Cement clinker crystal melting and calcining production process

Abstract

The invention discloses a cement clinker crystal melting and calcining production process. The production process comprises the following steps: S1, providing steel slag; s2, crushing the steel slag to obtain steel slag particles; s3, removing iron from the steel slag particles and spraying a fluxing agent; s4, sieving and sorting the iron-removed steel slag particles, and reserving 6-20mm steel slag particles as a seed crystal fluxing agent; and S5, mixing the seed crystal fluxing agent with the cement raw material, and putting the mixture into a rotary kiln for calcining treatment to generate cement clinker. The process and the flow are simple, the steel slag can be used as a seed crystal fluxing agent after being crushed, deironed and screened, the steel slag is used as the seed crystal fluxing agent and is wrapped and calcined with the cement raw material, the generated cement clinker is excellent and stable in quality, the coal consumption and the power consumption required by clinker sintering are reduced, and the production cost is reduced. Carbon emission and nitrogen oxide emission generated in the clinker calcining process are reduced to a certain extent.

Description

Technical Field

[0001] The invention relates to the technical field of producing cement clinker by utilizing steel slag, and in particular to a cement clinker crystal melting and calcining production process. Background Art

[0002] my country's steel production ranks first in the world, accounting for about 50% of the world's total. In 2022, the amount of steel slag produced was about 150 million tons, but the comprehensive utilization rate of steel slag was less than 30%. The cement industry is the main way to comprehensively utilize steel slag, among which the technology of calcining metallurgical waste slag in a rotary kiln is a common means. The existing technology of calcining metallurgical waste slag in a rotary kiln is to mix steel slag with other powder materials that are stirred and granulated with water in a certain proportion, put them into the tail smoke chamber of the rotary kiln, and then enter the rotary kiln with the raw materials to obtain cement clinker after calcination.

[0003] The Chinese invention patent with reference announcement number CN117303764A discloses a method for preparing cement clinker using powdered solid waste and steel slag, which comprises mixing the bonding raw material and the powdered solid waste through a mixer, adding 10% to 20% tap water to the mixed powder, stirring, conveying it to a granulator for granulation, conveying the granulated material to a dryer for drying to obtain dried granulated material, and then feeding the granulated material and steel slag particles into the smoke chamber at the rear of the rotary kiln in a certain proportion. A detailed analysis of the above patents shows that the model of utilizing steel slag by clinker calcination has the following defects: 1. The process flow is too complicated. Some cement production units cannot implement the above process flow due to limited space due to planning reasons; 2. Due to the different densities of granulated materials and steel slag particles, after entering the tail smoke chamber of the rotary kiln, they are affected differently by the air flow field in the kiln, which can easily cause changes in the working conditions in the rotary kiln, resulting in abnormal process conditions such as ringing and balling in the kiln; 3. Due to the different bonding degrees of granulated materials, steel slag particles and raw materials, the quality of the burned clinker is easily unstable. Summary of the invention

[0004] In view of the above-mentioned shortcomings of the prior art, the purpose of the present invention is to provide a cement clinker crystal melting calcination production process to reduce the coal consumption and electricity consumption required for clinker burning, improve the quality of clinker, and reduce the carbon emissions and nitrogen oxide emissions generated during the clinker calcination process.

[0005] A cement clinker melting and calcining production process comprises the following steps:

[0006] S1 provides steel slag;

[0007] S2 crushes the steel slag to obtain steel slag particles;

[0008] S3 steel slag particles are deironed and sprayed with flux;

[0009] S4 screens and sorts the steel slag particles after iron removal, and retains the steel slag particles of 6 mm to 20 mm as seed flux;

[0010] S5 takes the seed crystal flux and cement raw material and mixes them, and then puts them into a rotary kiln for calcination to generate cement clinker.

[0011] As a further improvement of the above solution, the steel slag is derived from a by-product produced during the steel smelting process, and is formed by solidification of impurities and oxides in molten steel during the cooling process.

[0012] As a further improvement of the above solution, the crushing process is carried out in a cone crusher; or, the crushing process is carried out in a jaw crusher.

[0013] As a further improvement of the above scheme, the method for iron removal is specifically operated as follows: the steel slag particles pass through an armored belt-type powerful electromagnetic iron remover, the electromagnetic coil in the iron remover is energized to generate a magnetic field, and the magnetic field absorbs ferromagnetic impurities in the steel slag, so that the ferromagnetic material and the steel slag are separated. The present invention utilizes the attraction of the magnetic field to the ferromagnetic material to absorb and separate the ferromagnetic impurities in the steel slag. The armored belt-type powerful electromagnetic iron remover used in the present invention can effectively avoid damage to the belt by sharp ferromagnetic debris due to its armored belt structure, thereby enhancing the durability of the iron remover.

[0014] As a further improvement of the above scheme, during the process of the steel slag particles passing through the armored belt type strong electromagnetic iron remover, a flux is sprayed; the flux accounts for 0.8% to 1.2% of the steel slag particles, and the flux adopts a calcium chloride solution or a magnesium chloride solution. The present invention reduces the melting point of the steel slag during subsequent calcination by spraying liquid flux on the steel slag particles.

[0015] As a further improvement of the above scheme, the screening and sorting method is specifically operated as follows: the steel slag particles after iron removal are sent to a drum-type vibrating screen machine equipped with a rotary vibrating screen, and are screened and sorted in sequence to obtain 20mm-40mm steel slag particles, 6mm-20mm steel slag particles, and 0-6mm steel slag particles, and 6mm-20mm steel slag particles are retained as seed flux. Considering that the screen of the vibrating screen is prone to get stuck with steel slag particles when vibrating, and that the surface of the steel slag particles is rough and uneven during the screening process of the vibrating screen, and that they are easy to mesh with each other, the present invention uses a rotary vibrating screen for vibratory screening.

[0016] As a further improvement of the above scheme, after the seed flux and cement raw material are mixed, they are transported to the clinker calcination preheater, decomposition furnace, and kiln tail smoke chamber in sequence through the relevant kiln tail conveying channel, and finally put into the rotary kiln and calcine at 1350-1430°C for 25-30 minutes to generate cement clinker.

[0017] As a further improvement of the above scheme, the amount of the seed flux added accounts for 3% to 15% of the rotary kiln clinker output; the cement raw material is obtained by mixing limestone, clay and iron raw materials, and the three rate values ​​of the cement raw material are as follows: lime saturation coefficient 0.95 to 0.99, silicon rate 2.3 to 2.8, and aluminum rate 1.2 to 1.7; the three rate values ​​of the cement clinker are as follows: lime saturation coefficient 0.87 to 0.91, silicon rate 2.2 to 2.8, and aluminum rate 1.3 to 1.8.

[0018] As a further improvement of the above scheme, the silicon content is SiO 2 Content and Al 2 O 3 , Fe 2 O 3 The ratio of the sum of the aluminum rate is Al 2 O 3 Content and Fe 2 O 3 The ratio of content. In the present invention, the silicon ratio reflects the relative content of silicate minerals and solvent minerals. If the silicon ratio is too low, the flux mineral content is too much, the liquid phase volume is large during calcination, it is easy to form rings and large lumps, making the firing difficult, affecting the yield and quality of cement. If the silicon ratio is too high, it means that the flux mineral content is low, the liquid phase volume is too small during calcination, which also makes the firing difficult. The aluminum ratio reflects the relative content of tricalcium aluminate and tetracalcium aluminoferrate in cement. The liquid phase formed by tricalcium aluminate has a large viscosity, and the liquid phase formed by tetracalcium aluminoferrate has a small viscosity. Therefore, the aluminum ratio also reflects the properties of the liquid phase during the calcination process.

[0019] As a further improvement of the above scheme, the lime saturation coefficient is the ratio of the total calcium oxide content minus the calcium oxide required for saturated acidic oxide to the calcium oxide content theoretically required for all silicon dioxide to be converted into tricalcium silicate.

[0020] As a further improvement of the above scheme, the saturated acidic oxide is Al 2 O 3 and Fe 2 O 3 The total calcium oxide content minus the calcium oxide required for saturated acidic oxides is the calcium oxide content that actually combines with silicon dioxide to form tricalcium silicate. In the present invention, the lime saturation coefficient is used to measure the degree to which silicon dioxide is saturated with calcium oxide to form A ore. The larger the lime saturation coefficient, the higher the strength of the cement clinker and the more difficult it is to burn.

[0021] Compared with the prior art, the present invention has the following beneficial effects:

[0022] The process of the present invention has a simple flow. After the steel slag is crushed and iron is removed, it can be used as a seed flux through screening. The steel slag is used as a seed flux and wrapped with cement raw materials for calcination. The generated cement clinker has excellent and stable quality. In addition, the process of the present invention reduces the coal consumption and electricity consumption required for clinker burning, and reduces the carbon emission and nitrogen oxide emission generated in the clinker calcination process to a certain extent. DETAILED DESCRIPTION

[0023] In order to make the purpose, technical scheme and advantages of the present invention clearer, the present invention is further described in detail below in conjunction with the embodiments. Additional aspects and advantages of the present invention will be given in part in the following description, and will become apparent from the following description, or will be understood through the practice of the present invention. It should be understood that the following description is only used to explain the present invention and is not intended to limit the present invention.

[0024] As used herein, the terms "comprises," "including," "contains," or any other variation thereof, are intended to cover a non-exclusive inclusion. For example, a composition, process, method, article, or apparatus that comprises the listed elements is not necessarily limited to only those elements but may include other elements not expressly listed or inherent to such composition, process, method, article, or apparatus.

[0025] When an amount, concentration, or other value or parameter is expressed as a range, a preferred range, or a range limited by a series of upper preferred values ​​and lower preferred values, this should be understood as specifically disclosing all ranges formed by any pairing of any range upper limit or preferred value with any range lower limit or preferred value, regardless of whether the range is disclosed separately. For example, when a range of "1 to 5" is disclosed, the described range should be interpreted as including a range of "1 to 4", "1 to 3", "1 to 2", "1 to 2 and 4 to 5", "1 to 3 and 5" etc. When a numerical range is described in this article, unless otherwise specified, the range is intended to include its end values ​​and all integers and fractions within the range.

[0026] The specific embodiments of the present invention are described in detail below.

[0027] Example 1

[0028] This embodiment provides a cement clinker melting and calcining production process, which includes the following steps:

[0029] S1 provides steel slag, which is a byproduct of steel smelting and is formed by solidification of impurities and oxides in molten steel during cooling.

[0030] S2 crushes the steel slag in a cone crusher to obtain steel slag particles.

[0031] The S3 steel slag particles pass through an armored belt-type powerful electromagnetic iron remover. The electromagnetic coil in the iron remover is energized to generate a magnetic field. The magnetic field absorbs ferromagnetic impurities in the steel slag, so that the ferromagnetic material and the steel slag are separated. In the process of the steel slag particles passing through the armored belt-type powerful electromagnetic iron remover, flux is sprayed. The flux accounts for 0.8% of the steel slag particles, and the flux is a calcium chloride solution.

[0032] In this embodiment, the attraction of the magnetic field to ferromagnetic materials is utilized to adsorb and separate the ferromagnetic impurities in the steel slag. The armored belt-type high-power electromagnetic iron remover adopted in the present invention can effectively avoid damage to the belt by sharp ferromagnetic debris due to its armored belt structure, thereby enhancing the durability of the iron remover. By spraying liquid flux on the steel slag particles, the melting point of the steel slag during subsequent calcination can be reduced.

[0033] S4 The steel slag particles after iron removal are sent to a drum-type vibrating screen machine equipped with a rotary vibrating screen, and are screened and sorted in turn to obtain 20mm-40mm steel slag particles, 6mm-20mm steel slag particles, and 0-6mm steel slag particles, and 6mm-20mm steel slag particles are retained as seed flux. Considering that the screen of the vibrating screen is easy to get stuck with steel slag particles when vibrating, and the surface of the steel slag particles is rough and uneven during the screening process of the vibrating screen, and it is easy to mesh with each other, this embodiment uses a rotary vibrating screen for vibration screening.

[0034] S5 takes the seed flux and cement raw material and mixes them, and then transports them to the clinker calcination preheater, decomposition furnace, and kiln tail smoke chamber in sequence through the relevant kiln tail conveying channel, and finally puts them into the rotary kiln and calcines them at 1350°C for 30 minutes to generate cement clinker. The amount of the seed flux added accounts for 3% of the rotary kiln clinker output.

[0035] The cement raw material is obtained by mixing limestone, clay and iron raw materials, and the three rate values ​​of the cement raw material are as follows: lime saturation coefficient 0.95, silicon rate 2.56, and aluminum rate 1.25. The three rate values ​​of the cement clinker are as follows: lime saturation coefficient 0.88, silicon rate 2.29, and aluminum rate 1.40. In this embodiment, it should be noted that the rotary kiln process control parameters can be fine-tuned according to the kiln conditions. When the raw material is batched, the iron oxide content is reduced by 0.1% to 0.3% for regulation. The lime saturation coefficient value of the cement raw material ratio is increased by 0.01 compared with the conventional situation, the silicon rate can be increased by 0.01, and the aluminum rate is increased by 0.1, which will not be elaborated here.

[0036] Silicon rate is SiO 2 Content and Al 2 O 3 , Fe 2 O 3 The ratio of the sum of the aluminum rate is Al 2 O 3 Content and Fe 2 O3 The lime saturation coefficient is the ratio of the total calcium oxide content minus the calcium oxide required for saturated acidic oxide to the calcium oxide content required for all silicon dioxide to be converted into tricalcium silicate in theory. The saturated acidic oxide is Al 2 O 3 and Fe 2 O 3 The total calcium oxide content minus the calcium oxide required for saturated acidic oxide is the calcium oxide content that actually combines with silicon dioxide to form tricalcium silicate.

[0037] In this example, the silicon content is used to reflect the relationship between silicate minerals and solvent minerals (Al 2 O 3 +Fe 2 O 3 ) relative content. If the silicon rate is too low, the flux mineral content is too high, and the liquid phase volume is large during calcination, which is easy to form rings and large lumps, making it difficult to burn, affecting the output and quality of cement. If the silicon rate is too high, it means that the flux mineral content is low, and the liquid phase volume is too small during calcination, which also makes burning difficult. The aluminum rate reflects the relative content of tricalcium aluminate and tetracalcium aluminoferrate in cement. The liquid phase formed by tricalcium aluminate has a large viscosity, and the liquid phase formed by tetracalcium aluminoferrate has a small viscosity. That is, the aluminum rate also reflects the properties of the liquid phase during calcination. The lime saturation coefficient is used to measure the degree to which silicon dioxide is saturated by calcium oxide into A ore. The larger the lime saturation coefficient, the higher the strength of the cement clinker and the more difficult it is to burn.

[0038] In this embodiment, the C in the seed flux (i.e., steel slag) 2 S and C 3 S has a seed effect during the clinker burning process, which can reduce C 2 S and C 3 The reaction barrier of S forms a nucleation structure with polycrystalline nuclei focused. The trace elements in steel slag play a mineralizing role in cement burning, causing the liquid phase to appear earlier and accelerating the C 3 The formation rate of S. The free calcium oxide released by steel slag at high temperature reacts with other components to form cement clinker mineral phase. The RO phase in the steel slag undergoes a transformation after reacting with cement raw materials. The high-temperature reconstructed steel slag has improved gelling activity, stability and grindability. The RO phase is a composite solid solution, which includes but is not limited to oxides such as CaO, FeO, MnO and MgO.

[0039] Example 2

[0040] This embodiment provides a cement clinker melting and calcining production process, which includes the following steps:

[0041] S1 provides steel slag, which is a byproduct of steel smelting and is formed by solidification of impurities and oxides in molten steel during cooling.

[0042] S2 crushes the steel slag in a jaw crusher to obtain steel slag particles.

[0043] The S3 steel slag particles pass through an armored belt-type powerful electromagnetic iron remover. The electromagnetic coil in the iron remover is energized to generate a magnetic field. The magnetic field absorbs ferromagnetic impurities in the steel slag, so that the ferromagnetic material and the steel slag are separated. In the process of the steel slag particles passing through the armored belt-type powerful electromagnetic iron remover, a flux is sprayed. The flux accounts for 1% of the steel slag particles, and the flux is a calcium chloride solution.

[0044] In this embodiment, the attraction of the magnetic field to ferromagnetic materials is utilized to adsorb and separate the ferromagnetic impurities in the steel slag. The armored belt-type high-power electromagnetic iron remover adopted in the present invention can effectively avoid damage to the belt by sharp ferromagnetic debris due to its armored belt structure, thereby enhancing the durability of the iron remover. By spraying liquid flux on the steel slag particles, the melting point of the steel slag during subsequent calcination can be reduced.

[0045] S4 The steel slag particles after iron removal are sent to a drum-type vibrating screen machine equipped with a rotary vibrating screen, and are screened and sorted in turn to obtain 20mm-40mm steel slag particles, 6mm-20mm steel slag particles, and 0-6mm steel slag particles, and 6mm-20mm steel slag particles are retained as seed flux. Considering that the screen of the vibrating screen is easy to get stuck with steel slag particles when vibrating, and the surface of the steel slag particles is rough and uneven during the screening process of the vibrating screen, and it is easy to mesh with each other, this embodiment uses a rotary vibrating screen for vibration screening.

[0046] S5 takes the seed flux and cement raw materials and mixes them, and then transports them to the clinker calcination preheater, decomposition furnace, and kiln tail smoke chamber in sequence through the relevant kiln tail conveying channel, and finally puts them into the rotary kiln and calcines them at 1400℃ for 27 minutes to generate cement clinker. The amount of seed flux added accounts for 5% of the rotary kiln clinker output.

[0047] The cement raw material is prepared by mixing limestone, clay and iron raw materials, and the three rate values ​​of the cement raw material are as follows: lime saturation coefficient 0.95, silicon rate 2.52, and aluminum rate 1.2. The three rate values ​​of the cement clinker are as follows: lime saturation coefficient 0.86, silicon rate 2.27, and aluminum rate 1.39. In this embodiment, it should be noted that the rotary kiln process control parameters can be fine-tuned according to the kiln conditions. When the raw material is batched, the iron oxide content is reduced by 0.1% to 0.3% for regulation. The lime saturation coefficient value of the cement raw material ratio is increased by 0.01 compared with the conventional situation, the silicon rate can be increased by 0.01, and the aluminum rate is increased by 0.1, which will not be elaborated here.

[0048] Silicon rate is SiO 2 Content and Al 2 O 3 , Fe2 O 3 The ratio of the sum of the aluminum rate is Al 2 O 3 Content and Fe 2 O 3 The lime saturation coefficient is the ratio of the total calcium oxide content minus the calcium oxide required for saturated acidic oxide to the calcium oxide content required for all silicon dioxide to be converted into tricalcium silicate in theory. The saturated acidic oxide is Al 2 O 3 and Fe 2 O 3 The total calcium oxide content minus the calcium oxide required for saturated acidic oxide is the calcium oxide content that actually combines with silicon dioxide to form tricalcium silicate.

[0049] In this example, the silicon content is used to reflect the relationship between silicate minerals and solvent minerals (Al 2 O 3 +Fe 2 O 3 ) relative content. If the silicon rate is too low, the flux mineral content is too high, and the liquid phase volume is large during calcination, which is easy to form rings and large lumps, making it difficult to burn, affecting the output and quality of cement. If the silicon rate is too high, it means that the flux mineral content is low, and the liquid phase volume is too small during calcination, which also makes burning difficult. The aluminum rate reflects the relative content of tricalcium aluminate and tetracalcium aluminoferrate in cement. The liquid phase formed by tricalcium aluminate has a large viscosity, and the liquid phase formed by tetracalcium aluminoferrate has a small viscosity. That is, the aluminum rate also reflects the properties of the liquid phase during calcination. The lime saturation coefficient is used to measure the degree to which silicon dioxide is saturated by calcium oxide into A ore. The larger the lime saturation coefficient, the higher the strength of the cement clinker and the more difficult it is to burn.

[0050] In this embodiment, the C in the seed flux (i.e., steel slag) 2 S and C 3 S has a seed effect during the clinker burning process, which can reduce C 2 S and C 3 The reaction barrier of S forms a nucleation structure with polycrystalline nuclei focused. The trace elements in steel slag play a mineralizing role in cement burning, causing the liquid phase to appear earlier and accelerating the C 3 The formation rate of S. The free calcium oxide released by steel slag at high temperature reacts with other components to form cement clinker mineral phase. The RO phase in the steel slag undergoes a transformation after reacting with cement raw materials. The high-temperature reconstructed steel slag has improved gelling activity, stability and grindability. The RO phase is a composite solid solution, which includes but is not limited to oxides such as CaO, FeO, MnO and MgO.

[0051] Example 3

[0052] This embodiment provides a cement clinker melting and calcining production process, which includes the following steps:

[0053] S1 provides steel slag, which is a byproduct of steel smelting and is formed by solidification of impurities and oxides in molten steel during cooling.

[0054] S2 crushes the steel slag in a jaw crusher to obtain steel slag particles.

[0055] The S3 steel slag particles pass through an armored belt-type high-power electromagnetic iron remover. The electromagnetic coil in the iron remover is energized to generate a magnetic field. The magnetic field absorbs ferromagnetic impurities in the steel slag, so that the ferromagnetic material and the steel slag are separated. In the process of the steel slag particles passing through the armored belt-type high-power electromagnetic iron remover, flux is sprayed. The flux accounts for 1.2% of the steel slag particles, and the flux is a calcium chloride solution.

[0056] In this embodiment, the attraction of the magnetic field to ferromagnetic materials is utilized to adsorb and separate the ferromagnetic impurities in the steel slag. The armored belt-type high-power electromagnetic iron remover adopted in the present invention can effectively avoid damage to the belt by sharp ferromagnetic debris due to its armored belt structure, thereby enhancing the durability of the iron remover. By spraying liquid flux on the steel slag particles, the melting point of the steel slag during subsequent calcination can be reduced.

[0057] S4 The steel slag particles after iron removal are sent to a drum-type vibrating screen machine equipped with a rotary vibrating screen, and are screened and sorted in turn to obtain 20mm-40mm steel slag particles, 6mm-20mm steel slag particles, and 0-6mm steel slag particles, and 6mm-20mm steel slag particles are retained as seed flux. Considering that the screen of the vibrating screen is easy to get stuck with steel slag particles when vibrating, and the surface of the steel slag particles is rough and uneven during the screening process of the vibrating screen, and it is easy to mesh with each other, this embodiment uses a rotary vibrating screen for vibration screening.

[0058] S5 takes the seed flux and cement raw material and mixes them, and then transports them to the clinker calcination preheater, decomposition furnace, and kiln tail smoke chamber in sequence through the relevant kiln tail conveying channel, and finally puts them into the rotary kiln and calcines them at 1430℃ for 25 minutes to generate cement clinker. The amount of seed flux added accounts for 6% of the rotary kiln clinker output.

[0059] The cement raw material is obtained by mixing limestone, clay and iron raw materials, and the three rate values ​​of the cement raw material are as follows: lime saturation coefficient 0.95, silicon rate 2.52, and aluminum rate 1.2. The three rate values ​​of the cement clinker are as follows: lime saturation coefficient 0.87, silicon rate 2.28, and aluminum rate 1.38. In this embodiment, it should be noted that the rotary kiln process control parameters can be fine-tuned according to the kiln conditions. When the raw material is batched, the iron oxide content is reduced by 0.1% to 0.3% for regulation. The lime saturation coefficient value of the cement raw material ratio is increased by 0.01 compared with the conventional situation, the silicon rate can be increased by 0.01, and the aluminum rate is increased by 0.1, which will not be elaborated here.

[0060] Silicon rate is SiO 2 Content and Al 2 O 3 , Fe 2 O 3 The ratio of the sum of the aluminum rate is Al 2 O 3 Content and Fe 2 O 3 The lime saturation coefficient is the ratio of the total calcium oxide content minus the calcium oxide required for saturated acidic oxide to the calcium oxide content required for all silicon dioxide to be converted into tricalcium silicate in theory. The saturated acidic oxide is Al 2 O 3 and Fe 2 O 3 The total calcium oxide content minus the calcium oxide required for saturated acidic oxide is the calcium oxide content that actually combines with silicon dioxide to form tricalcium silicate.

[0061] In this example, the silicon content is used to reflect the relationship between silicate minerals and solvent minerals (Al 2 O 3 +Fe 2 O 3 ) relative content. If the silicon rate is too low, the flux mineral content is too high, and the liquid phase volume is large during calcination, which is easy to form rings and large lumps, making it difficult to burn, affecting the output and quality of cement. If the silicon rate is too high, it means that the flux mineral content is low, and the liquid phase volume is too small during calcination, which also makes burning difficult. The aluminum rate reflects the relative content of tricalcium aluminate and tetracalcium aluminoferrate in cement. The liquid phase formed by tricalcium aluminate has a large viscosity, and the liquid phase formed by tetracalcium aluminoferrate has a small viscosity. That is, the aluminum rate also reflects the properties of the liquid phase during calcination. The lime saturation coefficient is used to measure the degree to which silicon dioxide is saturated by calcium oxide into A ore. The larger the lime saturation coefficient, the higher the strength of the cement clinker and the more difficult it is to burn.

[0062] In this embodiment, the C in the seed flux (i.e., steel slag) 2 S and C 3 S has a seed effect during the clinker burning process, which can reduce C 2 S and C 3 The reaction barrier of S forms a nucleation structure with polycrystalline nuclei focused. The trace elements in steel slag play a mineralizing role in cement burning, causing the liquid phase to appear earlier and accelerating the C 3 The formation rate of S. The free calcium oxide released by steel slag at high temperature reacts with other components to form cement clinker mineral phase. The RO phase in the steel slag undergoes a transformation after reacting with cement raw materials. The high-temperature reconstructed steel slag has improved gelling activity, stability and grindability. The RO phase is a composite solid solution, which includes but is not limited to oxides such as CaO, FeO, MnO and MgO.

[0063] Comparative Example

[0064] The difference between this comparative example and Example 1 is that no seed flux is introduced.

[0065] The following is a comparative analysis of the performance indicators of Example 1, Example 2, Example 3 and the comparative process using a rotary kiln system with an output of 5000 t / d. The analysis results are shown in Tables 1 and 2.

[0066] Table 1 Rotary kiln system performance index list

[0067]

[0068] Table 2 Analysis and performance details of cement raw materials and cement clinker

[0069]

[0070] In Table 2, KH represents the lime saturation coefficient, SM represents the silicon ratio, and IM represents the aluminum ratio.

[0071] A detailed analysis of Tables 1 and 2 shows that the process of the present invention reduces the coal consumption and electricity consumption required for clinker burning, and to a certain extent reduces the carbon emission and nitrogen oxide emission generated during the clinker calcination process. The cement clinker produced by the process of the present invention has significantly improved 28-day strength.

[0072] The above embodiments are merely preferred implementations of the present invention. Any simple modification, amendment and substitution of the above embodiments based on the technical essence of the present invention shall fall within the scope of the technical solution of the present invention.

Claims

1. A cement clinker melting and calcining production process, characterized in that: The following steps are involved: S1 provides steel slag; S2 crushes the steel slag to obtain steel slag particles; S3 steel slag particles are deironed and sprayed with flux; S4 screens and sorts the steel slag particles after iron removal, and retains the steel slag particles of 6 mm to 20 mm as seed flux; S5 takes the seed crystal flux and cement raw material and mixes them, and then puts them into a rotary kiln for calcination to generate cement clinker.

2. A cement clinker melting and calcining production process according to claim 1, characterized in that: The steel slag is a by-product generated during the steel smelting process, which is formed by the solidification of impurities and oxides in molten steel during the cooling process.

3. A cement clinker melting and calcining production process according to claim 1, characterized in that: The crushing process is carried out in a cone crusher; Alternatively, the crushing process is carried out in a jaw crusher.

4. A cement clinker melting and calcining production process according to claim 1, characterized in that: The iron removal method is specifically operated as follows: the steel slag particles pass through an armored belt-type strong electromagnetic iron remover, the electromagnetic coil in the iron remover is energized to generate a magnetic field, and the magnetic field absorbs ferromagnetic impurities in the steel slag, so that the ferromagnetic material and the steel slag are separated.

5. A cement clinker melting and calcining production process according to claim 4, characterized in that: When the slag particles pass through the armored belt type powerful electromagnetic iron remover, the flux is sprayed; The flux accounts for 0.8% to 1.2% of the steel slag particles, and the flux is a calcium chloride solution or a magnesium chloride solution.

6. A cement clinker melting and calcining production process according to claim 1, characterized in that: The screening and sorting method is specifically operated as follows: the steel slag particles after iron removal are sent to a drum-type vibrating screen machine equipped with a rotary vibrating screen, and are screened and sorted in sequence to obtain steel slag particles of 20 mm to 40 mm, steel slag particles of 6 mm to 20 mm, and steel slag particles of 0 to 6 mm, and the steel slag particles of 6 mm to 20 mm are retained as seed flux.

7. A cement clinker melting and calcining production process according to claim 1, characterized in that: After the seed crystal flux and cement raw material are mixed, they are transported to the clinker calcination preheater, decomposition furnace, and kiln tail smoke chamber in sequence through the relevant kiln tail conveying channel, and finally put into the rotary kiln and calcine at 1350-1430℃ for 25-30min to generate cement clinker.

8. A cement clinker melting and calcining production process according to claim 7, characterized in that: The amount of the seed flux added accounts for 3% to 15% of the rotary kiln clinker output; The cement raw material is prepared by mixing limestone, clay and iron raw materials, and the three rate values ​​of the cement raw material are as follows: lime saturation coefficient 0.95-0.99, silicon rate 2.3-2.8, aluminum rate 1.2-1.7; The three rate values ​​of the cement clinker are as follows: lime saturation coefficient 0.87-0.91, silicon rate 2.2-2.8, aluminum rate 1.3-1.

8.

9. A cement clinker melting and calcining production process according to claim 8, characterized in that: The silicon ratio is the ratio of SiO2 content to the sum of Al2O3 and Fe2O3, and the aluminum ratio is the ratio of Al2O3 content to Fe2O3 content; The lime saturation coefficient is the ratio of the total calcium oxide content minus the calcium oxide required for saturated acidic oxide to the calcium oxide content required for the theoretical conversion of all silicon dioxide into tricalcium silicate.

10. A cement clinker melting and calcining production process according to claim 9, characterized in that: The saturated acidic oxides are Al2O3 and Fe2O3. The value of the calcium oxide required for the saturated acidic oxides minus the total calcium oxide content is the calcium oxide content that actually combines with silicon dioxide to form tricalcium silicate.

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