阅读说明：本技术 一种高骨料基质比高性能耐火浇注料的制备方法 (Preparation method of high-aggregate-matrix-ratio high-performance refractory castable ) 是由 陈卢 许远超 郭鹏 魏昌晟 余同暑 尹洪丽 王冬冬 张晖 于 2021-08-25 设计创作，主要内容包括：本发明专利公开了一种高骨料基质比高性能耐火浇注料的制备方法,公开的一种高骨料基质比高性能浇注料的制备方法为先将基质与水或液体结合剂充分搅拌均匀,使液/固质量比达到9%～27%,充分润湿原料中的细粉和微粉粒子后得到基质料浆,再将基质料浆置于分散容器中,借助超声设备或振动电机分散基质料浆中细粉和微粉团聚,分散后使基质料浆流变性能更佳,粘度更低；然后再添加骨料进行湿混,骨料的加入量大于等于全组分浇注料的70%,基质料浆完全包裹骨料,在粗糙的骨料表面形成一层滑动薄膜,拖动其流动,实现浇注料致密化。该制备方法所制备的高性能浇注料可兼具优异的热震稳定性、高温力学性能和抗侵蚀性。(The invention discloses a preparation method of a high-aggregate-matrix-ratio high-performance refractory castable, which comprises the steps of fully and uniformly stirring a matrix and water or a liquid binder to ensure that the liquid/solid mass ratio reaches 9-27%, fully wetting fine powder and micro powder particles in raw materials to obtain matrix slurry, placing the matrix slurry in a dispersing container, dispersing fine powder and micro powder agglomeration in the matrix slurry by means of ultrasonic equipment or a vibration motor, and ensuring that the rheological property of the matrix slurry is better and the viscosity is lower after dispersion; and then adding aggregate for wet mixing, wherein the adding amount of the aggregate is more than or equal to 70% of the full-component castable, the matrix slurry completely wraps the aggregate, a layer of sliding film is formed on the surface of the rough aggregate, and the sliding film is dragged to flow, so that the densification of the castable is realized. The high-performance castable prepared by the preparation method has excellent thermal shock stability, high-temperature mechanical property and erosion resistance.)

1. A preparation method of a high aggregate-matrix-ratio high-performance castable is characterized by comprising the following steps: the preparation method comprises the steps of fully and uniformly stirring the matrix and water or a liquid binding agent to ensure that the liquid/solid mass ratio reaches 9-27%, fully wetting fine powder and micro powder particles in the raw materials to obtain matrix slurry, then placing the matrix slurry in a dispersing container, dispersing fine powder and micro powder agglomeration in the matrix slurry by means of ultrasonic equipment or a vibration motor, and ensuring that the rheological property of the matrix slurry is better and the viscosity is lower after dispersion; and then adding aggregate for wet mixing, wherein the adding amount of the aggregate is more than or equal to 70% of the full-component castable, the matrix slurry completely wraps the aggregate, a layer of sliding film is formed on the surface of the rough aggregate, and the sliding film is dragged to flow, so that the densification of the castable is realized.

2. The preparation method of the high aggregate-matrix-ratio high-performance castable according to claim 1, characterized in that: the dispersion method of the substrate slurry comprises ultrasonic dispersion and high-frequency vibration.

3. The preparation method of the high aggregate-matrix-ratio high-performance castable according to claim 1, characterized in that: the aggregate-matrix ratio of the high-performance castable is 70: 30-85: 15.

Technical Field

The invention belongs to the technical field of refractory materials, and relates to a preparation method of a high-aggregate-matrix-ratio refractory castable, which has excellent high-temperature mechanical property, high-temperature molten slag infiltration erosion resistance and thermal shock stability.

Background

The high-performance refractory castable is mainly applied to high-temperature equipment or a lining of a thermotechnical kiln, the use temperature is up to 1100-1700 ℃, and the high-performance refractory castable often needs to have the following characteristics: 1. excellent high-temperature mechanical property, and can bear the strong scouring and abrasion of high-temperature melt, blocky alloy, high-speed airflow and other media; 2. the high-temperature molten slag permeates into the castable along through air holes and cracks in the castable matrix and is sintered layer by layer along with chemical reaction to form a deteriorated layer, the surface layer of the castable becomes loose and is difficult to be washed by melt and air flow, and the material with a compact structure and low apparent porosity can effectively prevent the penetration and erosion of the molten slag; 3. the thermal shock resistance is excellent, the temperature of the lining of high-temperature equipment or a thermotechnical kiln is difficult to stabilize for a long time, when the production is discontinuous, or the lining is in contact with other materials for mass transfer and heat transfer, large thermal stress is generated on the working surface of the castable, when the thermal stress exceeds the local strength, micro cracks are induced to be generated, and when the thermal stress is serious, the material is cracked or peeled off, so the thermal shock resistance is very important for the castable of the lining.

Refractory castable materials are generally composed of refractory raw materials of different particle sizes, including granules and fine powders, micro powders, also known as matrices. The grain size distribution of the refractory castable material follows the closest packing principle, namely, a structural framework is formed by larger refractory aggregate, smaller aggregate is filled in the gaps of the structural framework, fine powder is filled in the gaps among the small aggregate, and the fine powder is further filled in the smaller gaps. The general particle size of the particles is 15-8mm, 8-5mm, 5-3mm, 3-1mm, 1-0.074 mm. The particle size of the universal fine powder is 200 meshes (namely less than or equal to 0.074 mm) and 325 meshes (namely less than or equal to 0.044 mm), and the particle size of the universal micro powder is D₅₀ ≤5μm、D₅₀≤2μm、D₅₀≤1μm。

Generally speaking, because the strength of a single aggregate of the same material is usually greater than that of a matrix, the larger the number of large aggregates, the more excellent the mechanical properties (such as normal-temperature breaking strength and high-temperature breaking strength) of the castable, the stronger the resistance to rapid cooling and rapid heating, when the temperature is rapidly changed, the greater thermal stress is generated inside the material, when the thermal stress exceeds the local strength, some microcracks are induced to be generated, the crack expansion resistance of the aggregate is stronger, cracks can be interrupted or deflected, and the crack expansion path is prolonged, so that the rapid expansion of the cracks is prevented, i.e. the thermal shock stability is better. Meanwhile, the compactness degree of the aggregate made of the same material is far greater than that of the matrix, and H in the matrix₂O or the liquid bonding agent volatilizes or decomposes and leaves more holes, and the holes have high penetration, when molten metal and slag invade, the molten metal and the slag firstly enter along micro defects such as air holes and the like to generate physical and chemical reactions with the matrix; compared with aggregate, the particle size of the matrix fine powder is several orders of magnitude smaller, the corresponding reaction activity is obviously increased, and the erosion and penetration of molten liquid and slag into the matrix fine powder are also aggravated, so that the scheme adopts the aggregate with higher proportion and the matrix with lower proportion during design, and is more favorable for improving the erosion and penetration resistance of the castable.

The aggregate-matrix ratio of common refractory castable is 65: 35-70: 30, and sometimes even lower than the area. The castable has higher aggregate-matrix ratio, and can enable the material to have excellent high-temperature mechanical property, molten slag infiltration and erosion resistance and thermal shock stability. However, high aggregate matrix ratios are difficult to achieve using traditional preparation methods. As shown in fig. 3, the conventional wet mixing method is: putting all the components including all the aggregates and the fine powder into a stirrer together, adding water or a liquid bonding agent (such as aluminum dihydrogen phosphate) for wet mixing, wherein the adding amount of the water or the liquid bonding agent is 3-9%, namely the liquid-solid ratio is 3-9%. Along with the increase of the content of the aggregate, when the adding amount of the aggregate is more than or equal to 70 percent, if the traditional method is still adopted during wet mixing and stirring, the fluidity of the castable during construction is influenced, the more the aggregate is, the greater the forming resistance is, even if a great vibration force is applied and the vibration time is prolonged, the finished product is difficult to cast finally, the adding amount of water is greatly increased, and the more pores and the particle segregation are caused after the castable is dried; the cross section of the prepared refractory castable is shown in figure 1.

Disclosure of Invention

In order to solve the problems, the invention aims to provide a preparation method of a high-aggregate-matrix-ratio high-performance castable.

The invention adopts the following technical scheme for achieving the purpose:

a preparation method of a high-aggregate-matrix-ratio high-performance castable adopts a two-step wet mixing method, namely, firstly, matrix, water or liquid binder are filled into planetary ball mill equipment and fully and uniformly stirred, so that the liquid/solid ratio reaches 9% -27%, fine powder and micro powder particles in raw materials are fully wetted to obtain matrix slurry, then the matrix slurry is placed into a dispersion container, and fine powder and micro powder aggregates in the matrix slurry are dispersed by means of ultrasonic equipment or a vibration motor; after dispersion, the rheological property of the matrix slurry is better, and the viscosity is lower; and adding aggregate for wet mixing, wherein the adding amount of the aggregate is more than or equal to 70% of that of the full-component castable, the matrix slurry completely wraps the aggregate, a layer of sliding film is formed on the surface of the rough aggregate, and the sliding film is dragged to flow, so that the densification of the castable is realized.

The aggregate-matrix ratio of the high-performance castable is 70: 30-85: 15.

The liquid binder is aluminum dihydrogen phosphate or water glass.

The dispersion method of the substrate slurry is ultrasonic dispersion, high-frequency vibration (more than or equal to 100 Hz) or high-speed stirring (more than or equal to 500 rpm).

The high aggregate matrix is formed by vibration casting or pumping casting with high performance casting material. For the vibration castable, the vibration time is reduced under the condition of lower water adding amount, and the occurrence probability of particle segregation can be correspondingly reduced.

According to the preparation method of the high-aggregate-matrix-ratio high-performance castable, the technical scheme is adopted, the number of the bonding interfaces of the aggregate and the matrix is greatly changed, and the number of the bonding interfaces of the aggregate and the matrix is rapidly reduced along with the increase of the aggregate-matrix ratio; the high-aggregate matrix ratio high-performance castable has excellent high-temperature mechanical property, high-temperature molten slag penetration and erosion resistance and thermal shock stability, and is applied to a high-temperature equipment working lining in a harsh use environment; the types of the binding agents of the high-aggregate matrix-to-high-performance castable comprise hydration binding, chemical binding, condensation binding, sol-gel binding and the like, and the high-aggregate matrix-to-high-performance castable has strong applicability to different binding agents; the high-bone material matrix ratio high-performance castable prepared by the technology is greatly improved in construction performance, the flow performance and the rheological property of the castable are obviously improved during field operation, the construction expansibility of the castable is reduced, and the pumpability is improved.

Drawings

FIG. 1 is a cross-sectional view of a conventional castable refractory.

FIG. 2 is a cross-sectional view of the pure calcium aluminate cement combined with chrome corundum castable material prepared by the invention.

FIG. 3 shows a preparation process of a traditional refractory castable.

FIG. 4 shows a process of the present invention.

In the figure: 1. aggregate, 2 and matrix.

Detailed Description

The invention is described in further detail below with reference to the figures and specific embodiments.

Example 1: FIG. 4 is a preparation process of an ultra-low cement-bonded corundum castable material with a high aggregate-matrix ratio; firstly, 17% of 325-mesh corundum fine powder, 4.5% of alumina micro powder, 2% of chromium oxide micro powder and 1.5% of various additives are added into a planetary ball milling tank, and a matrix/full-component castable = 25: 100 (mass ratio), aggregate/matrix = 75: 25 (mass ratio, ratio 3.00), and injecting water with set weight, performing high-speed ball milling, and rapidly and uniformly stirring the matrix powder by collision, throwing and grinding of grinding balls (step 1). Pouring the substrate slurry into a pre-dispersion container, and adding a high-frequency vibration motor on the outer wall of the container to apply an exciting force of 100Hz to the slurry (step 2). Meanwhile, corundum aggregate is dry-mixed in advance in a double-cone stirrer or a forced stirrer. Then pouring the premixed substrate slurry and the aggregate into a planetary mixer to be stirred for 3-5 min, and mixing and homogenizing the whole components (step 3); then, filling the wet mixed casting material into a mold, and placing the mold on a vibration table for vibration casting molding (step 4); and then carrying out a series of heat treatments on the casting material according to a drying system and a firing system (1600 ℃ multiplied by 3 h) (step 5): keeping the temperature at 110 ℃ for 24h, heating to 110-600 ℃ for 5h, keeping the temperature at 600 ℃ for 3h, heating to 600-1100 ℃ for 5h, keeping the temperature at 1100 ℃ for 3h, heating to 1100-1600 ℃ for 8h, and keeping the temperature at 1600 ℃ for 6 h; finally obtaining a high aggregate matrix ratio and low cement combined corundum castable product; the cross-sectional view of the prepared high aggregate matrix ratio low cement bonded corundum castable product is shown in fig. 2.

Example 2: firstly, adding 180-mesh bauxite fine powder of 5 percent, 325-mesh mullite fine powder of 7 percent, alumina micro powder of 4 percent, silica micro powder of 3 percent and various additives of 1 percent into stirring equipment such as a forced stirrer or a wheel-rolling stirrer, wherein the matrix/full-component castable = 20: 100 (mass ratio), aggregate/matrix = 80: 20 (mass ratio, ratio 4.00), injecting aluminum dihydrogen phosphate liquid, wherein the mass ratio of the liquid binder to the matrix is 15%, and uniformly stirring (step 1); pouring the substrate slurry which is wet mixed uniformly in advance into ultrasonic equipment, fully exerting the dispersing effect of the dispersing agent under the action of ultrasonic waves, and breaking up fine powder and micro powder aggregates as much as possible (step 2); simultaneously, the corundum aggregate is pre-dry mixed in a double-cone stirrer or a forced stirrer; then pouring the premixed matrix slurry and the aggregate into a planetary mixer to be mixed for 3-5 min, and mixing and homogenizing the whole components (step 3); and then filling the wet mixed castable into a mold, placing the mold on a vibration table for vibration casting molding (step 4), baking according to a heat treatment system (200 ℃ for 24 hours) (step 5), and finally obtaining the aluminum dihydrogen phosphate combined corundum-mullite castable product with high aggregate matrix ratio.

Example 3: firstly, putting various powders (5% of 325-mesh brown corundum fine powder, 11% of spinel fine powder, 8% of spinel fine powder, 2.5% of pure calcium aluminate cement and 0.5% of polycarboxylate dispersant) of the prepared castable and 12% of water into a horizontal ribbon mixer for mixing for 30min (step 1). The base material slurry was poured into a high-speed forced mixer at a rotation speed of 1000 rpm to suspend the fine powder and fine powder particles in the slurry and sufficiently disperse them (step 2). Adding various corundum aggregate (8-5 mm15% of brown corundum, 5-3mm18% of brown corundum, 3-1mm17% of brown corundum and less than 1mm 23% of white corundum) accounting for 73% of the total amount and the premixed matrix slurry into a slant disc type mixer to be stirred for 4min, and finishing the mixing of the full-component castable (step 3). And (4) injecting the uniformly mixed corundum spinel pumping castable into a pumping pipeline, and conveying the corundum spinel pumping castable to a working position for on-site pouring (step 4). After pouring, standing and maintaining for 24-48H, and baking along with the furnace, wherein the baking curve is as follows: the temperature is raised for 4 hours at 0-80 ℃; keeping the temperature at 80 ℃ for 12 h; the temperature is 80-150 ℃, and the temperature rise time is 8 h; keeping the temperature at 150 ℃ for 12 h; the temperature is 150-300 ℃, and the temperature rise time is 16 h; keeping the temperature at 300 ℃ for 24 h. And (5) baking the casting body, and putting the casting body into use.