Hybrid material, method of making and use thereof

Abstract

The application relates to the technical field of building materials, and discloses a mixed material, a preparation method and application thereof. The preparation method comprises the following steps: adding sodium hydroxide into dry shield dried soil, adding water after the sodium hydroxide is added, and carrying out mixing and grinding, drying after the mixing and grinding, and obtaining powdered raw material; calcining the powdered raw material at 500-680 DEG C, and rapidly cooling after the calcination is completed, so as to obtain clinker; adding calcium hydroxide into the clinker and carrying out mixing and grinding, so as to obtain the mixed material. The examples of the application can stimulate the potential water hardness of the mixed material, so as to improve the activity of the mixed material when preparing sulphoaluminate cement.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of building materials, in particular to a mixed material, a preparation method and application thereof. BACKGROUND

[0002] The mixed material refers to a man-made or natural mineral material added into a mill together with clinker and gypsum during cement grinding to improve the performance of cement, adjust the grade of cement and increase the yield of cement.

[0003] In the related art, when preparing sulphoaluminate cement, anhydrous calcium sulphoaluminate and dicalcium silicate as main mineral compositions are prepared by calcining limestone, bauxite and gypsum with appropriate ingredients as raw materials, and then mixed with a mixed material for common grinding. However, sulphoaluminate cement has the characteristic of low alkalinity of hardened paste, which leads to low activity of the mixed material and defects of strength reduction of sulphoaluminate cement. SUMMARY

[0004] The purpose of the present application is to provide a mixed material, a preparation method and application thereof, which can stimulate the potential hydraulicity of the mixed material to improve the activity of the mixed material when preparing sulphoaluminate cement.

[0005] The present application provides a preparation method of a mixed material, which comprises:

[0006] Sodium hydroxide is added to dry shield dried soil, water is added after adding sodium hydroxide for mixing and grinding, and drying is performed after mixing and grinding to obtain powdered raw material;

[0007] The powdered raw material is calcined at 500-680℃, and then rapidly cooled after calcination to obtain clinker;

[0008] Calcium hydroxide is added to the clinker and mixed and ground to obtain the mixed material.

[0009] Preferably, the mass fraction of sodium hydroxide is 0.3-3.0wt%.

[0010] Preferably, the calcination time of the powdered raw material is 30-120 minutes.

[0011] Preferably, the mass fraction of calcium hydroxide is 0.1-3.0wt%.

[0012] Preferably, the rapid cooling is air cooling or water cooling, and when the rapid cooling is water cooling, drying is performed after the rapid cooling.

[0013] Preferably, the mass of water added is 45-55% of the mass of the shield dried soil after adding sodium hydroxide.

[0014] The present application also provides a mixed material prepared by the preparation method of the mixed material.

[0015] The application further provides application of the mixed material in preparation of the sulphoaluminate cement.

[0016] The application has the following beneficial effects:

[0017] (1) A method for preparing a mixed material by using shield dry soil, wherein a proper amount of sodium hydroxide is mixed in the shield dry soil for calcination activation, and a proper amount of calcium hydroxide is added in the grinding process, and the sodium hydroxide and the calcium hydroxide synergistically stimulate the potential hydraulicity of the mixed material. The mixing of the sodium hydroxide in the shield dry soil for calcination activation can deeply optimize the structure of the shield dry soil, effectively improve the activity of the mixed material, and the sodium hydroxide has better fluxing effect, which can reduce the activation temperature of the shield dry soil. The addition of the calcium hydroxide in the grinding process synergistically modifies the calcined shield dry soil and improves the low-alkalinity environment of the slurry. The calcium hydroxide with low solubility and slow rate can stably and long-term stimulate the potential hydraulicity of the alkali-modified shield dry soil, meet the demand of secondary hydration reaction of the modified shield dry soil, continuously generate hydration products, continuously improve the slurry structure, and significantly improve the mechanical properties.

[0018] (2) The mixed material prepared by the method is applied to the preparation of sulphoaluminate cement. The low-alkalinity characteristic of the hardened sulphoaluminate cement slurry is fully considered, and a relatively larger amount of sodium hydroxide is used to modify the shield dry soil. This not only deeply optimizes the structure of the shield dry soil, effectively improves the activity of the mixed material, but also improves the low-alkalinity environment of the sulphoaluminate hardened slurry. In addition, the relatively larger amount of sodium hydroxide has better fluxing effect, which can reduce the activation temperature of the shield dry soil. DETAILED DESCRIPTION

[0019] The application will be further described in detail below with reference to specific examples. It should be understood that the specific examples described herein are only used to explain the application and are not intended to limit the application.

[0020] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used in the description herein is for describing the embodiments of the application only and is not intended to limit the application.

[0021] The application provides a method for preparing a mixed material, which comprises:

[0022] The sodium hydroxide is mixed in the dry shield dry soil, water is added after the mixing of the sodium hydroxide, and the mixture is ground, and then dried to obtain a powdered raw material;

[0023] The powdered raw material is calcined at 500-680 DEG C, and then rapidly cooled to obtain a clinker;

[0024] The calcium hydroxide is mixed into the clinker and is mixed and ground to obtain the mixed material.

[0025] Preferably, the mass fraction of sodium hydroxide is 0.3-3.0wt%.

[0026] Preferably, the calcination time of the powdered raw material is 30-120 minutes.

[0027] Preferably, the mass fraction of calcium hydroxide is 0.1-3.0wt%.

[0028] Preferably, the quenching is air cooling or water cooling, and when the quenching is water cooling, drying is performed after the quenching is completed.

[0029] Preferably, the mass of the water added is 45-55% of the mass of the shield dried soil after the sodium hydroxide is added.

[0030] The application will be further described below in combination with specific examples.

[0031] The shield dried soil in the following examples and comparative examples is mixed from 55.4wt% silicon dioxide, 27.8wt% aluminum oxide, 6.3wt% triiron tetroxide, 3.2wt% potassium oxide, 2.1wt% magnesium oxide, 1.3wt% titanium dioxide, 2.0wt% calcium oxide, 1.3wt% sodium oxide and 0.6wt% impurities.

[0032] Example 1

[0033] According to the mass fraction of sodium hydroxide added in the raw material being 0.3wt%, 997.0g of the shield dried soil, 3.0g of sodium hydroxide and 450.0g of water are weighed and mixed and ground, the powdered raw material after drying is calcined at 680℃ for 40 minutes and is then subjected to water cooling and drying, to obtain the clinker. According to the mass fraction of calcium hydroxide being 3.0wt%, 970.0g of the clinker and 30.0g of calcium hydroxide are weighed and ground together to obtain the high-activity mixed material. The activity index of the mixed material is detected according to the standard GB / T12957-2005, and the result is shown in Table 1, and the activity index is qualified (>65%).

[0034] Example 2

[0035] According to the mass fraction of sodium hydroxide added in the raw material being 3.0wt%, 970.0g of the shield dried soil, 30.0g of sodium hydroxide and 550.0g of water are weighed and mixed and ground, the powdered raw material after drying is calcined at 500℃ for 120 minutes and is then subjected to water cooling and drying, to obtain the clinker. According to the mass fraction of calcium hydroxide being 2.0wt%, 980.0g of the clinker and 20.0g of calcium hydroxide are weighed and ground together to obtain the high-activity mixed material. The activity index of the mixed material is detected according to the standard GB / T12957-2005, and the result is shown in Table 1, and the activity index is qualified (>65%).

[0036] Example 3

[0037] According to the mass fraction of sodium hydroxide added in the raw material is 1.0wt%, shield dry soil 990.0g, 10.0g of sodium hydroxide and 500.0g of water are weighed and mixed and ground, and the dried powdered raw material is calcined at 650℃ for 30 minutes and then water cooled and dried to obtain clinker. According to the mass fraction of calcium hydroxide is 0.1wt%, 999.0g of clinker and 1.0g of calcium hydroxide are weighed and ground together to obtain high-activity mixed material. The activity index of the mixed material is detected according to GB / T12957-2005 standard, and the results are shown in Table 1. The activity index is qualified (>65%).

[0038] Example 4

[0039] According to the mass fraction of sodium hydroxide added in the raw material is 2.0wt%, shield dry soil 980.0g, 20.0g of sodium hydroxide and 500.0g of water are weighed and mixed and ground, and the dried powdered raw material is calcined at 650℃ for 100 minutes and then air cooled to obtain clinker. According to the mass fraction of calcium hydroxide is 2.0wt%, 980.0g of clinker and 20.0g of calcium hydroxide are weighed and ground together to obtain high-activity mixed material. The activity index of the mixed material is detected according to GB / T12957-2005 standard, and the results are shown in Table 1. The activity index is qualified (>65%).

[0040] Comparative Example 1

[0041] According to the mass fraction of sodium hydroxide added in the raw material is 2.0wt%, shield dry soil 980.0g, 20.0g of sodium hydroxide and 500.0g of water are weighed and mixed and ground, and the dried powdered raw material is calcined at 650℃ for 100 minutes and then water cooled and dried to obtain clinker. According to the mass fraction of calcium hydroxide is 0.01wt%, 999.9g of clinker and 0.1g of calcium hydroxide are weighed and ground together to obtain mixed material. The activity index of the mixed material is detected according to GB / T12957-2005 standard, and the results are shown in Table 1. The activity index is unqualified (<65%).

[0042] Comparative Example 2

[0043] According to the mass fraction of sodium hydroxide added in the raw material is 2.0wt%, shield dry soil 980.0g, 20.0g of sodium hydroxide and 500.0g of water are weighed and mixed and ground, and the dried powdered raw material is calcined at 650℃ for 100 minutes and then water cooled and dried to obtain clinker. According to the mass fraction of calcium hydroxide is 5.0wt%, 950.0g of clinker and 50.0g of calcium hydroxide are weighed and ground together to obtain mixed material. The activity index of the mixed material is detected according to GB / T12957-2005 standard, and the results are shown in Table 1. The activity index is unqualified (<65%).

[0044] Comparative Example 3

[0045] According to the mass fraction of sodium hydroxide added in raw material is 0.02wt%, shield dry soil 999.8g, 0.2g of sodium hydroxide and 450.0g of water were mixed and ground, and the dried powdery raw material was calcined at 650℃ for 100 minutes and then water-cooled and dried to obtain clinker. According to the mass fraction of calcium hydroxide is 2.0wt%, 980.0g of clinker and 20.0g of calcium hydroxide were ground together to obtain mixed material. The activity index of the mixed material was detected according to GB / T12957-2005 standard, and the results are shown in Table 1. The activity index is unqualified (<65%).

[0046] Comparative Example 4

[0047] According to the mass fraction of sodium hydroxide added in raw material is 5.0wt%, shield dry soil 950.0g, 50.0g of sodium hydroxide and 550.0g of water were mixed and ground, and the dried powdery raw material was calcined at 650℃ for 100 minutes and then water-cooled and dried to obtain clinker. According to the mass fraction of calcium hydroxide is 2.0wt%, 980.0g of clinker and 20.0g of calcium hydroxide were ground together to obtain mixed material. The activity index of the mixed material was detected according to GB / T12957-2005 standard, and the results are shown in Table 1. The activity index is unqualified (<65%).

[0048] Comparative Example 5

[0049] According to the mass fraction of sodium hydroxide added in raw material is 2.0wt%, shield dry soil 980.0g, 20.0g of sodium hydroxide and 500.0g of water were mixed and ground, and the dried powdery raw material was calcined at 400℃ for 120 minutes and then water-cooled and dried to obtain clinker. According to the mass fraction of calcium hydroxide is 2.0wt%, 980.0g of clinker and 20.0g of calcium hydroxide were ground together to obtain mixed material. The activity index of the mixed material was detected according to GB / T12957-2005 standard, and the results are shown in Table 1. The activity index is unqualified (<65%).

[0050] Comparative Example 6

[0051] According to the mass fraction of sodium hydroxide added in raw material is 2.0wt%, shield dry soil 980.0g, 20.0g of sodium hydroxide and 500.0g of water were mixed and ground, and the dried powdery raw material was calcined at 650℃ for 10 minutes and then water-cooled and dried to obtain clinker. According to the mass fraction of calcium hydroxide is 2.0wt%, 980.0g of clinker and 20.0g of calcium hydroxide were ground together to obtain mixed material. The activity index of the mixed material was detected according to GB / T12957-2005 standard, and the results are shown in Table 1. The activity index is unqualified (<65%).

[0052] Comparative Example 7

[0053] According to the mass fraction of sodium hydroxide added in raw material is 2.0wt%, shield dry soil 980.0g, 20.0g of sodium hydroxide and 500.0g of water were mixed and ground, and the dried powder raw material was calcined at 800℃ for 30 minutes and then water cooled and dried to obtain clinker. According to the mass fraction of calcium hydroxide is 2.0wt%, 980.0g of clinker and 20.0g of calcium hydroxide were ground together to obtain active admixture. The active index of the admixture was detected according to GB / T12957-2005 standard, and the results are shown in Table 1. The active index is qualified (>65%).

[0054] Comparative Example 8

[0055] According to the mass fraction of sodium hydroxide added in raw material is 2.0wt%, shield dry soil 980.0g, 20.0g of sodium hydroxide and 500.0g of water were mixed and ground, and the dried powder raw material was calcined at 680℃ for 240 minutes and then water cooled and dried to obtain clinker. According to the mass fraction of calcium hydroxide is 2.0wt%, 980.0g of clinker and 20.0g of calcium hydroxide were ground together to obtain active admixture. The active index of the admixture was detected according to GB / T12957-2005 standard, and the results are shown in Table 1. The active index is qualified (>65%).

[0056] Table 1

[0057]

[0058]

[0059] From Table 1, it can be seen that the addition of a little more alkali in the calcination process can optimize the structure of the shield dry soil, and can reduce the calcination temperature or time of the shield dry soil, thereby saving the production cost. At the same time, matching a small amount of calcium hydroxide as an activator can effectively promote the secondary hydration reaction of the shield dry soil to occur, and continuously improve the mechanical properties of the hardened paste. For example, in Example 4, the 28d active index of the hardened paste is as high as 87.3%.

[0060] Further, the shield dry soil admixture for sulphoaluminate cement can be prepared by controlling the preparation process parameters (alkali content / calcium hydroxide content / calcination system, etc.) to match the actual application requirements. As can be seen from Comparative Examples 1 and 2, too low or too high calcium hydroxide content during hydration will result in unqualified activity index, because too low calcium hydroxide content will not effectively stimulate the potential hydraulicity of the alkali modified shield dry soil; too high calcium hydroxide content will result in a significant decrease in the slurry fluidity and form a large number of pores. As can be seen from Comparative Examples 3 and 4, too low or too high alkali content during calcination will result in unqualified activity index of the shield dry soil, because a small amount of alkali cannot make the activated shield dry soil match the low-alkali environment of the sulphoaluminate cement slurry; excessive alkali will form residues and promote the hydration of calcium sulphoaluminate minerals and increase the defects of the hardened slurry. As can be seen from Comparative Examples 5 and 6, too low calcination temperature or too short calcination time will result in unqualified activity index, because the alkali modification reaction of the shield dry soil cannot effectively occur at this time. As can be seen from Comparative Examples 7 and 8, a significant increase in calcination temperature or time will result in a decrease in the activity index, because the active substances formed at the beginning will gradually be converted into inactive substances such as nepheline.

[0061] The above specifically illustrates and describes exemplary embodiments of the present disclosure. It should be understood that the present disclosure is not limited to the described arrangements or implementation methods; on the contrary, the present disclosure is intended to cover various modifications and equivalent arrangements included in the spirit and scope of the appended claims.

Claims

1. A method for preparing a mixed material, characterized in that: include: Sodium hydroxide is added to dry shield-dried soil, water is added after the addition of the sodium hydroxide, mixed and ground, and dried after the mixing and grinding to obtain a powdered raw material; the mass fraction of the sodium hydroxide is 0.3-3.0% of the mass of the shield-dried soil after the addition of the sodium hydroxide; The powdered raw material is calcined at 500-680° C. and rapidly cooled after calcination to obtain clinker; Calcium hydroxide is added to the clinker and mixed and ground to obtain a mixed material; the mass fraction of the calcium hydroxide is 2.0-3.0% of the mass of the clinker after the calcium hydroxide is added.

2. The method for preparing a mixed material according to claim 1, wherein: The powdered raw material is calcined for 30-120 minutes.

3. The method for preparing a mixed material according to claim 1, wherein: The rapid cooling is air cooling or water cooling. When the rapid cooling is water cooling, drying is performed after the rapid cooling is completed.

4. The method for preparing a mixed material according to claim 1, wherein: The mass of the water added is 45-55% of the mass of the shield dried soil after being mixed with the sodium hydroxide.

5. A mixed material prepared by the method for preparing a mixed material according to any one of claims 1 to 4.

6. Use of the admixture as claimed in claim 5 in the preparation of sulphoaluminate cement.

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