High strength nano insulation board and its manufacturing method

Abstract

The present invention discloses a high-strength nano insulation board containing 43-75% by weight of insulation filler, 7-15% by weight of light shielding agent, 10-20% by weight of binder, 2-6% by weight of reinforcing fiber, 0.5-2% by weight of plasticizer, 1-5% by weight of performance additive, and 3-10% by weight of water. The nano board produced by the present invention has the characteristics of low cost, high normal temperature pressure resistance, and low thermal conductivity. The selected insulation fillers are all materials with low thermal conductivity and light weight, and the present invention also introduces alkali or alkali metal salts, which utilize these properties of low melting point, easy volatilization, and reaction with aluminum-silicon materials, so that the insulation board forms a new structural reinforcement phase in situ under the use condition and undergoes a large volume expansion, thereby avoiding the phenomenon of sintering and powdering of traditional insulation board materials during long-term use. The high-strength nano insulation board not only has excellent insulation performance, but also maintains sufficient strength at both normal and high temperatures to avoid loss of effect, which shows that the present invention has excellent innovation and economic value.

Description

[Technical field]

[0001] The present invention is in the field of materials, and more particularly relates to high strength nano insulation boards and methods for making same. [Background technology]

[0002] The energy consumption of China's steel industry is generally high, and energy saving and reduction of consumption have become important goals of all enterprises. Rationally and effectively reducing the temperature drop of molten steel in metallurgical vessels such as ladles is an important process in the metallurgical process. The key factor that determines the temperature drop of molten steel is the thermal insulation property of the lining material of metallurgical vessels such as ladles. At present, the lining insulation material of metallurgical vessels mainly uses lightweight castables, fiber insulation boards, nano insulation boards, etc. for insulation, among which nano insulation boards have the best thermal insulation effect.

[0003] Nano insulation board is made of ultra-fine SiO 2 It is a plate-shaped insulation product made by mixing and pressing fine powder as the main component. Chinese patent with authorized publication number CN 105541313B discloses a nano insulation material and a manufacturing method for the nanoboard, which has a room temperature compressive strength of 1.2-1.4 MPa and a thermal conductivity of 0.02-0.029 W / m K (600°C). Chinese patent with authorized publication number CN 102853211A discloses a high performance nano insulation board for heat treatment equipment and a manufacturing method thereof, which has a room temperature compressive strength of 3 MPa and a room temperature thermal conductivity of 0.021 W / m K.

[0004] At present, in the structural design of metallurgical vessels such as ladles, the insulation effect of the ladle is fully taken into consideration, so nano insulation board materials with low thermal conductivity are used. However, during use, especially at the end of the ladle's life, the ladle lining is heated by the high temperature molten steel, and the ladle's working lining bricks and permanent lining bricks expand, and combined with the static pressure of the molten steel and the thermal deformation of the jacket, the nano insulation board is pressed, and since it contains a lot of organic matter, it is easily broken at high temperatures, and the material is also sintered and powdered, so that the good insulation effect is lost. Summary of the Invention [Problem to be solved by the invention]

[0005] It is an object of the present invention to provide a method for producing nano insulation boards with high strength and low thermal conductivity using solid waste to improve the reliability of their use in metallurgical vessels such as ladles. [Means for solving the problem]

[0006] The technical solutions are as follows: The high-strength nano insulation board of the present invention is 43 to 75% by weight of insulating filler; 7 to 15% by weight of a light blocking agent; 10 to 20% by weight of a binder; 2 to 6% by weight of reinforcing fibers; 0.5 to 2% by weight of a plasticizer; 1 to 5 wt. % of a performance additive; and 3 to 10% by weight of water, The heat insulating filler is one or more of brown fused alumina ash, white carbon black, and cenospheres, and the particle size is 0.2 mm or less. The performance additive is an alkali or alkali metal salt, and the chemical formula is ROH, R 2 CO 3 (R is Li, Na or K) and the grain size is less than 0.044 mm.

[0007] Furthermore, the light blocking agent is one or two of nano silicon carbide and nano zircon, with a particle size of less than 200 nm.

[0008] Furthermore, the binder is magnesium aluminum silicate and has a particle size of less than 0.044 mm.

[0009] Furthermore, the reinforcing fibers are one or two of alumina fibers, zirconia fibers, and aluminum silicate fibers, and have a fiber length of less than 5 mm.

[0010] Further, the plasticizer is magnesium stearate and has a particle size of less than 0.044 mm.

[0011] The method for producing the high strength nano insulation board of the present invention comprises the steps of: A step (1) of preparing raw materials in a mixing ratio, mixing the reinforcing fibers and the plasticizer, and dispersing the mixture by mechanical stirring or an ultrasonic disperser; (2) blending the mixture with a heat insulating filler, a light blocking agent, a binder, a plasticizer, and a performance additive in a mixer, adding water and kneading to obtain a slurry; The slurry is pressed into plates of various sizes through a pressing process, dried and then vacuum packed in film or tin foil (3).

[0012] Furthermore, the blending time is 1 to 3 hours.

[0013] Furthermore, the kneading time is 20 to 60 minutes.

[0014] Furthermore, the drying temperature is 100 to 150°C. Effect of the Invention

[0015] The beneficial effects are as follows: Compared with the prior art, the present invention has the following significant advantages:

[0016] (3) The nanoboard produced by the present invention has the characteristics of low cost, high normal temperature pressure resistance and low thermal conductivity. The selected insulation fillers are all materials with low thermal conductivity and light weight. In addition, when nano silicon carbide and nano zircon are used as the light-shielding agent, the light-shielding agent can greatly suppress the radiative heat transfer of the insulation board during use. Magnesium stearate is used as the plasticizer, which not only has excellent lubricating and plasticizing effects, but also has low density, making it easy for fibers to disperse. The slurry obtained by kneading has good fluidity and compressibility, volatilizes at 200 ° C, and increases the porosity, which is favorable for insulation. Magnesium aluminum silicate as a binder is particularly suitable for adhesion of powder, and unlike other organic binders, it does not migrate to the surface of the insulation board during the drying process. This non-mobility is necessary to ensure the structural uniformity of the product. The present invention also introduces alkali or alkali metal salts, which have these characteristics of low melting point, easy to volatilize, and react with aluminum-silicon materials: R(OH)+SiO 2 / Al 2 O 3 →R 2 SiO 3 / RAlO 2 +H 2 O;R 2 CO 3 +SiO 2 / Al 2 O 3 →R 2 SiO 3 / RAlO 2 +CO 2 The above reaction allows the insulation board to form a new structural reinforcement phase in situ under use conditions and undergo a large volume expansion, avoiding the phenomenon of sintering and pulverization of traditional insulation board materials during long-term use. From the above, it can be seen that the high-strength nano insulation board not only has excellent insulation performance, but also maintains sufficient strength to avoid loss of effect at both normal and high temperatures, so that the present invention has excellent innovation and economic value. Bulk density / g cm -3 <0.3 Room temperature compressive strength / MPa >4.0 Thermal conductivity at 800℃ / W / m K <0.055 Linear change rate after heat treatment at 800℃ for 4 hours / % <0.50 Compressive strength / MPa >2.0 after heat treatment at 800℃*4h.

[0017] (2) The preparation method of the present invention is simple, efficient, environmentally friendly, and suitable for large-scale production. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0018] The technical solution of the present invention will be further described below.

[0019] Example 1 The insulating fillers used were 20% brown fused alumina ash, 20% white carbon black, and 35% cenospheres, with particle sizes of 0.2 mm or less, by weight, 3% nano silicon carbide with particle sizes of less than 200 nm, 4% nano zircon, 10% magnesium aluminum silicate with particle sizes of less than 0.044 mm, 1% alumina fiber with fiber lengths of less than 5 mm, 1% aluminum silicate fiber, 2% magnesium stearate with particle sizes of less than 0.044 mm, 1% LiOH with particle sizes of less than 0.044 mm, and 3% water, as performance additives.

[0020] The above raw materials were prepared in the appropriate ratio. First, the reinforcing fibers and magnesium stearate were mixed and dispersed by mechanical stirring or an ultrasonic disperser. Then, the mixture was blended with the insulating filler, light blocking agent, binder, plasticizer, and performance additives in a stirrer for 1 hour. An appropriate amount of water was then added and kneaded for 20 minutes to obtain a slurry. The slurry was then manufactured into plates of various sizes by a press molding process, dried at 100°C, and vacuum-packed in film.

[0021] Example 2 The insulating filler is 20% brown fused alumina ash and 23% white carbon black by weight, and the particle size of the insulating filler is 0.2 mm or less. The light shielding agent is 15% nano zircon with a particle size of less than 200 nm, the binder is 20% magnesium aluminum silicate with a particle size of less than 0.044 mm, the reinforcing fiber is 6% zirconia fiber with a fiber length of less than 5 mm, the plasticizer is 1% magnesium stearate with a particle size of less than 0.044 mm, and the performance additive is a particle size of less than 0.044 mm. のNa 2 WHAT 3 5% , 10% water was used.

[0022] The above raw materials were prepared in the appropriate ratio. First, the reinforcing fibers and magnesium stearate were mixed and dispersed by mechanical stirring or ultrasonic disperser. Then, the mixture was blended with the insulating filler, light blocking agent, binder, plasticizer, and performance additives in a stirrer for 3 hours. Then, an appropriate amount of water was added and the mixture was kneaded for 60 minutes to obtain a slurry. The slurry was then manufactured into plates of various sizes by a press molding process, dried at 150°C, and vacuum-packed in film or tin foil.

[0023] Example 3 The insulating filler is 20% white carbon black and 36% cenospheres, the particle size of which is less than 0.1 mm, the light shielding agent is 12% nano silicon carbide with a particle size of less than 150 nm, the binder is 15% magnesium aluminum silicate with a particle size of less than 0.030 mm, the reinforcing fibers are 2% alumina fiber with a fiber length of less than 5 mm, and 3% zirconia fiber, the plasticizer is 0.5% magnesium stearate with a particle size of less than 0.044 mm, and the performance additive is 0.05% magnesium stearate with a particle size of less than 0.044 mm. Lee 2 WHAT 3 4% , 7.5% water was used.

[0024] The above raw materials were prepared in the appropriate ratio. First, the reinforcing fibers and magnesium stearate were mixed and dispersed by mechanical stirring or an ultrasonic disperser. Then, the mixture was blended with the insulating filler, light blocking agent, binder, plasticizer, and performance additives in a stirrer for 2 hours. After that, an appropriate amount of water was added and the mixture was kneaded for 40 minutes to obtain a slurry. The slurry was then manufactured into plates of various sizes by a press molding process, dried at 120°C, and vacuum-packed in tin foil.

[0025] Example 4 The insulating filler used was 63% cenospheres by weight, with a particle size of 0.2 mm or less, the light blocking agent was 6% nano silicon carbide with a particle size of less than 150 nm, 6% nano zircon, the binder was 12% magnesium aluminum silicate with a particle size of less than 0.030 mm, the reinforcing fiber was 3% aluminum silicate fiber with a fiber length of less than 5 mm, the plasticizer was 1.5% magnesium stearate with a particle size of less than 0.044 mm, the performance additive was 2% KOH with a particle size of less than 0.044 mm, and water was 6.5%.

[0026] The above raw materials were prepared in the appropriate ratio. First, the reinforcing fibers and magnesium stearate were mixed and dispersed by mechanical stirring or an ultrasonic disperser. Then, the mixture was blended with the insulating filler, light blocking agent, binder, plasticizer, and performance additives in a stirrer for 1.5 hours. An appropriate amount of water was then added and kneaded for 30 minutes to obtain a slurry. The slurry was then manufactured into plates of various sizes by a press molding process, dried at 110°C, and vacuum-packed in film. [Table 1]

Claims

1. 43-75% by weight of insulating filler, 7-15% by weight of light blocking agent, 10-20% by weight of binder, 2-6% by weight of reinforcing fiber, 0.5-2% by weight of plasticizer, 1-5% by weight of performance additive, and 3-10% by weight of water; The heat insulating filler is one or more of brown fused alumina ash, white carbon black, and cenospheres, and has a particle size of 0.2 mm or less; The performance additive is an alkali or alkali metal salt having the formula ROH, R 2 CO 3 (R is Li, Na or K) and its particle size is less than 0.044 mm; The light blocking agent is one or two of nano silicon carbide and nano zircon, and has a particle size of less than 200 nm; the binder is magnesium aluminum silicate and has a particle size of less than 0.044 mm; The reinforcing fibers are one or two of alumina fibers, zirconia fibers, or aluminum silicate fibers, and have a fiber length of less than 5 mm. A high-strength nano insulation board characterized by:

2. 2. The high strength nano insulation board of claim 1, wherein the plasticizer is magnesium stearate and has a particle size of less than 0.044 mm.

3. A method for producing the high strength nano insulation board of claim 1, comprising: A step (1) of preparing raw materials in a compounding ratio, mixing reinforcing fibers and a plasticizer, and dispersing the mixture by mechanical stirring or an ultrasonic disperser; Step (2) of blending the mixture obtained in step (1) with a heat insulating filler, a light blocking agent, a binder, a plasticizer, and a performance additive in a mixer, adding water and kneading to obtain a slurry; (3) forming the slurry into various sizes of plates through a pressing process, drying, and then vacuum packaging with film or tin foil.

4. The method for producing high-strength nano insulation board according to claim 3, characterized in that the blending time is 1 to 3 hours.

5. The method for producing a high-strength nano insulation board according to claim 3, characterized in that the kneading time is 20 to 60 minutes.

6. The method for producing a high-strength nano insulation board according to claim 3, characterized in that the drying temperature is 100 to 150°C.

Images