阅读说明：本技术 一种纯铝酸钙水泥的制备方法 (Preparation method of pure calcium aluminate cement ) 是由 黄克忠 张东方 于 2021-09-24 设计创作，主要内容包括：本发明公开了一种纯铝酸钙水泥的湿法制备方法,具体涉及纯铝酸钙水泥的生产、制备工艺方法。采用全湿法、全封闭连续生产工艺,其优点是生产过程中无扬尘,生产环境良好,同时因为采用压滤脱水、真空成型、带式干燥的连续自动化生产方法,解决了以往湿法生产时间长、劳动强度大的问题,其生产运行成本约降低30%。添加专用SD-10分散剂中带有亲水性基团的高分子钠盐分散剂,同时含有的磺酸具有空间位阻和静电斥力作用,更能提高分散能力,使球磨效率增加。(The invention discloses a wet preparation method of pure calcium aluminate cement, and particularly relates to a production and preparation process method of the pure calcium aluminate cement. The continuous production process has the advantages of no dust emission, good production environment, long production time, low production cost (reduced by 30%), and continuous automation, such as filter pressing, dewatering, vacuum forming, and belt drying. The special SD-10 dispersant is added with a high molecular sodium salt dispersant with hydrophilic groups, and the sulfonic acid contained in the special SD-10 dispersant has the effects of steric hindrance and electrostatic repulsion, so that the dispersing capacity can be improved, and the ball milling efficiency is increased.)

1. The wet preparation method of the pure calcium aluminate cement is characterized by comprising the following steps of:

1, adding alumina, calcareous raw materials and a special SD-10 dispersing agent into a ball mill, adding water, and carrying out wet co-milling and homogenization;

2, placing the co-milled homogenized slurry obtained in the step 1 into a stirring tank for stirring and homogenizing;

3, pre-drying the slurry mixed in the step 2 in a belt dryer after filter pressing and dehydration;

4, carrying out vacuum hard plastic extrusion molding on the pre-dried mud cake obtained in the step 3 to obtain a semi-finished product;

5, drying the semi-finished product obtained in the step 4 in a belt dryer;

6, putting the dried material obtained in the step 5 into a rotary kiln for high-temperature calcination;

7, ball-milling the calcined clinker in the step 6;

and 8, conveying the qualified finished product powder ground in the step 7 to a storage tank with air stirring, uniformly stirring and packaging to obtain a finished product.

2. The wet process for preparing pure calcium aluminate cement as claimed in claim 2, wherein the weight ratio of said alumina to said calcareous raw materials in step 1 is 50-70: 30-50; the alumina is alpha-Al 2O3 or gamma-Al 2O3, and the calcium raw material is calcium carbonate, calcite or calcium hydroxide.

3. The wet preparation method of pure calcium aluminate cement as claimed in claim 1, wherein the preparation method of the special SD-10 dispersant in step 1 is:

step (1): mixing acrylic acid, sodium styrene sulfonate and hydroxy isopropyl acrylate, and stirring and heating with deionized water;

step (2): adding initiator ammonium persulfate, and keeping the temperature;

and (3): adjusting the pH value, and stirring to obtain the finished product.

4. The wet process for preparing pure calcium aluminate cement as claimed in claim 1, wherein in step (1), the molar ratio of acrylic acid, sodium styrene sulfonate and hydroxy isopropyl acrylate is 2.5-3: 0.8-1: 1-1.5.

5. The wet process for preparing pure calcium aluminate cement as claimed in claim 1, wherein in step (2), when the temperature is raised to 70-90 ℃, initiator ammonium persulfate accounting for 5-10% of hydroxyl isopropyl acrylate is added, and the temperature is maintained for 2-4 hours.

6. The wet process for preparing pure calcium aluminate cement as claimed in claim 1, wherein in step (3), after cooling to room temperature, sodium hydroxide is added to adjust the pH value to 7-9, and then stirring is continued for 1-2 hours to obtain the final product.

7. The wet process for preparing pure calcium aluminate cement as claimed in claim 1, wherein the proportion of the ball of the wet ball mill used in step 1 is 30-50% in terms of phi 20mm, 20-40% in terms of phi 30mm, 30-50% in terms of phi 50mm, 1.5-2.0% in terms of ball material water: 0.8-1.5: 1.0-2.0.

8. The wet process for preparing pure calcium aluminate cement according to claim 1, wherein the slurry is stirred in step 2 for a homogenization time of > 8 hours.

9. The wet process for preparing pure calcium aluminate cement as claimed in claim 1, wherein the water content after said press filtration and dehydration in step 3 is 15-25%, said predrying temperature is 150 ± 50 ℃, drying time is 0.5-2.5 hours, and water content after drying is 8-13%.

10. The wet process for preparing pure calcium aluminate cement as claimed in claim 1, wherein the drying material in step 5 is dried by a fully automatic belt dryer at a drying temperature of 200-350 ℃, a drying moisture content of less than 1.0%, a drying time of 2-4 hours, and a calcination temperature of 1450-1650 ℃ in step 6.

Technical Field

The invention relates to the technical field of cement materials, in particular to a production and preparation process method of pure calcium aluminate cement.

Background

The pure calcium aluminate cement is high-purity cement which is prepared by calcining industrial alumina and calcium-containing raw materials in a proportioning ratio and contains CA and CA2 as main minerals, and can be roughly divided into CA65, CA70, CA75, CA80 and the like according to the content of the alumina in the pure calcium aluminate cement.

The pure calcium aluminate cement has the characteristics of low impurity content, high early strength, high medium-temperature residual strength, high refractoriness (more than 1650 ℃) and the like, and is a high-quality bonding agent for preparing amorphous refractory materials. With the rapid increase of the proportion of the unshaped refractory material in the refractory material industry in recent years, the demand of pure calcium aluminate cement as an unshaped refractory material binding agent is more and more large, and the market prospect is wide.

At present, pure calcium aluminate cement is divided into a sintering method and an electric melting method according to production processes, the electric melting method is mostly adopted for production abroad, and the problems of high energy consumption, high production difficulty, high cost and the like exist in the electric melting method production; the sintering process for producing pure calcium aluminate cement is to dry grind alumina and calcium material into powder (325 mesh), add water to stir and roll the ball or press the powder into shape, calcine the powder in kiln and then grind the powder into finished product. The method has the defects of nonuniform material mixing, high calcining temperature, poor production environment, unstable mineral composition of a finished product, small crystal size, unclear crystal grain boundary and the like, and shows unstable performance in practical use. In addition, a semidry method is adopted for production, alumina and calcium raw materials are added with water according to a proportion for wet ball milling, the slurry is dehydrated and then directly enters a kiln for calcination, but the calcium raw materials in the slurry are easy to form calcium hydroxide by water, so that the dehydrated slurry has high water content (more than 30 percent), the slurry cake is soft and sticky, the water is rapidly volatilized after directly entering the kiln, the problems of powder formation, ring formation and the like are caused, and the production is greatly influenced.

Disclosure of Invention

Aiming at the problems of the prior dry sintering method for producing pure calcium aluminate cement, the invention aims to provide a wet preparation method of pure calcium aluminate cement.

The specific production technical scheme is as follows:

a wet preparation method of pure calcium aluminate cement comprises the following steps:

1, adding industrial alumina, a calcareous raw material and a special SD-10 dispersing agent into a lining brick ball mill with an alumina material inlaid on the inner wall according to a weight ratio, adding water into the lining brick ball mill, and co-milling and homogenizing by a wet method to obtain slurry;

2, placing the co-milled homogenized slurry obtained in the step 1 into a stirring tank for stirring and homogenizing;

3, pre-drying the slurry mixed in the step 2 in a belt dryer after filter pressing and dehydration;

4, carrying out vacuum hard plastic extrusion molding on the pre-dried mud cake obtained in the step 3 to obtain a semi-finished product;

5, drying the semi-finished product obtained in the step 4 in a belt dryer;

6, putting the dried material obtained in the step 5 into a rotary kiln for high-temperature calcination;

7, calcining the clinker in the step 6, and performing dry ball milling and grinding by using a lining brick with an alumina material embedded in the inner wall;

and 8, conveying the qualified finished product powder ground in the step 7 to a storage tank with air stirring, uniformly stirring and packaging to obtain a finished product.

Preferably, the weight ratio of the alumina to the calcareous raw materials in the step 1 is 50-70: 30-50;

preferably, the alumina in the step 1 can be alpha-Al 2O3 or gamma-Al 2O3, and the calcareous raw material is calcium carbonate, calcite or calcium hydroxide;

preferably, the contents of alpha-Al 2O3 and gamma-Al 2O3 are both more than 99 percent, the contents of calcium carbonate and calcite are both more than 98 percent, and the content of the main component of calcium hydroxide is more than 95 percent;

preferably, the preparation method of the special SD-10 dispersant in the step 1 comprises the following steps:

step 1: three raw materials of acrylic acid, sodium styrene sulfonate and acrylic acid hydroxy isopropyl ester are mixed according to the mol ratio of 2.5-3: 0.8-1: 1-1.5, stirring and heating by deionized water;

step 2: when the temperature is heated to 70-90 ℃, adding initiator ammonium persulfate accounting for 5-10% of hydroxyethyl acrylate, and preserving the heat for 2-4 hours;

and step 3: after cooling to room temperature, adding sodium hydroxide to adjust the pH value to 7-9, and continuing stirring for 1-2 hours to obtain a finished product.

Preferably, the proportion of the oxidation grinding balls used by the wet ball mill in the step 1 is that phi 20mm accounts for 30-50%, phi 30mm accounts for 20-40%, and phi 50mm accounts for 30-50%;

preferably, the ball material water ratio in the step 1 is 1.5-2.0: 0.8-1.5: 1.0-2.0;

preferably, the granularity of the ball milling slurry in the step 1 is 500-1000 meshes;

preferably, the slurry stirring homogenization time in the step 2 is more than 8 h;

preferably, the water content of the filter-pressed dehydrated water in the step 3 is 15-25%;

preferably, the pre-drying temperature in the step 3 is 150 +/-50 ℃, the drying time is 0.5-2.5 hours, and the moisture content after drying is 8-13%

Preferably, the vacuum hard plastic extrusion molding mud section phi in the step 4 is 10-20mm, and the vacuum pressure is less than-0.090 Mpa;

preferably, the drying material in the step 5 is dried by a full-automatic belt dryer, the drying temperature is 200 ℃ and 350 ℃, the drying moisture is less than 1.0 percent, and the drying time is 2 to 4 hours;

preferably, the calcining in the kiln in the step 6 is performed by adopting a rotary kiln, and the calcining temperature is 1450-1650 ℃;

the invention has the main beneficial technical effects that:

1. the invention adopts a full-wet method and full-closed continuous production process, has the advantages of no dust emission in the production process and good production environment, and simultaneously solves the problems of long production time and high labor intensity of the former wet method because of adopting a continuous automatic production method of filter pressing dehydration, vacuum forming and belt drying, and the production running cost is reduced by about 30 percent;

2. the SD-10 dispersant special for cement is mainly composed of acrylic acid copolymer, the copolymer is dissolved in water to generate ionization, and is adsorbed on inorganic salt microcrystal under the action of electrostatic repulsion force, so that the repulsion force is increased and the dispersion state is good, thereby reducing agglomeration, reducing ball milling time, and effectively solving the problems of large water consumption during ball milling, difficulty in subsequent dehydration and drying and the like.

3. The invention adopts three-stage homogenization processes of raw material co-grinding homogenization, ball-milling slurry stirring homogenization in a slurry pool, air stirring homogenization in a finished product storage tank and the like to ensure that chemical components are uniform and stable, and simultaneously, because a special SD-10 dispersing agent with hydrophilic groups is added in the ball-milling process, the contained sulfonic acid has the functions of steric hindrance and electrostatic repulsion, the dispersing capacity can be improved, the ball-milling efficiency is increased, superfine granularity can be obtained in a short time, the ball-milling energy consumption is reduced, the full reaction can be realized at low temperature, the gas consumption is reduced, the carbon emission is greatly reduced, and the invention is more energy-saving and environment-friendly;

4. the invention adopts a filter-pressing dehydration method, so that the water can be recycled, and compared with other wet-method production methods which adopt spray drying, a large amount of water resources are saved; meanwhile, after the waste heat at the tail of the rotary kiln is collected, the waste heat is conveyed to a dryer through a pipeline by using a fan for drying, so that the effects of saving energy and reducing consumption are achieved;

5. the ball mill used in the wet ball milling and clinker milling steps adopts alumina lining bricks and grinding balls with the content of alumina being more than 95 percent, thereby greatly reducing impurity pollution brought in the production process and ensuring the purity of the product.

Detailed Description

The present invention is intended to improve the production process and performance of pure calcium aluminate, and the following examples are given for a detailed, clear and complete description of the present invention.

Example 1

A wet preparation method of pure calcium aluminate cement comprises the following steps:

proportioning: weighing 50-60% of gamma-Al 2O3 and 40-50% of calcite according to the weight ratio, and adding 0.25% of SD-10 special dispersant;

grinding: the grinding granularity requirement is less than 2mm, the weight ratio of ball material to water is 2.0: 1.0: 1.5, ball milling for 20 hours, wherein the granularity of the slurry is required to be more than 95 percent through 600 meshes;

further, the wet ball mill adopts lining bricks with the lining made of materials with the alumina content of more than 95 percent, and the grinding balls are grinding balls with the alumina content of more than 95 percent;

further, the proportion of 95 oxidation grinding balls used by the wet ball mill is 35% of phi 20mm, 30% of phi 30mm and 35% of phi 50 mm;

stirring the slurry: placing the qualified ball-milled slurry into a slurry tank to be stirred for 6 hours, and ensuring that the ball-milled slurry is more uniform;

dehydration and predrying: performing filter pressing dehydration on the mixed ball milling slurry, wherein the filter pressing pressure is 2.0mpa, the filter pressing time is 5 minutes, and the water content after dehydration is 20 percent;

automatically conveying the dewatered mud cake into a belt type pre-dryer through a conveying belt, and drying for 1 hour at the temperature of 150 +/-50 ℃ to obtain a semi-finished product with the water content of 13%;

conveying the semi-finished product to vacuum extrusion and carrying out extrusion molding, wherein the diameter of a molded mud segment is 17mm, the length of the molded mud segment is 30mm, and the vacuum degree is less than-0.090 Mpa;

and (3) drying: directly conveying the formed mud segment into a multi-layer belt type dryer, and drying for 2 hours at the drying temperature of 150-350 ℃, wherein the water content of the mud segment after drying is less than 0.5 percent;

and (3) calcining: feeding the dried mud section obtained by drying into a rotary kiln for calcination, wherein the calcination temperature is 1500 +/-20 ℃, and the calcination time is 8 hours to obtain clinker;

grinding: cooling the rotary kiln calcined clinker, adding the cooled rotary kiln calcined clinker into a ball mill with lining bricks made of materials with the alumina content of more than 95 percent embedded in the inner wall, carrying out co-grinding by adopting grinding balls with the alumina content of more than 95 percent, and carrying out grinding for 24 hours, wherein the granularity D50 is controlled between 7 and 9 mu m;

further, the proportion of the grinding balls is as follows: the phi 30mm accounts for 40 percent, the phi 50mm accounts for 20 percent and the phi 60mm accounts for 40 percent;

and conveying the ground product to a finished product tank, stirring, uniformly mixing and packaging to obtain the CA-70C pure calcium aluminate cement.

Example 2

A wet preparation method of pure calcium aluminate cement comprises the following steps:

proportioning: weighing 50-60% of gamma-Al 2O3 and 40-50% of high-purity calcium carbonate according to the weight ratio, and adding 0.25% of SD-10 special dispersant;

grinding: the grinding granularity requirement is less than 2mm, the weight ratio of ball material to water is 2.0: 0.8: 1.5, ball milling for 20 hours, wherein the granularity of the slurry is required to be more than 95 percent of the 700-mesh passing rate;

further, the wet ball mill adopts lining bricks with the lining made of materials with the alumina content of more than 95 percent, and the grinding balls are grinding balls with the alumina content of more than 95 percent;

further, the proportion of 95 oxidation grinding balls used by the wet ball mill is 35% of phi 20mm, 30% of phi 30mm and 35% of phi 50 mm;

stirring the slurry: placing the qualified ball-milled slurry into a slurry tank to be stirred for 6 hours, and ensuring that the ball-milled slurry is more uniform;

dehydration and predrying: performing filter pressing dehydration on the mixed ball milling slurry, wherein the filter pressing pressure is 2.0mpa, the filter pressing time is 5 minutes, and the water content after dehydration is 20 percent;

automatically conveying the dewatered mud cake into a belt type pre-dryer through a conveying belt, and drying for 1 hour at the temperature of 150 +/-50 ℃ to obtain a semi-finished product with the water content of 13%;

conveying the semi-finished product to vacuum extrusion and carrying out extrusion molding, wherein the diameter of a molded mud segment is 17mm, the length of the molded mud segment is 30mm, and the vacuum degree is less than-0.090 Mpa;

and (3) drying: directly conveying the formed mud segment into a multi-layer belt type dryer, and drying for 2 hours at the drying temperature of 150-350 ℃, wherein the water content of the mud segment after drying is less than 0.5 percent;

and (3) calcining: feeding the dried mud section obtained by drying into a rotary kiln for calcination, wherein the calcination temperature is 1500 +/-20 ℃, and the calcination time is 8 hours to obtain clinker;

grinding: cooling the rotary kiln calcined clinker, adding the cooled rotary kiln calcined clinker into a ball mill with lining bricks made of materials with the alumina content of more than 95 percent embedded in the inner walls, co-milling grinding balls with the alumina content of more than 95 percent for 24 hours, and controlling the particle size D50 to be between 5 and 7 mu m;

further, the proportion of the grinding balls is as follows: the phi 30mm accounts for 40 percent, the phi 50mm accounts for 20 percent and the phi 60mm accounts for 40 percent;

and conveying the ground product to a finished product tank, stirring, uniformly mixing and packaging to obtain the CA-70A pure calcium aluminate cement.

Example 3

A wet preparation method of pure calcium aluminate cement comprises the following steps:

proportioning: weighing 60-70% of gamma-Al 2O3 and 30-40% of high-purity calcium hydroxide according to the weight ratio, and adding 0.35% of SD-10 special dispersant;

grinding: the grinding granularity requirement is less than 2mm, the weight ratio of ball material to water is 2.0: 1.0: 1.5, ball milling for 20 hours, wherein the granularity of the slurry is required to be more than 95 percent through 600 meshes;

further, the wet ball mill adopts lining bricks with the lining made of materials with the alumina content of more than 95 percent, and the grinding balls are grinding balls with the alumina content of more than 95 percent;

further, the proportion of 95 oxidation grinding balls used by the wet ball mill is 35% of phi 20mm, 30% of phi 30mm and 35% of phi 50 mm;

stirring the slurry: placing the qualified ball-milled slurry into a slurry tank to be stirred for 6 hours, and ensuring that the ball-milled slurry is more uniform;

dehydration and predrying: performing filter pressing dehydration on the mixed ball milling slurry, wherein the filter pressing pressure is 2.0mpa, the filter pressing time is 5 minutes, and the water content after dehydration is 20 percent;

automatically conveying the dewatered mud cake into a belt type pre-dryer through a conveying belt, and drying for 1 hour at the temperature of 150 +/-50 ℃ to obtain a semi-finished product with the water content of 13%;

conveying the semi-finished product to vacuum extrusion and carrying out extrusion molding, wherein the diameter of a molded mud segment is 17mm, the length of the molded mud segment is 30mm, and the vacuum degree is less than-0.090 Mpa;

and (3) drying: directly conveying the formed mud segment into a multi-layer belt type dryer, and drying for 2 hours at the drying temperature of 150-350 ℃, wherein the water content of the mud segment after drying is less than 0.5 percent;

and (3) calcining: feeding the dried mud section obtained by drying into a rotary kiln for calcination, wherein the calcination temperature is 1500 +/-20 ℃, and the calcination time is 8 hours to obtain clinker;

grinding: cooling the rotary kiln calcined clinker, adding the cooled rotary kiln calcined clinker into a ball mill with lining bricks made of materials with the alumina content of more than 95 percent embedded in the inner wall, carrying out co-grinding by adopting grinding balls with the alumina content of more than 95 percent for 24 hours, and controlling the particle size D50 to be between 8 and 10 mu m;

further, the proportion of the grinding balls is as follows: the phi 30mm accounts for 40 percent, the phi 50mm accounts for 20 percent and the phi 60mm accounts for 40 percent;

conveying the ground product to a finished product tank, stirring, uniformly mixing and packaging, and then naming as CA-70D pure calcium aluminate cement;

effect verification 1:

the CA70 pure calcium aluminate cement of Zhengzhou cyanine special cement Co., Ltd, which is marketed, was used as comparative example 1, and examples 1, 2, 3 and comparative example 1 were examined.

Detection standard:

1. GB/T205-.

2. GB/T1345-

3. GB/T8074-2008 cement determination method (Bo's method)

4. GB/T17671-1999 cement flexural strength, compressive strength determination method.

5. GB/T201-2015 appendix A cement setting time determination method.

6. GB/T12573-2008 cement sampling method.

The results of the measurement were as follows:

table 1: chemical index comparison results for example 1, example 2, example 3 and comparative example 1:

from the results, the total amount of impurities (Fe 2O3, SiO2, MgO) in examples 1, 2, 3 was reduced by 10%, 24%, 12% respectively, compared with the comparative examples, and the flexural strength and compressive strength at high temperature during actual use were remarkably improved.

Table 2: physical property comparison results after example 1, example 2, example 3 and comparative example 1 were prepared as mortars: (cement: 450 g. + -. 0.5g, sand 1350. + -.5 g)

The results show that: compared with the comparative example 1, the examples 1, 2 and 3 of the invention are as follows: the fineness of the calcium aluminate is increased, and the calcium aluminate is more beneficial to the hydration of pure calcium aluminate in practical use. The initial setting and final setting time interval is shortened, namely the early strength is good, and the breaking strength and the compressive strength are obviously improved.

Example 4

A wet preparation method of pure calcium aluminate cement comprises the following steps:

1. proportioning: weighing and proportioning 50-60% of gamma-Al 2O3 and 40-50% of high-purity calcium carbonate by weight ratio, and adding 0.30% of SD-10 special dispersant,

2. grinding: the grinding granularity requirement is less than 2mm, the weight ratio of ball material to water is 2.0: 0.8: 2.0, ball milling for 20 hours, wherein the granularity of the slurry is required to be more than 95 percent of the passing rate of 800 meshes;

3. stirring the slurry: placing the qualified ball-milled slurry into a slurry tank to be stirred for 4 hours, and ensuring that the ball-milled slurry is more uniform;

4. dehydration and predrying: performing filter pressing dehydration on the mixed ball milling slurry, wherein the filter pressing pressure is 2.0mpa, the filter pressing time is 5 minutes, and the water content after dehydration is 20 percent;

5. automatically conveying the dewatered mud cake to a belt type pre-dryer through a conveying belt, and drying at the temperature of 150 +/-50 ℃ for 1 hour to obtain a semi-finished product with the water content of 12.5 percent;

6. conveying the semi-finished product to vacuum extrusion and carrying out extrusion molding, wherein the diameter of a molded mud segment is 17mm, the length of the molded mud segment is 30mm, and the vacuum degree is less than-0.090 Mpa;

7. and (3) drying: directly conveying the formed mud segment into a multi-layer belt type dryer, and drying for 2 hours at the drying temperature of 150-350 ℃, wherein the water content of the mud segment after drying is less than 1.0 percent;

8. and (3) calcining: feeding the dried mud section obtained by drying into a rotary kiln for calcination, wherein the calcination temperature is 1500 +/-20 ℃, and the calcination time is 8 hours to obtain clinker;

9. grinding: cooling the rotary kiln calcined clinker, adding the cooled rotary kiln calcined clinker and alpha-Al 2o3 into a ball mill with a lining brick embedded with a material with the alumina content of more than 95% on the inner wall according to the proportion of 8:2, carrying out co-grinding by adopting grinding balls with the alumina content of more than 95%, and grinding for 24 hours, wherein the particle size is controlled to be D50 between 8 and 10 mu m;

10. conveying the ground product to a finished product tank, stirring, uniformly mixing and packaging, and then naming as CA-75E pure calcium aluminate cement;

effect verification 2

Example 4 and comparative example 2 were tested using as comparative example 2 a commercially available CA-75 pure calcium aluminate cement of Special Cement of Zhengzhou cyanine

Table 3 shows the properties of the mortar (cement: 500 g. + -. 0.5g, sand 1350. + -.5 g)

As can be seen from Table 3, the pure calcium aluminate cement prepared in example 4 has the advantages of large specific surface area, improved flexural and compressive strength, short initial setting and final setting interval time, namely good early strength performance and the like.

Application example 1

Example 1 was compared with comparative example 1 in each case with a corundum casting material.

Table 4 shows the corundum castable with different ratios of calcium aluminate cement:

table 5 shows the comparison of the water addition and the flow values of the corundum castable in example 1 and comparative example 1:

as is apparent from the table, in example 1, the amount of water added was reduced by 13% and the flow value was increased, which is directly related to the fine particle size and the uniform and stable sintered crystal phase in example 1.

Table 6 shows the comparison of the properties of example 1 and comparative example 1 after drying of corundum castable:

as is apparent from Table 6, the indexes of the embodiment 1 of the invention are superior to those of the comparative example 1, which reduces the granularity of the embodiment 1 of the invention, reduces the water consumption, has a great relationship with a hydration product with fine and uniform particles generated after hydration, improves the volume stability of the castable, and improves the rupture strength and the compressive strength of the castable at different temperatures. Meanwhile, the increase of the volume density of the embodiment 1 of the invention also improves the line change and the thermal shock stability of the castable after firing.