Preparation process of white sulphoaluminate cement clinker

Abstract

The invention discloses a preparation process of white sulphoaluminate cement clinker, which specifically comprises the following steps: S1, raw material preparation, S2, cement raw material preparation, and S4, calcining and grinding treatment, and relates to the technical field of sulphoaluminate cement clinker preparation. According to the preparation process of the white sulphoaluminate cement clinker, the strength of cement can be obviously improved by enriching the components of the early strength compound, the strength of the sulphoaluminate cement clinker is greatly improved, great impact is well resisted, the cement can be strictly desulfurized, and the quality of the cement is improved. According to the method, the content of harmful sulfides in cement is greatly reduced by grinding and screening the white sulphoaluminate cement clinker, and serious influence on the quality of the prepared cement is well avoided, so that the quality of the produced white sulphoaluminate cement clinker is ensured to be qualified, and the purpose of enabling the compactness of the cement to well meet the required requirement by grinding and screening the white sulphoaluminate cement clinker in batches for multiple times can be achieved.

Description

Technical Field

[0001] The invention relates to the technical field of sulphoaluminate cement clinker preparation, in particular to a process for preparing white sulphoaluminate cement clinker. Background Art

[0002] Sulphoaluminate cement is a new type of cement mainly composed of anhydrous calcium sulphoaluminate and dicalcium silicate. The mineral composition of this series of cement is characterized by a large amount of C4A3 minerals. This distinguishes it from other series of cement. It also constitutes the basic characteristics of the third series of cement, such as early strength, high strength, high impermeability, high frost resistance, corrosion resistance, low alkali and low production energy consumption. Sulphoaluminate clinker is mainly produced by crushing bauxite (SiO2≤14%, Al2O362%±1) and high calcium stone (SiO2≤2%, CaO≥52%) by crusher, and then mixing and grinding with gypsum in proportion by raw material drying and wind-sweeping mill, and then entering the preheater and decomposition furnace after passing through the homogenization tank, and finally calcining to the highest temperature of 1300℃ (a-Al2O3) in the dry rotary kiln to form a molten state.

[0003] Referring to a sulphoaluminate cement clinker preparation process with Chinese patent publication number CN113816628B, the amount of bauxite is reduced by adding inert alumina, effectively reducing production costs. At the same time, the original calcination process is adjusted to ensure a smooth production process and stable product quality, providing a new direction for the use of industrial solid waste.

[0004] With reference to a process for preparing Belite sulphoaluminate cement clinker by desulfurization of phosphogypsum with Chinese patent publication number CN115093135A, a low KH value ingredient is used to make the desulfurization effect of phosphogypsum good and stable, and considering the problem that the Belite sulphoaluminate cement clinker itself has a high Al2O3 content and thus has an adverse effect on the desulfurization effect of phosphogypsum, the IM value is restricted, thereby developing a method for efficiently desulfurizing phosphogypsum and preparing Belite sulphoaluminate cement clinker.

[0005] The existing sulphoaluminate cement clinker has poor strength and cannot withstand large impacts. Although the strength of cement is improved by adding early strength agents, the components of the early strength agents are single and the effect is not good. It is impossible to significantly improve the strength of cement by enriching the components of the early strength compound. At the same time, the existing cement is not thoroughly ground, resulting in large gaps between cement raw materials, which greatly reduces the compactness of cement mixing. It is impossible to achieve the purpose of achieving the required compactness of cement by performing multiple grinding and screening processes in batches, which brings great inconvenience to the preparation of sulphoaluminate cement clinker. Summary of the invention

[0006] 1. Technical issues to be solved

[0007] In view of the deficiencies in the prior art, the present invention provides a process for preparing white sulphoaluminate cement clinker, which solves the problem that the existing sulphoaluminate cement clinker has poor strength and cannot withstand large impacts. Although the strength of cement is improved by adding an early strength agent, the components of the early strength agent are single and the effect is not good, and it is impossible to achieve a significant improvement in the strength of cement by enriching the components of the early strength composite. At the same time, the existing cement is not thoroughly ground, resulting in large gaps between cement raw materials, which greatly reduces the compactness of the cement mixture, and it is impossible to achieve the problem of achieving the desired compactness of the cement by performing multiple grinding and screening processes in batches.

[0008] (II) Technical solution

[0009] To achieve the above objectives, the present invention is implemented by the following technical scheme: a process for preparing white sulphoaluminate cement clinker, specifically comprising the following steps:

[0010] S1. Preparation of raw materials: first, weigh 20-30 parts of alumina, 5-10 parts of high-calcium stone, 10-20 parts of bauxite, 10-20 parts of gypsum, 10-20 parts of composite raw materials, 5-10 parts of iron tailings, 5-10 parts of red mud, 5-10 parts of early strength compound and 3-5 parts of water reducer by weighing equipment;

[0011] S2, preparation of cement raw material: pour the raw materials weighed in step S1 into a drying device in turn, dry them at 50-70°C for 5-10 minutes, transfer them to a crushing and grinding device for breakage and grinding, and screen them through a 100-200 mesh sieve, and then pour the ground raw materials into a mixing device in turn for full mixing, thereby preparing cement raw material;

[0012] S3, calcination and grinding treatment: the cement raw material obtained in step S2 is transferred to a rotary kiln and calcined at a temperature of 1300-1400° C. for 2-3 hours, then taken out and cooled to 20-80° C. through a cooling device to obtain white sulphoaluminate cement clinker, and then the white sulphoaluminate cement clinker and a setting agent are sent to a grinding device together, and further ground through a 100-200 mesh sieve to obtain ultra-high whiteness white aluminate cement.

[0013] Preferably, the raw materials weighed for sulphoaluminate cement in step S1 include, by weight: 25 parts of alumina, 7 parts of calcium sulfate, 15 parts of bauxite, 15 parts of gypsum, 15 parts of composite raw materials, 7 parts of iron tailings, 7 parts of red mud, 7 parts of early strength compound and 4 parts of water reducer.

[0014] Preferably, the raw materials weighed for sulphoaluminate cement in step S1 include, by weight: 20 parts of alumina, 5 parts of calcium sulfate, 10 parts of bauxite, 10 parts of gypsum, 10 parts of composite raw materials, 5 parts of iron tailings, 5 parts of red mud, 5 parts of early strength compound and 3 parts of water reducer.

[0015] Preferably, the raw materials weighed for sulphoaluminate cement in step S1 include, by weight: 30 parts of alumina, 10 parts of calcium sulfate, 20 parts of bauxite, 20 parts of gypsum, 20 parts of composite raw materials, 10 parts of iron tailings, 10 parts of red mud, 10 parts of early strength compound and 5 parts of water reducer.

[0016] Preferably, the composite raw material is one or a combination of two or more of limestone, chalk, shell, carbide slag or quicklime.

[0017] Preferably, the early strength compound is a combination of two or more of sodium silicate, sodium carbonate, sodium gluconate, magnesium carbonate, sodium bisulfate, calcium sulfate, sodium dihydrogen phosphate, ammonium chloride, potassium aluminum sulfate, aluminum chloride or potassium hydroxide.

[0018] Preferably, in step S2, when crushing and grinding each raw material using a crushing and grinding device, a batch feeding and grinding process is adopted, 20-30% of the total raw material is added at a time, and after sufficient grinding, another 20-30% of the total raw material is added and repeated until all the raw materials are ground, so that each raw material can be fully ground in the chassis.

[0019] Preferably, the mixing device in step S2 is a tumbling mixer, and after the powders are added into the silo of the tumbling mixer, the tumbling mixer is started so that the silo drives the powders inside to be tumbled and mixed continuously.

[0020] Preferably, the setting regulator in step S4 is one of a setting accelerator, a setting accelerator and a setting retarder.

[0021] (III) Beneficial effects

[0022] The present invention provides a process for preparing white sulphoaluminate cement clinker. Compared with the prior art, the present invention has the following beneficial effects:

[0023] (1) The white sulphoaluminate cement clinker preparation process can significantly improve the strength of cement by enriching the components of the early strength compound, greatly improve the strength of the sulphoaluminate cement clinker, and well resist large impacts, thereby ensuring the quality of the white sulphoaluminate cement clinker produced.

[0024] (2) The white sulphoaluminate cement clinker preparation process can achieve the purpose of achieving the required compactness of cement by performing multiple grinding and screening processes in batches. By thoroughly grinding the cement raw materials, the gaps between the cement raw materials will not be too large, which greatly improves the compactness of the cement mixture, thereby greatly facilitating the preparation of sulphoaluminate cement clinker. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is a process flow chart of the present invention. DETAILED DESCRIPTION

[0026] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0027] See also Figure 1 The embodiment of the present invention provides three technical solutions: a process for preparing white sulphoaluminate cement clinker, specifically including the following embodiments:

[0028] Example 1

[0029] A process for preparing white sulphoaluminate cement clinker, specifically comprising the following steps:

[0030] S1. Preparation of raw materials: First, 25 parts of alumina, 7 parts of high-calcium stone, 15 parts of bauxite, 15 parts of gypsum, 15 parts of composite raw materials, 7 parts of iron tailings, 7 parts of red mud, 7 parts of early strength compounds and 4 parts of water reducers are measured by weighing equipment. The composite raw materials are a combination of limestone, chalk, shell, carbide slag and quicklime, and the early strength compound is a combination of sodium silicate, sodium carbonate, sodium gluconate, magnesium carbonate, sodium hydrogen sulfate, calcium sulfate, sodium dihydrogen phosphate, ammonium chloride, potassium aluminum sulfate, aluminum chloride and potassium hydroxide;

[0031] S2, preparation of cement raw material: pour the raw materials weighed in step S1 into the drying equipment in turn, dry them at 50-70℃ for 5-10min, transfer them to the crushing and grinding equipment for breakage and grinding, and screen them through a 100-200 mesh screen, and then pour the raw materials after grinding into the mixing equipment in turn for full mixing, so as to obtain cement raw material, when crushing and grinding the raw materials with the crushing and grinding equipment, batch feeding and grinding are adopted, 20-30% of the raw materials of the total materials are added at one time, and after full grinding, 20-30% of the raw materials of the total materials are added again, and this is repeated until all the raw materials are ground, so that all the raw materials can be fully ground in the chassis, and the mixing equipment adopts a tumbling mixer, after adding each powder into the silo of the tumbling mixer, the tumbling mixer is started, so that the silo drives each powder inside to continuously tumble and mix;

[0032] S3, calcination and grinding treatment: the cement raw material obtained in step S2 is transferred to a rotary kiln and calcined at a temperature of 1300-1400° C. for 2-3 hours, then taken out and cooled to 20-80° C. by a cooling device to obtain white sulphoaluminate cement clinker, and then the white sulphoaluminate cement clinker and a setting regulator are sent to a grinding device together, and continue to be ground through a 100-200 mesh sieve to obtain ultra-high whiteness white aluminate cement, and the setting regulator is one of a setting accelerator, a setting accelerator and a setting retarder.

[0033] Example 2

[0034] A process for preparing white sulphoaluminate cement clinker, specifically comprising the following steps:

[0035] S1. Preparation of raw materials: First, 20 parts of alumina, 5 parts of high-calcium stone, 10 parts of bauxite, 10 parts of gypsum, 10 parts of composite raw materials, 5 parts of iron tailings, 5 parts of red mud, 5 parts of early strength compound and 3 parts of water reducer are measured by weighing equipment respectively. The composite raw material is a combination of one or more of limestone, chalk, shell, carbide slag or quicklime, and the early strength compound is a combination of sodium silicate, sodium carbonate, sodium gluconate, magnesium carbonate, sodium hydrogen sulfate and calcium sulfate.

[0036] S2, preparation of cement raw material: pour the raw materials weighed in step S1 into the drying equipment in turn, dry them at 50-70℃ for 5-10min, transfer them to the crushing and grinding equipment for breakage and grinding, and screen them through a 100-200 mesh screen, and then pour the raw materials after grinding into the mixing equipment in turn for full mixing, so as to obtain cement raw material, when crushing and grinding the raw materials with the crushing and grinding equipment, batch feeding and grinding are adopted, 20-30% of the raw materials of the total materials are added at one time, and after full grinding, 20-30% of the raw materials of the total materials are added again, and this is repeated until all the raw materials are ground, so that all the raw materials can be fully ground in the chassis, and the mixing equipment adopts a tumbling mixer, after adding each powder into the silo of the tumbling mixer, the tumbling mixer is started, so that the silo drives each powder inside to continuously tumble and mix;

[0037] S3, calcination and grinding treatment: the cement raw material obtained in step S2 is transferred to a rotary kiln and calcined at a temperature of 1300-1400° C. for 2-3 hours, then taken out and cooled to 20-80° C. by a cooling device to obtain white sulphoaluminate cement clinker, and then the white sulphoaluminate cement clinker and a setting regulator are sent to a grinding device together, and continue to be ground through a 100-200 mesh sieve to obtain ultra-high whiteness white aluminate cement, and the setting regulator is one of a setting accelerator, a setting accelerator and a setting retarder.

[0038] Example 3

[0039] A process for preparing white sulphoaluminate cement clinker, specifically comprising the following steps:

[0040] S1. Preparation of raw materials: First, 30 parts of alumina, 10 parts of high-calcium stone, 20 parts of bauxite, 20 parts of gypsum, 20 parts of composite raw materials, 10 parts of iron tailings, 10 parts of red mud, 10 parts of early strength compound and 5 parts of water reducer are measured by weighing equipment respectively. The composite raw material is a combination of one or more of limestone, chalk, shell, carbide slag or quicklime, and the early strength compound is a combination of sodium dihydrogen phosphate, ammonium chloride, potassium aluminum sulfate, aluminum chloride and potassium hydroxide;

[0041] S2, preparation of cement raw material: pour the raw materials weighed in step S1 into the drying equipment in turn, dry them at 50-70℃ for 5-10min, transfer them to the crushing and grinding equipment for breakage and grinding, and screen them through a 100-200 mesh screen, and then pour the raw materials after grinding into the mixing equipment in turn for full mixing, so as to obtain cement raw material, when crushing and grinding the raw materials with the crushing and grinding equipment, batch feeding and grinding are adopted, 20-30% of the raw materials of the total materials are added at one time, and after full grinding, 20-30% of the raw materials of the total materials are added again, and this is repeated until all the raw materials are ground, so that all the raw materials can be fully ground in the chassis, and the mixing equipment adopts a tumbling mixer, after adding each powder into the silo of the tumbling mixer, the tumbling mixer is started, so that the silo drives each powder inside to continuously tumble and mix;

[0042] S3, calcination and grinding treatment: the cement raw material obtained in step S2 is transferred to a rotary kiln and calcined at a temperature of 1300-1400° C. for 2-3 hours, then taken out and cooled to 20-80° C. by a cooling device to obtain white sulphoaluminate cement clinker, and then the white sulphoaluminate cement clinker and a setting regulator are sent to a grinding device together, and continue to be ground through a 100-200 mesh sieve to obtain ultra-high whiteness white aluminate cement, and the setting regulator is one of a setting accelerator, a setting accelerator and a setting retarder.

[0043] Application examples:

[0044] By utilizing existing cement kilns, cement mills and other process facilities, without increasing any capital investment, a solution for the preparation process of white sulphoaluminate cement clinker is studied and developed, and high-quality cement clinker is produced. The process of the present invention solves the problem that the existing sulphoaluminate cement clinker has poor strength and cannot resist large impacts by selecting the raw material rate value and optimizing the desulfurization and grinding process. Although the strength of cement is improved by adding an early strength agent, the early strength agent has a single component and poor effect, and it is impossible to achieve a significant improvement in the strength of cement by enriching the components of the early strength compound. At the same time, the existing cement grinding is not thorough, resulting in large gaps between cement raw materials, greatly reducing the compactness of cement mixing, and it is impossible to achieve the problem of achieving the desired compactness of cement by performing multiple grinding and screening processes in batches. The social and economic benefits are obvious, and it can be promoted and applied on a large scale, and it has strong practicality.

[0045] The chemical composition of raw materials of various embodiments and existing cement is shown in Table 1:

[0046] Table 1: Chemical composition of each raw material

[0047] project CaO <![CDATA[SiO2]]> <![CDATA[Al2O3]]> <![CDATA[Fe2O3]]> MgO <![CDATA[SO3]]> <![CDATA[K2O]]> <![CDATA[Na2O]]> loss Example 2 44.80 7.88 2.10 1.27 2.58 0.18 0.92 0.10 39.58 Example 1 7.08 54.77 14.22 2.22 3.13 0.65 0.51 0.26 16.15 Example 3 4.98 64.90 1.28 16.20 4.05 0.06 0.16 0.14 2.57 Existing cement 4.98 71.90 1.28 11.20 4.05 0.06 0.16 0.14 2.57

[0048] It can be seen from Table 1 that the chemical composition of the white sulphoaluminate cement clinker prepared in Example 1 of the present invention best meets the actual needs, and the white sulphoaluminate cement clinker prepared in Example 1 of the present invention is subjected to chemical analysis, and its proportion analysis is shown in Table 2:

[0049] Table 2: Chemical analysis data table

[0050]

[0051] In Table 2, the clinker ratio values ​​are saturation ratio KH = 0.91 ± 0.02, silicon ratio SM = 2.50 ± 0.1, and aluminum ratio IM = 1.50 ± 0.1.

[0052] In summary, the present invention can achieve a significant improvement in the strength of cement by enriching the components of the early-strength composite material, greatly improve the strength of sulphoaluminate cement clinker, and well resist large impacts. The purpose of achieving the desired compactness of cement can be achieved by performing multiple grinding and screening processes in batches. By thoroughly grinding the cement raw materials, the gaps between the cement raw materials will not be too large, which greatly improves the compactness of the cement mixture, thereby greatly facilitating the preparation of sulphoaluminate cement clinker.

[0053] Meanwhile, the contents not described in detail in this specification belong to the prior art known to those skilled in the art.

[0054] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device.

[0055] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A process for preparing white sulphoaluminate cement clinker, characterized in that: The specific steps include: S1. Preparation of raw materials: first, weigh 20-30 parts of alumina, 5-10 parts of high-calcium stone, 10-20 parts of bauxite, 10-20 parts of gypsum, 10-20 parts of composite raw materials, 5-10 parts of iron tailings, 5-10 parts of red mud, 5-10 parts of early strength compound and 3-5 parts of water reducer by weighing equipment; S2, preparation of cement raw material: pour the raw materials weighed in step S1 into a drying device in turn, dry them at 50-70°C for 5-10 minutes, transfer them to a crushing and grinding device for breakage and grinding, and screen them through a 100-200 mesh sieve, and then pour the ground raw materials into a mixing device in turn for full mixing, thereby preparing cement raw material; S3, calcination and grinding treatment: the cement raw material obtained in step S2 is transferred to a rotary kiln and calcined at a temperature of 1300-1400° C. for 2-3 hours, then taken out and cooled to 20-80° C. through a cooling device to obtain white sulphoaluminate cement clinker, and then the white sulphoaluminate cement clinker and a setting agent are sent to a grinding device together, and further ground through a 100-200 mesh sieve to obtain ultra-high whiteness white aluminate cement.

2. A process for preparing white sulphoaluminate cement clinker according to claim 1, characterized in that: The raw materials weighed for sulphoaluminate cement in step S1 include, by weight: 25 parts of alumina, 7 parts of calcium sulfate, 15 parts of bauxite, 15 parts of gypsum, 15 parts of composite raw materials, 7 parts of iron tailings, 7 parts of red mud, 7 parts of early strength compound and 4 parts of water reducing agent.

3. A process for preparing white sulphoaluminate cement clinker according to claim 1, characterized in that: The raw materials weighed for sulphoaluminate cement in step S1 include, by weight: 20 parts of alumina, 5 parts of calcium sulfate, 10 parts of bauxite, 10 parts of gypsum, 10 parts of composite raw materials, 5 parts of iron tailings, 5 parts of red mud, 5 parts of early strength compound and 3 parts of water reducing agent.

4. A process for preparing white sulphoaluminate cement clinker according to claim 1, characterized in that: The raw materials weighed for sulphoaluminate cement in step S1 include, by weight: 30 parts of alumina, 10 parts of calcium sulfate, 20 parts of bauxite, 20 parts of gypsum, 20 parts of composite raw materials, 10 parts of iron tailings, 10 parts of red mud, 10 parts of early strength compound and 5 parts of water reducing agent.

5. A process for preparing white sulphoaluminate cement clinker according to any one of claims 1 to 4, characterized in that: The composite raw material is one or a combination of two or more of limestone, chalk, shell, carbide slag or quicklime.

6. A process for preparing white sulphoaluminate cement clinker according to any one of claims 1 to 4, characterized in that: The early strength compound is a combination of two or more of sodium silicate, sodium carbonate, sodium gluconate, magnesium carbonate, sodium hydrogen sulfate, calcium sulfate, sodium dihydrogen phosphate, ammonium chloride, potassium aluminum sulfate, aluminum chloride or potassium hydroxide.

7. A process for preparing white sulphoaluminate cement clinker according to claim 1, characterized in that: In step S2, when crushing and grinding each raw material using the crushing and grinding equipment, batch feeding and grinding are adopted, 20-30% of the total raw material is added at one time, and after sufficient grinding, 20-30% of the total raw material is added again, and this is repeated until all the raw materials are ground, so that each raw material can be fully ground in the chassis.

8. A process for preparing white sulphoaluminate cement clinker according to claim 1, characterized in that: The mixing device in step S2 is a tumbling mixer. After the powders are added into the silo of the tumbling mixer, the tumbling mixer is started to drive the powders inside the silo to continuously tumble and mix.

9. A process for preparing white sulphoaluminate cement clinker according to claim 1, characterized in that: In step S3, the setting regulator is one of a setting accelerator, a setting accelerator and a setting retarder.

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