CN111333409A

CN111333409A - Regenerated magnesia-carbon tundish dry material and preparation method thereof

Info

Publication number: CN111333409A
Application number: CN202010166784.0A
Authority: CN
Inventors: 于九利; 胡玲军; 赵现华; 任林; 刘丽; 颜浩; 赵伟; 高梅
Original assignee: Tianjin Ruilixin Environmental Protection Technology Co ltd
Current assignee: Tianjin Ruilixin Environmental Protection Technology Co ltd
Priority date: 2020-03-11
Filing date: 2020-03-11
Publication date: 2020-06-26

Abstract

The invention belongs to the field of refractory materials. The invention provides a reclaimed magnesia-carbon tundish dry vibrating material which is prepared from the following components in parts by weight: 30-70 parts of regenerated magnesia carbon brick particles, 0-40 parts of fused magnesia particles or dead burned magnesia particles, 10-30 parts of fused magnesia fine powder or dead burned magnesia fine powder, 4-6 parts of a bonding agent, 2-4 parts of an antioxidant and 1-2 parts of a burning promoter. The invention further provides a preparation method of the dry vibration material. The dry material provided by the invention has low sintering degree, is easy to turn, pack and disintegrate after being used, and the graphite introduced into the regenerated magnesia carbon brick which is not wetted by steel slag can improve the slag corrosion resistance of the material; the waste magnesia carbon bricks are used as raw materials, so that the environmental pollution is reduced, the cost of refractory materials and the steel-making cost are reduced, a new way is provided for recycling the waste magnesia carbon bricks, and the method has important significance for energy conservation, consumption reduction and environmental protection.

Description

Regenerated magnesia-carbon tundish dry material and preparation method thereof

Technical Field

The invention relates to the technical field of refractory materials, in particular to a tundish dry vibration material taking regenerated magnesia carbon brick particles as raw materials and a preparation method thereof.

Background

The steel market is increasingly competitive. Under the condition of surplus steel products, steel enterprises need to gain initiative in market competition, and have low cost advantages besides good-performance products. Therefore, for survival, steel enterprises pay more attention to the internal excavation and cost reduction of the enterprises than ever before.

Currently, among the refractory materials in China, the amount of annual waste is very large. The existence of the waste materials not only occupies the arable land space, but also causes pollution to the environment, and is not beneficial to the realization of the current energy-saving and environment-friendly concept. In recent years, with the development of enterprises, most companies have paid attention to recycling of waste durable materials. The reusable refractory materials processed by the method can be used for preparing new refractory materials, and some refractory materials can also be used for preparing finished products of refractory materials with higher performance. The recycling of the used waste refractory materials not only saves energy and resources of the country, reduces the pollution of the waste materials to the surrounding environment due to accumulation or burying, but also reduces the cost for treating the waste materials. Therefore, in view of the long-term development of our country, the recycling of these waste refractory materials should be studied, which is a subject of great research significance.

The main raw material of the magnesium tundish dry vibrating material is fused magnesia, and the price of the magnesia greatly exceeds the cost along with the change of market demand in recent years, so that the production of the magnesium tundish dry vibrating material has no economic benefit basically. The regenerated magnesia carbon brick is a secondary resource after processing the waste ladle brick, and belongs to waste recycling. However, the recycling of the waste materials lacks corresponding encouragement measures and technical support, and the typical treatment method of the recycled magnesia carbon bricks is burying. Not only increases the production cost of the product, but also causes the waste of materials. In recent years, as environmental protection is emphasized, the use of waste refractory materials has been advanced to some extent, but there are still some disadvantages in the depth and breadth of research, and the overall utilization rate is still low.

Disclosure of Invention

The invention aims to provide a dry vibration material of a tundish, which is low in cost, saves resources and has long service life and takes a regenerated magnesia carbon brick as a main raw material, and a preparation method thereof. The invention uses the recycled magnesia carbon brick particles to replace most of the fused magnesia to prepare the magnesia carbon tundish dry vibration material, improves the utilization rate of the material, improves the economic benefit, and achieves the purposes of protecting the environment and saving resources.

In order to achieve the above object, the present invention provides the following technical solutions:

the invention provides a regenerated magnesia-carbon tundish dry vibrating material which is prepared from the following components in parts by weight:

preferably, in the regenerated magnesia carbon brick particles, the weight ratio of the components with the particle size of 3-5 mm, the components with the particle size of 1-3 mm to the components with the particle size of less than or equal to 1mm is 15-20: 25-30: 20 to 30.

Preferably, the particle size of the fused magnesia fine powder or the dead burned magnesia fine powder is not more than 0.1 mm.

Preferably, the binder is phenolic resin and/or glucose.

Preferably, the antioxidant is one or more of metal silicon powder, metal aluminum powder and silicon carbide.

Preferably, the burning accelerant is one or more of red clay, water glass and titanium dioxide.

The invention also provides a preparation method of the regenerated magnesia-carbon tundish dry vibrating material, which comprises the following steps:

mixing the raw materials, performing vibration molding and baking to obtain the regenerated magnesia-carbon tundish dry vibration material.

Preferably, the vibration molding time is 8-10 min.

Preferably, the baking temperature is 250-400 ℃, and the baking time is 1.5-2 h.

The beneficial effects of the invention include the following:

1) the dry vibrating material has good slag erosion resistance, low sintering degree in the application process and easy ladle disassembly after use.

2) The graphite in the regenerated magnesia-carbon brick particles with low expansibility and non-wettability to steel slag is introduced into the magnesia refractory material, so that the defects of large high-temperature thermal expansion, poor slag penetration resistance and poor thermal shock resistance of the magnesia material are overcome, and the magnesia refractory material has strong adaptability to the alkalinity fluctuation of the steel slag.

3) The antioxidant is introduced into the magnesia refractory material, so that the formation of a protective layer in the refractory material can be promoted to improve the oxidation resistance and the erosion resistance of the material.

4) The invention takes the recycled magnesia carbon brick as the main raw material, not only saves the national mineral resources and energy, but also reduces the environmental pollution, reduces the cost of refractory materials and the steel-making cost, and makes the harmless and recycling treatment of the waste refractory materials become an important development direction. The invention provides a new way for recycling the waste magnesia carbon bricks, and has important significance for saving energy, reducing consumption and protecting the environment.

Detailed Description

the raw material for preparing the regenerated magnesia carbon tundish dry vibrating material comprises 30-70 parts of regenerated magnesia carbon brick particles, preferably 40-60 parts, and more preferably 45-55 parts.

The content of MgO in the regenerated magnesia carbon brick particles is preferably more than or equal to 70 percent, and more preferably more than or equal to 80 percent; al (Al)₂O₃The content is preferably 5% or less, more preferably 3% or less.

The weight ratio of the components with the particle size of 3-5 mm, the components with the particle size of 1-3 mm and the components with the particle size of less than or equal to 1mm in the regenerated magnesia carbon brick particles is preferably 15-20: 25-30: 20 to 30, and more preferably 16 to 18: 26-28: 22-28.

The components with the particle size of 3-5 mm in the regenerated magnesia carbon brick particles comprise components with the particle size of 5mm, and do not comprise components with the particle size of 3 mm; the components with the particle size of 1-3 mm comprise components with the particle size of 3mm and do not comprise components with the particle size of 1 mm.

The regenerated magnesia carbon brick particles are preferably self-made products, and the preparation method of the regenerated magnesia carbon brick particles preferably comprises the following steps:

(1) after the tank is disassembled at the iron-making and steel-making site, the magnesia carbon brick is recovered;

(2) sorting and removing impurities: removing soil, slag and iron blocks on the surface of the waste brick by using an iron hammer, knocking out the deteriorated layer, and orderly stacking the deteriorated layer in a pretreatment area as required;

(3) hydration treatment: soaking in water at room temperature for more than or equal to 24h by a water washing method;

(4) and (3) drying: putting the waste magnesia carbon bricks subjected to hydration treatment into a kiln car, feeding the kiln car into a tunnel drying kiln, and drying for 24 hours at the temperature of 110-130 ℃;

(5) removing false particles: grinding the dried waste magnesia carbon bricks to granules by a mixer and an edge runner mill, and stripping off fine powder matrixes on the surfaces of the granules to separate the granular aggregates and the fine powder matrixes of the magnesia carbon bricks;

(6) screening: and (3) discharging the aggregate from the mixing mill, screening to obtain 5-3 mm, 3-1 mm and 1-0 mm regenerated particles, and returning the particles larger than 5mm to the step (5) to grind again until the particle sizes of all the particles are less than or equal to 5 mm.

The raw material for preparing the dry vibrating material of the reclaimed magnesia carbon tundish comprises 0-40 parts of fused magnesia particles or dead burned magnesia particles, preferably 10-40 parts, and more preferably 20-40 parts.

In the present invention, MgO in the fused magnesia particles is preferably not less than 94.5%, more preferably not less than 96%; SiO 2₂Preferably < 3.0%, more preferably < 2.0%; the volume density is preferably not less than 3.35g/cm³More preferably not less than 4.35g/cm³(ii) a MgO in the dead-burned magnesite grains is preferably equal to or more than 91 percent, and more preferably equal to or more than 95 percent; SiO 2₂Preferably < 3.0%, more preferably < 2.0%; the volume density is preferably not less than 3.1g/cm³More preferably not less than 4.1g/cm³。

The raw material for preparing the dry vibrating material of the reclaimed magnesia carbon tundish comprises 10-30 parts of fused magnesia fine powder or dead burned magnesia fine powder, preferably 10-20 parts, and more preferably 15-20 parts.

The particle size of the fused magnesia fine powder or the dead burned magnesia fine powder is preferably less than or equal to 0.1mm, more preferably less than or equal to 0.09mm, and even more preferably less than or equal to 0.088 mm.

The raw material for preparing the regenerated magnesia-carbon tundish dry vibrating material comprises 4-6 parts of a binding agent, preferably 4.5-5.5 parts, and more preferably 5 parts.

The binder of the present invention is preferably a phenolic resin and/or glucose.

The raw material for preparing the regenerated magnesia carbon tundish dry vibrating material comprises 2-4 parts of antioxidant, preferably 2.5-3.5 parts, and more preferably 3 parts.

The antioxidant is preferably one or more of metal silicon powder, metal aluminum powder and silicon carbide.

The raw material for preparing the dry vibrating material of the reclaimed magnesia-carbon tundish comprises 1-2 parts of a burning promoter, preferably 1.5 parts.

The burning promoter is preferably one or more of red clay, water glass and titanium dioxide.

The mixing of the invention is preferably to pre-mix the dead burnt magnesia fine powder or the electric melting magnesia fine powder, the bonding agent, the antioxidant and the burning promoter in a forced mixer for 8-12 min, and then to uniformly mix with the rest raw materials in a mixer.

The time for vibration molding is preferably 8-10 min, more preferably 8.5-10 min, and even more preferably 8.5-9.5 min.

The vibration forming is preferably performed by adopting a three-phase asynchronous motor with the power of 2-2.5 kw.

In the baking process, the baking temperature is preferably 250-400 ℃, more preferably 250-350 ℃, and further preferably 250-300 ℃.

In the baking process, the baking time is preferably 1.5-2 h, and more preferably 2 h.

According to the invention, after the baking is finished, the demolding is carried out after forced air cooling for 1-2 hours; further preferably, forced air cooling is performed for 1 hour.

The reclaimed magnesia-carbon tundish dry vibration material and the preparation method thereof provided by the invention are explained in detail with reference to the following examples, but the invention is not to be construed as being limited by the scope of the invention.

Example 1

Premixing 20kg of fused magnesia fine powder (the particle size is less than or equal to 0.1mm), 4kg of phenolic resin, 4kg of silicon carbide and 2kg of water glass in a forced mixer for 8min to obtain uniformly mixed fine powder; and then putting the uniformly mixed fine powder, 30kg of regenerated magnesia carbon brick particles (the weight ratio of the components with the particle size of 3-5 mm to the components with the particle size of 1-3 mm to the components with the particle size of less than or equal to 1mm is 18: 28: 28) and 40kg of fused magnesia particles into a stirrer, uniformly stirring, vibrating for 9min by adopting a three-phase asynchronous motor with the power of 2.2kw for forming, baking for 2h at the temperature of 250 ℃, carrying out forced air cooling for 1h, and then demoulding to obtain the brick.

Example 2

Pre-mixing 20kg of dead burned magnesia fine powder (the particle size is less than or equal to 0.09mm), 6kg of glucose, 2kg of metal aluminum powder and 2kg of red clay in a forced mixer for 10min to obtain uniformly mixed fine powder; and then putting the uniformly mixed fine powder, 20kg of dead burned magnesia particles and 50kg of regenerated magnesia carbon brick particles (the weight ratio of components with the particle size of 3-5 mm to components with the particle size of 1-3 mm to components with the particle size of less than or equal to 1mm is 17: 27: 27) into a stirrer, uniformly stirring, vibrating by adopting a three-phase asynchronous motor with the power of 2.2kw for 10min for forming, baking for 1.5h at the temperature of 300 ℃, carrying out forced air cooling for 1h, and then demoulding to obtain the brick.

Example 3

Premixing 20kg of fused magnesia fine powder (the particle size is less than or equal to 0.088mm), 6kg of phenolic resin, 3kg of metal silicon powder and 1kg of titanium dioxide in a forced mixer for 12min to obtain uniformly mixed fine powder; and then putting the uniformly mixed fine powder and 70kg of regenerated magnesia carbon brick particles (the weight ratio of the components with the particle size of 3-5 mm to the components with the particle size of 1-3 mm to the components with the particle size of less than or equal to 1mm is 20: 30: 30) into a stirrer, uniformly stirring, vibrating for 8min by adopting a three-phase asynchronous motor with the power of 2.2kw for forming, baking for 2h at the temperature of 400 ℃, carrying out forced air cooling for 1h, and then demoulding to obtain the brick.

Comparative example

This comparative example provides a dry vibration material, which differs from example 1 only in that instead of the recycled magnesia carbon brick granules, there are fused magnesia granules, the MgO of which is not less than 94.5%, SiO₂Not more than 3.0 percent and volume density not less than 3.35g/cm³The particle size distribution of the fused magnesia particles is the same as that of the recycled magnesia carbon brick particles in the embodiment 1.

The dry vibration material obtained in each example and comparative example was measured for properties, and the results are shown in table 1.

Table 1: performance detection result of dry vibration material

As can be seen from the detection results in Table 1, when the addition amount of the regenerated magnesia carbon brick particles is 30-70 kg, all performance indexes of the produced dry vibration material can meet the requirements of field use. The linear change rate and the normal-temperature compressive strength of the examples 1 to 3 added with the regenerated magnesia carbon brick particles after heat preservation for 3 hours at 1500 ℃ are obviously lower than those of a comparative example, which shows that the dry vibration material added with the regenerated magnesia carbon brick particles has low sintering degree and is easy to turn, pack and disintegrate in use.

The foregoing is only a preferred embodiment of the present invention, and it should be noted that, for those skilled in the art, various modifications and decorations can be made without departing from the principle of the present invention, and these modifications and decorations should also be regarded as the protection scope of the present invention.

Claims

1. The dry vibration material for the reclaimed magnesia-carbon tundish is characterized by being prepared from the following components in parts by weight:

2. the dry vibration material according to claim 1, wherein in the regenerated magnesia carbon brick particles, the weight ratio of the component with the particle size of 3-5 mm, the component with the particle size of 1-3 mm and the component with the particle size of less than or equal to 1mm is 15-20: 25-30: 20 to 30.

3. A dry vibration material as claimed in claim 1 or 2, wherein the fused magnesia fine powder or the dead burned magnesia fine powder has a particle size of 0.1mm or less.

4. A dry vibration material as claimed in claim 3, wherein the binder is a phenolic resin and/or glucose.

5. The dry vibration material as claimed in claim 3, wherein the antioxidant is one or more of metal silicon powder, metal aluminum powder and silicon carbide.

6. A dry vibration material as claimed in claim 3, wherein the combustion improver is one or more of red clay, water glass and titanium dioxide.

7. The method for preparing the reclaimed magnesia-carbonaceous tundish dry vibrating material according to any one of claims 1 to 6, characterized by comprising the following steps:

8. The method according to claim 7, wherein the vibration molding time is 8 to 10 min.

9. The preparation method according to claim 7 or 8, wherein the baking temperature is 250-400 ℃, and the baking time is 1.5-2 h.