JPS62185838A - Manufacture of coldbond briquette - Google Patents

Abstract

PURPOSE:To improve collapsing strength and to minimize generation of fine powder due to rolling, by adding water and cement as binder material to a raw material to undergo kneading, by forming the above into briquettes, and by allowing a cement accelerating agent to adhere to the surface of the briquettes. CONSTITUTION:The powdered or granular material such as iron ore, coal, coke, etc., cement as binder material, and water are introduced into a kneader 1 and kneaded thoroughly, which is fed into a hopper 3 and then fed to rolls 4 for briquetting by means of a material feeding screw 2 provided in the bottom of the hopper 3. The formed briquettes 6 drop down and, midway through the falling, the cement accelerating agent is sprayed from nozzles 5 onto the briquette 6 surface by means of a pump.

Description

[Detailed Description of the Invention] Industrial Application Field] The present invention relates to a method for producing cold bond briquettes,
More specifically, the present invention relates to a method for producing cold bond briquette 7F using powdered or granular iron ore, stone JR, coke, and other raw materials and cement as a binder.

[Prior art 1] Cement as a binder is generally formed by adding cement as a binder to powdered or granular iron ore, coal, coke, or other raw materials using a briquetting machine. For example, when charging a blast furnace with iron ore, which is a blast furnace raw material, it contains many unnecessary components and is an impurity to the iron ore, so the amount of cement added as a binder increases. Doing so causes a decline in the quality of iron ore briquettes from a component standpoint. Therefore, it is desirable to use a molding method in which the amount of cement used as a binder is as small as possible.

(2) If Cement F is simply added as a binder, the strength of the briquettes formed after kneading with raw materials will require a long period of time, from several hours to several tens of hours, to reach a strength sufficient to withstand use. , a large area is required to store the briquettes before use.

There is a problem.

Therefore, prompt hardening after briquette molding leads to improved productivity.

Furthermore, the generation of fine powder is generally unavoidable when transporting agglomerated ores such as briquettes.

A cement quick setting agent used for concrete spraying was added to the raw materials together with cement as a binder.

However, this method has the following problems: (1) If the cement quick-setting agent is added together with the raw materials and water and kneading is started, the hardening reaction of the cement quick-setting agent is extremely fast; The curing reaction starts in seconds, and after kneading, it hardens by the time it passes through the hopper and is molded in a briquette machine (usually takes a dozen to several tens of minutes). In particular, it is very difficult to adjust the curing time, and the curing and adhesion of raw materials to the walls of the kneading machine causes operational problems.

(2) Since cement quick setting agents are expensive, it is desirable to use as little amount as possible.

Due to these problems, there is a demand for a briquette forming method that does not require a cement quick-setting agent to be added to the raw materials and that reduces the amount of cement used.

[Problems to be Solved by the Invention] The present invention was developed by the present inventor in view of several problems in the production of briquettes made from various raw materials when cement is used as a binder in the conventional art as explained above. As a result of intensive research, powder, granular iron ore, coal, coke,
When manufacturing cold bond briquettes by adding cement as a binder to other raw materials, a cement quick-setting agent is not added to the raw materials, and a small amount of cement is used as a binder, reducing the amount of cement used as a binder. At the same time, they developed a method for producing cold bond briquettes that can provide the briquettes with sufficient strength to withstand use.

■Means for solving the problems] The feature of the method for producing cold bond briquettes according to the present invention is that cement, a water-based binder, is added to the raw materials, thoroughly kneaded, and then molded into briquettes. The purpose is to attach a cement quick setting agent to the surface of the cement.

The method for manufacturing cold bond briquettes according to the present invention will be described in detail below.

As raw materials, powdered or granular iron ore, coal, coke, and other materials can be used.

The method for producing cold bond briquettes according to the present invention includes:
Water and cement as a binder are added to the raw materials, thoroughly kneaded in a kneader, and then fed to a briquette machine. The cement quick-setting agent can be sprayed directly onto the surface of the briquettes, or the cement quick-setting agent can be sprayed, applied, or dripped onto the surface of the briquette roll. As the briquette rotates, it is deposited from the roll surface to the briquette surface.

Next, the method for manufacturing cold bond briquettes according to the present invention will be specifically explained with reference to the drawings.

In Fig. 1, raw materials, cement as a binder, and water are thoroughly kneaded in a mixer 8!1, and then sent to a hopper 3.
The raw material is supplied to the briquette forming roll 4 by the screw 2 for pushing the raw material provided at the bottom of the hopper 3, and a cement quick setting agent is applied by a pump to the surface of the briquettes 6 which are being formed and falling. In addition, as shown in Figure 2, raw materials and cement water as a binder are kneaded and sent to the hopper 3, and the screw 2 for pushing the raw materials is used to make briquettes. The process of supplying the cement to the forming roll 4 is the same as that shown in FIG. The cement quick-setting agent is applied to the surface of the briquette forming roll 4. In addition to the above-mentioned spraying, the cement quick-setting agent can be applied to the surface of the briquette forming roll 4 by applying it with a brush or by applying it onto the roll. A dropping method may also be used, as long as the cement quick-setting agent can be effectively attached to the surface of the formed briquette.

In FIG. 2, point A indicates the starting point of contact between the kneaded raw materials and the briquette forming roll, and point B indicates the point at which briquette shaping is completed and forming ends. The film forming range of the cement quick setting agent on the circumferential surface of the briquette forming roll is the briquette F forming area (as seen from the roll rotation direction in Fig. 2) on the roll surface with respect to the roll rotation direction.
(range from point A to point B), that is, B-A excluding the range from A to B where the supplied raw material after kneading comes into contact with the roll surface and bites into the dog and ends forming. The range (range from point B to point A on the circumferential surface of the roll) is defined as the formation area of the cement quick-setting agent film, and the cement quick-setting agent film is formed on the surface of the briquette forming roll in this range. Next, the kneaded raw materials are bitten into rolls through a cement quick setting agent coating.

In the briquettes produced in this way, the cement quick-setting agent adheres only to the surface of the briquette, preventing it from penetrating into the briquette and being mixed with it, and the cement quick-setting agent becomes viscous after forming the briquette. Because it comes into contact with the binder cement for the first time, the hardening reaction begins after molding, so the use of a cement quickening agent poses no problem in terms of production.

Figure 3 shows the case of a 5.5 cc briquette with 3% cement added without adding a cement quick-setting agent (indicated by 10- in Figure 3) and the case where an aqueous cement quick-setting agent solution was sprayed on the briquette surface (shown in Figure 3). In Figure 3, it is indicated by ×...)
The relationship between the crushing strength of briquettes and the elapsed time is shown. 1
An improvement in strength of 30% in hours and 63% in 2 hours was observed. The cement quick-setting agent aqueous solution is an aqueous solution prepared by mixing 1% quick-setting agent with respect to the amount of cement at a ratio of 1 part quick-setting agent to 2 parts water. Further, it may be added up to 8% based on the amount of cement, and the ratio with water was that the quick-setting agent was not used as it was, but was diluted with twice the amount of water. (See Table 1.) From this Figure 3, the crushing strength of the briquettes is 30 to 63%.
In order to maintain a constant overall strength per briquette, the internal strength can be weakened, and overall the amount of cement used as a binder can be reduced by at least 10% compared to before. It can be seen that it can be reduced by about 15%.

Figure 4 shows the cement mixing ratio of the same binder for a pocket size of 5.5 cc, with the cement quick-setting agent not attached to the surface of the briquettes (indicated by ×, ... in Figure 4) and when it was attached. A comparison of the fine powder generation rate by the transfer test of the fourth mill after briquette molding in the cases (indicated by 10- in FIG. 4) is shown. As is clear from FIG. 4, when the cement quick setting agent was applied to the briquette surface, the surface hardness was significantly improved and the generation of fine powder was reduced. (
(See Table 2) The raw materials for the briquettes used were 40% magnetically separated concentrate (Samalf ore) and several types of mixed ore (silo raw material).
The blending ratio is 60%.

The analysis values of the raw materials used are as follows.

Samalf ore: T, Fe 67.41wt%, FeO
O, 14wt%, Ca00.05wt%, 5iO21,
48wt%, Ahosl, 00wt%, MgO<0.
01wt%, CO, 05wt%, I [+-1oss
1.19wL%.

Silo raw materials: T, Fe 52.78wt%, FeO4,
21wt%, CaO5, 93wt%, 5ift 3.8
8wL%, A I 20 sl, 7011It%, Mg
o 2.74wt%, C2,08u+t%, Ig-1o
ss 8,66wL%.

[Effect of the invention 1] As explained above, since the method for producing cold bond briquettes according to the present invention has the above configuration, it is possible to effectively utilize a cement quick setting agent with a short reaction time, Moreover, this cement quick setting agent does not penetrate into the interior of the briquettes, and the produced briquettes have excellent effects such as improved crushing strength and less generation of fine powder due to transfer.

[Brief explanation of drawings]

Figures 1 and 2 are explanatory diagrams of the method for producing cold bond briquettes according to the present invention, and Figure 3 shows the relationship between time after molding and crushing strength when cement quick-setting agents are attached to the briquettes and when they are not. A diagram showing the relationship, FIG. 4, is a diagram showing the relationship between the number of transfers and the fine powder generation rate when a cement quickening agent is attached to the briquettes and when it is not. 1. Kneading machine, 2. Screw for pushing raw materials, 3.
Hopper, 4. Roll for briquette forming, 5. Nozzle, 6. Falling briquette. Fang 1 figure anti-blasphemy speed & (k7)

Claims (1)

[Claims] A method for producing cold bond briquettes, which comprises adding water and cement as a binder to raw materials, thoroughly kneading the mixture, forming the mixture into briquettes, and adhering a cement quick-setting agent to the surface of the briquettes.