A special cement for wind power generation concrete tower and preparation method thereof

Abstract

A special cement for wind power generation concrete tower and a preparation method thereof belong to the technical field of cement. The cement comprises the following components by weight: 80-85 parts of clinker, 3-5 parts of gypsum, 3-4 parts of stone, 8-12 parts of mineral powder and a grinding aid; the content of tetracalcium aluminoferrate in the clinker is ≥14%, and the alkali content is 0.45-0.55%; the steps are as follows: (1) adding clinker, gypsum and stone to a roller press for extrusion to obtain component A; (2) component A is selected by a powder selector and then mixed with a grinding aid to obtain component B; (3) the mineral powder and the milled component B are mixed to obtain a special cement for wind power generation concrete tower. The special cement for wind power generation concrete tower prepared by the present invention has high compressive strength; it has high adaptability by adopting low-alkali clinker, and the content of tetracalcium aluminoferrate in the clinker is ≥14%, so that it has high flexural strength; the proportion of clinker in the special cement for wind power generation concrete tower is high and the proportion of other auxiliary materials is low, so the water consumption of cement standard consistency can be effectively reduced.

Description

Technical Field

[0001] The invention belongs to the technical field of cement, and in particular relates to special cement for wind power generation concrete tower and a preparation method thereof. Background Art

[0002] At present, wind power generation has become one of the most important renewable energy sources in my country and even in the world. With the continuous development and improvement of my country's wind power technology, the role of wind power generation in the power grid has become more and more prominent. However, the high cost of steel structure towers in the construction process of wind power generation, the difficulty of later maintenance, and the inability to meet the large-scale wind turbines need to be solved urgently; under this background, the use of high-grade new concrete cement towers to replace steel towers has become a development trend in the wind power industry. At the same time, wind power concrete towers also put forward higher requirements on cement performance: specific surface area ≥400m 2 / kg, 3-day flexural strength ≥5.5MPa, 28-day flexural strength ≥9.5Mpa, 3-day compressive strength ≥35.0MPa, 28-day compressive strength ≥65.0MPa, standard consistency water requirement ≤27.0%, particle size 3~30um ≥70%, alkali content ≤0.6%. It is difficult for traditional cement to meet the above technical requirements. Summary of the invention

[0003] The technical problem to be solved by the present invention is: to overcome the shortcomings of the prior art and provide a special cement for wind power generation concrete towers. The special cement for wind power generation concrete towers prepared by the present invention has high compressive strength; low-alkali clinker is used to make it highly adaptable, and the content of tetracalcium aluminoferrate in the clinker is ≥14% to make it have high flexural strength; the proportion of clinker in the special cement for wind power generation concrete towers is high and the proportion of other auxiliary materials is low, so the water consumption of cement standard consistency can be effectively reduced.

[0004] The technical solution adopted by the present invention to solve the technical problem is: the special cement for wind power generation concrete tower comprises the following components by weight: 80-85 parts of clinker, 3-5 parts of gypsum, 3-4 parts of gravel, 8-12 parts of mineral powder and grinding aid; the content of tetracalcium aluminoferrite in the clinker is ≥14%, and the alkali content of the clinker is 0.45-0.55%.

[0005] The applicant found in the study that one of the important reasons why traditional cement is difficult to meet the construction requirements of concrete towers is the selection and addition of clinker; too high alkali content of clinker will lead to its low adaptability, and when the proportion of clinker in cement is low, it will also lead to high water consumption of cement standard consistency. The clinker in the present invention is formed by calcining limestone, sandstone and iron powder under high temperature conditions, and rapidly cooling after partial melting; the clinker in the present invention is low-alkali clinker; the clinker includes tricalcium silicate, dicalcium silicate, tricalcium aluminate and tetracalcium aluminoferrite; the strength of clinker is 30MPa in 3 days and 50MPa in 28 days. Clinker is the main component of cement for wind power concrete towers and the main source of cement strength. Since wind power concrete towers generally exceed 100 meters, wind power concrete tower cement needs to have high strength and durability as well as high flexural strength. The tetracalcium aluminoferrite in the clinker is ≥14wt%, which can ensure its durability and flexural strength.

[0006] By using low-alkali clinker, it has high adaptability, and the content of tetracalcium aluminoferrate in the clinker is ≥14%, which makes it have higher flexural strength; clinker accounts for a high proportion in the special cement for wind power concrete towers and other auxiliary materials account for a low proportion, so it can effectively reduce the water consumption of cement standard consistency.

[0007] The adaptability of special cement for wind power concrete tower is related to the safety and durability of the tower. During the prefabrication process of wind power concrete tower, a large amount of water reducer and reinforcing agent needs to be added to improve the performance of the concrete tower. The alkali content directly affects the adaptability of the cement. Too high alkali content can destroy the retarding mechanism of cement, increase water demand, and be unfavorable to hydration. The alkali content of special cement for wind power concrete tower comes from various raw materials, and the alkali content of different raw materials is different. In this application, gravel with an alkali content of 0.3%~0.4% and a particle size of 5mm is selected as an auxiliary material for adjusting the alkali content.

[0008] The factory temperature of the special cement for wind power concrete tower is ≤70℃. The factory temperature in the present invention refers to the temperature of the cement when it leaves the production line after batching, grinding and homogenization, and then packaging or bulk delivery. The applicant found that if the factory cement temperature is too high, it will cause the concrete slump to be too high, and even false setting and rapid setting will occur, which will seriously affect the performance of the cement. Therefore, in the production link, a multi-warehouse and multi-scale matching feeding method is implemented from the batching link to reduce the temperature of clinker entering the mill, and a warehouse is configured as a special warehouse to store low-temperature clinker; large ventilation and cooling measures are taken in the grinding link, and the excess heat in the mill is discharged by increasing the ventilation volume of the dust collector fan at the end of the mill; in the storage link, the cement warehouse is strictly controlled to be below 15m, and the homogenization and dust collector are turned on to effectively take away the heat, ensuring that the cement factory temperature is ≤70℃.

[0009] The content of sulfur trioxide in the gypsum is ≥40wt%. The gypsum is purchased from Zibo Gufeng New Building Materials Technology Co., Ltd. In addition to sulfur trioxide, the gypsum also includes fluorinated gypsum, stone powder and reinforcing agent; fluorinated gypsum is mainly used as a basic material in gypsum to ensure the basic performance of gypsum products; stone powder is mainly used in gypsum to improve the physical properties of the material; reinforcing agent can improve the crack resistance and flexural strength of the material. Gypsum can adjust the setting time of cement, and the appropriate setting time can reduce the slump of concrete and give full play to the performance of concrete; at the same time, the sulfur trioxide in the gypsum can react with tricalcium ferroaluminate and tetracalcium aluminate in the clinker to generate needle-shaped calcium sulfoaluminate, which can improve the strength and corrosion resistance of cement; the sulfur trioxide content of gypsum is ≥40wt%, which has a certain grinding aid effect and is conducive to adjusting the sulfur trioxide content in cement.

[0010] The specific surface area of ​​the mineral powder is ≥400m 2 / kg, 7-day activity ≥85%, 28-day activity ≥115%; the applicant's research found that the unreasonable grade of traditional cement grinding body will lead to a small specific surface area. Mineral powder, as an active material, plays a vital role in the later strength of cement, and mineral powder can reduce the alkali content. When the specific surface area of ​​mineral powder is large, it can more effectively absorb free calcium ions in cement, promote the formation of cement stone, and thus improve the early and late strength; the large specific surface area of ​​mineral powder can refine the pore structure of concrete and enhance durability.

[0011] The grinding aid is added in an amount of 0.05% to 0.15% of the total mass of clinker, gypsum, gravel and mineral powder. The compressive strength of the cement for wind power concrete tower after adding the grinding aid is at least 3.0MPa higher than that of the cement without adding the grinding aid. The grinding aid is a chemical raw material that can improve the grindability and strength of cement. It is called the fourth raw material of cement and plays a vital role in the performance of cement. The grinding aid is composed of carboxylic acid, triethanolamine and antistatic agent; carboxylic acid can adjust the setting time and hardening speed of cement, and improve the strength and durability of cement; triethanolamine can play a good grinding aid effect in the cement grinding process, significantly improve the specific surface area and micro-powder particle content of cement, and enhance the compressive and flexural strength of cement; antistatic agent can reduce the static electricity accumulation of cement during storage and transportation, prevent agglomeration, and ensure the quality and fluidity of cement; according to the needs of wind power concrete tower cement, the grinding aid can meet the grinding aid needs and enhance the later strength of cement through its chemical action and physical effect, and improve the overall performance and economic benefits of cement. The working principle of grinding aid is that its hydrophilic groups are tightly adsorbed on the surface of particles, and the hydrophobic groups are arranged outwards, thereby reducing the surface energy of powder particles. Grinding aid enters the micro cracks of particles, accumulates destructive stress, produces a splitting effect, and improves grinding efficiency.

[0012] According to another aspect of the present invention, there is also provided a method for preparing special cement for wind power generation concrete tower, the method comprising the following steps:

[0013] (1) Add clinker, gypsum and stone into a roller press and squeeze them through the roller press to obtain component A;

[0014] (2) Component A is selected by a powder selector, mixed with a grinding aid, and ground by a mill to obtain component B;

[0015] (3) The mineral powder is mixed with the ground component B to obtain cement specially used for wind power generation concrete towers.

[0016] In step (2), component A is selected by a powder selector, and the powder with a particle size of ≤45 um accounts for ≥30% of the selected material; the particle size of ≤45 um is easy to grind.

[0017] The preparation method obtains a 3~30um particle size distribution of the special cement for wind power concrete towers of ≥70%; the applicant found that the unreasonable grinding system will lead to a lower particle size distribution of 3~30um. In this application, the mill selects a double closed-circuit combined grinding system. When the double closed-circuit combined grinding system only adopts the lowering table, it will lead to over-grinding and reduce the 3~30um content; therefore, firstly, the powder selector at the end of the mill adopts a large ventilation and high speed, and the powder selector and the powder selector fan speed reaches 38~40 Hz to effectively select 3~30um particles; the amount of abrasive entering step (2) is 185±5t / h; secondly, the second bin activation liner is changed to give full play to the forging and grinding effect of the second bin.

[0018] The feeding device of the roller press in step (1) adopts a split embedded side baffle structure. The split embedded side baffle structure realizes double-layer sealing, effectively preventing end face leakage and reducing the risk of roller end face wear; secondly, the device also adopts a screw fixing method, the screw is fixed to the fixed roller base with bolts, one end is fixed to the baffle plate, and the spring tension is used to adjust the baffle plate amplitude, which can not only protect the baffle plate from damage, but also ensure that the end face does not leak.

[0019] The powder classifier described in step (2) is a V-type powder classifier. The feeding device of the V-type powder classifier is composed of two parts, the first part is the upper step-breaking uniform part, and the second part is the lower material collection part. The first part is the upper step-breaking uniform part, which is in the shape of a step. During the movement of the material cake on the internal step, the material cake can be completely broken up due to the step drop, which plays a dispersing role; the second part is the lower material collection part, starting from the left side of the first step of the feeding device, there are four step-breaking openings every 300 mm to the last step, and finally gathered at the V-type powder classifier feeding opening to ensure that the material enters the V-type powder classifier evenly.

[0020] The feeding device composed of the upper and lower parts has more advantages in breaking up the materials than the original three uniform feeding chutes, and can preliminarily break up the material cake from the roller press; secondly, the uniformity is better. The new V-selection feeding device runs through the whole body, and from the beginning it relies on the step-by-step self-uniformity of the feeding device itself to gradually even out the materials. Secondly, it relies on the four V-selection chutes arranged side by side at the bottom, which have stronger uniformity than the original three discharge chutes, thereby improving the uniformity of the material distribution and enhancing the powder selection effect of the V-type powder classifier.

[0021] In step (2), the proportion of 12×14 mm steel segments in the second bin of the grinding body in the mill is 32.82%, and the proportion of 10×12 mm steel segments is 22.02%. The grading of the grinding body is adjusted. The main function of the grinding body in the first bin is impact crushing, which has a small effect on the increase of the specific surface area. The main function of the second bin is grinding and spheroidization, which has a greater effect on the specific surface area, and the proportion of 12×14 mm and 10×12 mm steel forgings is increased.

[0022] Compared with the prior art, the present invention has the following beneficial effects:

[0023] 1. The special cement for wind power generation concrete tower prepared by the present invention has high compressive strength; low-alkali clinker is used to make it highly adaptable, and the content of tetracalcium aluminoferrate in the clinker is ≥14% to make it have high flexural strength; the proportion of clinker in the special cement for wind power generation concrete tower is high and the proportion of other auxiliary materials is low, so the water consumption of cement standard consistency can be effectively reduced.

[0024] 2. The factory temperature of the special cement for wind power generation concrete tower of the present invention is ≤70°C, which avoids the phenomenon of excessive concrete slump, false setting and rapid setting, and can effectively promote the performance of cement.

[0025] 3. The present invention adjusts the grinding body level to make it have a larger specific surface area, adopts a double closed-circuit combined grinding system, and the powder selector at the end of the mill adopts large ventilation and high speed. The speed of the powder selector and the powder selector fan reaches 38-40 Hz, which can make the particle grading of 3-30um higher. DETAILED DESCRIPTION

[0026] Embodiment 1 is the best embodiment of the special cement for wind power generation concrete tower, and the present invention is further explained in combination with specific embodiments and comparative examples.

[0027] The chemical additives used in the examples and comparative examples of the present invention are all commercially available, and their specific information is as follows:

[0028] Clinker: industrial grade, purchased from Shandong Donghua Technology Co., Ltd.; gypsum: industrial grade, purchased from Zibo Gufeng New Building Materials Technology Co., Ltd.; grinding aid: industrial grade, purchased from Zibo Gufeng New Building Materials Technology Co., Ltd.; mineral powder: industrial grade, purchased from Jinan Shanjia Building Materials Co., Ltd.; gravel: industrial grade, purchased from Hebei Benge Mineral Products Co., Ltd.

[0029] In the paper on practical experience in exploring the grinding potential of a double closed-circuit combined grinding system, a novel V-type powder selector feeding device and a novel roller press feeding device have been described in detail. The embodiments of the present invention all use the equipment in the paper on practical experience in exploring the grinding potential of a double closed-circuit combined grinding system.

[0030] Example 1

[0031] A method for preparing special cement for wind power generation concrete tower comprises the following steps:

[0032] (1) 82.5 parts of clinker, 4 parts of gypsum and 3.5 parts of gravel are weighed by a weighing belt, discharged into a batching belt, transported to a weighing bin, and then sent to a roller press for extrusion after steady flow. Component A is obtained by extrusion of the roller press;

[0033] (2) Component A enters the V-type powder concentrator through the elevator. After the selection, the powder with a particle size of ≤45um accounts for ≥30% of the material. It is then mixed with 0.1 part of a grinding aid and added to the mill. It is ground by a double closed-circuit combined grinding system to obtain component B. The speed of the powder concentrator and the fan of the powder concentrator at the end of the grinding system reaches 39 Hz. The proportion of 12×14mm steel segments in the second bin of the grinding body in the mill is 32.82%, and the proportion of 10×12mm steel segments is 22.02%;

[0034] (3) 10 parts of mineral powder and component B are mixed in an air chute while controlling the factory temperature to obtain cement for wind power concrete towers.

[0035] Example 2

[0036] A method for preparing special cement for wind power generation concrete tower comprises the following steps:

[0037] (1) 80 parts of clinker, 5 parts of gypsum and 3 parts of gravel are weighed by a weighing belt, discharged into a batching belt, transported to a weighing bin, and then sent to a roller press for extrusion after steady flow. Component A is obtained by extrusion of the roller press;

[0038] (2) Component A enters the V-type powder concentrator through the elevator. After the selection, the powder with a particle size of ≤45um accounts for ≥30% of the material. It is then mixed with 0.1 part of a grinding aid and added to the mill. It is ground by a double closed-circuit combined grinding system to obtain component B. The speed of the powder concentrator and the fan of the powder concentrator at the end of the grinding system reaches 39 Hz. The proportion of 12×14mm steel segments in the second bin of the grinding body in the mill is 32.82%, and the proportion of 10×12mm steel segments is 22.02%;

[0039] (3) 12 parts of mineral powder and component B discharged from the mill are mixed in an air chute while controlling the factory temperature to obtain cement specially used for wind power generation concrete towers.

[0040] Example 3

[0041] A method for preparing special cement for wind power generation concrete tower comprises the following steps:

[0042] (1) 85 parts of clinker, 3 parts of gypsum and 4 parts of gravel are weighed by a weighing belt, discharged into a batching belt, transported to a weighing bin, and then sent to a roller press for extrusion after steady flow. After extrusion by the roller press, component A is obtained;

[0043] (2) Component A enters the V-type powder concentrator through the elevator. After selection, the powder with a particle size of ≤45um accounts for ≥30% of the material. It is then mixed with 0.1 part of a grinding aid and added to the mill. It is ground by a double closed-circuit combined grinding system to obtain component B. The speed of the powder concentrator and the fan of the powder concentrator at the end of the grinding system reaches 39 Hz. The proportion of 12×14mm steel segments in the second bin of the grinding body in the mill is 32.82%, and the proportion of 10×12mm steel segments is 22.02%;

[0044] (3) 8 parts of mineral powder and component B discharged from the mill are mixed in an air chute while controlling the factory temperature to obtain cement specially used for wind power generation concrete towers.

[0045] Example 4

[0046] A method for preparing special cement for wind power generation concrete tower comprises the following steps:

[0047] (1) 82.5 parts of clinker, 4 parts of gypsum and 3.5 parts of gravel are weighed by a weighing belt, discharged into a batching belt, transported to a weighing bin, and then sent to a roller press for extrusion after steady flow. Component A is obtained by extrusion of the roller press;

[0048] (2) Component A enters the V-type powder concentrator through the elevator. After the selection, the powder with a particle size of ≤45um accounts for ≥30% of the material. It is then mixed with 0.03 parts of grinding aid and added to the mill. It is ground by the double closed-circuit combined grinding system to obtain component B. The speed of the powder concentrator and the fan of the powder concentrator at the end of the grinding system reaches 39 Hz. The proportion of 12×14mm steel segments in the second bin of the grinding body in the mill is 32.82%, and the proportion of 10×12mm steel segments is 22.02%;

[0049] (3) 10 parts of mineral powder and component B are mixed in an air chute while controlling the factory temperature to obtain cement for wind power concrete towers.

[0050] Example 5

[0051] A method for preparing special cement for wind power generation concrete tower comprises the following steps:

[0052] (1) 82.5 parts of clinker, 4 parts of gypsum and 3.5 parts of gravel are weighed by a weighing belt, discharged into a batching belt, transported to a weighing bin, and then sent to a roller press for extrusion after steady flow. Component A is obtained by extrusion of the roller press;

[0053] (2) Component A enters the V-type powder concentrator through the elevator. After the selection, the powder with a particle size of ≤45um accounts for ≥30% of the material. It is then mixed with 0.05 parts of grinding aid and added to the mill. It is ground by the double closed-circuit combined grinding system to obtain component B. The speed of the powder concentrator and the fan of the powder concentrator at the end of the grinding system reaches 39 Hz. The proportion of 12×14mm steel segments in the second bin of the grinding body in the mill is 32.82%, and the proportion of 10×12mm steel segments is 22.02%;

[0054] (3) 10 parts of mineral powder and component B are mixed in an air chute while controlling the factory temperature to obtain cement for wind power concrete towers.

[0055] Example 6

[0056] A method for preparing special cement for wind power generation concrete tower comprises the following steps:

[0057] (1) 82.5 parts of clinker, 4 parts of gypsum and 3.5 parts of gravel are weighed by a weighing belt, discharged into a batching belt, transported to a weighing bin, and then sent to a roller press for extrusion after steady flow. Component A is obtained by extrusion of the roller press;

[0058] (2) Component A enters the V-type powder concentrator through the elevator. After selection, the powder with a particle size of ≤45um accounts for ≥30% of the material. It is then mixed with 0.1 part of a grinding aid and added to the mill. It is ground by a double closed-circuit combined grinding system to obtain component B. The speed of the powder concentrator and the fan of the powder concentrator at the end of the grinding system reaches 38 Hz. The proportion of 12×14mm steel segments in the second bin of the grinding body in the mill is 32.82%, and the proportion of 10×12mm steel segments is 22.02%;

[0059] (3) 10 parts of mineral powder and component B are mixed in an air chute while controlling the factory temperature to obtain cement for wind power concrete towers.

[0060] Example 7

[0061] A method for preparing special cement for wind power generation concrete tower comprises the following steps:

[0062] (1) 82.5 parts of clinker, 4 parts of gypsum and 3.5 parts of gravel are weighed by a weighing belt, discharged into a batching belt, transported to a weighing bin, and then sent to a roller press for extrusion after steady flow. Component A is obtained by extrusion of the roller press;

[0063] (2) Component A enters the V-type powder concentrator through the elevator. After selection, the powder with a particle size of ≤45um accounts for ≥30% of the material. It is then mixed with 0.15 parts of grinding aid and added to the mill. It is ground by the double closed-circuit combined grinding system to obtain component B. The speed of the powder concentrator and the fan of the powder concentrator at the end of the grinding system reaches 40 Hz. The proportion of 12×14mm steel segments in the second bin of the grinding body in the mill is 32.82%, and the proportion of 10×12mm steel segments is 22.02%;

[0064] (3) 10 parts of mineral powder and component B are mixed in an air chute while controlling the factory temperature to obtain cement for wind power concrete towers.

[0065] Comparative Example 1

[0066] The method for preparing a special cement for wind power generation concrete tower described in this comparative example is the same as that in Example 1, the only difference is that in step (1), 75 parts of clinker, 6.5 parts of gypsum and 6 parts of gravel are used.

[0067] Comparative Example 2

[0068] The method for preparing a special cement for wind power generation concrete tower described in this comparative example is the same as that in Example 1, except that the factory temperature in step (3) is controlled to be 74°C.

[0069] Comparative Example 3

[0070] The method for preparing a special cement for wind power generation concrete tower described in this comparative example is the same as that in Example 1, the only difference is that in step (2), the double closed-circuit combined grinding system only adopts a lowering table.

[0071] Comparative Example 4

[0072] The preparation method of a special cement for wind power generation concrete tower described in this comparative example is the same as that in Example 1, except that in step (3), the 12×14 mm steel segments in the second grinding body bin of the mill account for 26.79%, and the 10×12 mm steel segments account for 18%.

[0073] Performance Testing

[0074] The performance of the high temperature resistant unsaturated polyester resins prepared in the examples and comparative examples was tested. The specific test results are shown in Table 1.

[0075] The compressive strength of cement specially used for wind power concrete towers is tested for performance in accordance with GB / T17671-2021 "Cement mortar strength test".

[0076] The flexural strength of cement specially used for wind power concrete tower is tested with reference to GB / T17671-1999 "Test Method for Strength of Cement Mortar (ISO)".

[0077] The water requirement of cement specially used for wind power concrete tower is tested for performance according to GB / T1346-2011 "Test Methods for Water Consistency, Setting Time and Stability of Cement of Standard Consistency".

[0078] The specific surface area of ​​cement used for wind power concrete tower is tested for performance in accordance with GB / T8074-2008 "Determination of specific surface area of ​​cement - Blaine method".

[0079] The performance test of cement particle size distribution for wind power concrete tower is carried out according to JC / T721-2006 "Laser method for determination of cement particle size distribution".

[0080] The alkali content of cement used for wind power concrete towers is tested for performance in accordance with GB / T176-2008 “Chemical Analysis Methods for Cement”.

[0081] The performance test of the cement outlet temperature for wind power concrete towers is carried out in accordance with GB175-2023 "General Portland Cement".

[0082] Table 1 Performance test results of special cement for wind power generation concrete tower in embodiments and comparative examples

[0083] .

[0084] As shown in Table 1, the specific surface area of ​​the cement for wind power generation concrete tower provided by the present invention can reach 405m 2 / kg, the compressive strength can reach 35.0MPa in 3 days, the flexural strength can reach 6.9MPa in 3 days, the compressive strength can reach 66.3MPa in 28 days, the flexural strength can reach 10.2MPa in 28 days, the water consumption of cement standard consistency is 26.5%, the particle grading of 3~30um can reach 71.9%, and the alkali content is 0.55%.

[0085] It can be seen from the results of comparative example 1 that clinker is the main source of cement strength. When the proportion of clinker in the special cement for wind power concrete tower is low and the proportion of other auxiliary materials is high, its flexural strength is lower than the requirements of wind power concrete tower for cement performance; it can be seen from the results of comparative example 2 that when the factory temperature of the special cement for wind power concrete tower is higher than 70°C, the performance of the cement is seriously affected; it can be seen from the results of comparative example 3 that when the double closed-circuit combined grinding system only adopts the lowering table, it will lead to over-grinding and reduce the 3~30um content; therefore, the tail powder classifier adopts large ventilation and high speed, and the speed of the powder classifier and the powder classifier fan reaches 38~40 Hz; it can be seen from the results of comparative example 4 that the two-bin forging plays a role in grinding and spheroidization. When the proportion of 12×14mm and 10×12mm steel forgings is reduced, the specific surface area is reduced.

[0086] In summary, the special cement for wind power generation concrete tower provided by the present invention has the properties of high strength, high adaptability and low water demand; the cement factory temperature is controlled to be ≤70°C, which avoids the phenomenon of excessive slump, false setting and rapid setting of concrete, and can effectively promote the performance of cement; it has a large specific surface area and a high particle gradation of 3~30um.

[0087] The above is only a preferred embodiment of the present invention, and does not limit the present invention in other forms. Any technician familiar with the profession may use the above disclosed technical content to change or modify it into an equivalent embodiment with equivalent changes. However, any simple modification, equivalent change and modification made to the above embodiment according to the technical essence of the present invention without departing from the technical solution of the present invention still belongs to the protection scope of the technical solution of the present invention.

Claims

1. A special cement for wind power generation concrete tower, characterized by: The composition comprises the following components by weight: 80-85 parts of clinker, 3-5 parts of gypsum, 3-4 parts of gravel, 8-12 parts of mineral powder and grinding aid; the content of tetracalcium aluminoferrate in the clinker is ≥14%, and the content of alkali in the clinker is 0.45-0.55%; The preparation method comprises the following steps: (1) Add clinker, gypsum and stone into a roller press and squeeze them through the roller press to obtain component A; (2) Component A is selected by a powder selector, mixed with a grinding aid, and ground by a mill to obtain component B; (3) Mixing the mineral powder and the ground component B to obtain cement for wind power generation concrete tower; The powder selector in step (2) is a V-type powder selector. The feeding device of the V-type powder selector is composed of two parts, the first part is the upper step-breaking uniform part, and the second part is the lower material collection part. Component A is selected by the powder selector, and the powder with a particle size of ≤45um in the material after selection accounts for ≥30%; The powder classifier at the end of the mill adopts large ventilation and high speed. The speed of the powder classifier and the fan of the powder classifier reaches 38~40 Hz, and particles of 3~30um are selected; the obtained 3~30um particle grading of the special cement for wind power concrete tower is ≥70%.

2. The special cement for wind power generation concrete tower according to claim 1, characterized in that: The factory temperature of the special cement for wind power generation concrete tower is ≤70°C.

3. The special cement for wind power generation concrete tower according to claim 1, characterized in that: The content of sulfur trioxide in the gypsum is ≥40wt%.

4. The special cement for wind power generation concrete tower according to claim 1, characterized in that: The specific surface area of ​​the mineral powder is ≥400m 2 / kg.

5. The special cement for wind power generation concrete tower according to claim 1, characterized in that: The grinding aid is added in an amount of 0.05% to 0.15% of the total mass of the clinker, gypsum, gravel and mineral powder.