SU1144762A1 - Method of lining ingot mould tops - Google Patents

Abstract

1 .. METHOD OF LAYING BALTED EXTENDINGS OF POSITIONS, which includes supplying a moist refractory fireclay cement mixture into the cavity between the body of the profitable extension and the template and compaction of the mixture using vibration, characterized in that, in order to increase the service life of the lining, in the lower part of the cavity of profitable superstructure a portion of the fire-cement mixture, equal to 0.5-0.8 by mass of the lining, and compacted for 3-10 s, then held for 5-12 min, and then the rest of the mixture is fed and the whole mass is compressed to a density of 1.9-2 , 1 g / cm. 2. The method according to claim 1, characterized in that the water-cement ratio of the portion of the mixture is 0.40-0.45, and the rest of the mixture is 0.35-0.40. (L

Description

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The invention relates to metallurgy and can be used in the lining with wetted chamottocement mixture of primer extensions used in the casting of calm steel into molds and is intended for use mainly in ferrous metallurgy.

There is a method of lining profitable extensions by laying out the internal cavity of the body of the extension with fireclay refractory brick l.

However, with this method, it is almost impossible to mechanize the process of making brick lining, there are greater demands on the inner surface of the frame, the presence of seams on the lining leading to metal leakage, suspension of the ingot and the formation of transverse cracks on it. In addition, brick lining has a low thermal resistance.

The closest to the present invention is a method of lining profitable extensions, including filling with a chamottocement mixture a cavity between

the body of the near extension and the template and compaction of the mixture is vibration for days 2,,

However, the known method does not allow to realize the advantages of high-alumina cement as an effective binder at rapidly changing temperatures.

The purpose of the invention is to increase the service life of the lining.

The goal is achieved by the fact that according to the method of lining profitable extensions, which include supplying a moist refractory chamotocem1 {tny mixture into the cavity between the body of the profitable extension and the template and compacting the mixture using vibration, in the lower part of the cavity of the profitable extension, first serve a portion of the chamotocement mixture equal to 0.5 -0.8 lining weights; and, and compacted for 3–10 s, after which they stand for 5–12 MHHj and the rest of the mixture is fed with a zema and the whole mass is compressed to a density of 1.9–2.1 g / cm.

The water-cement ratio of the first portion of the mixture is 0.40-0.45, and the rest of the mixture is 0.35-0.40.

To prevent the binder from moving into the upper laminations, the first portion of the mixture (0.5-0.8 mass

X liners compacted slightly (3-10 seconds) and held (5-12 yins) until the calcium hydroxide contained in the cement mortar is partially transformed into an amorphous state. Such a transition is accompanied by an increase in the viscosity of the cement slurry, as a result of which its transfer from the lower layers to the upper layers does not occur during vibrating. Since, during operation, the lining most intensively wears out the lining in its lower part, which is approximately 1/3 of the height or 0.5 weight of the mass, this part of the mixture is reinforced in order to increase its strength and thermal properties. A portion of the mixture of more than 0.8 lining mass in the unconsolidated state does not fit into the cavity of the extension.

When the first portion is compacted less than 3 seconds, the mixture is unevenly distributed over the volume of the extension cavity and the mixture dries up. If the mixture is compacted for more than 10 s, then the lower layers of the mixture are depleted in cement mortar.

When holding the first doring mixture for less than 5 minutes, the formation of amorphous hydroxide does not occur yet and the cement mortar content is low. It is inexpedient to infuse the mixture for more than 12 minutes, as the period of setting the fire-cement mass begins. It is known that for the manufacture. for concrete products or monolithic linings, the dry mixture is moistened with water in an amount of 0.5-0.6 by weight of cement (water-cement ratio 0.5-0.6). Concrete is laid using a vibrator.

In the manufacture of lining profitable extensions, removal of extensions (demoulding) from the container should be carried out immediately after compacting the mixture. However, when using a mixture with a water-cement ratio of 0.5-0.6 and removing the extension-without exposure, the lining is destroyed. It should be noted that the insertion of the molded extension is unacceptable, since after setting the concrete it is difficult to remove the extension from the template, in addition, the productivity of the installation sharply decreases. Experience has shown that destruction during the removal of an extension is subject to greater

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the degree of the upper part of the lining than the bottom.

Therefore, the first portion of the mixture is 0.5-0.8 lining masses, the circle has a water-cement ratio of 0.4-0.45, and the rest is 0.350, 4. An increase in the water-percentage ratio of the fire-cement mixture more than 0.45 for the top of the lining and more than 0.4 for the bottom leads to its destruction when removed from the template, and a decrease in the water-cement ratio is less than 0.4 for the top and 0.35 for the bottom to a decrease in weight after setting concrete.

Example. Half of the required amount of mass consisting of chamotte powder FR. 0-30 mm (200 kg) and high-alumina cement OVHTS (40 kg) were loaded into a concrete mixer and mixed until a homogeneous composition 5 for 2 minutes, then 16 l of water were added, mixed for 2 minutes (water / cement ratio of 0.4).

The prepared mixture was poured into the cavity between the body of the extension and the template and at the same time compacted with the aid of a YaVKM brand vibrator for 5 s. Then the vibrator and the weakly compacted mass were turned off for 10 minutes.

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The second half of the mass was also prepared as the first, but the amount of water was injected with 14 liters (water-cement ratio 0.35). Then, a J vibrator was turned on and the mix was put on. The whole mass was compressed for 6 minutes, while the density of the compacted mass was 2 kg / cm.

Zafretovannuyu extension removed 10 with vibrozablon and placed in the steam chamber. After 24 h, the steaming was put on drying.

Duration not less than 15 h.

Manufactured by the proposed

and the known methods of lining (10 pieces each) were tested in the casting of 10 tons of raecht20 rail steel ingots from above.

The service life of the lining is increased by 1.5 times. .

The expected economic effect from the use of the invention is 25 0.067 rubles / ton of steel.

The proposed lining method of profitable extensions allows the lining service life to be increased 1.5 times JQ and reduce the consumption of chamotte powder and high alumina cement at the same rate.

Claims (2)

(.57) 1 METHOD FOR LIFTING PROFITABLE SUPPLIES FROM ESTABLISHMENTS, including supplying a moistened refractory shamo cement cement mixture to the cavity between the housing of the profitable extension and the template and compaction of the mixture by vibration, characterized in that, in order to increase the service life of the lining, the pore is first fed into the lower part of the cavity of the profitable extension a mixture equal to 0.5-0.8 of the mass of the lining, and compacted for 3-10 s, after which it is held for 5-12 minutes, and then the rest of the mixture is served and the whole mass is compacted to a density of 1.9-2.1 g / cm ³ . 2. The method according to p. ^ Characterized in that. Water-cement ·. The ratio of the portion of the mixture of 0.40-0.45, and the rest of the mixture is 0.35-0.40.