JPS5841757A - Manufacture of graphitic refractories using organic binder - 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 The present invention relates to graphite refractories for iron making, steel making, and non-ferrous metals (graphite-alumina, graphite-magnesia, graphite, norconia, graphite-carbonized) that use an organic binder. The present invention relates to a method for producing silicone materials, etc.

Conventionally, both inorganic and organic binders have been used as binders used in the manufacturing method of graphite refractories, but mainly organic binders such as tar pitch and synthetic resins have been used.

Conventional manufacturing methods for graphite refractories using organic binders as binders include adding organic binders to various raw material aggregates, heating and kneading the mixture, or cross-fertilizing without heating. A method is known in which the mixed material is once cooled and then molded at atmospheric temperature (in the atmosphere).

In such conventional manufacturing methods, the viscosity of the organic binder in the crosstalk is affected by the atmospheric atmosphere during molding, for example, as shown in Figure 1, the relationship between temperature and viscosity of resol type phenolic resin (resin content 79 ± 3%). As shown in the example of the figure, the temperature changes slightly, and therefore the temperature like this? The difference has a significant impact on the final product. In particular, when the viscosity of the binder increases significantly at temperatures below 15°C, the retraceability of raw material contaminants is impaired, which may cause lamination to occur in the product, and furthermore, physical property values may vary greatly. Become. Therefore, it cannot be used stably in places where usage conditions are severe.

Therefore, this invention was made to solve the above problems, and it is a graphite refractory using an organic binder that includes a process of kneading and molding a plurality of graphite refractories using an organic binder. In the manufacturing method, the raw material temperature in both the crossing and forming steps or the forming step is 15°C.
It is characterized by the above.

That is, in the present invention, by heating the raw material temperature to 15°C or higher, the organic binder, which is the cause of variations in the product (physical property values), can be uniformly dispersed in the raw material, and therefore,・It is possible to obtain a product without any wobble. Also, during molding, the raw materials (mixed materials) should be kept at 15°C.
By heating above the viscosity of the organic binder,
It can be set to the most appropriate value for molding, and therefore,
As a result of being able to optimize the moldability of the raw material, it is possible to make the product (physical property values) uniform and homogeneous.

Heating raw materials is particularly effective in the winter when temperatures drop. Furthermore, heating of the molding special raw material mixture is effective in the process of cooling the raw material mixture to room temperature and then molding it in terms of keeping the viscosity of the organic binder within a range suitable for moldability.

Next, embodiments of this invention will be described.

As shown in Table 1, raw materials with the mixing ratio of The pieces were molded at a molding pressure of 1 ton/6 J to different heating temperatures, coated with an antioxidant, and then oxidized and fired at 1000°C for 10 hours. In addition, in order to check for variations, the product was manufactured in three batches and its physical property values were measured. The results are shown in Tables 2 and 3. In addition, in Tables 2 and 3, the O mark indicates the corresponding condition ★.

As is clear from Examples 1 and 2, at least the porosity is 25% or less, which is the property required when graphite-alumina is used for continuous casting nozzles, by heating the raw material to 15°C or higher during molding. It is possible to obtain a product that satisfies both requirements of strength of 60 yards or more at the same time and has less roughness.

Table 1* *
Table 2)) "9'I. Even in graphite-silicon carbide and graphite-magnesia refractories, when an organic binder is used as a binder,
The same results as in Example 1.2 were obtained by heating the raw material to 15° C. or higher at least during molding.

As explained above, in the present invention, it is possible to stably produce a graphite refractory using an organic binder with no variation in physical properties.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing the relationship between temperature and viscosity of resol type phenolic resin. Applicant Tokyo Ceramics Co., Ltd. Agent Keitabe Tsutsumi and 1 other person

Claims (1)

[Claims] Two types:::::::: In the method for producing graphite refractories using an organic binder including the steps of kneading and molding a plurality of raw materials for graphite refractories, both the above-mentioned mixing and forming steps or the above-mentioned A method for producing a graphite refractory using an organic binder, characterized in that the raw material temperature in the forming process is kept at 15° C. or higher.