Multi-variety universal cement clinker, preparation method and application thereof

Abstract

The application discloses a multi-variety general-purpose cement clinker and a preparation method and application thereof. The multi-variety general-purpose cement clinker is prepared from the following raw materials in percentage by mass: 83.5-85.0% of calcium material, 8.5-9.5% of silicon correction material, 3.7-4.5% of iron correction material and 2.8-3.5% of aluminum correction material. The cement clinker has a KH value of 0.83-0.87, a silicon ratio of 2.5-2.9, an aluminum ratio of 0.5-0.9 and an R2O value of less than 0.6%. The multi-variety general-purpose cement clinker and the preparation method and application thereof can meet the requirements of different special cements on the cement clinker by controlling the composition of the cement clinker and the preparation process of the cement clinker, so that the cement clinker has a wider application range and solves the technical problems of management, resource waste and energy consumption caused by the use of different cement clinkers for different cements.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of cement manufacturing, and particularly relates to a multi-variety general-purpose cement clinker and a preparation method and application thereof. BACKGROUND

[0002] With the continuous development of society, users have more and more special requirements for cement, and ordinary Portland cement cannot obviously meet the market requirements. Therefore, cement varieties are divided into Portland cement, ordinary Portland cement, slag Portland cement, fly ash Portland cement, pozzolanic Portland cement, composite Portland cement and other special cements according to the types of mixed materials added, such as road Portland cement, sulfate-resistant Portland cement, G-grade oil well cement, A-grade oil well cement, low-heat, medium-heat Portland cement, and Portland cement for nuclear power engineering.

[0003] Portland cement clinker is defined as a product with calcium silicate as the main component, which is calcined from raw materials with appropriate components to partial melting.

[0004] Cement clinker is divided into general-purpose Portland clinker, low-alkali cement clinker, medium-sulfate-resistant cement clinker, high-sulfate-resistant cement clinker, medium-heat cement clinker, low-heat cement clinker, road cement clinker, and (G-grade and A-grade) oil well cement clinker according to the use and characteristics. The physical and chemical properties of these varieties of cement clinker are different, and the raw materials need to be matched and calcined according to the characteristics of each category during production to obtain different varieties of clinker.

[0005] However, the above cement clinker has the following disadvantages:

[0006] (1) Different varieties of cement have different requirements for clinker indexes, and the raw material ratio, calcination time and calcination temperature and other parameters need to be adjusted during production, which affects the thermal system and cannot ensure the stability of the average value, increasing energy consumption.

[0007] (2) Different varieties of clinker need to be stored in designated clinker warehouses (areas), and most cement plants cannot meet the separate storage of multi-variety clinker.

[0008] (3) Different varieties of cement need to be stored in designated cement warehouses, and a large number of cement warehouses need to be built due to the large number of Portland cement varieties, which most cement enterprises cannot meet.

[0009] (4) When the clinker is replaced, a certain amount of transition material will be produced, which can only be used at a lower level, causing resource waste and increasing costs.

[0010] (5) Different varieties of clinker in the production of varieties, due to the change of raw material batching, the calcination temperature will be adjusted accordingly, will lead to kiln system fluctuation, thermal system changes, affect the desulfurization and denitrification effect, increase the environmental pressure.

[0011] Therefore, the present application provides a new cement clinker and its preparation method and application, which solves the technical problems caused by different cement clinkers for different varieties of cement and meets the performance requirements of multi-variety cement. SUMMARY

[0012] The application aims to provide a multi-variety universal cement clinker, which balances different components in the cement clinker, allowing multi-variety cement to use the same clinker, and is a multi-variety universal clinker, which is more convenient for unified storage management and avoids resource waste.

[0013] To achieve the above purpose, the technical scheme adopted is:

[0014] A multi-variety universal cement clinker is prepared from the following raw materials in mass percentage:

[0015] Calcium material 83.5-85.0%, silicon correction material 8.5-9.5%, iron correction material 3.7-4.5%, and aluminum correction material 2.8-3.5%;

[0016] The cement clinker has a rate value: KH is 0.83-0.87, silicon rate is 2.5-2.9, aluminum rate is 0.5-0.9, and R2O is less than 0.6%.

[0017] Further, the calcium material has CaO≥50%, MgO≤3.0%, R2O≤0.5%, and particle size≤500mm;

[0018] The silicon correction material has SiO2≥80%, R2O≤1.5%, and water content≤5.0%;

[0019] The iron correction material has Fe2O3≥40%, R2O≤1.8%, and water content≤12%;

[0020] The aluminum correction material has R2O≤1.5%, Al2O3≥15%, and water content≤10%.

[0021] Further, the calcium material is limestone;

[0022] The iron correction material is iron powder;

[0023] The silicon correction material is sandstone or silica;

[0024] The aluminum correction material is shale and bauxite.

[0025] Further, the physical properties of the cement clinker are as follows:

[0026] (1) 3d flexural strength is 4.3-5.3Mpa, 7d flexural strength is 5.8-6.5Mpa, 28d flexural strength is 8.3-8.7Mpa; 3d compressive strength is 18.3-22.4Mpa, 7d compressive strength is 29.2-34.2Mpa, 28d compressive strength is 52.0-55.5Mpa;

[0027] (2) 3d hydration heat is 220-243kJ / kg, 7d hydration heat is 269-290kJ / kg.

[0028] Another object of the present application is to provide a preparation method of a multi-variety universal cement clinker, which reduces fluctuation to the calcining kiln system while reducing energy consumption and improving economic benefits.

[0029] In order to achieve the above object, the technical scheme adopted is:

[0030] A preparation method of a multi-variety universal cement clinker, comprising the following steps:

[0031] (1) crushing, grinding calcium material, silicon correction material, iron correction material and aluminum correction material to obtain raw material;

[0032] The calcium material is 83.5-85.0% by mass percentage, the silicon correction material is 8.5-9.5%, the iron correction material is 3.7-4.5%, and the aluminum correction material is 2.8-3.5%.

[0033] (2) preheating the raw material, calcining at 1300-1350℃ for 30-60min, and then rapidly cooling to room temperature to obtain the cement clinker.

[0034] Further, in the step (1), the grinding is to pass through an 80-micron square hole sieve, and the fineness of the raw material discharged from the mill is ≤15%;

[0035] In the step (2), the cooling is to room temperature within 10-15min.

[0036] Further, the calcium material: CaO≥50%, MgO≤3.0%, R2O≤0.5%, and particle size≤500mm;

[0037] The silicon correction material: SiO2≥80%, R2O≤1.5%, and moisture≤5.0%;

[0038] The ferruginous correction material: Fe2O3 is greater than or equal to 40%, R2O is less than or equal to 1.8%, and moisture is less than or equal to 12%;

[0039] The aluminous correction material: R2O is less than or equal to 1.5%, Al2O3 is greater than or equal to 15%, and moisture is less than or equal to 10%.

[0040] Further, the calcareous material is limestone,

[0041] The ferruginous correction material is iron powder;

[0042] The siliceous correction material is sandstone and silica;

[0043] The aluminous correction material is shale and bauxite.

[0044] Further, in the step (1), the control range of Cao in the raw material is ±0.3%, the control range of Fe2O3 is ±0.2%, KH is 0.86-0.90, the silicon rate is 2.3-2.7, and the aluminum rate is 0.5-0.9.

[0045] The application also has an application purpose of providing a multi-variety universal cement clinker, which has a wider application range and solves the technical problems caused by different cement clinkers for different varieties of cement.

[0046] The cement clinker is applied in Portland cement, G-grade oil well cement, A-grade oil well cement, moderate heat Portland cement, ordinary Portland cement, Portland cement, high-sulfur-resistant Portland cement and road Portland cement.

[0047] Compared with the prior art, the application has the following beneficial effects:

[0048] 1. The cement clinker has the characteristics of low hydration heat, low chloride ion, low alkali content, high resistance to sulfate ion erosion, high wear resistance, moderate thickening time and high strength, and has the properties of various cements, so as to meet the requirements of various cements on the cement clinker and be applied in Portland cement, G-grade oil well cement, A-grade oil well cement, moderate heat Portland cement, ordinary Portland cement, Portland cement, high-sulfur-resistant Portland cement and road Portland cement.

[0049] 2、The cement clinker in the preparation process, calcination temperature is between 1300-1350℃, relative to ordinary Portland cement clinker 1450℃, can greatly reduce energy consumption; also can reduce the raw material loss in the sintering process, reduce production cost, clinker quality stable, the production and running rate is improved.

[0050] 3、The cement clinker in the preparation process, by quenching to room temperature, the mineral crystal C2S in the prepared clinker, round particle type, shape regular, boundary is obvious and size is smaller, therefore the clinker is easy to grind, and it creates conditions for reducing power consumption of cement grinding process.

[0051] 4、The finished cement made of the cement clinker, the content of dicalcium silicate (C2S) is high, which is more conducive to generating stable hydration products at high temperature, and is beneficial to the high temperature mechanical properties of cement, and more effectively improves the high temperature strength stability, the performance of resistance to sulfate and high temperature is excellent in the test, and the quality is more stable in the later use process. And high content of dicalcium silicate makes the later strength stable growth, the hydration slurry is dense, and the impermeability is good. High content of tetracalcium aluminoferrite (C4AF) makes the 28-day flexural strength of the finished cement product reach more than 8.5MPa, so that the cement has good wear resistance. DETAILED DESCRIPTION

[0052] In order to further illustrate the application of a kind of multi-species universal cement clinker and its preparation method, achieve the intended purpose of the application, the following preferred embodiments, according to the application of a kind of multi-species universal cement clinker and its preparation method, application, its specific implementation, structure, characteristics and its efficacy, detailed description as follows. In the following description, different "an embodiment" or "embodiments" do not necessarily refer to the same embodiment. In addition, the specific features, structures or characteristics of one or more embodiments can be combined in any suitable form.

[0053] Before detailing the application of a kind of multi-species universal cement clinker and its preparation method, it is necessary to further illustrate the related materials mentioned in the application, in order to achieve better results.

[0054] Cement clinker is divided into: general Portland clinker, low alkali cement clinker, medium sulfate-resistant cement clinker, high sulfate-resistant cement clinker, medium heat cement clinker and low heat cement clinker, road cement clinker and (G, A) oil well cement clinker, etc. according to use and characteristics. The physical and chemical properties of these varieties of cement clinker are shown in Tables 1-6.

[0055] Table 1 Basic chemical index requirements of Portland cement clinker

[0056]

[0057] Table 2 Property Chemical performance (clinker, %)

[0058]

[0059]

[0060] Table 3 Cement clinker compressive strength

[0061]

[0062] Table 4 Cement mineral composition of each variety (%)

[0063] [C3A] [C3S] [C2S] [C4AF] Sulphate resisting cement clinker ≤3.0 ≤50.0 - - Moderate heat cement clinker - ≤55.0 - - Cement clinker for nuclear power engineering ≤7.0 ≤57.0 - - Road portland cement clinker ≤5.0 - - ≥15.0 G-class oil well clinker ≤3.0 48-65 - - A-class oil well clinker - - - -

[0064] Table 5 National standard of cement chemical composition of each variety (%)

[0065] LOSS Cl - ]] SO3 Insoluble matter MgO [R2O] f-CaO High sulphate resisting cement ≤3.0 - ≤2.5 ≤1.50 ≤5.0 ≤0.60 - Moderate heat cement ≤3.0 - ≤3.5 - ≤5.0 ≤0.60 - Cement for nuclear power engineering ≤3.0 0.06 ≤3.0 ≤0.75 ≤5.0 ≤0.60 ≤1.0 Road portland cement ≤3.0 0.06 ≤3.5 - ≤5.0 ≤0.60 ≤1.0 G-class oil well cement ≤3.0 - ≤3.0 - ≤6.0 ≤0.75 - A-class oil well cement ≤3.0 - ≤3.5 ≤0.75 ≤6.0 - -

[0066] Table 6 National standard of cement physical test of each variety

[0067]

[0068] After understanding the related materials mentioned in the application, the following will combine specific examples to further introduce the multi-variety universal cement clinker, its preparation method and application in detail:

[0069] In order to solve the technical problems in management, resources, production system and other aspects caused by different cement clinkers for different varieties of cement, the application provides a multi-variety universal cement clinker, its preparation method and application, and the technical scheme adopted is:

[0070] A multi-variety universal cement clinker is prepared from the following raw materials in mass percentage:

[0071] 83.5-85.0% of calcium material, 8.5-9.5% of silicon correction material, 3.7-4.5% of iron correction material and 2.8-3.5% of aluminum correction material;

[0072] The cement clinker has a rate value of KH of 0.83-0.87, a silicon rate of 2.5-2.9, an aluminum rate of 0.5-0.9 and R2O < 0.6%.

[0073] Preferably, the calcium material has CaO ≥ 50%, MgO ≤ 3.0%, R2O ≤ 0.5% and a particle size ≤ 500 mm;

[0074] The silicon correction material has SiO2 ≥ 80%, R2O ≤ 1.5% and water content ≤ 5.0%;

[0075] The iron correction material: Fe2O3≥40%, R2O≤1.8%, moisture≤12%;

[0076] The aluminum correction material: R2O≤1.5%, Al2O3≥15%, moisture≤10%.

[0077] Preferably, the calcareous material is limestone;

[0078] The iron correction material is iron powder;

[0079] The siliceous correction material is sandstone / silica;

[0080] The aluminum correction material is shale / bauxite.

[0081] In the above technical solution, the rate values of the cement clinker adopt the conventional meanings in the field, and are specifically as follows: KH represents a lime saturation coefficient, which refers to the saturation degree of silicon dioxide by calcium oxide, and its calculation formula is as follows: KH=(CaO-1.85*Al2O3-0.35*Fe2O3) / 2.8*SiO2. The silicon rate is a silica rate (N value), which is calculated by the proportion of silicon dioxide and the sum of aluminum trioxide and iron trioxide, and the formula is as follows: SM=SiO2 / (Al2O3+Fe2O3). The aluminum rate (P value) is calculated by the proportion of aluminum trioxide and iron trioxide, and the formula is as follows: IM=Al2O3 / Fe2O3.

[0082] The content of R2O represents the alkali content of the cement clinker, which is obtained by calculating the content of potassium oxide and the content of sodium oxide, and the calculation formula is as follows: R2O=0.658*K2O+Na2O.

[0083] Preferably, the physical properties of the cement clinker are as follows:

[0084] (1) Its 3d flexural strength is 4.3-5.3Mpa, 7d flexural strength is 5.8-6.5Mpa, and 28d flexural strength is 8.3-8.7Mpa; its 3d compressive strength is 18.3-22.4Mpa, 7d compressive strength is 29.2-34.2Mpa, and 28d compressive strength is 52.0-55.5Mpa;

[0085] (2) Its 3d hydration heat is 220-243kJ / kg, and 7d hydration heat is 269-290kJ / kg.

[0086] The cement produced by the cement clinker has the characteristics of low hydration heat, low chloride ion, low alkali content, resistance to sulfate ion erosion, high wear resistance, moderate thickening time and high strength, has the characteristics of various cements, and has a wider application range than single variety cement clinker, can solve the problems of occupying storage resources due to the separate storage of different varieties of clinker in a cement plant, and facilitates unified storage management.

[0087] A preparation method of a multi-variety universal cement clinker, comprising the following steps:

[0088] (1) crushing, grinding calcium material, siliceous correction material, iron correction material and aluminum correction material to obtain raw material;

[0089] The calcium material is 83.5-85.0% by mass percentage, the siliceous correction material is 8.5-9.5%, the iron correction material is 3.7-4.5%, and the aluminum correction material is 2.8-3.5%.

[0090] (2) the raw material is preheated and calcined at 1300-1350℃ for 30-60min, and then rapidly cooled to room temperature to obtain the cement clinker.

[0091] In the above technical solution, the preheating process of the raw material is a conventional preheating decomposition process in the art, which is preheated and decomposed at 300-330, 400-500, 500-600, 700-800 and 850-900℃ in turn, and then enters the rotary kiln for calcination.

[0092] In the preparation process of the cement clinker, the calcination temperature is between 1300-1350℃, which is relatively lower than 1450℃ of ordinary Portland cement clinker, so that the energy consumption can be greatly reduced; the raw material loss in the sintering process can be reduced, the production cost can be reduced, the clinker quality is stable, and the production capacity and operation rate are improved.

[0093] Preferably, in the step (1), the grinding is to pass through an 80-micron square hole screen, and the raw material fineness is ≤15%;

[0094] In the step (2), the cooling is to room temperature within 10-15min.

[0095] The C2S in the clinker has strong wear resistance, and if the crystal is too large, the energy consumption in the grinding process will inevitably increase. In the preparation process of the cement clinker, the rapid cooling to room temperature is beneficial to the A mineral to maintain a small and complete crystal form, reduces the C2S pulverization, and makes the mineral crystal C2S in the prepared clinker in a round particle form, with regular shape, obvious boundary and small size. Therefore, the clinker has good grindability, which creates conditions for reducing the power consumption of the cement grinding process.

[0096] Preferably, the calcareous material: CaO is greater than or equal to 50%, MgO is less than or equal to 3.0%, R2O is less than or equal to 0.5%, and the particle size is less than or equal to 500 mm;

[0097] The siliceous correction material: SiO2 is greater than or equal to 80%, R2O is less than or equal to 1.5%, and the moisture content is less than or equal to 5.0%;

[0098] The ferruginous correction material: Fe2O3 is greater than or equal to 40%, R2O is less than or equal to 1.8%, and the moisture content is less than or equal to 12%;

[0099] The aluminous correction material: R2O is less than or equal to 1.5%, Al2O3 is greater than or equal to 15%, and the moisture content is less than or equal to 10%.

[0100] Preferably, the calcareous material is limestone,

[0101] The ferruginous correction material is iron powder;

[0102] The siliceous correction material is sandstone / silica;

[0103] The aluminous correction material is shale / bauxite.

[0104] In the above technical solution, the siliceous correction material uses sandstone, silica commonly used in the field, the ferruginous correction material uses iron powder commonly used in the field, and the aluminous correction material uses shale, bauxite commonly used in the field.

[0105] Preferably, in step (1), the control range of CaO in the raw material is ±0.3%, the control range of Fe2O3 is ±0.2%, KH is 0.86-0.90, the silica rate is 2.3-2.7, and the aluminum rate is 0.5-0.9.

[0106] Only by selecting good raw and fuel materials can the quality of the clinker be better controlled. According to the test results of the raw and fuel materials entering the factory, the raw material batching scheme of the portland cement clinker is calculated according to the material quality and the composition of the cement clinker, the control range of CaO, Fe2O3 and three rate values of the raw material is determined, CaO is ±0.3%, Fe2O3 is ±0.2%, KH is 0.88±0.02, n is 2.5±0.2, and p is 0.7±0.2. During the production of the portland cement clinker, the control range is narrower than that of the ordinary portland cement clinker, and the standard is strictly executed, so that the performance of the clinker is more stable, and the control range of the three rate values of the clinker can reach KH: 0.85±0.02, n: 2.7±0.2, p: 0.7±0.2, and Fe2O3 is greater than or equal to 5.0%.

[0107] The cement clinker is used in Portland cement, G-grade oil well cement, A-grade oil well cement, moderate heat Portland cement, ordinary Portland cement, Portland cement, high-sulfur-resistant Portland cement, and road Portland cement.

[0108] The detection methods of the various properties in the present application are all tested by the conventional methods in the art.

[0109] Loss is the percentage of weight lost after the raw material dried at 105-110℃ is burned at 1000-1100℃. The content of loss of raw material is mainly used to represent the content of gaseous products, such as H2O, CO2, etc., and the content of organic matter in the heating decomposition of the raw material, so as to determine whether the raw material needs to be calcined in advance to make the volume of the raw material stable.

[0110] The chemical composition analysis of the cement clinker is performed by the conventional method in the art. Among them, the value of magnesium oxide is directly measured, and the result can be obtained by chemical analysis or fluorescence analysis. Potassium oxide and sodium oxide are generally measured by flame photometry.

[0111] Free calcium oxide refers to the calcium oxide that does not exist in a combined state but exists in a free state in the cement clinker, also known as free lime (f-CaO).

[0112] Example 1.

[0113] The specific operation steps are as follows:

[0114] (1) After crushing the calcium material (limestone), the silicon correction material (sandstone / silica), the iron correction material (iron powder), and the aluminum correction material (shale / bauxite) raw materials, the materials are proportioned.

[0115] Among them, the calcium material is limestone, which requires: CaO≥50%, MgO≤3.0%, R2O≤0.5%, and particle size≤500mm.

[0116] The silicon correction material: SiO2≥80%, R2O≤1.5%, and water content≤5.0%;

[0117] The iron correction material: Fe2O3≥40%, R2O≤1.8%, and water content≤12%;

[0118] The aluminum correction material: R2O≤1.5%, Al2O3≥15%, and water content≤10%.

[0119] The raw material proportioning control range: limestone = 83.5-85.0wt%; silica / sandstone = 8.5-9.5wt%; bauxite / shale = 2.8-3.5wt%; and iron powder = 3.7-4.5wt%.

[0120] (2) The prepared raw material is conveyed by a belt to a raw mill for grinding treatment, and is finely ground to 80 μm square hole screen, and the fineness of the powder with a screen residue of ≤15%.

[0121] The following points are noted during the grinding operation:

[0122] ① The matching between the material, air and mill outlet temperature is adjusted during the operation.

[0123] ② The mill feeding amount is stable, the feeding amount is small, and the feeding speed needs to be moderate.

[0124] ③ Prevent material breakage or uneven incoming material, set appropriate grinding pressure, and stabilize the material bed thickness.

[0125] ④ Control the particle size of the material entering the mill to be ≤40 mm, the moisture content to be ≤4.0%, and the moisture content of the material leaving the mill to be ≤0.5%;

[0126] The raw material controlled in this way has good grindability and burnability, which is helpful for improving the quality of the subsequent clinker.

[0127] (3) The ground raw material is sent to a raw material homogenization warehouse by a conveying device for sufficient homogenization, and the raw material is obtained.

[0128] The control range of CaO in the raw material is ±0.3%, the control range of Fe2O3 is ±0.2%, KH is 0.86-0.90, the silicon rate is 2.3-2.7, and the aluminum rate is 0.5-0.9.

[0129] (4) The raw material is sent to a preheater and a decomposition furnace, and after preheating and decomposition, it is sent to a rotary kiln, the burning temperature is controlled at 1300-1350℃, the calcination time is 30-60 min, and the material in the kiln is quickly burned by thin material to obtain clinker.

[0130] The bituminous coal used in the calcination process has a heat value of ≥5800 kcal / kg, an ash content of ≤21%, a volatile content of ≥28%, a total sulfur content of ≤1.0%, and a water content of ≤14%.

[0131] (5) The clinker is cooled by a grate cooler, and is quickly cooled to room temperature (the temperature of the grate cooler is within +10℃ of the ambient temperature) in a short time (10-15 min), and the cement clinker is obtained.

[0132] The rapid cooling of the clinker at a high temperature stage is beneficial to the formation of minerals, the A mineral maintains a small and complete crystal form, and the C2S powdering is reduced.

[0133] Example 2.

[0134] The specific operation steps are as follows:

[0135] (1) The calcareous material (limestone), siliceous correction material (sandstone / silica), ferruginous correction material (iron powder), and aluminous correction material (shale / bauxite) raw materials are crushed and then proportioned.

[0136] The calcareous material is limestone, and the requirements are: CaO≥50%, MgO≤3.0%, R2O≤0.5%, and particle size≤500mm.

[0137] The siliceous correction material has the following properties: SiO2≥80%, R2O≤1.5%, and water content≤5.0%.

[0138] The ferruginous correction material has the following properties: Fe2O3≥40%, R2O≤1.8%, and water content≤12%.

[0139] The aluminous correction material has the following properties: R2O≤1.5%, Al2O3≥15%, and water content≤10%.

[0140] The chemical composition of the raw materials is shown in Table 7.

[0141] Table 7 Chemical composition of raw materials (content in mass percentage, %)

[0142]

[0143] The coal ash content is 12.36%, the calorific value is 5812kCal / kg, the clinker heat consumption is 759kCal / kg, and the coal ash incorporation amount is 1.6%. The raw material dry basis proportioning is: limestone=83.94wt%, silica=8.66wt%, bauxite=3.32wt%, and iron powder=4.09wt%.

[0144] (2) The proportioned raw materials are conveyed by a belt to a raw mill for grinding treatment, and are finely ground to 80μm square hole sieve, and the fineness of the powder with a sieve residue of≤15%.

[0145] The following points are noted during the grinding operation process:

[0146] ① The matching between the material, air, and mill outlet temperature is adjusted during the operation process.

[0147] ② The mill feeding amount is stable, the feeding amount range is small, and the feeding speed needs to be moderate.

[0148] ③ The material is prevented from being broken or uneven, the suitable grinding pressure is set, and the material bed layer thickness is stabilized.

[0149] ④ The particle size of the material entering the mill is controlled to≤40mm, the moisture content is≤4.0%, and the moisture content of the material exiting the mill is≤0.5%.

[0150] The raw material that has been finely controlled has good grindability and burnability, which is helpful for improving the quality of the subsequent clinker.

[0151] (3) The ground raw meal is sent into the raw meal homogenizing bin by a conveying device for sufficient homogenization to obtain the raw meal. The chemical composition and mineral composition of the raw meal are detected four times, and Table 8 shows the details.

[0152] Table 8 Chemical composition and mineral composition of the raw meal (content in mass percentage, %)

[0153]

[0154] Raw meal rate value: KH = 0.89, SM = 2.65, and IM = 0.76

[0155] The control range of CaO in the raw meal is ±0.3%, the control range of Fe2O3 is ±0.2%, KH is 0.86-0.90, the silicon rate is 2.3-2.7, and the aluminum rate is 0.5-0.9.

[0156] (4) The raw meal is lifted to the preheater and the decomposing furnace, and after preheating and decomposing, it is sent to the rotary kiln, the sintering temperature is controlled at 1300-1350℃, the calcination time is 40-60 min, and the material in the kiln is quickly sintered to form the clinker.

[0157] The bituminous coal used in the calcination process has a heat value of ≥5800 kcal / kg, an ash content of ≤21%, a volatile content of ≥28%, a total sulfur content of ≤1.0%, and a water content of ≤14%.

[0158] (5) The clinker discharged from the kiln needs to be rapidly cooled in the grate cooler, and is cooled to room temperature (the temperature of the grate cooler meets the ambient temperature +10℃) in a short time (10-15 min) to obtain the cement clinker, which is finally transported to the clinker bin for storage.

[0159] The rapid cooling of the clinker at a high temperature stage is beneficial to the formation of minerals, the A mineral maintains a fine and complete crystal form, and the C2S pulverization is reduced.

[0160] Example 3.

[0161] The specific operation steps are as follows:

[0162] (1) The calcium material (limestone), the silicon correction material (sandstone / silica), the iron correction material (iron powder), and the aluminum correction material (shale / bauxite) are crushed and then proportioned.

[0163] The calcium material is limestone, and the requirements are as follows: CaO≥50%, MgO≤3.0%, R2O≤0.5%, and particle size ≤500 mm.

[0164] The silicon correction material: SiO2≥80%, R2O≤1.5%, and water content ≤5.0%;

[0165] Iron-based corrective material: Fe2O3 ≥ 40%, R2O ≤ 1.8%, moisture ≤ 12%;

[0166] Aluminum correction material: R2O≤1.5%, Al2O3≥15%, moisture≤10%.

[0167] The chemical composition of the raw materials is detailed in Table 9.

[0168] Table 9 Chemical composition of raw materials (content in mass percentage, %)

[0169]

[0170] The raw material dry basis proportions are: limestone = 84.05 wt%, silica = 8.11 wt%, bauxite = 3.41 wt%, and iron powder = 4.43 wt%.

[0171] (2) The prepared raw materials are then conveyed to the raw material mill by belt for grinding, and ground until the residue on an 80μm square hole sieve is ≤15%.

[0172] The following points should be noted during the grinding process:

[0173] ① During operation, adjust the matching between the material, air, and mill outlet temperature.

[0174] ② The mill feed rate should be stable, the increase or decrease in feed should be small, and the increase or decrease speed should be moderate.

[0175] ③ Prevent material interruption or uneven material supply, set appropriate grinding pressure, and stabilize the thickness of the material bed.

[0176] ④ Control the particle size of the material entering the mill to ≤40mm; moisture content: ≤4.0%; moisture content of the material exiting the mill to ≤0.5%;

[0177] Raw materials that have undergone this precise control have good grindability and burnability, which greatly helps to improve the quality of subsequent clinker production.

[0178] (3) The ground raw meal is fed into a raw meal homogenization silo via a conveying device for thorough homogenization. The raw meal is then obtained. The chemical composition and mineral composition of the raw meal are tested four times, as detailed in Table 10.

[0179] Table 10 Chemical composition and mineral composition of raw meal (content in mass percentage, %)

[0180]

[0181] Raw material yield values: KH = 0.89, SM = 2.63, IM = 0.78

[0182] The control range of CaO in raw meal is ±0.3%, the control range of Fe2O3 is ±0.2%, KH is 0.86-0.90, the silicon rate is 2.3-2.7, and the aluminum rate is 0.5-0.9.

[0183] (4) The raw meal is lifted to a preheater and a decomposing furnace, and after preheating and decomposing, is sent to a rotary kiln, and the sintering temperature is controlled at 1300-1310 DEG C, and the calcination is performed for 60 minutes, and the material in the kiln is quickly sintered by thin material, and the cement clinker is obtained.

[0184] The bituminous coal used in the calcination process has a heat value of ≥5800 kcal / kg, an ash content of ≤21%, a volatile content of ≥28%, a total sulfur content of ≤1.0%, and a water content of ≤14%.

[0185] (5) The cement clinker is cooled by a grate cooler, and is cooled to room temperature in a short time (10 minutes), and the temperature of the grate cooler satisfies the ambient temperature +10 DEG C, and the cement clinker is obtained, and finally is transported to a clinker storage.

[0186] The mineral composition, chemical composition and physical properties of the prepared cement clinker are detected, and the results are shown in Tables 11-12.

[0187] Table 11 Mineral composition and rate value (content is in mass percentage, %)

[0188]

[0189]

[0190] Table 12 Chemical composition (content is in mass percentage, %)

[0191] LOSS SiO2 Al2O3 Fe2O3 CaO MgO [R2O] f-CaO 1 0.29 21.96 3.82 5.12 62.23 3.26 0.55 0.93 2 0.26 22.14 3.71 5.20 62.41 3.32 0.56 0.79 3 0.31 22.16 3.74 4.99 62.32 3.26 0.56 0.69 4 0.19 22.70 3.45 5.03 62.76 2.98 0.53 0.88

[0192] Example 4.

[0193] The specific operation steps are as follows:

[0194] (1) After crushing, the calcium material (limestone), the silicon correction material (sandstone / silica), the iron correction material (iron powder) and the aluminum correction material (shale / bauxite) are proportioned.

[0195] The calcium material is limestone, and the requirements are as follows: CaO≥50%, MgO≤3.0%, R2O≤0.5%, and particle size≤500 mm.

[0196] The silicon correction material: SiO2≥80%, R2O≤1.5%, and water content≤5.0%;

[0197] The iron correction material: Fe2O3≥40%, R2O≤1.8%, and water content≤12%.

[0198] Aluminum correction material: R2O≤1.5%, Al2O3≥15%, moisture≤10%.

[0199] The chemical composition of the raw materials is shown in Table 13.

[0200] Table 13 Chemical composition of raw materials (content in mass percentage, %)

[0201]

[0202] The dry raw material ratio is: limestone = 84.7wt%, silica = 8.60wt%, bauxite = 3.0wt%, iron powder = 3.7wt%.

[0203] (2) The prepared raw materials are conveyed by a belt to a raw mill for grinding treatment, and are finely ground to a powder with a 80μm square hole sieve, and the sieve residue is 16%.

[0204] The following points should be noted during the grinding operation process:

[0205] ① The matching between the material, air and mill outlet temperature should be adjusted during the operation process.

[0206] ② The mill feeding amount should be stable, the feeding amount should be small, and the feeding speed should be moderate.

[0207] ③ Prevent material breakage or uneven incoming material, set appropriate grinding pressure, and stabilize the material bed layer thickness.

[0208] ④ Control the particle size of the material entering the mill to be ≤40mm, moisture: ≤4.0%, and the moisture of the material leaving the mill to be ≤0.5%;

[0209] The raw material controlled in this way has good grindability and burnability, which is helpful for improving the quality of the subsequent clinker.

[0210] (3) The ground raw material is sent to a raw material homogenization warehouse by a conveying device for sufficient homogenization, and the raw material is obtained. The chemical composition and mineral composition of the raw material are detected four times, and the specific values are shown in Table 14.

[0211] Table 14 Chemical composition and mineral composition of raw material (content in mass percentage, %)

[0212]

[0213] The raw material rate value: KH = 0.88, SM = 2.70, and IM = 0.70.

[0214] The control range of CaO in the raw material is ±0.3%, the control range of Fe2O3 is ±0.2%, KH is 0.86-0.90, the silicon rate is 2.3-2.7, and the aluminum rate is 0.5-0.9.

[0215] (4) The raw meal is lifted to the preheater and the decomposing furnace, and after preheating and decomposing, it is put into the rotary kiln, and the burning temperature is controlled at 1325-1350°C, and the calcination is performed for 50 min, and the material in the kiln is quickly burned through thin material, and the calcined clinker is obtained.

[0216] The bituminous coal used in the calcination process has a heat value of ≥5800 kcal / kg, an ash content of ≤21%, a volatile content of ≥28%, a total sulfur content of ≤1.0%, and a water content of ≤14%.

[0217] (5) The clinker discharged from the kiln needs to be rapidly cooled in a grate cooler, and is cooled to room temperature (the temperature of the grate cooler satisfies the ambient temperature +10°C) in a short time (12 min), so that the cement clinker is obtained, and finally is transported to a clinker storage for storage.

[0218] Example 5.

[0219] The specific operation steps are as follows:

[0220] (1) After crushing, the calcium material (limestone), the silicon correction material (sandstone / silica stone), the iron correction material (iron powder), and the aluminum correction material (shale / bauxite) are proportioned.

[0221] The calcium material is limestone, and the requirements are as follows: CaO≥50%, MgO≤3.0%, R2O≤0.5%, and particle size≤500 mm.

[0222] The silicon correction material has the following properties: SiO2≥80%, R2O≤1.5%, and water content≤5.0%.

[0223] The iron correction material has the following properties: Fe2O3≥40%, R2O≤1.8%, and water content≤12%.

[0224] The aluminum correction material has the following properties: R2O≤1.5%, Al2O3≥15%, and water content≤10%.

[0225] The chemical composition of the raw materials is shown in Table 15.

[0226] Table 15 Chemical composition of raw materials (content in mass percentage, %)

[0227]

[0228] The dry basis proportioning of the raw meal is as follows: limestone = 83.87wt%, silica stone = 8.69wt%, bauxite = 3.24wt%, and iron powder = 4.20wt%.

[0229] (2) The proportioned raw materials are transported to a raw mill by a belt, and are ground to a powder with a 80 μm square hole sieve residue of ≤15%.

[0230] The following points are noted during the grinding operation:

[0231] ①Adjust the matching between the material and the air and the mill outlet temperature during the operation.

[0232] ②The mill feeding amount is stable, the feeding and reducing range is small, and the feeding and reducing speed needs to be moderate.

[0233] ③Prevent material breakage or uneven incoming material, set appropriate grinding pressure, and stabilize the material bed layer thickness.

[0234] ④Control the particle size of the material entering the mill ≤40mm; moisture: ≤4.0%; moisture of the material leaving the mill ≤0.5%;

[0235] The raw meal controlled in this way has good grindability and burnability, which helps to improve the quality of the subsequent clinker.

[0236] (3) The ground raw meal is sent to the raw meal homogenization warehouse by a conveying device for sufficient homogenization to obtain the raw meal. The chemical composition and mineral composition of the raw meal are detected four times, and the specific values are shown in Table 16.

[0237] Table 16 Chemical composition and mineral composition of raw meal (content in mass percentage, %)

[0238]

[0239] Raw meal rate value: KH = 0.89, SM = 2.60, IM = 0.80

[0240] The control range of CaO in the raw meal is ±0.3%, the control range of Fe2O3 is ±0.2%, KH is 0.86-0.90, the silicon rate is 2.3-2.7, and the aluminum rate is 0.5-0.9.

[0241] (4) The raw meal is sent to the preheater and the decomposition furnace, and after preheating and decomposition, it is sent to the rotary kiln, the burning temperature is controlled at 1340-1350℃, and the calcination time is 30min. The material in the kiln is quickly burned by thin material, and the calcined clinker is obtained.

[0242] (5) The clinker leaving the kiln needs to be rapidly cooled by the grate cooler within 15min to room temperature (the temperature leaving the grate cooler satisfies the ambient temperature +10℃), and the cement clinker is obtained. Finally, it is transported to the clinker warehouse for storage.

[0243] The mineral composition, chemical composition and physical properties of the prepared cement clinker are detected, and the results are shown in Tables 17-19.

[0244] Table 17 Mineral composition and rate value

[0245]

[0246] Table 18 Chemical composition (content in mass percentage, %)

[0247]

[0248] Table 19 Physical properties

[0249]

[0250] In combination with the table, the cement clinker of the present application contains a certain amount of early strength minerals calcium silicate calcium aluminate, which can greatly reduce the shrinkage of cement; and can form ettringite in the hydration process, not only to produce early strength, but also to make up for the overall volume expansion in the hydration process and the dry shrinkage phenomenon caused by ordinary portland cement system after hardening.

[0251] The clinker of the present application presents low shrinkage after losing water, which has no destructive effect on construction use; at the same time, it contains a high amount of dicalcium silicate, so that the late strength increases stably, the hydration slurry is dense, and the impermeability is good; compared with single variety cement clinker, the application range is more extensive.

[0252] The cement clinker described in the present application has low contents of C3A, C3S, f-CaO and R2O (alkali metal oxide) after calcination, high contents of C2S and C4AF, and relatively perfect and coarse crystalline phase of silicate minerals, slow early hydration, low hydration heat, and ideal effect. Moreover, the cement clinker described in the present application presents low shrinkage after losing water, which has no destructive effect on construction use.

[0253] Example 6.

[0254] The specific operation steps are as follows:

[0255] After mixing the cement clinkers 1-6 prepared in Example 5 with 4-5wt% of natural dihydrate gypsum, the closed-circuit grinding production process method of the company is used for grinding (a transmission device (reamer, FU, belt) is added below the dust collector and discharger of the original cement grinding production line, the material directly returned to the grinding head dust collector is directly fed into the discharge elevator of the grinding tail through the transmission device, and no longer returns to the grinding, which greatly reduces the over-grinding phenomenon of the material in the grinding machine and reduces the circulating load of the grinding machine), the produced cement finished product has reasonable particle size grading and uniform particle size distribution. The physical properties of the produced cement are tested, and the results are shown in Table 14.

[0256] Table 20 Physical properties of cement

[0257]

[0258]

[0259] In combination with the analysis of Table 20, the cement clinker produced by the present application has the following advantages:

[0260] (1) The clinker calcined by the present application has the following characteristics: low hydration heat, low chloride ion, low alkali content, resistance to sulfate ion erosion, high abrasion resistance, moderate thickening time, and high strength, etc.

[0261] Low hydration heat means that the cement releases less heat during hydration, and when the cement solidifies, expansion does not occur, and fine cracks in the concrete do not occur, thereby improving the construction quality.

[0262] (2) From the perspective of on-site construction, the presence of too much chloride ion in the cement can cause freeze-thaw of the concrete and corrosion of the steel bars in the concrete, affecting the service life and safety of the concrete structure. From the perspective of early strength, chloride ion is effective and beneficial, but its early strength mechanism can also cause an increase in the water demand of the cement, a faster loss of slump, and a deterioration of plasticity, which affects the efficiency of the concrete and increases the difficulty of construction. The clinker of the present application is mixed with high-activity calcareous and siliceous materials in a specific proportion, which can reduce the use amount of clinker while ensuring the compressive strength requirement of low-grade cement, is conducive to energy saving and environmental protection in the cement industry, reduces carbon emissions, and thus effectively reduces costs and improves the economic benefits of enterprises.

[0263] (3) The clinker calcined by the present application has a high C2S content, which is more conducive to the formation of stable hydration products during high-temperature hydration, is beneficial to the high-temperature mechanical properties of the cement, and more effectively improves the high-temperature strength stability, sulfate resistance, and high-temperature resistance, which are excellent in tests and more stable in quality during the later use.

[0264] (4) The cement clinker produced by the present application can be used to produce cement that can simultaneously meet the requirements of the production of Portland cement for nuclear power engineering, G-grade oil well cement, A-grade oil well cement, moderate-heat Portland cement, ordinary Portland cement, Portland cement, high-sulfate-resistant Portland cement, and road Portland cement.

[0265] The cement prepared from the cement clinker described in the present embodiment has been applied to multiple varieties (oil well, nuclear power, moderate-heat, road, and ordinary Portland cement, etc.) of the present company after being tested and qualified by the laboratory of the present company, and the physical tests and chemical analysis (special requirements) meet the requirements of each variety of cement and have been used in the construction of national key projects such as the Tianwan Nuclear Power Plant in Lianyungang, Daqing Oilfield, Jilin Oilfield, and airports.

[0266] The above is only the preferred embodiment of the present application, and does not limit the present application in any form. Any simple modification, equivalent change and modification of the above embodiment according to the technical essence of the present application are still within the scope of the technical solution of the present application.

Claims

1. A multi-variety universal cement clinker, characterized by, Prepared from the following raw materials in mass percentage: calcium material 83.5-85.0%, silicon correction material 8.5-9.5%, iron correction material 3.7-4.5%, aluminum correction material 2.8-3.5%; the cement clinker has a KH value of 0.83-0.87, a silicon ratio of 2.5-2.9, an aluminum ratio of 0.5-0.9, and R2O < 0.6%; the calcium material has CaO ≥ 50%, MgO ≤ 3.0%, R2O ≤ 0.5%, and a particle size ≤ 500 mm; the silicon correction material has SiO2 ≥ 80%, R2O ≤ 1.5%, and moisture ≤ 5.0%; the iron correction material has Fe2O3 ≥ 40%, R2O ≤ 1.8%, and moisture ≤ 12%; the aluminum correction material has R2O ≤ 1.5%, Al2O3 ≥ 15%, and moisture ≤ 10%.

2. The cement clinker according to claim 1, characterized in that: the calcium material is limestone; the iron correction material is iron powder; the silicon correction material is sandstone or silica; the aluminum correction material is shale or bauxite.

3. The cement clinker according to claim 1, characterized in that: the cement clinker has the following physical properties: (1) 3d flexural strength of 4.3-5.3 MPa, 7d flexural strength of 5.8-6.5 MPa, 28d flexural strength of 8.3-8.7 MPa, 3d compressive strength of 18.3-22.4 MPa, 7d compressive strength of 29.2-34.2 MPa, and 28d compressive strength of 52.0-55.5 MPa; (2) 3d hydration heat of 220-243 kJ / kg and 7d hydration heat of 269-290 kJ / kg.

4. Process for the production of cement clinker according to any one of claims 1 to 3, characterized in that, comprising the following steps: (1) crushing and grinding the calcium material, the silicon correction material, the iron correction material, and the aluminum correction material to obtain raw material; the calcium material 83.5-85.0%, the silicon correction material 8.5-9.5%, the iron correction material 3.7-4.5%, and the aluminum correction material 2.8-3.5% in mass percentage; (2) preheating the raw material, calcining at 1300-1350 ℃ for 30-60 min, and then rapidly cooling to room temperature to obtain the cement clinker.

5. The preparation method according to claim 4, characterized in that: in step (1), the grinding is performed to a 80-micron square-hole sieve, and the fineness of the raw material after grinding is ≤ 15%; in step (2), the cooling is performed to room temperature within 10-15 min.

6. The preparation method according to claim 4, characterized in that: the calcium material has CaO ≥ 50%, MgO ≤ 3.0%, R2O ≤ 0.5%, and a particle size ≤ 500 mm; the silicon correction material has SiO2 ≥ 80%, R2O ≤ 1.5%, and moisture ≤ 5.0%; the iron correction material has Fe2O3 ≥ 40%, R2O ≤ 1.8%, and moisture ≤ 12%; The aluminum correction material: R2O≤1.5%, Al2O3≥15%, moisture≤10%.

7. The preparation method according to claim 4, characterized in that, The calcium material is limestone; The iron correction material is iron powder; The silicon correction material is sandstone or silica; The aluminum correction material is shale or bauxite.

8. The preparation method according to claim 4, characterized in that, In step (1), the control range of Cao in raw material is ±0.3%, the control range of Fe2O3 is ±0.2%, KH is 0.86-0.90, the silicon rate is 2.3-2.7, and the aluminum rate is 0.5-0.

9.

9. The use of the cement clinker according to any one of claims 1-3 or the cement clinker prepared by the preparation method according to any one of claims 4-8 in G-grade oil well cement, A-grade oil well cement, moderate-heat Portland cement, high-sulfur-resistant Portland cement, and road Portland cement.

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