Method for testing performance of cement raw material and cement clinker

Abstract

The invention discloses a cement raw material and cement clinker performance test method, the cement raw material comprises the following raw materials by weight: 92-89 parts of limestone, 5 parts of clay, 2 parts of iron powder and 1-4 parts of phosphorus slag, and before the phosphorus slag is mixed with other raw materials, the phosphorus slag is pretreated. The raw material burnability can be effectively improved, coal consumption is reduced, clinker crystal form conversion is promoted, clinker quality and clinker performance are improved, the phosphorus slag partially replaces limestone, and the material cost for raw material batching can be effectively reduced.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of cement production, in particular to a performance testing method of cement raw material and cement clinker. BACKGROUND

[0002] Under the current environment of resource constraints and increasingly stringent environmental requirements, efficient utilization of industrial solid waste has become a key path to achieve sustainable development. Phosphorus slag, as a large amount of secondary product generated in the production process of phosphate fertilizer, has a huge annual output. Its chemical composition is highly similar to the required ingredients for cement production, and is rich in calcium oxide, silicon dioxide, aluminum oxide, and iron oxide. If it can be reasonably applied to cement production, not only can it effectively solve the environmental pollution problem caused by phosphorus slag storage, but also can reduce the consumption of limestone and other primary resources, realizing the comprehensive utilization of resources.

[0003] Currently, phosphorus slag is mainly used in the fields of cement admixture and concrete admixture, and its application in cement raw material is still in the exploratory stage. Most enterprises currently still face problems such as large fluctuations in phosphorus slag composition, unclear influence of phosphorus slag on cement performance, and poor process adaptability, which limits the large-scale application of phosphorus slag. SUMMARY

[0004] In view of the above-mentioned deficiencies in the prior art, the present application provides a cement raw material, wherein the added phosphorus slag is pretreated before being mixed with other raw materials, so as to ensure the composition of the phosphorus slag and its influence on the performance of the cement, and is suitable for large-scale application of phosphorus slag in cement raw material.

[0005] In addition, the present application also provides a performance testing method of cement clinker.

[0006] In order to solve the above technical problems, the present application adopts the following technical solutions:

[0007] A cement raw material, comprising the following raw materials in a weight ratio: limestone 92-89 parts, clay 5 parts, iron powder 2 parts, and phosphorus slag 1-4 parts.

[0008] Preferably, before the phosphorus slag is mixed with other raw materials, the phosphorus slag is pretreated as follows:

[0009] Crushing;

[0010] Determining the mass percentage of P2O5 in the crushed phosphorus slag;

[0011] According to the mass percentage of P2O5 in the phosphorus slag, the phosphorus slag is treated in a set manner.

[0012] Preferably, the phosphorus slag is placed in a crusher for crushing treatment, and a filter screen is used to filter the crushed phosphorus slag to obtain phosphorus slag with a particle size of less than 5 mm.

[0013] Preferably, the method for determining the mass percentage of P2O5 in the crushed phosphorous slag is as follows:

[0014] A certain weight of phosphorous slag is taken from the crushed phosphorous slag;

[0015] The certain weight of phosphorous slag is soaked in water for 15-20 minutes;

[0016] The weight of the phosphorous slag after soaking is measured;

[0017] The weight of the phosphorous slag after soaking is compared with the weights of a plurality of different standard phosphorous slags, and the mass percentage of P2O5 in the current phosphorous slag is determined according to the comparison result.

[0018] Preferably, the weights of the plurality of different standard phosphorous slags include:

[0019] The weight of the first standard phosphorous slag is the weight of the phosphorous slag with a mass percentage of P2O5 of 1% after being soaked in water for 15-20 minutes;

[0020] The weight of the second standard phosphorous slag is the weight of the phosphorous slag with a mass percentage of P2O5 of 2% after being soaked in water for 15-20 minutes;

[0021] The weight of the third standard phosphorous slag is the weight of the phosphorous slag with a mass percentage of P2O5 of 3% after being soaked in water for 15-20 minutes.

[0022] Preferably, the weight of the phosphorous slag after soaking is compared with the weights of the first standard phosphorous slag, the second standard phosphorous slag, and the third standard phosphorous slag, respectively:

[0023] When the weight of the phosphorous slag after soaking is less than the weight of the first standard phosphorous slag, it is determined that the mass percentage of P2O5 in the current phosphorous slag is less than 1%;

[0024] When the weight of the phosphorous slag after soaking is greater than or equal to the weight of the first standard phosphorous slag and less than the weight of the second standard phosphorous slag, it is determined that the mass percentage of P2O5 in the current phosphorous slag is 1%-2%;

[0025] When the weight of the phosphorous slag after soaking is greater than or equal to the weight of the second standard phosphorous slag and less than the weight of the third standard phosphorous slag, it is determined that the mass percentage of P2O5 in the current phosphorous slag is 2%-3%;

[0026] When the weight of the phosphorous slag after soaking is greater than or equal to the weight of the third standard phosphorous slag, it is determined that the mass percentage of P2O5 in the current phosphorous slag is greater than 3%.

[0027] Preferably, the method for treating the phosphorous slag according to the mass percentage of P2O5 in the phosphorous slag in a set manner is as follows:

[0028] when the mass percentage of P2O5 in the phosphorous slag is less than 1%, the phosphorous slag is directly dried by a dryer, and the water content of the dried phosphorous slag is less than 2%;

[0029] when the mass percentage of P2O5 in the phosphorous slag is 1% to 2%, a certain amount of mineralizer is added to the phosphorous slag, and then the phosphorous slag containing the mineralizer is dried by a dryer, and the water content of the dried phosphorous slag is less than 2%;

[0030] when the mass percentage of P2O5 in the phosphorous slag is 2% to 3%, a certain amount of mineralizer is added to the phosphorous slag, and then the phosphorous slag containing the mineralizer is dried at a high temperature greater than 1350℃ for more than 30 minutes, and the water content of the dried phosphorous slag is less than 2%;

[0031] when the mass percentage of P2O5 in the phosphorous slag is greater than 3%, the phosphorous slag is mixed with the phosphorous slag with a mass percentage of P2O5 less than 1% according to a certain proportion, and then the mass percentage of P2O5 is re-determined.

[0032] Preferably, the limestone is 90 parts, the clay is 5 parts, the iron powder is 2 parts, and the phosphorous slag is 3 parts.

[0033] A performance testing method of a cement clinker, the cement clinker is made of the above cement raw material, and includes burnability testing and chemical composition testing.

[0034] Preferably, the method for testing the burnability of the cement clinker is as follows:

[0035] calcining in a rotary kiln, setting the initial calcination temperature to 1300℃, the heating rate to 10℃ / min, adjusting 50℃ up and down for each test, recording the kiln tail temperature, CO / CO2 concentration, and kiln current data of the rotary kiln in real time, and observing the material granulation; after the calcination is completed, the cement clinker is rapidly cooled to less than 30℃, weighed, and the appearance characteristics are recorded;

[0036] The method for testing the chemical composition of the cement clinker is as follows:

[0037] determining the contents of CaO, SiO2, Al2O3, Fe2O3, and MgO in the cement clinker, monitoring the change trend of MgO with the phosphorous slag content; detecting the contents of P2O5 and F⁻, establishing a correlation model of trace elements and clinker performance, and indirectly controlling the setting time of the clinker by controlling the content of magnesium oxide in the clinker.

[0038] Compared with existing technologies, this invention pre-treats the phosphorus slag before mixing it with other raw materials. This pre-treatment increases the specific surface area of ​​the phosphorus slag and disrupts its original dense structure. Simultaneously, by detecting and controlling the mass percentage of P2O5 in the phosphorus slag within a certain range, the impact of the added phosphorus slag on the overall performance of the cement raw meal is controllable. This solves the problems of large fluctuations in phosphorus slag composition and unclear influence on cement performance in existing technologies, enabling the large-scale application of phosphorus slag in cement raw meal. Detailed Implementation

[0039] Furthermore, the terms “comprising” and “having”, and any variations thereof, are intended to cover non-exclusive inclusion, such that a process, method, system, product, or apparatus that includes a series of steps or units is not necessarily limited to those steps or units that are explicitly listed, but may include other steps or units that are not explicitly listed or that are inherent to such process, method, product, or apparatus.

[0040] Furthermore, in describing representative embodiments, the specification may have presented methods and / or processes as a specific sequence of steps. However, the method or process should not be limited to the specific order of steps described herein, to the extent that it does not depend on such a specific order. As will be understood by those skilled in the art, other sequences of steps are also possible. Therefore, the specific order of steps set forth in the specification should not be construed as a limitation on the embodiments. Moreover, the method and / or process should not be limited to the steps performed in the written order; those skilled in the art will readily understand that these orders can be varied and still remain within the spirit and scope of the embodiments of this application.

[0041] Phosphate slag, a secondary product of phosphate fertilizer production, is produced in large quantities. Like cement raw materials, it contains calcium oxide, silicon dioxide, aluminum oxide, and ferric oxide, making it suitable for normal batching. After harmless treatment, it can be used in cement production, reducing limestone usage and achieving comprehensive resource utilization. Furthermore, because its chemical composition is essentially the same as cement materials and it contains trace elements such as phosphorus and fluorine, phosphate slag, in addition to replacing limestone in batching, can improve the burnability of raw materials, lower kiln calcination temperature, and reduce energy consumption. Therefore, the comprehensive utilization of phosphate slag resources maximizes their use and reduces environmental pollution and damage. This not only effectively reduces production costs but also improves clinker quality.

[0042] However, P2O5 (phosphorus pentoxide) in phosphate slag is a key limiting factor affecting its application in cement. P2O5 reacts with Ca(OH)2, a cement hydration product, to form a thin film of insoluble calcium phosphate on the surface of cement particles, hindering water penetration and significantly delaying cement setting and hardening. Simultaneously, due to the delayed hydration process, the early strength (3 days, 7 days) of cement decreases significantly. Furthermore, excessive P2O5 interferes with the formation of C3S (tricalcium silicate), a major mineral in cement clinker, reducing its content while increasing C2S (dicalcium silicate), directly leading to poorer early strength. These reasons preclude the large-scale application of phosphate slag in cement raw materials.

[0043] Based on the above-mentioned technical problems, this specific embodiment provides a cement raw material, which includes the following raw materials in the following weight ratio: 92-89 parts limestone, 5 parts clay, 2 parts iron powder, and 1-4 parts phosphorus slag.

[0044] Specifically, before the phosphorus slag is mixed with other raw materials, the phosphorus slag is pretreated as follows:

[0045] 1) Crushing: The phosphorus slag is placed in a crusher for crushing, and then filtered through a filter screen to obtain phosphorus slag with a particle size of less than 5 mm. Crushing increases the specific surface area of ​​the phosphorus slag and destroys its original dense structure.

[0046] 2) Determine the mass percentage of P2O5 in the crushed phosphorus slag.

[0047] 2.1) Take a set weight of phosphorus slag from the crushed phosphorus slag; in specific production practice, the set weight can be selected as needed, such as selecting 1 kg of phosphorus slag for subsequent processing. The weight of phosphorus slag selected here should correspond to the weight of the standard phosphorus slag used in the subsequent process.

[0048] 2.2) Soak the set weight of phosphate slag in water for 15-20 minutes. Phosphate slag has strong hygroscopic properties, so when it is soaked in water, it will absorb water, which will cause a change in the weight of the phosphate slag. The specific soaking time can be selected according to the actual situation, but it needs to correspond to the soaking time of the subsequent standard phosphate slag. In this specific embodiment, the soaking time of the phosphate slag is 20 minutes.

[0049] 2.3) Weigh the phosphate slag after soaking; the weight of the phosphate slag after soaking can reflect the moisture absorption of the phosphate slag, and thus reflect the content of P2O5 in the phosphate slag. Therefore, the content of P2O5 in the phosphate slag can be further judged based on the weight of the phosphate slag after soaking.

[0050] 2.4) Compare the weight of the soaked phosphorus slag with the weight of several different standard phosphorus slags, and determine the mass percentage of P2O5 in the current phosphorus slag based on the comparison results.

[0051] The weight of the soaked phosphate slag was compared with the weights of the first, second, and third standard phosphate slags, respectively:

[0052] The weight of the first standard phosphorus slag is: the weight of phosphorus slag with a mass percentage of 1% P2O5 after soaking in water for 15-20 minutes; in this specific embodiment, the weight of the first standard phosphorus slag is the weight of 1 kg of phosphorus slag with a mass percentage of 1% P2O5 after soaking in water for 20 minutes.

[0053] The weight of the second standard phosphorus slag: The weight of the second standard phosphorus slag is the weight of phosphorus slag with a P2O5 mass percentage of 2% after soaking in water for 15-20 minutes; In this specific embodiment, the weight of the second standard phosphorus slag is the weight of 1 kg of phosphorus slag with a P2O5 mass percentage of 2% after soaking in water for 20 minutes.

[0054] The weight of the third standard phosphorus slag: The weight of the third standard phosphorus slag is the weight of phosphorus slag with a P2O5 mass percentage of 3% after soaking in water for 15-20 minutes; In this specific embodiment, the weight of the third standard phosphorus slag is the weight of 1 kg of phosphorus slag with a P2O5 mass percentage of 3% after soaking in water for 20 minutes.

[0055] Given that P2O5 has extremely strong hygroscopic properties, when the initial content of phosphorus slag is 1 kg, the higher the mass percentage of P2O5, the stronger the hygroscopicity of the phosphorus slag in water, and the heavier its weight after soaking for 20 minutes. Therefore, the weight of the first standard phosphorus slag < the weight of the second standard phosphorus slag < the weight of the third standard phosphorus slag. Thus, by comparing the weight of the soaked phosphorus slag with the weight of each standard phosphorus slag, the mass percentage of P2O5 in the current phosphorus slag can be determined.

[0056] Specifically, if the weight of the phosphate slag after soaking is less than the weight of the first standard phosphate slag, then the mass percentage of P2O5 in the current phosphate slag is determined to be less than 1%.

[0057] When the weight of the phosphate slag after soaking is greater than or equal to the weight of the first standard phosphate slag and less than the weight of the second standard phosphate slag, the mass percentage of P2O5 in the current phosphate slag is determined to be 1%~2%.

[0058] When the weight of the phosphate slag after soaking is greater than or equal to the weight of the second standard phosphate slag and less than the weight of the third standard phosphate slag, the mass percentage of P2O5 in the current phosphate slag is determined to be 2%~3%.

[0059] When the weight of the phosphate slag after soaking is greater than or equal to the weight of the third standard phosphate slag, the mass percentage of P2O5 in the current phosphate slag is determined to be greater than 3%.

[0060] 2.5) Based on the mass percentage of P2O5 in the phosphorus slag obtained in 2.4), the phosphorus slag shall be treated in the following manner.

[0061] When the mass percentage of P2O5 in the current phosphorus slag is less than 1%, the phosphorus slag is directly dried using a dryer, ensuring that the moisture content of the dried phosphorus slag is less than 2%. When the mass percentage of P2O5 in the phosphorus slag is less than 1%, the impact of P2O5 on the performance of cement raw materials and the prepared cement clinker is within a controllable range. Therefore, the phosphorus slag at this stage only needs to be dried before it can be directly mixed with other raw materials. Simultaneously, controlling the moisture content of the dried phosphorus slag to below 2% can avoid the adverse effects of moisture on activity activation.

[0062] When the mass percentage of P2O5 in the current phosphorus slag is 1%~2%, a set amount of mineralizer is added to the phosphorus slag, and then the phosphorus slag containing the mineralizer is dried using a dryer, so that the moisture content of the dried phosphorus slag is less than 2%. When the mass percentage of P2O5 in the phosphorus slag is 1%~2%, P2O5 has a certain impact on the performance of cement raw materials and prepared cement clinker. At this time, by adding a small amount of mineralizer (such as fluorite (CaF2)) to the phosphorus slag, the ratio of phosphorus slag to mineralizer is set according to specific conditions. In this specific embodiment, the ratio of phosphorus slag to mineralizer is 100:1. The addition of mineralizer can reduce the clinker formation temperature, promote the formation of C3S, and to a certain extent offset the side effects of P2O5. Thus, the impact of P2O5 in the phosphorus slag on the performance of cement raw materials and prepared cement clinker after adding mineralizer can be kept within a controllable range.

[0063] When the mass percentage of P2O5 in the current phosphorus slag is 2%~3%, a set amount of mineralizing agent is added to the phosphorus slag, and then the phosphorus slag containing the mineralizing agent is dried at a high temperature of more than 1350℃ for more than 30 minutes, so that the moisture content of the dried phosphorus slag is less than 2%. When the mass percentage of P2O5 in phosphorus slag is 2%~3%, P2O5 has a significant impact on the performance of cement raw materials and the prepared cement clinker. In this case, a small amount of mineralizer (such as fluorite (CaF2)) is first added to the phosphorus slag. In this specific embodiment, the ratio of phosphorus slag to mineralizer is 100:1. The mineralizer is used to offset the side effects of P2O5 to a certain extent. Then, the phosphorus slag containing mineralizer is dried at a high temperature of 1350℃. Since P2O5 will partially volatilize at a high temperature above 1350℃, and the drying time is set to be greater than 30 minutes, the volatilization effect of P2O5 in phosphorus slag is improved, thereby reducing the mass percentage of P2O5 in phosphorus slag. Combined with the addition of mineralizer, the impact of P2O5 in phosphorus slag on the performance of cement raw materials and the prepared cement clinker after the addition of mineralizer can be kept within a controllable range.

[0064] When the mass percentage of P2O5 in the current phosphorus slag is greater than 3%, the phosphorus slag should be mixed with phosphorus slag with a P2O5 mass percentage of less than 1% in a set ratio, and then the mass percentage of P2O5 should be measured again. When the mass percentage of P2O5 in the phosphorus slag is greater than 3%, the impact of P2O5 on the performance of cement raw materials and prepared cement clinker exceeds its own effect. Therefore, the phosphorus slag at this time cannot be used directly. In this case, a homogenization method can be used to mix phosphorus slag with a P2O5 mass percentage greater than 3% and phosphorus slag with a P2O5 mass percentage of less than 1% to reduce the mass percentage of P2O5 in the overall phosphorus slag. The mass percentage of P2O5 in the mixed phosphorus slag should then be measured again using the method of this scheme, and the appropriate treatment method can be selected again based on the measurement results.

[0065] To more comprehensively investigate the effect of phosphorus slag content on cement, multiple sets of experiments were conducted in this specific embodiment, and the experiments were divided into a basic group and an experimental group. The basic group used the traditional cement raw material ratio (93 parts limestone, 5 parts clay, and 2 parts iron powder) as a control, while the experimental group used phosphorus slag with different ratios. The phosphorus slag ratios and experimental results of different experimental groups are shown in the table below:

[0066] In the above experiments, three parallel tests were set up for each mix ratio, and the average value was taken as the test result for that mix ratio to reduce experimental error. Finally, the particle size distribution of the raw meal was tested to analyze the particle distribution of the raw meal under different phosphorus slag admixtures and to study its impact on the flowability of the raw meal and the calcination process. By utilizing the synergistic effect of phosphorus slag with raw materials such as clay and iron powder, the chemical composition and mineral composition of the raw meal were changed, and the particle size distribution of the raw meal was adjusted, so that the synergistic effect among the raw materials was enhanced, which jointly affected the burnability of the raw meal and laid the foundation for the subsequent calcination process and the improvement of clinker performance.

[0067] As can be seen from the table above, the optimal ratio of phosphorus slag is around 3 parts. This ensures sufficient magnesium oxide in the clinker, optimal clinker setting time, and improved raw material burnability, thus guaranteeing standard coal consumption. Therefore, in this specific embodiment, a ratio of 90 parts limestone, 5 parts clay, 2 parts iron powder, and 3 parts phosphorus slag is used.

[0068] In addition, this specific embodiment also provides a performance testing method for cement clinker, which is made from the above-mentioned cement raw meal, including burnability testing and chemical composition testing.

[0069] The method for testing the burnability of cement clinker is as follows:

[0070] The cement clinker was calcined in a rotary kiln with an initial calcination temperature of 1300℃ and a heating rate of 10℃ / min. The temperature was adjusted by 50℃ for each test. The kiln tail temperature, CO / CO2 concentration, and kiln current data were recorded in real time, and the granulation of the material was observed. After calcination, the cement clinker was rapidly cooled to less than 30℃, weighed, and its appearance characteristics, such as color and particle hardness, were recorded.

[0071] The method for testing the chemical composition of cement clinker is as follows:

[0072] The contents of CaO, SiO2, Al2O3, Fe2O3, and MgO in cement clinker were determined (accuracy ±0.5%), and the trend of MgO change with the amount of phosphorus slag was monitored (MgO increases by approximately 0.3% for every 1% increase in phosphorus slag). The contents of P2O5 and F⁻ were also measured, and a correlation model between trace elements and clinker performance was established. The setting time of clinker was indirectly controlled by controlling the magnesium oxide content. The chemical composition of the clinker was analyzed, focusing on the contents of major components such as magnesium oxide, calcium oxide, silicon dioxide, aluminum oxide, and ferric oxide, as well as the changes in the contents of trace elements such as phosphorus and fluorine, to study their relationship with the amount of phosphorus slag.

[0073] Specifically, in the actual production process, the cement process parameters, including the grinding parameters of the raw material grinding equipment, are adjusted according to the amount of phosphorus slag added to ensure that the fineness and particle size distribution of the raw material meet the requirements.

[0074] At the same time, it adapts to the calcination system of the rotary kiln, such as adjusting the calcination temperature, heating rate, and holding time, to ensure high-quality clinker calcination under the new proportions.

[0075] Furthermore, a dynamic adjustment mechanism for process parameters should be established to make timely fine adjustments to the process parameters based on fluctuations in raw material quality and actual on-site conditions.

[0076] In this specific scheme, by implementing a linkage design between "phosphorus slag dosage and calcination temperature" in the rotary kiln central control system, the calcination temperature is automatically reduced by 30℃ to 1420℃ when 3 parts of phosphorus slag are added; at the same time, the kiln current and feed rate are automatically fine-tuned through PID control algorithm to ensure that the output fluctuation is ≤5%.

[0077] The cement raw material ratio is as follows: limestone: 90 parts, clay: 5 parts, iron powder: 2.0 parts, phosphorus slag: 3 parts. After calcination, the clinker magnesium oxide content is 2.6%, the raw material burnability is 80, and the standard coal consumption is reduced by 1.2t. This can ensure the clinker magnesium oxide content and clinker setting time, improve the raw material burnability, and guarantee the standard coal consumption.

[0078] Compared with existing technologies, this invention pre-treats the phosphorus slag before mixing it with other raw materials. This pre-treatment increases the specific surface area of ​​the phosphorus slag and disrupts its original dense structure. Simultaneously, by detecting and controlling the mass percentage of P2O5 in the phosphorus slag within a certain range, the impact of the added phosphorus slag on the overall performance of the cement raw meal is controllable. This solves the problems of large fluctuations in phosphorus slag composition and unclear influence on cement performance in existing technologies, enabling the large-scale application of phosphorus slag in cement raw meal.

[0079] Meanwhile, this invention improves the burnability of raw materials by more than 10%, reduces standard coal consumption by more than 1 kgce / t, promotes clinker crystal transformation, improves clinker quality and performance, and reduces the material cost of raw material batching by using phosphorus slag to partially replace limestone.

[0080] After adopting this solution and applying phosphate slag on a large scale in cement raw materials, the cost of phosphate slag upon entering the plant is zero. Replacing limestone, and using limestone from our own mine at a unit price of 15 yuan, with a raw material mix ratio of 3%, and assuming a raw material grinding table of 600 hours per day, operating for 20 hours daily, the daily savings would be 600 * 0.03 * 20 * 15 = 5400 yuan. Assuming 300 days per year, one production line could bring the company an economic benefit of 5400 * 300 = 1,620,000 yuan. Therefore, the research of this invention is of great significance for actual production.

[0081] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit the technical solutions. Those skilled in the art should understand that any modifications or equivalent substitutions to the technical solutions of the present invention without departing from the spirit and scope of the present invention should be covered within the scope of the claims of the present invention.

Claims

1. A cement raw material, characterized in that, The raw materials include the following weight ratios: 92-89 parts limestone, 5 parts clay, 2 parts iron powder, and 1-4 parts phosphorus slag.

2. The cement raw meal according to claim 1, characterized in that, Before the phosphorus slag is mixed with other raw materials, the phosphorus slag is pretreated as follows: broken; Determine the mass percentage of P2O5 in the crushed phosphorus slag; The phosphorus slag is treated according to the set method based on the mass percentage of P2O5 in the phosphorus slag.

3. The cement raw material according to claim 2, characterized in that, The phosphorus slag is placed in a crusher for crushing and then filtered through a filter screen to obtain phosphorus slag with a particle size of less than 5 mm.

4. The cement raw material according to claim 3, characterized in that, The method for determining the mass percentage of P2O5 in crushed phosphorus slag is as follows: Take a predetermined weight of phosphorus slag from the crushed phosphorus slag; Soak the set weight of phosphorus residue in water for 15-20 minutes; Weigh the phosphorus residue after soaking; The weight of the soaked phosphorus slag is compared with the weight of several different standard phosphorus slags, and the mass percentage of P2O5 in the current phosphorus slag is determined based on the comparison results.

5. The cement raw meal according to claim 4, characterized in that, The weights of several different standard phosphorus slags include: The weight of the first standard phosphorus slag: The weight of the first standard phosphorus slag is the weight of phosphorus slag with a mass percentage of 1% P2O5 after soaking in water for 15-20 minutes. The weight of the second standard phosphorus slag: The weight of the second standard phosphorus slag is the weight of phosphorus slag with a mass percentage of 2% P2O5 after soaking in water for 15-20 minutes. The weight of the third standard phosphorus slag: The weight of the third standard phosphorus slag is the weight of phosphorus slag with a P2O5 mass percentage of 3% after soaking in water for 15-20 minutes.

6. The cement raw meal according to claim 5, characterized in that, The weight of the soaked phosphate slag was compared with the weights of the first, second, and third standard phosphate slags, respectively: When the weight of the phosphate slag after soaking is less than the weight of the first standard phosphate slag, it is determined that the mass percentage of P2O5 in the current phosphate slag is less than 1%. When the weight of the phosphate slag after soaking is greater than or equal to the weight of the first standard phosphate slag and less than the weight of the second standard phosphate slag, the mass percentage of P2O5 in the current phosphate slag is determined to be 1% to 2%. When the weight of the phosphate slag after soaking is greater than or equal to the weight of the second standard phosphate slag and less than the weight of the third standard phosphate slag, the mass percentage of P2O5 in the current phosphate slag is determined to be 2% to 3%. When the weight of the phosphate slag after soaking is greater than or equal to the weight of the third standard phosphate slag, the mass percentage of P2O5 in the current phosphate slag is determined to be greater than 3%.

7. The cement raw meal according to claim 6, characterized in that, The method for treating phosphorus slag according to the mass percentage of P2O5 in the phosphorus slag and in a predetermined manner is as follows: When the mass percentage of P2O5 in the current phosphorus slag is less than 1%, the phosphorus slag is directly dried using a dryer, so that the moisture content of the dried phosphorus slag is less than 2%. When the mass percentage of P2O5 in the current phosphorus slag is 1% to 2%, a set amount of mineralizing agent is added to the phosphorus slag, and then the phosphorus slag containing the mineralizing agent is dried using a dryer, so that the moisture content of the dried phosphorus slag is less than 2%. When the mass percentage of P2O5 in the current phosphorus slag is 2% to 3%, a set amount of mineralizing agent is added to the phosphorus slag, and then the phosphorus slag containing the mineralizing agent is dried at a high temperature of more than 1350℃ for more than 30 minutes, so that the moisture content of the dried phosphorus slag is less than 2%. If the mass percentage of P2O5 in the current phosphorus slag is greater than 3%, the phosphorus slag should be mixed with phosphorus slag with a mass percentage of P2O5 of less than 1% in a set ratio, and then the mass percentage of P2O5 should be measured again.

8. The cement raw meal according to claim 1, characterized in that, 90 parts limestone, 5 parts clay, 2 parts iron powder, and 3 parts phosphorus slag.

9. A method for testing the performance of cement clinker, characterized in that, The cement clinker is made from cement raw meal as described in any one of claims 1 to 8, including burnability testing and chemical composition testing.

10. The performance testing method for cement clinker according to claim 9, characterized in that, The method for testing the burnability of cement clinker is as follows: The cement clinker was calcined in a rotary kiln. The initial calcination temperature was set at 1300℃, and the heating rate was 10℃ / min. The temperature was adjusted by 50℃ for each test. The kiln tail temperature, CO / CO2 concentration, and kiln current data were recorded in real time, and the granulation of the material was observed. After calcination, the cement clinker was rapidly cooled to less than 30℃, weighed, and its appearance characteristics were recorded. The method for testing the chemical composition of cement clinker is as follows: The contents of CaO, SiO2, Al2O3, Fe2O3, and MgO in cement clinker were determined, and the trend of MgO variation with the amount of phosphorus slag was monitored; P2O5 and F were also detected. - By controlling the magnesium oxide content in clinker, a correlation model between trace elements and clinker performance was established, and the setting time of clinker was indirectly controlled by controlling the magnesium oxide content in clinker.

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