JPH03126667A - Material for refractory - Google Patents

Abstract

PURPOSE:To inhibit generation of a crack by blending self-hardening refractory aggregate grains wherein refractory aggregate is compounded by a thermosetting resin binder with self-hardening carbon granules wherein carbon powder is consolidated by the thermosetting resin binder. CONSTITUTION:A raw material of thermosetting resin such as phenolic resin which consists of phenols, aldehydes and a catalyst is charged to a reactor. Furthermore, one kind or a plurality of kinds of carbon powder such as graphite and coke powder having about 1-200mum grain diameter are charged so as to be regulated to 30-99wt.%. These are mixed, heated, stirred and allowed to react and self-hardening carbon powder having about 5-2000mum grain diameter is obtained. Further, refractory aggregate such as magnesia having about 100mum-10mm grain diameter is charged to the reactor and heated and also the raw material of thermosetting resin such as phenol resin is charged so as to be regulated to 1.0-10wt.% and these are allowed to react. Self-hardening refractory aggregate grains having about 100mum-10mm grain diameter are obtained. Then material for refractory is obtained by blending the self-hardening refractory aggregate grains different in the content of the binder with the self- hardening carbon granules.

Description

[Detailed description of the invention] [Industrial application field]

The present invention relates to a refractory material used for furnace materials, nozzles, etc. of furnaces for iron manufacturing, steel manufacturing, and similar non-ferrous metals.

[Conventional technology]

In order to minimize corrosion damage caused by molten metal and increase its service life in areas such as furnace materials and nozzles that come into contact with molten metal, there is a need for bricks that are less wettable with molten metal. Carbonaceous bricks have traditionally been used as such bricks. Carbonaceous bricks are made of carbonaceous material and have reduced wettability to molten metal. The refractory material used to manufacture this carbonaceous brick is prepared by blending carbon powder, refractory aggregate, and a thermosetting resin as a binder, and then mixing these.

[Problem to be solved by the invention]

However, carbon powder has poor miscibility with refractory aggregates and thermosetting resins, so when blending a large amount of carbon powder, it is necessary to mix a large amount of solvent to increase the crosstalk of the carbon powder. If a refractory material is prepared by blending a large amount of solvent in this way, a large amount of the solvent will volatilize when the refractory material is molded to make bricks, increasing the porosity of the bricks and conversely causing the molten metal to evaporate. This resulted in a decrease in corrosion resistance, wear resistance, etc. Furthermore, the thermosetting resin used as a binder is used in liquid form in order to uniformly mix it with the refractory aggregate, which has a large variation in particle size, and the refractory material is prepared as a highly viscous kneaded material. Therefore, if air gets mixed into the refractory material due to mixing during mixing, it will be difficult to escape, and there is a risk that this air will get mixed in when forming bricks. If air is mixed in during molding, the air will be compressed when molding pressure is applied, but when molding pressure is removed, the air will return to its original volume, which may cause cracks in the brick. There was a risk that the cracks would become enlarged during heat drying and curing, making the resin unusable. Additionally, since the thermosetting resin is in a liquid state, during drying and curing after being molded into bricks, solvents and monomers may volatilize and cause cracks, and in some cases, the sudden generation of gas may cause explosions. There was also a risk that it would happen. The present invention was made in view of the above points, and it is possible to uniformly blend carbonaceous powder without using a large amount of solvent, and there is no need to use a liquid thermosetting resin binder. The object of the present invention is to provide a refractory material in which refractory aggregate can be uniformly blended.

[Means to solve the problem]

The refractory material according to the present invention includes a self-hardening carbon powder in which carbon powder is solidified with a thermosetting resin binder, and a self-hardening refractory aggregate in which a refractory aggregate is composited with a thermosetting resin binder. It is characterized by being blended with grains,
The present invention will be explained in detail below. Self-curing carbon powder is produced by solidifying carbon powder using a thermosetting resin as a binder, that is, by coating carbon powder particles thinly with a thermosetting resin and consolidating them via the thermosetting resin. By solidifying the carbon powder, it is prepared as a solid powder. - It is something that is Here, the carbon powder can generally be used as long as it is a carbonaceous powder, such as natural graphite, artificial graphite, carbon black, coke powder, charcoal powder, rice husk charcoal, etc. , these can be used either singly or in combination. The particle size of the carbon powder is not particularly limited, but is preferably about 1 to 200 microns. Furthermore, the thermosetting resin used as the binder is not particularly limited, but a semi-cured thermosetting resin (so-called B-stage state) that hardens by heating etc., that is, has self-curing properties, is used. Among thermosetting resins, phenolic resin, melamine resin,
7 run resin etc. are suitable. To create self-hardening carbon powder, carbon powder and thermosetting resin are put into a kneader such as a pressurized kneader, and after kneading this with a solvent such as water or alcohol, the kneaded material is mixed. This can be carried out by taking the mixture out of the kneader, putting it into an extrusion molding machine, extruding it while further kneading it, drying the extrusion molded pieces, and pulverizing them.

Claims (2)

[Claims] (1) A mixture of self-hardening carbon granules in which carbon powder is solidified with a thermosetting resin binder and self-hardening fire-resistant aggregate particles in which fire-resistant aggregate is composited with a thermosetting resin binder. A refractory material characterized by: (2) The refractory material according to claim 1, wherein the self-hardening carbon powder and the self-hardening refractory aggregate have different binder contents.