Cement raw material

Abstract

The invention discloses a cement raw material which comprises the following raw materials: carbide slag dry powder, titanium slag, sandstone, sulfuric acid slag and red ash, the mass ratio of the carbide slag dry powder to the titanium slag to the sandstone to the sulfuric acid slag to the red ash is (77-79): (0.8-2): (11-14): (1-3): (5-10), TiO2 in the titanium slag is less than or equal to 3%, Cl <-> is less than or equal to 1%, and the carbon content is less than or equal to 5%; the titanium slag is used as an iron correction raw material for batching of the cement raw material, iron in the titanium slag is fully utilized, emission of titanium slag solid waste is reduced, the resource utilization rate is increased, meanwhile, the use amount of sulfuric-acid slag is reduced, the production cost is reduced, and the components and proportion of the titanium slag are controlled; the adverse effects of higher contents of TiO2, Cl <-> and carbon in the titanium slag on cement clinker production are solved, and the quality of cement products is ensured.

Description

Technical Field

[0001] The present invention relates to the technical field of cement preparation, and more specifically, to a cement raw material. Background Art

[0002] The quality of cement clinker mainly depends on the rate value of raw materials, whether the composition is uniform and the content of harmful components. To prepare suitable raw materials and adapt to the requirements of calcination equipment, certain requirements must be placed on raw materials; CaO in cement clinker mainly comes from calcareous raw materials, SiO2, Al2O3 and Fe2O3 mainly come from clay raw materials. In order to supplement the deficiency of certain components, it is necessary to introduce correction raw materials such as iron ore or iron powder, bauxite, sandstone, etc. In order to improve resource utilization, when mixing raw materials, waste slag with a higher iron content is usually used to replace the iron correction raw material. Sulfate slag is generally used as the iron correction raw material in the industry.

[0003] For example, the invention patent with publication number CN103848581A provides a raw material composition required for preparing cement clinker, and the mass percentage range of each raw material is: waste concrete 30% to 67%, aluminum oxide 5% to 10%, iron oxide 5% to 10%, limestone 10% to 20%, sandstone 5% to 15%, clay 5% to 10%, and sulfate slag 3% to 5%. For another example, the invention patent with publication number CN111533471A provides a cement raw material using high-magnesium stone, and the mass percentage range of each raw material is: low-magnesium limestone 12% to 15%, high-magnesium limestone 8% to 10%, shale 12% to 15%, sandstone 10% to 15%, sulfate slag 5% to 10%, and fly ash 45% to 55%; wherein the SiO2 in the low-magnesium limestone is 10% to 15%, Al2O3 is 10% to 20%, Fe2O3 is 2% to 30%, and Fe2O3 is 10% to 20%. 10%, CaO is 50%~60%, and MgO is 5%~15%; in high-magnesium limestone, SiO2 is 15%~20%, Al2O3 is 10%~15%, Fe2O3 is 5%~15%, CaO is 20%~30%, and MgO is 15%~30%; in shale, SiO2 is 60%~65%, Al2O3 is 10%~20%, Fe2O3 is 5%~15%, CaO is 3%~10%, and MgO is 5%~10%.

[0004] In addition, there are also other waste slags with higher iron content as iron correction raw materials. For example, the invention patent with publication number CN109354424A provides a raw material formula for cement raw materials. The raw material components are as follows: 75-80 parts of limestone, 1-15 parts of magnesium slag, 3-7 parts of sandstone, 1-5 parts of bottom slag, and 1-5 parts of steel slag; the main chemical components of limestone are SiO21%-5%, Al2O31%-2.5%, Fe2O31%-2.5%, CaO48%-50%, and MgO 1%-2%; the main chemical components of magnesium slag are SiO220%-30%, Al2O31%-2.0%, Fe2O34%-6%, CaO 50%-55%, MgO 8%~12%; the main chemical components of sandstone are SiO280%~90%, Al2O32%~5.0%, Fe2O32%~5%, CaO0.5%~1.5%, MgO 0.5%~2%; the main chemical components of bottom slag are SiO245%~55%, Al2O320%~30%, Fe2O32%~5%, CaO 0.5%~5%, MgO 0.5%~5%; the main chemical components of steel slag are SiO25%~15%, Al2O33%~7%, Fe2O320%~35%, CaO 30%~40%, MgO 3%~8%.

[0005] The chloride process of titanium dioxide will produce a large amount of titanium slag solid waste, leading to environmental problems. A method is urgently needed to reuse it. The titanium slag contains iron oxide, which can theoretically be used as an iron raw material to produce cement clinker, thereby improving resource utilization and reducing costs. Summary of the invention

[0006] In view of the above, the present invention provides a cement raw material, which uses titanium slag as an iron correction raw material to prepare the cement raw material, thereby overcoming the problem of TiO2, Cl - The high content of carbon has adverse effects on cement clinker and the production of cement clinker.

[0007] The present invention provides a cement raw material, the raw materials of which include carbide slag dry powder, sandstone, sulfuric acid slag, red ash and titanium slag, wherein the mass of the titanium slag is 0.8% to 2% of the total raw material mass, and the TiO2, Cl - The mass percentages of TiO2 and Cl are: - ≤1%, carbon ≤5%.

[0008] Titanium slag is the solid waste obtained by the chlorination process to produce titanium dioxide. The mass percentage of its main components is: SiO2 0.47-37.41%, Al2O3 4.34-11.83%, Fe2O3 3.55-50.94%, CaO 0.6-3.0%, MgO 0.21-5.28%, TiO2 5.36-7.24%, Cl - 4.67~6.98%, carbon 4.35~9.63%; the mass percentages of the main components of the sulfate slag are: SiO20.48~4.89%, Al2O3 1.38~8.98%, Fe2O366.70~76.70%, CaO 2.71~7.14%, MgO0.32~3.07%, Cl - 0.01~0.05%, carbon 0.01~0.05%.

[0009] The Fe2O3 content of titanium slag is lower than that of sulfuric acid slag. Therefore, the amount of titanium slag used will be larger than that of sulfuric acid slag, which can not only recycle titanium slag, but also reduce the amount of sulfuric acid slag and reduce production costs. However, the carbon content and Cl content of titanium slag are - The content is much higher than that of sulfuric acid slag. The prepared cement raw meal has a certain calorific value. In the process of using cement raw meal to produce cement clinker, during the pre-decomposition in the decomposition furnace, carbon burns and generates heat, destroying the thermal balance of the decomposition furnace and the rotary kiln, and causing adverse effects on the process, equipment and the quality of cement clinker: it causes crusting in the smoke chamber, affecting the ventilation and feeding of the kiln system; the combustion of C2 in the ascending flue produces a liquid phase, which adheres to the cement raw meal powder to form an unstable crust. Once the crust falls off, it will directly cause the C2 discharge pipe to be blocked, forcing the rotary kiln to stop; a local liquid phase will appear in advance, and the uneven liquid phase will cause the rear end clinker granulation to deteriorate and serious flying sand; at the same time, the Cl in the produced cement clinker - High content, far exceeding the industry standard Cl - The content is not higher than 0.06%.

[0010] In addition, titanium slag contains a certain amount of TiO2, which affects the amount of liquid phase during clinker calcination, resulting in difficulty in granulation of materials in the rotary kiln, serious flying sand in front of the kiln, inability to observe flames at the kiln head, adhesion of materials in the kiln, large pieces of kiln lining and material balls, and makes it difficult to calcine cement clinker and causes the free CaO in the cement clinker to continue to increase and fluctuate greatly.

[0011] Therefore, the present invention uses titanium slag as an iron correction raw material to prepare cement raw materials, and it is necessary to accurately control the TiO2, Cl - , carbon content, in order to overcome the adverse effects of cement raw materials with original titanium slag ingredients on the production process, equipment and quality of cement clinker.

[0012] At the same time, when mixing the raw materials of cement, the three rates need to be controlled. The silicon dioxide, iron and aluminum components in the titanium slag will cause the three rates to fluctuate. Therefore, the appropriate ratio of adding titanium slag is 0.8% to 2% of the total raw material mass, which can stabilize the quality of the raw material ratio and obtain cement clinker that meets the quality standards; and avoid excessive addition of titanium slag, which may cause Cl - A higher content makes the Cl content of the final cement clinker - The content is higher than the standard.

[0013] The mass ratio of carbide slag dry powder to titanium slag is 77-79:0.8-2, which ensures that the TiO2 content in the titanium slag is appropriate and will not have an adverse effect on the CaO in the carbide slag dry powder during the clinker calcination process, while matching various component indicators.

[0014] The mass ratio of titanium slag, sandstone, sulfuric acid slag and red ash is 0.8-2:11-14:1-3:5-10, which ensures the matching of titanium slag with silicon dioxide, iron, aluminum and other components in each raw material, stabilizes the three rate values ​​in the raw material ratio, and ensures the quality of the produced cement clinker.

[0015] The present invention uses titanium slag as an iron correction raw material to prepare cement raw materials, fully utilizes the iron in the titanium slag, realizes the effective utilization of a large amount of titanium slag solid waste generated by the chloride titanium dioxide process, reduces the discharge of titanium slag solid waste, improves resource utilization, increases environmental benefits, reduces the amount of sulfuric acid slag used, and reduces production costs; and controls the TiO2, Cl - , carbon content and the amount of titanium slag, overcoming the TiO2, Cl - The adverse effect of high carbon content on the production of cement clinker is eliminated, the quality of cement clinker is guaranteed, various standards for the production of cement clinker are met, and cement clinker that meets national standards is obtained. DETAILED DESCRIPTION

[0016] The embodiments of the present application will be described in more detail below. The application can be implemented in various forms, and should not be construed as being limited to the embodiments set forth herein, but rather these embodiments are provided to provide a more thorough and complete understanding of the present application. It should be understood that the embodiments of the present application are only for exemplary purposes and are not intended to limit the scope of protection of the present application.

[0017] The proportion of the cement raw material of the embodiment of the present invention is as follows:

[0018] The mass ratio of carbide slag powder, titanium slag, sandstone, sulfuric acid slag and red ash is 77-79: 0.8-2: 11-14: 1-3: 5-10; among which TiO2, Cl - The mass percentages of TiO2 and Cl are: - ≤1%, carbon ≤5%.

[0019] Table 1 shows the specific proportions of cement raw materials in Examples 1 to 3, and Table 2 shows the quality of cement clinker produced with the proportions of cement raw materials in Examples 1 to 3 for more than 15 consecutive days. It can be seen from Table 2 that Examples 1 to 3 can produce cement clinker that meets national standards, proving that titanium slag can be used as an iron correction raw material to produce cement clinker. At the same time, the TiO2 and Cl in the titanium slag produced by the chlorination process to produce titanium dioxide can be controlled. - The content of carbon and the proportion of titanium slag can be better applied to the production of cement clinker, overcoming the problems of TiO2, Cl - , and the adverse effects of high carbon content on the cement clinker production process are eliminated, and cement clinker that meets national standards is obtained, thus realizing waste utilization, reducing the use of sulfuric acid slag, and improving resource utilization.

[0020] Table 1: Cement raw material ratio of Examples 1 to 3

[0021]

[0022]

[0023] Table 2: Quality of cement clinker produced in Examples 1 to 3

[0024]

[0025]

[0026] The above description is only a specific implementation mode of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can easily think of changes or substitutions within the technical scope disclosed in this application, which should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims

1. A cement raw material, whose raw materials include carbide slag powder, sandstone, sulfuric acid slag, and red lime, characterized in that: The raw materials of the cement raw material also include titanium slag whose mass accounts for 0.8% to 2% of the total raw material mass, wherein TiO2, Cl - The mass percentages of carbon are: TiO2≤3%, Cl - ≤1%, carbon ≤5%.

2. A cement raw material according to claim 1, characterized in that: The mass ratio of the carbide slag dry powder to the titanium slag is 77-79:0.8-2.

3. A cement raw material according to claim 1, characterized in that: The mass ratio of the titanium slag, sandstone, sulfuric acid slag and red ash is 0.8-2:11-14:1-3:5-10.

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