Production control method for LC3 cement

Abstract

The invention discloses a production control method for LC3 cement. The production control method comprises the following steps: 1) calcining clay under different calcining conditions; constructing the relationship between the color and ignition loss of the obtained calcined clay and the calcining condition; 2) mixing the obtained calcined clay, silicate clinker, desulfurized gypsum and water to prepare cement paste; (3) gradually adding a reference water reducing agent into the cement paste, and adjusting the dosage of the reference water reducing agent until the target viscosity value requirement is met, wherein the viscosity of the cement paste is measured by adopting a rotary viscometer; constructing a relationship between the reference water reducing agent dosage and clay calcining conditions; 4) regulating and controlling the calcining conditions of the clay in actual industrial production.The method can quickly and accurately guide the calcining conditions of the clay industrial production, and is low in cost, simple to operate, short in period and suitable for popularization and application.

Description

Technical Field

[0001] The present invention belongs to the technical field of building materials, and specifically relates to a method for 3 Cement production control methods. Background Art

[0002] Limestone Calcined Clay Cement (LC 3 ) is a new type of low carbon cement, a typical LC with a clinker coefficient of 50% 3 -50 is composed of 50% silicate clinker, 30% calcined clay, 15% limestone and 5% gypsum. It mainly uses calcined clay with high pozzolanic activity and limestone to replace a large amount of silicate cement. Low-density hydration products such as hydrated calcium silicate aluminate and hydrated calcium carbon aluminate are generated in the cement structure to ensure strength and durability. It can effectively reduce CO2 emissions and cement production costs, and improve economic benefits.

[0003] The activity of calcined clay obtained at different calcination temperatures varies significantly. Clay calcination usually adopts the relatively simple and economical rotary kiln method. A simple production control method is needed to quickly determine the calcination temperature of clay at different stages in the kiln, so that process personnel can quickly adjust the kiln operating parameters to achieve stable production of calcined clay. In addition, the introduction of calcined clay will significantly reduce the working performance of cement. A fast and effective method is also needed to control the LC obtained by subsequent calcination. 3 The usage conditions of cement's factory-produced water reducer should be adjusted. Summary of the Invention

[0004] The main purpose of the present invention is to provide a method for LC 3 Cement production control method, guide the control of clay calcination conditions in industry, and adjust LC 3 The use of cement factory water reducer to meet the performance requirements has the advantages of low cost, simplicity, speed and high accuracy, which is conducive to promoting LC 3 The industrial application of cement is of great significance.

[0005] To achieve the above object, the technical solution adopted by the present invention is as follows: One for LC 3 The production control method of cement comprises the following steps: (1) Weigh clay samples and calcine them under different calcination conditions; obtain the relationship between the color and loss on ignition of the calcined clay and the calcination conditions; (2) calcined clay obtained under different calcination conditions is mixed with silicate clinker and desulfurized gypsum to prepare a base cement, which is then stirred and mixed with water to prepare a cement paste; (3) gradually adding a reference water reducer to the cement paste and stirring and mixing, and measuring the viscosity of the cement paste using a rotational viscometer, adjusting the amount of the reference water reducer until the measured viscosity value reaches the target viscosity value requirement, wherein the viscosity of the cement paste is measured using a rotational viscometer; based on the calcination condition data corresponding to the reference water reducer dosage, constructing the relationship between the reference water reducer dosage (cumulative dosage) and the clay calcination conditions; (4) Based on the relationship between the obtained benchmark water reducer dosage and the clay calcination conditions, and combined with the relationship between the color and loss on ignition of the calcined clay and the calcination conditions, the calcination conditions for the actual industrial production of this type of clay are guided and regulated.

[0006] In the above solution, the calcination step is carried out in a rotary kiln or a high-temperature furnace.

[0007] Furthermore, the calcination step in step (1) adopts a high-temperature furnace; the industrial production process adopts a rotary kiln.

[0008] According to the above scheme, the total mass proportion of CaO and MgO in the chemical composition of the clay in step (1) does not exceed 30%, and the total mass proportion of CaCO3 and MgCO3 in the mineral composition does not exceed 50%.

[0009] According to the above scheme, the main mineral components and contents (mass percentage) in the silicate clinker include: C3S 55-80%, C2S 5-25%, C3A 0-10%, and C4AF 3-15%.

[0010] According to the above scheme, the calcination conditions in step (1) include calcination temperature and calcination time, preferably calcination temperature.

[0011] Furthermore, the calcination temperature is selected from 500-1000° C., and the calcination time is selected from 30-120 min.

[0012] Preferably, in the process of constructing the relationship between the color and loss on ignition of the calcined clay and the calcination conditions, it is preferred to construct the relationship between the color and loss on ignition of the clay and the calcination conditions at 550-650°C and 750-850°C.

[0013] According to the above scheme, the relationship between the color of the calcined clay and the calcination conditions is: the calcined clay obtained at 550-650°C is orange-yellow, and the RGB values are (100-130, 90-110, 60-80); the calcined clay obtained at 750-850°C is orange-red, and the RGB values are (130 (excluding 130)-150, 90-110, 60-80).

[0014] According to the above scheme, the relationship between the ignition loss of the calcined clay and the calcination conditions is to obtain the relationship between the ignition loss and the calcination temperature under the conditions of 550-650°C and 750-850°C.

[0015] Preferably, the loss on ignition is measured under calcination conditions at 950°C.

[0016] According to the above scheme, the proportion of the reference cement in step (2) is as follows: silicate clinker 9-90%, desulfurized gypsum 1-5%, and calcined clay 9-90% by mass.

[0017] According to the above scheme, the water-cement ratio of the base cement to water in step (2) is 0.5.

[0018] According to the above scheme, the viscosity test method described in step (3) is: the rotational viscometer is selected with a range of 5000-15000 mPa·s and a rotor speed of 6-30 r / min.

[0019] Furthermore, the stirred cement slurry should be measured within 30 s, and the viscosity value should be recorded when the viscosity change does not exceed 20 mPa·s. The (single) viscosity test process should be completed within 60 s.

[0020] According to the above scheme, the target viscosity value is 1000-2000 mPa·s.

[0021] According to the above scheme, the base water reducer can be selected from one of polycarboxylic acid water reducer, naphthalene water reducer, etc.; the water reduction rate is 15-45%.

[0022] According to the above scheme, the relationship between the reference water reducer dosage and the calcined clay obtained under different calcination conditions is plotted as a calcination temperature-reference water reducer dosage curve.

[0023] According to the above scheme, in the calcination condition data corresponding to the benchmark water-reducing agent dosage, the overall (mostly) benchmark water-reducing agent dosage shows a decreasing trend as the calcination temperature increases.

[0024] Furthermore, the base water reducer dosage in the temperature range of 550-800°C will correspond to 2-3 calcination temperatures at the same time.

[0025] Furthermore, the step of constructing the calcination temperature-benchmark water-reducing agent dosage curve includes: based on the obtained data, taking the temperature value of the previous set of data at which the benchmark water-reducing agent dosage first increases with the increase in calcination temperature as the first turning point, and then obtaining the temperature value corresponding to the highest benchmark water-reducing agent dosage that continues to increase with temperature as the second turning point; constructing the linear relationship between calcination temperature and benchmark water-reducing agent dosage in the interval between the lowest calcination temperature and the first turning point, the interval between the first turning point and the second turning point, and the interval between the second turning point and the highest calcination temperature, respectively.

[0026] Preferably, within the range of 550-800°C, the calcination conditions for the actual industrial production of this type of clay are guided and regulated based on the linear relationship in the corresponding range and the relationship between the color and loss on ignition of the calcined clay and the calcination conditions (in other temperature ranges, the calcination conditions for the actual industrial production of this type of clay are directly guided and regulated based on the corresponding linear relationship).

[0027] Preferably, in the range of 550-800°C, if the difference between the temperature determined according to the linear relationship in the corresponding range and the temperature determined according to the color and loss on ignition of the calcined clay exceeds ±10°C, the calcination temperature in the kiln is directly determined based on the relationship between the color and loss on ignition of the calcined clay and the calcination conditions (the calcination temperature is determined directly, or the average of the calcination temperatures corresponding to two adjacent benchmark water reducer dosages is taken).

[0028] Preferably, the calcination temperature for clay to exhibit high activity is 750-850°C. The industry mainly focuses on regulating the data at 700-900°C, especially the critical temperature of 800°C.

[0029] Furthermore, guiding and regulating the calcination conditions for industrial production includes: taking the calcined clay, repeating steps (2) and (3), obtaining the benchmark water reducer dosage and the corresponding calcination temperature (the actual operating temperature in the calcination equipment), and adjusting to the target calcination temperature (optimum calcination temperature) of this type of clay.

[0030] Furthermore, the target calcination temperature is based on the calcination step in step 1) combined with the calcined clay to prepare LC 3 The mortar strength (maximum mortar strength) is determined.

[0031] Furthermore, the step of adjusting to the target calcination temperature includes adjusting the reference water reducer dosage of the obtained calcined clay to meet the reference water reducer dosage requirement corresponding to the target calcination temperature.

[0032] According to the above scheme, the total amount of the benchmark water reducer is less than 5% of the mass of the benchmark cement.

[0033] Furthermore, in the step of adjusting the amount of the reference water reducer, the amount of the reference water reducer is increased by 0-1% (not 0) of the mass of the reference cement each time.

[0034] According to the above scheme, the principle of guiding and regulating the calcination conditions of this type of clay in industry in step (4) is that the working performance of the cement mixed with the clay after calcination under different parameter conditions is different, and the amount of water reducer required to achieve the required working performance requirements is different. The viscosity value of the cement slurry measured by the present invention can reflect the working performance of the cement, and the water reducer can be continuously adjusted to determine the amount of water reducer; at the same time, combined with the loss on ignition test and color comparison for optimization, the calcination conditions of the clay can be quickly judged, and the relationship between the benchmark water reducer amount and the clay calcination conditions can be effectively established, which is then used to guide and regulate the calcination conditions of the actual industrial production of this type of clay.

[0035] Furthermore, the mass proportion of silicate clinker in the benchmark cement mix of the present invention is regulated to be no less than 10%, which effectively ensures the alkalinity of the cement slurry so that the water reducer can play a role.

[0036] Furthermore, considering that the viscosity of cement made from different types of calcined clay is different, when the viscosity of cement made from calcined clay used in the factory is relatively low overall, the proportion of calcined clay in the benchmark cement can be appropriately increased; when the viscosity of cement made from calcined clay used in the factory is relatively high overall, the proportion of calcined clay in the benchmark cement can be appropriately reduced.

[0037] Compared with the prior art, the present invention has the following beneficial effects: 1) The present invention uses the viscosity value obtained by the rotational viscometer and combines the clay loss on ignition and the color characteristics of the calcined clay to effectively establish the relationship between the reference water reducer dosage and the clay calcination conditions, which can efficiently and accurately guide the LC 3 The industrial production conditions of cement are adjusted dynamically to the process conditions in the actual industrial production process to achieve stable production of calcined clay and effectively guarantee the quality of the obtained LC 3 Properties of cement; 2) This invention proposes, for the first time, the use of a rotational viscometer (and optimized testing conditions) to measure cement paste viscosity to characterize cement performance. Compared to traditional mortar fluidity methods, this method offers advantages such as lower cost, greater simplicity, speed, higher accuracy, and a wider measurement range. It also eliminates the need for standard sand and its influence, and eliminates the need for equipment such as a mortar mixer and a jump table. The entire process, from mixing the cement paste to viscosity testing, can be completed within 2 minutes, significantly shortening the testing cycle. 3) The cement paste used in this invention is a suspension (not a homogeneous solution) and is continuously hydrated, causing its measured viscosity to fluctuate. Furthermore, the viscosity of the benchmark cement without a water reducer is higher. This invention uses a rotational viscometer and optimizes its range, speed, test time, and other conditions to ensure rapid and accurate results. 4) Cement mortar is drier than cement paste. After the jump table test using the mortar fluidity method, the cement mortar will lose more water and paste due to its high dryness and large contact area with the jump table, which can easily lead to large errors when the cement mortar is recovered for secondary testing. In addition, the secondary mixing requires the use of a mortar mixer to mix evenly again, which has low accuracy and sensitivity, and the mortar sample needs to be prepared again to ensure accuracy. The method described in the present invention can continuously adjust the water reducer to efficiently determine the amount of water reducer, with high accuracy and sensitivity. The same cement paste can be used multiple times to quickly and accurately determine the amount of water reducer. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 The linear relationship fitting results between the dosage of the benchmark water reducer and the calcination temperature of clay 1# (500-950℃); Figure 2 The calcination temperature of clay 1# and the LC 3 The relationship between the 28d compressive strength of cement mortar; Figure 3 The linear relationship fitting results between the viscosity of cement paste obtained by adding standard cement and standard water reducer with different calcined clays and the fluidity of cement mortar; Figure 4 The linear relationship fitting results of comparative example 1. DETAILED DESCRIPTION

[0039] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0040] The present invention is not limited to the above-described embodiments. Persons skilled in the art may make various improvements and modifications without departing from the principles of the present invention, and such improvements and modifications are deemed to be within the scope of protection of the present invention. Any matters not described in detail in this specification constitute prior art known to those skilled in the art.

[0041] The chemical compositions of the clay and high-magnesium limestone used in the examples of the present invention are shown in Table 1, the mineral composition of the silicate clinker is shown in Table 2, and the mineral composition of the desulfurized gypsum is shown in Table 3. The reference water reducer uses a polycarboxylate water reducer with a solid content of 40% and a water reduction rate of 30%.

[0042] Table 1 Chemical composition of raw materials (wt%)

[0043] Table 2 Mineral composition of silicate clinker (%)

[0044] Table 3 Mineral composition of desulfurized gypsum (%)

[0045] Example 1 One for LC 3 The production control method of cement comprises the following steps: (1) Five portions of 60 g of clay 1# were weighed and placed into five corundum mullite crucibles of 100 mm × 100 mm × 30 mm in size. The crucibles were calcined in a high-temperature furnace at 500°C, 550°C, 600°C, 650°C, 700°C, 750°C, 800°C, 850°C, 900°C, and 950°C for 60 min, respectively. The calcined clays based on different calcination conditions were obtained. The relationship between the color and loss on ignition of the calcined clay and the calcination conditions was established. The relationship between the color of the calcined clay and the calcination conditions is as follows: the calcined clay obtained at 550-650℃ is orange-yellow, with RGB values of (100-130, 90-110, 60-80); the calcined clay obtained at 750-850℃ is orange-red, with RGB values of (130-150, 90-110, 60-80); The loss on ignition is measured under calcination conditions at 950°C; preferably, the relationship between the loss on ignition and calcination temperature of the calcined clay obtained under conditions of 550-650°C and 750-850°C is recorded; Among them, the clay calcined at 550℃, 600℃, 650℃, 700℃, 750℃ and 800℃ was tested for loss on ignition at 950℃, and the loss on ignition was 6.24%, 5.88%, 4.82%, 4.62%, 4.61% and 3.18% respectively; (2) Weigh 91g (65%) silicate clinker, 7g (5%) desulfurized gypsum, and 42g (30%) burned clay #1 (5 burned clays were mixed into reference cement in the same proportion for measurement) and grind them into powder using a disc mill for 1 min. Weigh 120g of the obtained powder as reference cement, add 60g of tap water at 20±1℃ into a 100mL beaker, and then pour the reference cement into the beaker. Stir with a glass rod for 30s to mix into cement slurry. (3) Rotary viscometer (range: 10000 mPa·s) with rotor No. 3 and a speed of 12 r / min. Place the rotor below the specified scale of the cement paste and start measuring the viscosity. The viscosity value will change before stabilizing. When the viscosity value changes by no more than 20 mPa·s, the viscosity value is recorded as the test result. The stirred cement paste is measured within 30 s, and the viscosity test process is completed within 60 s. Usually the measured viscosity value will be higher than 2000mPa·s. At this time, take out the cement paste, add 0.1% (120g*0.1%=0.12g) of the standard water reducer by the standard cement mass and stir with a glass rod for 30s. Use the rotational viscometer to measure the viscosity of the cement paste again. If the measured viscosity value is still higher than 2000mPa·s, continue to add 0.1% of the standard water reducer by the standard cement mass to the cement paste. Repeat the operation until the viscosity value is between 1000-2000mPa·s. Get 500℃, 550℃, 600℃, 650℃, 700℃, 750℃, 800℃, 850℃, 90 The total dosage of the benchmark water reducer for the benchmark cement prepared with clay 1# after burning at 0℃ and 950℃ is 1.2%, 0.8%, 0.5%, 0.8%, 0.7%, 0.6%, 0.5%, 0.3%, 0.2% and 0.1% respectively. The corresponding viscosity values are 1470mPa·s, 1510mPa·s, 1400mPa·s, 1480mPa·s, 1390mPa·s, 1350mPa·s, 1500mPa·s, 1460mPa·s, 1240mPa·s and 1700mPa·s respectively. The linear relationship fitting results between the dosage of benchmark water reducer and the calcination temperature of clay 1# are as follows: Figure 1 As shown, it is divided into linear sections of 500-600℃ (first turning point), 600-650℃ (second turning point), and 650-950℃. Among them, the amount of water reducer at 550-800℃ will correspond to 2-3 calcination temperatures at the same time. In the temperature section of 550-800℃, it is necessary to combine the loss on ignition test and color comparison of the calcined clay to confirm; In addition, LC was prepared based on clay 1# calcined at different temperatures in step (1). 3 In the cement mortar strength test, the optimal calcination temperature of clay 1# was 800℃, that is, the industrial kiln production needs to burn clay 1# to 800℃ (to ensure good application effect). Since the key temperature of 800℃ cannot be determined only by the amount of water reducer (0.5% water reducer dosage corresponds to 600℃ and 800℃ at the same time), it is necessary to further combine the clay calcined at 550℃, 600℃, 650℃, 700℃, 750℃, and 800℃ to conduct ignition loss test at 950℃, and the ignition loss was 6.24%, 5.88%, 4.03%, 5.07%, 6.08%, 6.09%, 6.10%, 6.24%, 6.08%, 6.11%, 6.12%, 6.13%, 6.14%, 6.15%, 6.16%, 6.17%, 6.18%, 6.19%, 6.20%, 6.21%, 6.23%, 6.24%, 6.25%, 6.26%, 6.27%, 6.28%, 6.29%, 6.30%, 6.31%, 6.32%, 6.33%, 6.34%, 6.35%, 6.36%, 6.37%, 6.38%, 6.39%, 6.40%, 6.41%, 6.42%, 6.43%, 6.44%, 6.45%, 6.46%, 6.47%, 6.48%, 6.40 ... .82%, 3.42%, 3.21%, 3.18% (the actual ignition loss of clay 1# after calcination has a fluctuation range of about 1%. The test can easily distinguish the difference between 550-650℃ and 700-800℃, but it is difficult to distinguish the difference within 700-800℃. The method of measuring the amount of water reducer with a viscometer combined with the ignition loss test can distinguish 700-800℃). The clay calcined at 600℃ is orange-yellow (RGB is 121, 93, 67), and the clay calcined at 800℃ is orange-red (RGB is 145, 96, 63); (4) Take clay 1# calcined in an industrial rotary kiln and follow steps (2) and (3) to obtain the reference water reducer dosage (total dosage) of the reference cement of clay 1# calcined in the industrial rotary kiln, which is 0.5%. Figure 1 According to the fitting curve, the water reducer dosage corresponds to calcination temperatures of 600°C and 800°C. The calcined clay 1# is further tested for loss on ignition, and the loss on ignition is 3.20%. It also appears orange-red (RGB is 143, 94, 64). This indicates that the actual operating temperature in the industrial rotary kiln is 800°C at this time. This temperature is the target temperature, and no adjustment is required to the parameters in the kiln (calcined clay 1 is obtained). In addition, since the temperature in the kiln fluctuates due to the influence of many factors, clay 1# calcined in the industrial rotary kiln is taken again at different time periods. According to steps (2) and (3), the reference water reducer dosage (total dosage) of the reference cement mixed with clay 1# calcined in the industrial rotary kiln is obtained to be 0.3%, that is, the temperature in the industrial rotary kiln is determined to be 850℃ (higher than the optimal calcination temperature of 800℃) at this time. The kiln parameters (according to appropriate reduction of coal dosage in the kiln, ventilation volume, appropriate increase of clay feed, etc.) are immediately adjusted. The calcination temperature is lowered by adjusting the amount of clay 1# calcined in the industrial rotary kiln. The clay 1# calcined in the industrial rotary kiln is taken again. According to steps (2) and (3), the reference water reducer dosage (total dosage) of the reference cement prepared for the clay 1# calcined in the industrial rotary kiln is 0.5%. The calcined clay 1# is further subjected to a loss on ignition test, and the loss on ignition is 3.15%, and it is orange-red (RGB is 144, 95, 63). The calcination temperature in the kiln is adjusted from 850°C to 800°C (calcined clay 2 is obtained).

[0046] The obtained calcined clay 1 was prepared into LC 3 The cement (50% silicate clinker, 5% desulfurized gypsum, 30% burned clay 1#, 15% high magnesium limestone, the same below) was tested for mortar strength and the 28d compressive strength was 51.0MPa. The calcined clay 2 was prepared into LC 3 The cement mortar strength test showed that the 28d compressive strength was 50.8MPa; Figure 2 The calcination temperature of clay 1# and the LC 3 The relationship curve of the 28d compressive strength of cement mortar. The method of the present invention can guide and dynamically adjust the calcination temperature of the industrial rotary kiln, effectively ensuring that the calcined clay is calcined in LC 3 Application effect in cement.

[0047] Based on the above scheme, the subsequent preparation of LC 3The types and dosages of cement water reducers at the factory include: taking the cement ground from the industrial ball mill with 50% silicate clinker, 5% desulfurized gypsum, 30% burned clay 1#, and 15% high magnesium limestone as the base cement. The prices of powder water reducer 1, powder water reducer 2, and powder water reducer 3 on the market are 5000 yuan / ton, 6000 yuan / ton, and 8000 yuan / ton respectively. According to (2) and (3), the powder water reducer is obtained. The dosage of powder water reducer 1, powder water reducer 2, and powder water reducer 3 are 0.5%, 0.4%, and 0.25% respectively, so the cost values of using powder water reducer 1, powder water reducer 2, and powder water reducer 3 are 5000×0.5%=25, 6000×0.4%=24, and 8000×0.25%=20 respectively. Powder water reducer 3 is selected, and then cement and powder water reducer 3 with a dosage of 0.25% are mixed evenly to obtain LC 3 Cement products.

[0048] Example 2 The production control method described in Example 2 differs from that in Example 1 in that: Clay 2# is used as the clay, and the total amount of the benchmark water reducer for the benchmark cement prepared with Clay 2# after calcination at 500°C, 600°C, 750°C, 800°C, 850°C, 900°C, and 950°C is 1.0%, 0.8%, 0.5%, 0.4%, 0.3%, 0.2%, and 0.1%, respectively. The corresponding viscosity values at this time are 1510 mPa·s, 1460 mPa·s, 1360 mPa·s, 1350 mPa·s, 1440 mPa·s, 1270 mPa·s, and 1370 mPa·s, respectively. The relationship between the benchmark water reducer amount and the calcination temperature of Clay 2# is thus obtained; More reference cements of Example 1 and Example 2 were prepared, and the total amount of reference water reducer measured by the rotational viscometer was added and the cement mortar fluidity test was performed. The relationship between the viscosity measured by the rotational viscometer and the mortar fluidity was shown in Table 4 and Figure 3 As shown, the present invention proposes for the first time that viscosity and mortar fluidity have a good correlation by given an operating method, a scientific benchmark cement ratio, an optimal range of the viscometer, a rotor, a rotation speed, and a required range of viscosity values. A large number of experiments have confirmed that a rotational viscometer viscosity of 1000-2000 mPa·s is equivalent to a mortar fluidity of 220-180 mm, which can characterize the working performance of cement. The relationship between the benchmark water reducer dosage and the calcination temperature of clay 1# is shown in FIG. Figure 1 As shown, combined with the loss on ignition test and the color of the fired clay for further optimization, it can be used to guide the calcination temperature control of clay 1#.

[0049] Table 4 Relationship between viscosity value measured by rotational viscometer and mortar fluidity

[0050] Comparative Example 1 A regulatory LC 3 The method of cement production process conditions is different from that of Example 1 in that the data of the reference water reducer dosage and the calcination temperature of clay 1# obtained in step (3) are directly fitted into a standard curve (see Figure 4 ).

[0051] Take the calcined clay 1# obtained in a certain stage in an industrial rotary kiln, and operate according to steps (2) and (3) to obtain the reference water reducer dosage (total dosage) of the reference cement mixed with the calcined clay 1# in the industrial rotary kiln as 0.5%. It is directly determined that the temperature in the industrial rotary kiln at this time is 800°C, and it is considered that the target temperature is reached, and the kiln parameters are not adjusted. However, according to the method of the present invention, further combined with the color and ignition loss information of the calcined clay, the actual temperature should be determined to be 600°C, and the temperature in the rotary kiln should be increased according to the method of the present invention.

[0052] After testing, the LC 3 The 28d compressive strength of cement is 44.3MPa, resulting in LC 3 The significant decrease in the compressive strength of cement mortar makes it impossible to effectively control the clay calcining conditions in the rotary kiln.

[0053] Comparative Example 2 The difference from Example 1 is that the rotational viscometer uses rotor No. 2 and a rotation speed of 3 r / min. At this time, the range is 0-10000 mPa·s. The viscosity value will change before stabilization. Because the rotation speed is too slow, the viscosity value takes too long to stabilize. The benchmark cement has produced a small amount of sedimentation and long-term hydration, resulting in the viscosity value changing by more than 20 mPa·s. The viscosity value cannot be measured and the measured viscosity value is distorted.

[0054] Comparative Example 3 The difference from Example 1 is that the rotational viscometer uses rotor No. 3 and a rotation speed of 60 r / min. At this time, the measuring range is 0-2000 mPa·s. The measured viscosity values and mortar fluidity are shown in Table 5, in which Example 1 is used as a comparison.

[0055] Table 5 Relationship between viscosity value measured by rotational viscometer and mortar fluidity

[0056] In Comparative Example 3, due to the high rotational speed, the measured viscosity values were generally low. Even after stabilization, the viscosity values still varied by 10-20 mPa·s. However, the viscosity intervals between the various base water-reducing agent dosages were narrow, resulting in a suitable viscosity range of 500-600 mPa·s. This narrow range made it difficult to accurately read the viscosity readings, which could easily lead to significant errors. The mortar fluidity test was significantly inferior to the rotational viscometer test because the mortar dryness was high when the fluidity was below 180 mm, and segregation occurred when the fluidity was above 220 mm.

[0057] The above embodiments are only preferred embodiments of the present invention and cannot be used to limit the scope of protection of the present invention. Any non-substantial changes and replacements made by those skilled in the art on the basis of the present invention are required by the present invention.

Claims

1. A method for LC 3 The cement production control method is characterized in that: The following steps are involved: 1) Calcinate clay under different calcination conditions; obtain the relationship between the color and loss on ignition of the calcined clay and the calcination conditions; 2) mixing the obtained calcined clay with silicate clinker, desulfurized gypsum and water to prepare cement slurry; 3) Gradually add a baseline water reducer to the cement paste and adjust its dosage until the target viscosity is achieved. The viscosity of the cement paste is measured using a rotational viscometer. A relationship between the baseline water reducer dosage and clay calcination conditions is established. 4) utilizing the relationship constructed in step 3) and combining the color and loss on ignition information of the calcined clay to control the calcination conditions in the industrial production process of the clay.

2. The production control method according to claim 1, characterized in that: The calcination conditions include calcination temperature and calcination time; the calcination temperature is selected from 500-1000° C., and the calcination time is selected from 30-120 min.

3. The production control method according to claim 1, characterized in that: The relationship between the color of the calcined clay and the calcination conditions is: the calcined clay obtained at 550-650°C is orange-yellow, and the RGB values are (100-130, 90-110, 60-80); the calcined clay obtained at 750-850°C is orange-red, and the RGB values are (130-150, 90-110, 60-80).

4. The production control method according to claim 1, characterized in that: The total mass proportion of CaO and MgO in the chemical composition of the clay does not exceed 30%, and the total mass proportion of CaCO3 and MgCO3 in the mineral composition does not exceed 50%; in the silicate clinker, the main mineral components and their mass percentages include: C3S 55-80%, C2S 5-25%, C3A 0-10%, and C4AF 3-15%.

5. The production control method according to claim 1, characterized in that: The silicate clinker, desulfurized gypsum and calcined clay in the cement paste constitute the benchmark cement, and the proportion of the benchmark cement includes, by mass percentage, 9-90% silicate clinker, 1-5% desulfurized gypsum and 9-90% calcined clay.

6. The production control method according to claim 1, characterized in that: The water-cement ratio used in preparing the cement paste in step 2) is 0.

5.

7. The production control method according to claim 1, characterized in that: In the viscosity testing step, a rotational viscometer with a measuring range of 5000-15000 mPa·s and a rotor speed of 6-30 r / min is selected; the stirred cement slurry is measured within 30 seconds, and the viscosity value when the viscosity value changes by no more than 20 mPa·s is recorded. The viscosity testing process is completed within 60 seconds.

8. The production control method according to claim 1, characterized in that: The target viscosity value is 1000-2000 mPa·s.

9. The production control method according to claim 5, characterized in that: In the step of adjusting the amount of the base water reducer, the base water reducer amount is increased by 0-1% of the base cement amount each time.

10. The production control method according to claim 1, characterized in that: The steps of regulating the calcination conditions in the clay industrial production process include: taking the calcined clay obtained from the calcination equipment, repeating steps 2) and 3), obtaining the reference water reducer dosage, determining the corresponding calcination temperature, and adjusting the temperature at this stage to the target calcination temperature of this type of clay.

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