JPH0131446B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a method for manufacturing carbonaceous materials. Usually, carbonaceous materials are produced by heating and combining carbonaceous aggregates such as pitch coke, petroleum coke, and carbon black with organic binders such as tar and pitch, extruding or press-molding this mixture, and then sintering. Furthermore, it is manufactured through a process of graphitization if necessary. In the above manufacturing process, the coalescence step is carried out for the purpose of uniformly adhering the binder to the surface of the carbonaceous aggregate particles, increasing the mutual affinity of the aggregate particles, and obtaining a homogeneous and strong molded product. The binder is carbonized during the firing process, but some of it is volatilized and released, causing porosity and cracking, which reduces the mechanical strength of the final carbon product. Therefore, binders with high residual elements such as tar and pitch and low volatile content are used, but these binders have high viscosity and have a very large shearing force when used as is. If it is not used, a homogeneous mixture cannot be obtained. Therefore, a method is generally used in which the viscosity is lowered by heating at the time of melting. However, even if this heated compound is extruded or pressure molded at a high temperature, since the viscosity is low, the pressing force is not sufficiently transmitted throughout the product, making it difficult to obtain a homogeneous and strong molded product. Therefore, the heated compound must be cooled to a predetermined temperature and molded while maintaining appropriate viscoelasticity. Conventionally, this cooling method has generally been carried out by charging the heated mixture into a cooler and kneading it while cooling the peripheral wall of the cooler with a water cooling jacket or the like. However, this indirect cooling method requires a long time to cool down due to poor cooling efficiency, and during that time, the compound is separated into lumps of various sizes from large lumps to small particles due to agglomeration and classification effects, and Phenomena such as oxidative deterioration of binders such as tar and pitch, and further pulverization of carbonaceous aggregates occur, making it difficult to form homogeneous and strong molded products. As a result, the structure of the fired or graphitized carbonaceous material also lacks homogeneity, which causes a decrease in mechanical strength. The object of the present invention is to provide a method for producing a carbonaceous material that does not have the above drawbacks. That is, the present invention is a carbonaceous material manufacturing process in which a carbonaceous aggregate and a binder are heated together, and then the heated mixture is directly quenched in the carbonaceous material production process in which carbonaceous aggregate and binder are heated and then formed, fired, and graphitized. Regarding the manufacturing method. The compound has a low thermal conductivity, and an effective method for rapid cooling is to add water directly to the compound and utilize the latent heat of vaporization of the water. Water has a large latent heat of vaporization, and it completely vaporizes at temperatures above 100°C under atmospheric pressure, so it does not remain in the compound.
It is a preferable cooling agent because a molded product that is sufficiently compacted and strong in subsequent molding steps can be obtained by cooling to about .degree. In the cooling operation, the heated mixture is first put into a cooler, and water is directly poured into the mixture while kneading it. The injected water uniformly contacts the heated mixture and immediately vaporizes, and its latent heat of vaporization causes the cooling effect to proceed effectively, allowing the mixture to be cooled to a predetermined temperature in a short period of time. When injecting water, it is preferable to sprinkle water in a shower to ensure uniform and good contact with the compound.Additionally, when adding water in the form of a mist, it is preferable to heat the water to ensure even and rapid contact with the compound. As the cooling time progresses, the cooling time can be further shortened, contributing to improved production efficiency. Furthermore, the cooling rate can be adjusted very easily by adjusting the method and amount of water added. As described above, according to the present invention, uniform cooling can be achieved in a short period of time, so compared to conventional indirect cooling methods, it is possible to reduce the amount of particles generated in the cooling process, such as large lumps of compound to mixture of small particles, oxidation deterioration of the binder, and carbon. It is possible to prevent the crushing of quality aggregate, and it is possible to form a homogeneous and strong molded product. As a result, the strength of the carbonaceous material is improved. The present invention will be specifically described below based on examples. Example 1 In order to determine the amount of water to be injected for cooling in advance, samples of heated composites with various mixing ratios were prepared using coke powder as the carbonaceous aggregate and coal tar pitch as the feed material. A certain amount of this heated mixture was put into a small kneading machine, water was added while kneading it, and the relationship between the cooling temperature and the amount of water was determined, and the amount of water to be injected for cooling was determined from this relationship. Note that when the cooling temperature was 105°C or higher, the moisture remaining in the mixture was substantially negligible. Next, add coal tar pitch to 110 kg of the coke.
Add 30Kg to the combiner (capacity 120) and make 140
They were fully combined at a temperature of ℃. While this mixture was put into a cooler and kneaded, Water 2 was uniformly sprinkled using a shower nozzle. Cooling time required is 5 minutes
Cooled to 110°C. Almost all of the water was vaporized and volatilized; the amount remaining in the mixture was negligible. This mixture was extruded at a pressure of 50 kg/cm ² to obtain a molded product of 200 mm x 1800 mm. The molded product was cut into three equal parts in the length direction to obtain circular test pieces, and each test piece was further divided into three equal parts in the diameter direction to obtain nine test pieces. The bulk density and bending strength of each sample were measured and the results are shown in Table 1. Example 2 The same method as in Example 1 was carried out except that water was atomized and added, and the characteristics of each molded product sample were evaluated in the first test.
Shown in the table. The time required for cooling was 4 minutes, and the cooling temperature was 110°C. Comparative Example The same method as in Example 1 was carried out except that the compound was cooled to 110°C by an indirect cooling method in which the surrounding wall of the cooler was cooled with a water-cooled jacket, and the characteristics of each specimen of the molded product are shown in Table 1. It was shown to. The time required for cooling was 30 minutes.

[Table] As is clear from the comparison between Examples and Comparative Examples shown in Table 1, it is clear that in the case of the present invention example in which the heated compound is directly quenched, a homogeneous and strong molded product can be obtained. Next, each molded article was fired at 1000°C, and further heated and graphitized at 3000°C for 1 hour. The mechanical properties of this graphitized product are shown in Table 2.

[Table] The results in Table 2 show that the mechanical strength of the carbonaceous material according to the example of the present invention is improved compared to the comparative example. As described above, according to the present invention, a homogeneous and strong molded article can be formed, and as a result, the mechanical strength of the carbonaceous material is improved. Furthermore, the cooling time can be shortened and adjusted easily, which has the effect of contributing to improving production efficiency.

Claims (1)

[Claims] 1. A carbonaceous material characterized by directly quenching the heated mixture by sprinkling or spraying water on it in the manufacturing process of a carbonaceous material in which carbonaceous aggregate and binder are heated and kneaded, then shaped, fired, and graphitized. How the material is manufactured.