JPS58185475A - Manufacture of carbonaceous refractories - 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 a method for producing a carbon-containing refractory that has excellent wear resistance and a low coefficient of thermal expansion.

Since carbon-containing refractories have excellent slag resistance and spalling resistance, their range of use has been rapidly expanding in recent years, and refractory materials made from combinations with various oxide raw materials are now in production. It is offered to the furnace.・Among them, 1. It is applied to many furnaces such as converters, external smelting furnaces, and pig iron mixers, and contributes to a dramatic extension of furnace life.

Generally, these Mg0-C bricks are made of coal tar ruby, (
It is a so-called unfired brick that is treated at a temperature below 500℃ using an organic binder such as phenolic resin or furan resin, but it is a carbon bond that does not actually bond with oxides. The hot fighting strength is low, and since this carbon bond is easily oxidized compared to IL, the strength properties may deteriorate by liquid phase oxidation due to white oxidation production in the gas phase or slag. This is a drawback.

As a means to improve the oxidation resistance and hot strength characteristics, which are the drawbacks of such MgOC bricks, H4 such as A1°Si, Mg, etc.
It has been proposed to add oxidizing metals, but the addition of 3i has a slightly low slag resistance in the 1-4 axis direction, and
g is the danger of handling.

There are problems associated with this during the manufacturing of bricks, and among these problems, Ae is said to be the most suitable overall. .

However, A7! Added oil g O-C brick is 10
It has major disadvantages in that the thermal expansion coefficient increases significantly from around 00°C and the residual expansion coefficient increases, and a peeling phenomenon caused by this, so-called "cutting", is often observed in actual furnaces.

The present invention solves the drawbacks associated with the addition of AI by causing the added Al to react with carbon during the firing process, resulting in the addition of 114
This was completed based on the knowledge that this problem could be solved by producing C3, and a fired brick with high hot strength and no abnormal expansion could be obtained.

Al4 in the firing process of added AI and carbonaceous material
If the amount of C3 produced is less than 0.5% by weight, the hot strength after firing will be extremely low, and for example, in the case of Mg0-C bricks, spinel (MgO, A
j! 203) is not preferred because it results in low F of corrosion resistance. In addition, when the amount of Al4C3 produced in the firing process exceeds 5% by weight, the expansion property during firing is large;
There is no way to break the brick structure. Therefore, it is essential that the content of Al4C3 after firing is 0.5 to 5% by weight.

The refractory kits that can be used in 4 Komei include magnetic screw l', h +1.
Examples include Jl oxides such as silicon nitride. Ingredients such as Magudoro, Murai 1, Nrukong, Nrika etc. are 4 in the ingredients:
Mic-friendly FI! 203, F e O,C+
203.

:,; i (j 2 is included in 11, so 7a [A in coexistence
7! This is not preferable because it inhibits the oxidation of 8′4′-′3 to the 17th base.

, charcoal J2j≦C can be used as a material with phosphorous graphite, earthy graphite 1, leeho schizoshinoku, 21-x, etc. However, natural graphite contains easily reducible components such as ζFe2.
As the natural graphite containing f13,5i02 and used in the present invention, the total amount of Fe2O3,5i02 is 10 dI
It is desirable that it be within the range of the bar. Is it necessary that the ratio of heavy-duty materials and carbon materials be 50 to 95% for the former and 5 to 50% for the latter? This is based on the reason that the spalling property is insufficient, and that if the area is oxidized in an area of more than 50% overlap, the deterioration of the structure becomes noticeable, which is undesirable.

In the present invention it is added to fire-resistant formulations. 61 [Particle size is
Any material can be used depending on the particle size distribution of the refractory raw material to be added, but after firing, 0.5 to 511 iit% Al1
In order to produce 4C3, it is necessary to add 1% by weight or more of Lθ)AN. In addition, added AI2 does not necessarily mean A
It is not necessary to use a single metal; an Ap gold alloy with any metal can be used, and 81, Mg, etc. can also be used in addition.

The Bider used in the production of the refractory of the present invention may be any material as long as it has good wettability with the refractory raw material and carbon raw material. In consideration of this, it is desirable to use fixed carbon with an output of more than 20% AI, such as phenol resin, according to the JISK-2425 fixed carbon measurement method.

Q by combining Al and C added during the composition of fired bricks
Regarding the firing conditions for forming 14C3, it is necessary to make the oxygen partial pressure as low as possible, and specifically, firing in coke or inert gas is recommended. The firing temperature needs to be 1000°C or higher, taking into account the production amount P1 of /l/14C3, and if the temperature is lower than that, the production of /17!4C3 will not be sufficient, resulting in abnormal expansion similar to that of unfired bricks. Since it has 4", it is not Ijf.

The carbon-containing fired refractory according to the present invention has higher hot strength and lower residual expansion coefficient than conventional all-added carbonaceous refractories, but after firing, the carbon-containing fired refractory has a large amount of fixed carbon. Al14 formed during calcination by impregnation in
It is possible to strengthen the carbon bond of C3 and increase the spalling resistance of the brick itself.

In order to explain the present invention in detail, examples are shown below along with comparative examples.

(Example) As shown in Table 1, sintered magnesia as a refractory raw material,
Carbon-containing refractory bricks were prepared using fused spinel and phosphorous graphite as the carbonaceous raw material. As is clear from the test results of the bricks after firing, the Al shown in Comparative Example 1
Those that do not generate 4C3 during firing, or Comparative Examples 2~
As shown in 3, even if AN4G is formed, the amount formed is other than 0.5 to 5.0% by weight for fired refractories, Examples 1 to 3 of fired refractories within the scope of the present invention The material shown in No. 5 shows excellent results in both hot bending strength and thermal expansion coefficient.

- Continuation of amendment 1. Indication of matter 14 ■ 157th year Patent layer No. 69090 2 Name of invention Method for manufacturing carbon-containing refractories 3, ? #Relationship with ancient matters f4 to correct Patent applicant address Kurosaki Yogyo name Kurosaki Ceramics Funding Company 61, agent name (8216) Patent attorney Tegori Masu 5, Supplement ■ - Order No. 11 attached Showa year month
Day +11 The scope of claims is amended as shown in the attached sheet.

(2) “Manufacture” on page 2, line 13 of the specification is corrected to “component”.

(3) Ibid., page 3, lines 14-15, ``Most of J in ``and carbon...'' is oxidized during the firing process, and as a result, is corrected to 1.''

(4) On page 4, line 8, "Magudoro" is corrected to "Magukuro".

(5) Add ", chrome" after "silica" on page 4, line 9 of the same page.

(6) ``The spalling resistance of the brick itself'' on page 6, line 16 is corrected to ``1 hot strength''.

Special 6'1N required range 1, refractory II #150-95% by weight and carbonaceous raw material 5
~50ffili! 1. A method for producing a carbon-containing refractory, which comprises adding Al or /1 alloy to a compound consisting of IG, forming the compound, and then firing the mixture to at least 100F1'c in a non-oxidizing atmosphere.

2.-(50 to 95% by weight of fire coolant and 5 to 5% of carbonaceous raw material
Al or AI in a formulation consisting of 0% and 9%! After adding the alloy to LIL and forming, in a non-oxidizing atmosphere, at least +00
It is characterized by being calcined at 0° (゛) and further impregnated with an organic compound containing 20% by weight of P-fixed carbon.
A manufacturing method for carbon-containing refractories.

Claims (1)

[Scope of Claims] 1. Refractory raw material 50-95 coul% and carbonaceous raw material 5-5%
A method for producing a carbon-containing refractory, characterized in that A1 is added to a blend consisting of 0% by weight, and after molding, the mixture is fired in a non-oxidizing atmosphere to at least IQ 00゛(:). 2. A refractory raw material. 50-95% by weight and carbonaceous raw material 5-5
A7! in a formulation consisting of 0.11% by weight. After molding, bake at at least +000°C in a non-oxidizing atmosphere,
A method for producing a carbon-containing refractory, further comprising impregnating it with an organic compound containing 20% by weight of fixed carbon.