Method for preparing cement clinker by using coal gangue as raw material

Abstract

The invention discloses a method for preparing cement clinker by taking coal gangue as a raw material, and belongs to the field of solid waste recycling. The preparation method comprises the following steps: crushing coal gangue, transferring the crushed coal gangue into a ball-milling tank, adding perovskite manganese oxide nano powder, and carrying out ball-milling mixing, so as to obtain modified coal gangue powder after the ball-milling mixing is finished; and performing acoustic resonance mixing on the ground and dried limestone, manganese slag, copper slag, silica fume, disodium hydrogen phosphate and modified coal gangue powder, calcining after mixing, and cooling to obtain the cement clinker. The coal gangue is used for replacing part of raw materials, under the condition that the quality of the cement clinker is ensured, coal gangue solid waste can be properly treated, waste resources are recycled, organic matter, ash, lignin and other components in the coal gangue can provide part of heat energy, the use amount of fuel coal can be saved, energy consumption is remarkably reduced, and the cost is reduced. Therefore, the production cost of the clinker is reduced.

Description

Technical Field

[0001] The invention relates to the technical field of solid waste recycling, and in particular to a method for preparing cement clinker using coal gangue as raw material. Background Art

[0002] Gangue is a solid waste discharged during the coal mining and coal washing process. It is a kind of black-gray rock with low carbon content and harder than coal that is associated with coal seams during the coal formation process. It includes excavation gangue during tunnel excavation, gangue mined from the roof, floor and interlayer during mining, and washed gangue selected during coal washing. The emission accounts for about 10% to 15% of coal production. Gangue is also an important industrial resource. The comprehensive utilization of gangue is an important measure to save resources, protect the environment and achieve sustainable development.

[0003] At present, most domestic cement plants use clay as a siliceous raw material in raw material preparation. According to the cement formula, about 0.15-0.18 tons of clay are needed to produce one ton of ordinary cement. With the production of cement, clay resources are decreasing day by day. It is very important to find a raw material that can replace clay. The main component of coal gangue is Al 2 O 3 、SiO 2 , and also contains varying amounts of Fe 2 O 3 , CaO, MgO, Na 2 O.K 2 O.P 2 O 5 、SO 3 As well as organic components, using coal gangue as a silicon-alumina raw material for raw material batching can replace part of clay and reduce the amount of clay used. However, using coal gangue as the main raw material to produce cement requires that the coal gangue must have good activity. However, most of the coal gangue currently has low activity as a mixed material, and the effect of cement clinker prepared by adding it to raw materials is not ideal. Even if coal gangue is used to replace clay, the amount of addition is small, accounting for about 5%, usually not more than 10%, and the processing volume is small.

[0004] In addition, cement clinker production has always required a large amount of fuel coal. In recent years, the price of fuel coal has risen, causing the coal consumption cost of clinker to continue to rise. Therefore, it is urgent to reduce the coal consumption of clinker and thus reduce the production cost of clinker. At the same time, under the background of dual carbon, it is a general trend for cement companies to increase the use of alternative raw materials. In the process of preparing cement clinker, if solid waste can be converted into usable resources to replace part of the raw materials and reduce energy consumption, it will be of great benefit to the green transformation and upgrading of cement companies. Summary of the invention

[0005] The purpose of the present invention is to solve the above problems existing in the prior art and provide a method for preparing cement clinker using coal gangue as raw material. The present invention replaces part of the raw materials with coal gangue. Under the condition of ensuring the quality of cement clinker, the coal gangue solid waste can not only be properly treated and the waste resources can be recycled, but also the organic matter, ash, lignin and other components in the coal gangue can provide part of the heat energy, which can save the use of fuel coal, significantly reduce energy consumption, and thus reduce the production cost of clinker.

[0006] In order to achieve the above object, the technical solution of the present invention is as follows:

[0007] A method for preparing cement clinker using coal gangue as raw material comprises the following steps:

[0008] (1) Weigh the following raw materials by weight: 100-200 parts of limestone, 70-90 parts of coal gangue, 20-30 parts of manganese slag, 5-10 parts of copper slag, 5-10 parts of silica fume, and 5-10 parts of disodium hydrogen phosphate;

[0009] (2) crushing the coal gangue and transferring it into a ball mill, adding perovskite manganese oxide nanopowder and performing ball milling mixing, wherein the amount of the perovskite manganese oxide nanopowder added is 0.5-2% of the weight of the coal gangue, and after the ball milling mixing is completed, a modified coal gangue powder is obtained;

[0010] (3) adding the ground and dried limestone, manganese slag, copper slag, silica fume, disodium hydrogen phosphate and modified coal gangue powder into a mixer and mixing them evenly, and then performing acoustic resonance mixing. The acoustic resonance mixing conditions are as follows: humidity 70-80%, temperature 50-60° C., vibration frequency 60-80 Hz, mixing time 10-20 min, and then calcining and cooling to obtain cement clinker.

[0011] Furthermore, the coal gangue contains the following components by weight: 40-50% SiO 2 , 20-35%Al 2 O 3 , 3-8%Fe 2 O 3 , 1-3% MgO, 1-3% CaO, 1-2% K 2 O, 1-2% Na 2 O.

[0012] Furthermore, the manganese slag contains the following components by weight: 20-25% Al 2 O 3 , 18-22%Fe 2 O 3 , 15-20% SO 3 , 12-15% MnO, 10-15% SiO 2 , 1-3% K2 O.

[0013] Furthermore, the copper slag contains the following components by weight: 40-45% Fe, 30-35% SiO 2 , 8-12%Fe 3 O 4 , 3-5%Al 2 O 3 , 1-3% CaO, 1-3% MgO, 0.8-1.5% Cu.

[0014] Further, in step (2), the ball milling mixing reaction conditions are as follows: the ball milling atmosphere is NH 3 :H 2 O:O 2 The molar ratio of the mixed gas is 0.5-1:0.2-0.3:0.2-0.4, the temperature is 60-90°C, the rotation speed is 300-500r / min, and the time is 1-2h.

[0015] Furthermore, in step (3), the calcination temperature of the cement clinker is 900-1200°C.

[0016] The beneficial effects of the present invention are as follows:

[0017] 1. The present invention modifies coal gangue and mixes it into raw meal to replace part of the raw materials. The organic matter, ash, lignin and other components in the coal gangue can provide a part of the heat energy, thereby saving the use of fuel coal, which has a great effect on reducing the standard coal consumption of clinker and the comprehensive electricity consumption of clinker and improving the quality of kiln clinker.

[0018] 2. The present invention uses perovskite manganese oxide to activate and modify coal gangue, which can improve the activity of coal gangue. When the amount of coal gangue added is large, it can ensure that the quality of the final cement clinker meets the standard. At the same time, the organic matter, lignin, etc. in the coal gangue can be burned more fully, increasing more heat and reducing energy consumption.

[0019] 3. The present invention uses raw materials such as limestone, modified coal gangue, manganese slag, copper slag, silica fume, and disodium hydrogen phosphate. Tests have shown that the strength of the clinker out of the kiln is not ideal after calcination in the ordinary way. The present invention adds an acoustic resonance mixing process and mixes under conditions of medium temperature, medium humidity, and a certain vibration frequency, which greatly reduces the ball-enclosing phenomenon, achieves a better mixing effect, and can effectively improve the strength of the cement clinker. DETAILED DESCRIPTION

[0020] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with embodiments.

[0021] Example 1

[0022] A method for preparing cement clinker using coal gangue as raw material comprises the following steps:

[0023] (1) Weigh the following raw materials by weight: 150 parts of limestone, 80 parts of coal gangue, 25 parts of manganese slag, 7 parts of copper slag, 80 parts of silica fume, and 8 parts of disodium hydrogen phosphate;

[0024] The coal gangue contains the following components by weight: 44.3% SiO 2 , 26.5%Al 2 O 3 , 4.1%Fe 2 O 3 , 2.2%CaO, 1.9%MgO, 1.3%Na 2 O, 1.2% K 2 O;

[0025] The manganese slag contains the following components by weight: 22.6% Al 2 O 3 , 19.8%Fe 2 O 3 , 18.2% SO 3 , 14.0% MnO, 12.7% SiO 2 , 1.8% K 2 O;

[0026] The copper slag contains the following components by weight: 43.8% Fe, 33.1% SiO 2 , 10.7%Fe 3 O 4 , 4.6%Al 2 O 3 , 1.7% CaO, 1.5% MgO, 0.9% Cu.

[0027] (2) The coal gangue is crushed and transferred into a ball mill, and then perovskite manganese oxide nanopowder is added for ball milling and mixing. The perovskite manganese oxide nanopowder is perovskite manganese oxide La0.67Ca0.33MnO3 nanopowder purchased from Xi'an Qiyue Biotechnology Co., Ltd. The amount of perovskite manganese oxide nanopowder added is 1% of the weight of the coal gangue. The ball milling mixing reaction conditions are as follows: the ball milling atmosphere is NH 3 :H 2 O:O 2 The mixed gas with a molar ratio of 0.8:0.2:0.3, the temperature is 80°C, the rotation speed is 400r / min, and the time is 1.5h; after the mixed ball milling, it is dried to obtain modified coal gangue powder.

[0028] (3) Add the ground and dried limestone, manganese slag, copper slag, silica fume, disodium hydrogen phosphate, and modified coal gangue powder into a mixer, mix them evenly, and then perform acoustic resonance mixing. The acoustic resonance mixing conditions are as follows: humidity 75%, temperature 55° C., vibration frequency 70 Hz, and mixing time 15 min. Then, calcination is performed at a calcination temperature of 1000° C. After calcination, cooling is performed to obtain cement clinker.

[0029] Example 2

[0030] A method for preparing cement clinker using coal gangue as raw material comprises the following steps:

[0031] (1) Weigh the following raw materials by weight: 120 parts of limestone, 70 parts of coal gangue, 22 parts of manganese slag, 6 parts of copper slag, 6 parts of silica fume, and 6 parts of disodium hydrogen phosphate;

[0032] The coal gangue, the manganese slag and the copper slag are the same as those in Example 1.

[0033] (2) After the coal gangue is crushed, it is transferred into a ball mill, and then perovskite manganese oxide nanopowder is added for ball milling and mixing. The amount of the perovskite manganese oxide nanopowder added is 0.8% of the weight of the coal gangue. The ball milling mixing reaction conditions are as follows: the ball milling atmosphere is NH 3 :H 2 O:O 2 The molar ratio of the mixed gas is 0.5:0.2:0.2, the temperature is 60°C, the speed is 500r / min, and the time is 2h; after the mixed ball milling, it is dried to obtain modified coal gangue powder;

[0034] (3) Add the ground and dried limestone, manganese slag, copper slag, silica fume, disodium hydrogen phosphate, and modified coal gangue powder into a mixer, mix them evenly, and then perform acoustic resonance mixing. The acoustic resonance mixing conditions are as follows: humidity 70%, temperature 50° C., vibration frequency 80 Hz, mixing time 20 min, and then calcine at a calcination temperature of 1200° C. After calcination, cool down to obtain cement clinker.

[0035] Example 3

[0036] A method for preparing cement clinker using coal gangue as raw material comprises the following steps:

[0037] (1) Weigh the following raw materials by weight: 190 parts of limestone, 90 parts of coal gangue, 28 parts of manganese slag, 10 parts of copper slag, 9 parts of silica fume, and 8 parts of disodium hydrogen phosphate;

[0038] The coal gangue, the manganese slag and the copper slag are the same as those in Example 1.

[0039] (2) The coal gangue is crushed and transferred into a ball mill, and then perovskite manganese oxide nanopowder is added for ball milling and mixing. The amount of the perovskite manganese oxide nanopowder added is 2% of the weight of the coal gangue. The ball milling mixing reaction conditions are as follows: the ball milling atmosphere is NH 3 :H 2 O:O 2 The mixed gas with a molar ratio of 1:0.3:0.4, a temperature of 90°C, a rotation speed of 300r / min, and a time of 1h; after the mixed ball milling, it is dried to obtain modified coal gangue powder;

[0040] (3) Add the ground and dried limestone, manganese slag, copper slag, silica fume, disodium hydrogen phosphate, and modified coal gangue powder into a mixer, mix them evenly, and then perform acoustic resonance mixing. The acoustic resonance mixing conditions are as follows: humidity 80%, temperature 60° C., vibration frequency 60 Hz, mixing time 10 min, and then calcine at a calcination temperature of 1100° C. After calcination, cool down to obtain cement clinker.

[0041] Comparative Example 1

[0042] A method for preparing cement clinker using coal gangue as raw material comprises the following steps:

[0043] (1) The following raw materials are weighed in parts by weight: 150 parts of limestone, 80 parts of coal gangue, 25 parts of manganese slag, 7 parts of copper slag, 80 parts of silica fume, and 8 parts of disodium hydrogen phosphate; the coal gangue, the manganese slag, and the copper slag are the same as those in Example 1.

[0044] (2) The gangue is crushed and dried to obtain gangue powder.

[0045] (3) Add the ground and dried limestone, manganese slag, copper slag, silica fume, disodium hydrogen phosphate, and coal gangue powder into a mixer, mix them evenly, and then perform acoustic resonance mixing. The acoustic resonance mixing conditions are as follows: humidity 75%, temperature 55° C., vibration frequency 70 Hz, and mixing time 15 min. Then, calcination is performed at a calcination temperature of 1000° C. After calcination, cooling is performed to obtain cement clinker.

[0046] Comparative Example 2

[0047] A method for preparing cement clinker using coal gangue as raw material comprises the following steps:

[0048] (1) The following raw materials are weighed in parts by weight: 150 parts of limestone, 80 parts of coal gangue, 25 parts of manganese slag, 7 parts of copper slag, 80 parts of silica fume, and 8 parts of disodium hydrogen phosphate; the coal gangue, the manganese slag, and the copper slag are the same as those in Example 1.

[0049] (2) The coal gangue is crushed and transferred into a ball mill, and then perovskite manganese oxide nanopowder is added for ball milling and mixing. The perovskite manganese oxide nanopowder is the same as that in Example 1. The amount of the perovskite manganese oxide nanopowder added is 1% of the weight of the coal gangue. The ball milling mixing reaction conditions are as follows: the ball milling atmosphere is air, the temperature is 80° C., the rotation speed is 400 r / min, and the time is 1.5 h; after the mixed ball milling is completed, it is dried to obtain modified coal gangue powder.

[0050] (3) Add the ground and dried limestone, manganese slag, copper slag, silica fume, disodium hydrogen phosphate, and modified coal gangue powder into a mixer, mix them evenly, and then perform acoustic resonance mixing. The acoustic resonance mixing conditions are as follows: humidity 75%, temperature 55° C., vibration frequency 70 Hz, and mixing time 15 min. Then, calcination is performed at a calcination temperature of 1000° C. After calcination, cooling is performed to obtain cement clinker.

[0051] Comparative Example 3

[0052] A method for preparing cement clinker using coal gangue as raw material comprises the following steps:

[0053] (1) The following raw materials are weighed in parts by weight: 150 parts of limestone, 80 parts of coal gangue, 25 parts of manganese slag, 7 parts of copper slag, 80 parts of silica fume, and 8 parts of disodium hydrogen phosphate; the coal gangue, the manganese slag, and the copper slag are the same as those in Example 1.

[0054] (2) After the coal gangue is crushed, it is transferred into a ball mill, and then perovskite manganese oxide nanopowder is added for ball milling and mixing. The perovskite manganese oxide nanopowder is the same as that in Example 1. The amount of the perovskite manganese oxide nanopowder added is 1% of the weight of the coal gangue. The ball milling mixing reaction conditions are as follows: the ball milling atmosphere is NH 3 :H 2 O:O 2 The mixed gas with a molar ratio of 0.8:0.2:0.3, the temperature is 80°C, the rotation speed is 400r / min, and the time is 1.5h; after the mixed ball milling, it is dried to obtain modified coal gangue powder.

[0055] (3) adding the ground and dried limestone, manganese slag, copper slag, silica fume, disodium hydrogen phosphate and modified coal gangue powder into a mixer, mixing them evenly and then calcining them at a calcination temperature of 1000° C. After calcination, cooling is performed to obtain cement clinker.

[0056] Related data analysis:

[0057] The comparative test data analysis of production energy consumption and related technical indicators of Examples 1-3 and Comparative Examples 1-3 are shown in Table 1 below:

[0058] Table 1

[0059]

[0060] As can be seen from the data in Table 1, compared with Comparative Examples 1-3, the heat consumption per ton of clinker and the standard coal consumption of Example 1 are significantly reduced, and the compressive strength of clinker is effectively improved. It can be seen that the present invention can improve the activity of coal gangue by using perovskite manganese oxide and modifying coal gangue under certain conditions, so that organic matter, lignin, etc. in coal gangue can be burned more fully, more heat can be added, energy consumption can be reduced, and compressive strength can be improved; by mixing the raw materials by acoustic resonance, the compressive strength of clinker can be improved.

[0061] Although the present invention has been disclosed as above with preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art may make some modifications and improvements without departing from the spirit and scope of the present invention. Therefore, the scope of protection of the present invention shall be based on the definition of the claims.

Claims

1. A method for preparing cement clinker using coal gangue as raw material, It is characterized in that The steps include: (1) Weigh the following raw materials by weight: 100-200 parts of limestone, 70-90 parts of coal gangue, 20-30 parts of manganese slag, 5-10 parts of copper slag, 5-10 parts of silica fume, and 5-10 parts of disodium hydrogen phosphate; (2) crushing the coal gangue and transferring it into a ball mill, adding perovskite manganese oxide nanopowder and performing ball milling mixing, wherein the amount of the perovskite manganese oxide nanopowder added is 0.5-2% of the weight of the coal gangue, and after the ball milling mixing is completed, a modified coal gangue powder is obtained; (3) adding the ground and dried limestone, manganese slag, copper slag, silica fume, disodium hydrogen phosphate and modified coal gangue powder into a mixer and mixing them evenly, and then performing acoustic resonance mixing. The acoustic resonance mixing conditions are as follows: humidity 70-80%, temperature 50-60° C., vibration frequency 60-80 Hz, mixing time 10-20 min, and then calcining and cooling to obtain cement clinker.

2. A method for preparing cement clinker using coal gangue as raw material according to claim 1, Features: The coal gangue contains the following components by weight: 40-50% SiO 2 , 20-35%Al 2 O 3 , 3-8%Fe 2 O 3 , 1-3% MgO, 1-3% CaO, 1-2% K 2 O, 1-2% Na 2 O.

3. A method for preparing cement clinker using coal gangue as raw material according to claim 1, Features: The manganese slag contains the following components by weight: 20-25% Al 2 O 3 , 18-22%Fe 2 O 3 , 15-20% SO 3 , 12-15% MnO, 10-15% SiO 2 , 1-3% K 2 O.

4. A method for preparing cement clinker using coal gangue as raw material according to claim 1, Features: The copper slag contains the following components by weight: 40-45% Fe, 30-35% SiO 2 , 8-12%Fe 3 O 4 , 3-5%Al 2 O 3 , 1-3% CaO, 1-3% MgO, 0.8-1.5% Cu.

5. A method for preparing cement clinker using coal gangue as raw material according to claim 1, Features: In step (2), the ball milling mixing reaction conditions are as follows: the ball milling atmosphere is NH 3 :H 2 O:O 2 The molar ratio of the mixed gas is 0.5-1:0.2-0.3:0.2-0.4, the temperature is 60-90°C, the rotation speed is 300-500r / min, and the time is 1-2h.

6. A method for preparing cement clinker using coal gangue as raw material according to claim 1, Features: In step (3), the calcination temperature of the cement clinker is 900-1200°C.

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