyor 14, roll compression IiE is performed again.
The molding machine 13 is sent back by the conveyor 17 with fins, and compression molded together with the mixture. 18 is a hot air generator ij;
19 is an exhaust fan. The finished product box is air permeable, and the coke briquette in the finished product 1r-1ji 20 is naturally cured until it has a strength suitable for charging into a converter.

In the method of the present invention, coke powder is dried because coke is porous, so the moisture content is usually as high as 13 to 17, due to water cooling during coke production or water absorption in outdoor storage areas. If the temperature is high, compression will be relaxed due to the special moisture content of the molding, resulting in weak briquettes and i! Also, the surface tension of water on the roll form surface absorbs the briquettes, worsens the mold separation, and tends to cause insufficient molding, resulting in a poor molding yield. In addition, a binder is added to maintain the strength f immediately after molding, but this is to eliminate the drawback that the binder is diluted by excess moisture and the caking effect is completely degraded.

The appropriate strength of the moisture content in the present invention is determined by the required strength of the briquette depending on the regulations of the converter factory.For example, in a converter factory with a structure with a small head, the strength may be sufficient to withstand the fall. .

Therefore, the compression force during molding is approximately 600 kg/cn? i-1
, 600 kg/-, the briquette can withstand normal use, so the porosity of the product under these conditions is used as the standard for the moisture range, and in the examples, the moisture of the binder added separately is also taken into account. Moisture content 6 to 6 determined by the present invention
If it is within the range of 12 inches, it has a satisfactory briquette strength.

If the moisture content is below 6, the method of the present invention may be followed by cooling the wet coke powder.

Next, it is sieved into 5 ml by vibrating conveyor 4.
The strength of the briquette after compression molding will affect the intergranular composition of the raw material.
This is an example of adjusting the particle size structure according to the customer's briquette strength. Since coke powder is stored in piles at storage sites, the particle size distribution tends to be segregated. Therefore, coarse particles are easily broken during compression molding, and coarse particles have a high porosity, so The bonding force is weak, the molding yield is poor, and the briquette is easily mixed with weak briquettes.

Therefore, in order to make a uniform briquette, it is necessary to sieve to obtain a uniform and optimal particle size composition, and if the particle size is 3 mm or less and exceeds 80 mm, even if the particle size is 3 to 10 mm, the powder will not work. The impact on briquette strength is particularly small. In addition, since it is highly cohesive coke, it is relatively strong, unlike coke generated in the city gas process, so it is rated at 3 to 10%. , π is less than 20, there is little chance of breakage during compression molding. Furthermore, the particle size is 10mm'?
j: If it exceeds, it may cause the strength of the briquette to be weakened during compression molding, so in the present invention, the size is set not to exceed 10 degrees.

FIG. 3 is a diagram showing the relationship between molding yield and crushing strength in a distribution of 3 mm or less during compression molding. Section A indicates the area of globular yield, and Section B indicates the area of crushing strength. wg Figure 3: The crushing strength is set to 3.5 in order to facilitate handling immediately after molding.
It can be seen that in order to secure more than 80 kg of coke powder, the proportion of coke powder with a particle size of 3 mm or less needs to be 80% or more.

With such a blend, a solid briquette can be obtained, which can be handled immediately after molding, and a good briquette can be easily obtained. FIG. 4 shows the particle size distribution of the coke powder of the example. The received coke powder has a large variation in particle size, which may cause unevenness in the strength of the molding process. Therefore, by sieving the coke powder, the variation can be reduced and the product can be molded in a uniform state.

In addition, the reason why steelmaking slag powder is added and mixed in the present invention is that coke powder is porous and it is a weld group of +tllll amorphous spherical surfaces, so coke powder alone has a weak bonding force between particles. Compression molding has the disadvantage of requiring a large amount of a strong adhesive binder, so compression molding is performed by adding crystalline steelmaking slag to surround the coke particle surface and enclosing the crystalline particles. , in order to form a dense and strong briquette. Also, during curing after molding, tz
Lime is bathed out or crystallized from unprocessed lime and calcium silicate in steel slag, and oostite is leached from the iron contained in the steel slag.
! It has the advantage of having a self-hardening effect, such as penetrating into the pores of the particles and contributing to bonding between particles. In addition, when charging into a converter, copper-making slag is a product of the converter, so it is harmless to smelting, and as briquette, the softening effect of steel-making slag prevents sudden thermal decomposition. Also, since the specific gravity of the briquette is increased, floating flow in the furnace is prevented, which has the effect of increasing thermal efficiency.

Therefore, the relatively thin steelmaking slag used to increase the strength of the briquettes described above has a good ability to fill minute gaps, and also has a good self-hardening reaction during curing when small particles have a large surface area. is 100 meshes or less is 80
% or more, the effect is remarkable. The amount added should be enough to cover the surface of the coke and fill the voids in the particles during molding, and adding a large amount will increase the surface area and increase the effect of the binder added to maintain strength after molding. However, in the Examples, it was possible to obtain an idea of this by adding in a range of 5 to 20 parts.

The binder is added only to the above-mentioned steelmaking slag, which is strong against compressive fracture immediately after forming but is brittle. Therefore, the binder is added to the steel slag 9, which has a hardness that is weak against 1' and below and can withstand falling on the handling surface.

Therefore, it is desired that the binder has a fast-acting [dλr] force and also contains components that are harmless to converter scouring.
Suitable polymers include polymers containing hydrogen or element as the main component, such as those containing lignin as the main component, dense polymers, or polymer resins such as polyvinyl alcohol 7z. Since it is an inherent substance, it has a calorific value and can contribute to the calorific value of the briquette.The amount added is as described above.
(The amount that can withstand fj.L< is sufficient, and varies depending on the contact strength of the substance to be added, but may be approximately in the range of 0.3 to 4%.

Figure 2 shows two examples of the manufacturing process in which the entire amount of coke powder is molded. The vibration conveyor 4 and mixing (soot 8 is replaced with a dryer 21 and a fret mill 22,
After drying, the coke powder is crushed using a fret mill 22 until particles of 3 mm or less are 80% or less. There is almost no difference from the first embodiment. Therefore, coke powder may be sized by either classification or pulverization.

The drop strength of the coke briquette produced by the method of the present invention immediately after forming was such that it could withstand a single drop from 1 to 2 meters onto a steel plate, but after 7 days of natural air curing, steelmaking slag Due to the effects of the powder and binder, a strong briquette is formed as shown in Figure 5. Figure 5 is 10 on the iron plate? After repeatedly dropping from the height of n three times, 5 mm was divided into 151j by 5 mrπ mesh.
It shows a yield rate of 5 m as the number of curing days passes.
The yield of m or more increased, and in 7 days it was almost the usual large 8! ! It becomes a briquette that can withstand the use of a converter.

As for the size of the briquette, if it becomes large, it will easily break due to the impact of falling due to its own weight, and it cannot be used to raise the temperature in a short period of time. Burning is required for a certain amount of time, and any remaining burnt material results in energy loss.
Since the short diameter tends to be less than m and has the disadvantage of being easily scattered in the converter, it is preferable that the short axis is in the range of 10 to 50 mm.

In addition, the shape is preferably spherical with no corners because it is resistant to falling impact.

(Example) Examples are shown in Table 1 below.

(Effect of the invention) As mentioned above, the coke briquette produced by the method of the present invention has
By adding steelmaking slag powder, which was previously unused, it has almost the same effect as lump coke, contributes to thermal energy, and contributes to improving steelmaking yields and increasing steelmaking production at a low cost. However, with the recent new iron manufacturing methods, it is especially desired for old men.

[Brief explanation of drawings]

FIG. 1 is a diagram showing the manufacturing process of the coke briquette of the present invention, FIG. 2 is a diagram showing another manufacturing process of the present invention, and FIG. 3 is a diagram showing the particle size distribution, molding yield, and strength of coke before compression molding. FIG. 4 is a diagram showing the particle size structure of coke powder sized in the example,
FIG. 5 is a diagram showing the drop strength after curing in the example. 1; Reception hopper 2; Held feeder 3.6, 13, 15, 17; Key to belt core 4: Vibration conveyor 5: Sieve gift box 7; Sub-hopper 8; Mixer 9; Hopper 10; Feeder 11; Tank 12: Quantitative Roll compression molding machine 1/I; Net conveyor 16; Product box 18; Heat generator 19; Exhaust fan 20; Product storage area 21; Drying 22; Fret mill A; B; Particle size composition range of coke powder after grading C; Molding yield No. 3

Claims (2)

[Claims] (1) Strong coking coal coke powder + li! ! Coke briquette made by compression molding a mixture of steel slag powder and organic binder. (2) The particle size of the strongly coking coal coke powder is 10 mm or less, and the particle size of 3 mm or less is sized so that the weight factor is 80 or more, and the moisture content is adjusted to below 12 weight plates, so that the water-containing coke is A method for producing coke briquettes, which comprises adding slag powder in an amount of 5 to 20 layers (・4 to 4 or less of a viscosity introducing agent) and compression molding.