Method for co-processing high-sulfur materials in a cement kiln

Abstract

The present application relates to the field of environmental protection, and more particularly to a method for cement kiln co-processing high-sulfur materials; in the method, hollow glass microspheres modified by diamino are subjected to Michael addition reaction with 1,1,3,3-tetramethyl guanidine propylene acid salt, and then linoleoyl diethanolamine is grafted on the surface of the hollow glass microspheres to obtain tetramethyl guanidine salt-diethanolamine-siloxyl combined on the surface of the hollow glass microspheres; since the hollow glass microspheres have a small density, they can be blown up by hot air and rapidly and fully mixed with flue gas, thereby realizing desulfurization operation; after the high-sulfur waste materials are treated by the cement kiln, the sulfur content in the tail gas is effectively reduced, and the environmental protection requirements for tail gas emission are met; the present application has no wastewater discharge and no solid waste discharge, and the high-sulfur material treatment meets the requirements of the Cement Industry Air Pollutant Emission Standard (GB4915-2013), thereby achieving the purposes of solid waste reduction and final treatment, and generating good social and economic benefits.

Description

Technical Field

[0001] This invention relates to the field of environmental protection, and in particular to a method for co-processing high-sulfur materials in a cement kiln. Background Technology

[0002] The petrochemical, chemical, coal chemical and coking industries produce a large amount of sulfur-containing waste liquids byproducts, which contain sulfuric acid, elemental sulfur, ammonium sulfate, ammonium thiosulfate, ammonium thiocyanate and sulfides. Due to differences in raw materials and production processes, these sulfur-containing waste liquids have complex compositions, varying viscosity and strong corrosiveness, and are classified as hazardous wastes.

[0003] CN201911414670.7 discloses a screening production equipment for high-sulfur mineral material rubber reinforcing agents, solving the technical problem of iron wires in the waste powder. The key technical point is that the screening production equipment for high-sulfur mineral material rubber reinforcing agents includes a frame, a first vibrating screen, and a second vibrating screen. The frame has a first mounting platform for the first vibrating screen and a second mounting platform for the second vibrating screen, with the first mounting platform being higher than the second mounting platform. The discharge pipe of the first vibrating screen is connected to the feed pipe of the second vibrating screen. The aperture of the vibrating screen of the first vibrating screen is larger than that of the vibrating screen of the second vibrating screen. This screening production equipment for high-sulfur mineral material rubber reinforcing agents not only improves the quality of the rubber powder obtained from screening but also reduces the probability of iron wire clogging the vibrating screen compared to directly using a vibrating screen with a smaller aperture.

[0004] CN201921219850.5 describes a high-sulfur solid waste incinerator, comprising a furnace body, an exhaust pipe, a chimney, a first blower, a waste heat boiler, a first liquid extraction device, a second blower, and a desulfurization tower. The furnace body is equipped with a first input port, a second input port for supplying fuel to the furnace body, a third input port, and an exhaust port. The furnace body contains a storage plate and a filter plate, and a scraper assembly for cleaning the filter plate is also provided. The first input port is connected to the first blower; the third input port is connected to the second blower; the exhaust pipe is connected to both the exhaust port and the inlet of the waste heat boiler; the outlet of the waste heat boiler is connected to a desulfurization tower for desulfurizing the flue gas; the outlet of the desulfurization tower is connected to a first liquid extraction device for discharging the ammonium sulfate solution produced within the desulfurization tower and using the ammonium sulfate solution to produce ammonium sulfate products; the exhaust port is connected to the chimney. This invention can fully incinerate high-sulfur solid waste and effectively treat the generated flue gas.

[0005] CN201910918549.1 discloses a method for synthesizing an organic high-sulfur stabilizer based on industrial waste sulfur slag. The method involves uniformly mixing sulfur slag with a deodorizing agent, a co-solvent, an alkali metal sulfide, a catalyst, and a solvent. After stirring and reacting, a purifying agent is added to precipitate and remove impurities, yielding an organic high-sulfur stabilizer with high sulfur content and good stability. This method utilizes low-cost raw materials and mild reaction conditions, achieving the resource utilization of waste sulfur slag.

[0006] The applicant's earlier application, CN201910225293.6, discloses a method for co-processing chromium-containing waste in a cement kiln, comprising the following steps: pre-process blending, a three-stage blending process, mid-process control, calcination solidification and linkage monitoring, post-process adjustment, and reduction stabilization. The pre-process blending, through three control stages—source control, multiple homogenization stages of classified stacking, and rational addition—ensures the chromium-containing waste has a uniform composition. During the mid-process control, the clinker lattice in the cement kiln can solidify heavy metal ions, specifically Cr ions from the hazardous waste, which are then solidified into the lattice. Furthermore, the relatively weak oxidizing atmosphere of the cement kiln reduces Cr content. 3+ To Cr 6+ The oxidation rate reduces Cr. 6+ The content of Cr in the cement is adjusted by adding a composite reducing agent during the cement grinding process. 6+ The method for co-processing chromium-containing waste in a cement kiln is stable in operation, environmentally friendly, and achieves the effects of solid waste reduction and energy conservation and emission reduction; however, this technical solution cannot yet be used for the treatment of high-sulfur waste liquid and requires further improvement.

[0007] Current technologies for treating high-sulfur waste typically employ incineration. Pre-treated sulfur-containing waste liquid is sent to an incinerator for combustion. At high temperatures, sulfuric acid, ammonium thiosulfate, ammonium thiocyanate, and other sulfur-containing substances undergo thermal decomposition and oxidation reactions to generate sulfur dioxide-containing flue gas. This gas is then purified through dry filtration, conversion, and absorption to produce commercial-grade sulfuric acid. The exhaust gas is treated for desulfurization and denitrification before being discharged in compliance with standards. However, incineration of high-sulfur waste often fails to achieve complete combustion. Incomplete combustion of high-sulfur waste, in particular, generates large amounts of SO2 and SO2 gases, which pollute the environment and harm human health. Therefore, a new process is needed to address the treatment of high-sulfur waste.

[0008] China's "Emission Standard of Air Pollutants for Cement Industry" (GB4915-2013) stipulates that the SO2 emission concentration in the flue gas from cement kilns should be ≤200 mg / Nm³. 3 The unit clinker emission rate must be less than 0.6 kg / t, and the SO2 emission concentration in the flue gas from cement kilns in special areas must be ≤100 mg / Nm³. 3In view of the shortcomings of the existing technology, and to solve the technical problem that high-sulfur waste often cannot be completely and fully incinerated, especially when high-sulfur waste is incompletely incinerated, resulting in the generation of a large amount of SO and SO2 gas, this invention improves and enhances the technical solution based on CN201910225293.6. Summary of the Invention

[0009] To address the above problems, this invention provides a method for co-processing high-sulfur materials in a cement kiln, the operation steps of which are as follows:

[0010] S1: Pretreatment of high-sulfur waste: Mix 100-200 parts of high-sulfur waste with an excess of lime slurry containing 7-14% water by weight until the pH reaches 8-9, then stop adding lime slurry, filter by pressure, and dry until the moisture content is 1-5 wt% to obtain high-sulfur waste containing calcium sulfate.

[0011] S2: Cement Preparation: By weight, limestone 120-152 parts, slag powder 25-30 parts, silicate clinker powder 5-15 parts, high-sulfur waste containing calcium sulfate 20-30 parts, steel slag 3-10 parts, activator 5-8 parts, mix and grind into dry raw meal powder.

[0012] S3: The dry raw meal powder is sent to the homogenization silo, and after homogenization, it is sent to the preheater. After preheating to 860-880℃, it enters the decomposition kiln. The decomposed raw meal then enters the rotary kiln and is calcined into clinker in 30-40 minutes.

[0013] S4: The desulfurizing agent is added to the mixing tank in the middle of the kiln tail flue gas conveying pipeline. Due to the low density of the hollow glass microspheres, they can be blown up by hot air and quickly and fully mixed with the flue gas, thereby realizing the flue gas desulfurization operation.

[0014] The silicate clinker powder mentioned is silicate clinker with a strength of 50-60 MPa, ground to a specific surface area of ​​350-400 mm². 2 / kg.

[0015] The temperature at the top of the decomposition kiln of the rotary kiln is 870℃-890℃, and the temperature at the tail smoke chamber is 980℃-1050℃.

[0016] The thickness of the rotary kiln material layer is maintained at 350mm-400mm.

[0017] The secondary air temperature of the rotary kiln is 1200℃-1300℃.

[0018] The tertiary air temperature of the rotary kiln is between 800℃ and 900℃.

[0019] The amount of desulfurizing agent added is approximately 0.02%-0.4% of the total cement raw materials.

[0020] The method for preparing a desulfurizing agent as described above:

[0021] S1: According to the mass fraction, add 100-160 parts of hollow glass microspheres to 800-1200 parts of water, add 2-5 parts of diaminosilane coupling agent, stir vigorously at 40-50℃ for 2-5 hours, centrifuge, and dry to obtain diamino-modified hollow glass microspheres.

[0022] S2: Add 500-1000 parts of DMF and 100-128 parts of diamino-modified hollow glass microspheres to a sealed reactor, purge with nitrogen to replace the air, stir vigorously for 20-50 minutes, then add 5-8 parts of 1,1,3,3-tetramethylguanidine acrylate, and continue the reaction at 70-80℃ for 30-60 minutes. Then add 13-17 parts of linoleyl diethanolamine and 2-5 parts of potassium persulfate, and continue the reaction for 100-140 minutes. Filter and dry to obtain the desulfurizing agent.

[0023] The diaminosilane coupling agent used is N-2-(aminoethyl)-8-aminooctyltrimethyloxysilane or N-2-(aminoethyl)-3-aminopropyltrimethoxysilane.

[0024] The method for preparing the 1,1,3,3-tetramethylguanidine acrylate is as follows:

[0025] Add 10-20 parts by weight of 1,1,3,3-tetramethylguanidine to the reactor, add 6-14 parts by weight of acrylic acid, and start stirring. Stir at 10-20°C for 20-60 minutes to obtain 1,1,3,3-tetramethylguanidine acrylic acid.

[0026] Reaction mechanism:

[0027] Diamino-modified hollow glass microspheres undergo an amino-olefin Michael addition reaction with 1,1,3,3-tetramethylguanidine acrylate, followed by grafting of linoleyl diethanolamine onto its surface. The resulting tetramethylguanidine-diethanolamine-siloxy group is bonded to the surface of the hollow glass microspheres. Due to the low density of the hollow glass microspheres, they can be blown up by hot air and quickly and thoroughly mixed with the flue gas, thereby achieving desulfurization.

[0028] Technical effects:

[0029] This invention provides a method for co-processing high-sulfur materials in a cement kiln.

[0030] 1. This invention effectively reduces the sulfur content in the exhaust gas by treating high-sulfur waste in a cement kiln, thereby meeting the environmental protection requirements for exhaust gas emissions.

[0031] 2. This invention produces no wastewater discharge and no solid waste discharge. The disposal of high-sulfur materials meets the requirements of the "Emission Standard of Air Pollutants for Cement Industry" (GB4915-2013), achieving the purpose of solid waste reduction and final treatment. It greatly reduces the inventory of sulfur-containing materials, generating good social and economic benefits.

[0032] 3. This disposal plan not only takes advantage of the inherent advantages of cement kilns in co-processing solid waste, eliminating the need to introduce new energy sources to incinerate high-sulfur materials, thus reducing the impact on the surrounding environment and achieving the goal of energy conservation and consumption reduction, but also uses the inorganic components as raw materials for cement production, avoiding waste. Detailed Implementation

[0033] The invention will be further illustrated below through specific embodiments:

[0034] The testing method is in accordance with GB / T214.

[0035] Example 1

[0036] A method for co-processing high-sulfur materials in a cement kiln, comprising the following steps:

[0037] S1: Pretreatment of high-sulfur waste: Mix 100 kg of high-sulfur waste with an excess of lime slurry containing 7% water until pH = 8, then stop adding lime slurry. Filter under pressure and dry until the moisture content is 1 wt% to obtain high-sulfur waste containing calcium sulfate.

[0038] S2: Cement preparation: 120kg limestone, 25kg slag powder, 5kg silicate clinker powder, 20kg high-sulfur waste containing calcium sulfate, 3kg steel slag, 5kg activator, mixed and ground into dry raw meal powder.

[0039] S3: The dry raw meal powder is sent to the homogenization silo, and after homogenization, it is sent to the preheater. After preheating to 860°C, it enters the decomposition kiln. The decomposed raw meal then enters the rotary kiln and is calcined into clinker in 30 minutes.

[0040] S4: The desulfurizing agent is added to the mixing tank in the middle of the kiln tail flue gas conveying pipeline. Due to the low density of the hollow glass microspheres, they can be blown up by hot air and quickly and fully mixed with the flue gas, thereby realizing the flue gas desulfurization operation.

[0041] The silicate clinker powder is silicate clinker with a strength of 50 MPa, ground to a specific surface area of ​​350 mm². 2 / kg.

[0042] The temperature at the top of the decomposition chamber of the rotary kiln is 870℃, and the temperature at the tail flue gas chamber is 980℃.

[0043] The thickness of the rotary kiln material layer is maintained at 350 mm.

[0044] The secondary air temperature of the rotary kiln is 1200℃.

[0045] The tertiary air temperature of the rotary kiln is 800℃.

[0046] The amount of desulfurizing agent added accounts for approximately 0.02% of the total cement raw materials.

[0047] The method for preparing a desulfurizing agent as described above:

[0048] S1: Add 100 kg of hollow glass microspheres to 800 kg of water, add 2 kg of diaminosilane coupling agent, stir vigorously at 40 °C for 2 h, centrifuge, and dry to obtain diamino-modified hollow glass microspheres.

[0049] S2: Add 500 kg of DMF and 100 kg of diamino-modified hollow glass microspheres to a sealed reactor, purge with nitrogen to replace the air, stir vigorously for 20 min, then add 5 kg of 1,1,3,3-tetramethylguanidine acrylate, continue the reaction at 70 °C for 30 min, then add 13 kg of linoleyl diethanolamine and 2 kg of potassium persulfate, continue the reaction for 100 min, filter, and dry to obtain the desulfurizing agent.

[0050] The diaminosilane coupling agent used is N-2-(aminoethyl)-8-aminooctyltrimethyloxysilane.

[0051] The method for preparing the 1,1,3,3-tetramethylguanidine acrylate is as follows:

[0052] 10 kg of 1,1,3,3-tetramethylguanidine was added to the reactor, 6 kg of acrylic acid was added dropwise, and stirring was started. The mixture was stirred at 10°C for 20 minutes to obtain 1,1,3,3-tetramethylguanidine acrylic acid.

[0053] Example 2

[0054] A method for co-processing high-sulfur materials in a cement kiln, comprising the following steps:

[0055] S1: Pretreatment of high-sulfur waste: Mix 140 kg of high-sulfur waste with an excess of lime slurry containing 10% water until pH = 8, then stop adding lime slurry. Filter under pressure and dry until the moisture content is 2 wt% to obtain high-sulfur waste containing calcium sulfate.

[0056] S2: Cement preparation: 130 kg limestone, 26 kg slag powder, 8 kg silicate clinker powder, 24 kg high-sulfur waste containing calcium sulfate, 5 kg steel slag, and 6 kg activator are mixed and ground into dry raw meal powder.

[0057] S3: The dry raw meal powder is sent to the homogenization silo, and after homogenization, it is sent to the preheater. After preheating to 865°C, it enters the decomposition kiln. The decomposed raw meal then enters the rotary kiln and is calcined into clinker in 35 minutes.

[0058] S4: The desulfurizing agent is added to the mixing tank in the middle of the kiln tail flue gas conveying pipeline. Due to the low density of the hollow glass microspheres, they can be blown up by hot air and quickly and fully mixed with the flue gas, thereby realizing the flue gas desulfurization operation.

[0059] The silicate clinker powder is silicate clinker with a strength of 55 MPa, ground to a specific surface area of ​​360 mm². 2 / kg.

[0060] The temperature at the top of the decomposition chamber of the rotary kiln is 875℃, and the temperature at the tail flue gas chamber is 1000℃.

[0061] The thickness of the rotary kiln material layer is maintained at 360 mm.

[0062] The secondary air temperature of the rotary kiln is 1240℃.

[0063] The tertiary air temperature of the rotary kiln is 840℃.

[0064] The amount of desulfurizing agent added accounts for approximately 0.1% of the total cement raw materials.

[0065] The method for preparing a desulfurizing agent as described above:

[0066] S1: Add 120 kg of hollow glass microspheres to 900 kg of water, add 3 kg of diaminosilane coupling agent, stir vigorously at 45 °C for 3 h, centrifuge, and dry to obtain diamino-modified hollow glass microspheres.

[0067] S2: Add 600 kg of DMF and 110 kg of diamino-modified hollow glass microspheres to a sealed reactor, purge with nitrogen to replace the air, stir vigorously for 300 min, then add 6 kg of 1,1,3,3-tetramethylguanidine acrylate, continue the reaction at 75 °C for 40 min, then add 14 kg of linoleyl diethanolamine and 3 kg of potassium persulfate, continue the reaction for 110 min, filter, and dry to obtain the desulfurizing agent.

[0068] The diaminosilane coupling agent used is N-2-(aminoethyl)-8-aminooctyltrimethyloxysilane.

[0069] The method for preparing the 1,1,3,3-tetramethylguanidine acrylate is as follows:

[0070] 14 kg of 1,1,3,3-tetramethylguanidine was added to the reactor, 8 kg of acrylic acid was added dropwise, and stirring was started. The mixture was stirred at 15°C for 30 minutes to obtain 1,1,3,3-tetramethylguanidine acrylic acid.

[0071] Example 3

[0072] A method for co-processing high-sulfur materials in a cement kiln, comprising the following steps:

[0073] S1: Pretreatment of high-sulfur waste: Mix 180 kg of high-sulfur waste with an excess of lime slurry with 12% water content until pH = 9, then stop adding lime slurry. Filter under pressure and dry until the moisture content is 4 wt% to obtain high-sulfur waste containing calcium sulfate.

[0074] S2: Cement preparation: 140 kg limestone, 28 kg slag powder, 13 kg silicate clinker powder, 28 kg high-sulfur waste containing calcium sulfate, 8 kg steel slag, and 7 kg activator are mixed and ground into dry raw meal powder.

[0075] S3: The dry raw meal powder is sent to the homogenization silo, and after homogenization, it is sent to the preheater. After preheating to 875°C, it enters the decomposition kiln. The decomposed raw meal then enters the rotary kiln and is calcined into clinker in 35 minutes.

[0076] S4: The desulfurizing agent is added to the mixing tank in the middle of the kiln tail flue gas conveying pipeline. Due to the low density of the hollow glass microspheres, they can be blown up by hot air and quickly and fully mixed with the flue gas, thereby realizing the flue gas desulfurization operation.

[0077] The silicate clinker powder is silicate clinker with a strength of 55 MPa, ground to a specific surface area of ​​380 mm². 2 / kg.

[0078] The temperature at the top of the decomposition chamber of the rotary kiln is 885℃, and the temperature at the tail flue gas chamber is 1020℃.

[0079] The thickness of the rotary kiln material layer is maintained at 380 mm.

[0080] The secondary air temperature of the rotary kiln is 1280℃.

[0081] The tertiary air temperature of the rotary kiln is 880℃.

[0082] The amount of desulfurizing agent added accounts for approximately 0.3% of the total cement raw materials.

[0083] The method for preparing a desulfurizing agent as described above:

[0084] S1: Add 140 kg of hollow glass microspheres to 1100 kg of water, add 4 kg of diaminosilane coupling agent, stir vigorously at 45 °C for 4 h, centrifuge, and dry to obtain diamino-modified hollow glass microspheres.

[0085] S2: Add 800 kg of DMF and 120 kg of diamino-modified hollow glass microspheres to a sealed reactor, purge with nitrogen to replace the air, stir vigorously for 40 min, then add 7 kg of 1,1,3,3-tetramethylguanidine acrylate, continue the reaction at 75 °C for 50 min, then add 16 kg of linoleyl diethanolamine and 4 kg of potassium persulfate, continue the reaction for 130 min, filter, and dry to obtain the desulfurizing agent.

[0086] The diaminosilane coupling agent used is N-2-(aminoethyl)-3-aminopropyltrimethoxysilane.

[0087] The method for preparing the 1,1,3,3-tetramethylguanidine acrylate is as follows:

[0088] 18 kg of 1,1,3,3-tetramethylguanidine was added to the reactor, 12 kg of acrylic acid was added dropwise, and stirring was started. The mixture was stirred at 15°C for 50 minutes to obtain 1,1,3,3-tetramethylguanidine acrylic acid.

[0089] Example 4

[0090] A method for co-processing high-sulfur materials in a cement kiln, comprising the following steps:

[0091] S1: Pretreatment of high-sulfur waste: Mix 200 kg of high-sulfur waste with an excess of lime slurry with 14% water content until pH = 9, then stop adding lime slurry. Filter under pressure and dry until the moisture content is 5 wt% to obtain high-sulfur waste containing calcium sulfate.

[0092] S2: Cement preparation: 152 kg limestone, 30 kg slag powder, 15 kg silicate clinker powder, 30 kg high-sulfur waste containing calcium sulfate, 10 kg steel slag, and 8 kg activator are mixed and ground into dry raw meal powder.

[0093] S3: The dry raw meal powder is sent to the homogenization silo, and after homogenization, it is sent to the preheater. After preheating to 880°C, it enters the decomposition kiln. The decomposed raw meal then enters the rotary kiln and is calcined into clinker in 40 minutes.

[0094] S4: The desulfurizing agent is added to the mixing tank in the middle of the kiln tail flue gas conveying pipeline. Due to the low density of the hollow glass microspheres, they can be blown up by hot air and quickly and fully mixed with the flue gas, thereby realizing the flue gas desulfurization operation.

[0095] The silicate clinker powder is silicate clinker with a strength of 60 MPa, ground to a specific surface area of ​​400 mm². 2 / kg.

[0096] The temperature at the top of the decomposition chamber of the rotary kiln is 890℃, and the temperature at the tail flue gas chamber is 1050℃.

[0097] The thickness of the rotary kiln material layer is maintained at 400 mm.

[0098] The secondary air temperature of the rotary kiln is 1300℃.

[0099] The tertiary air temperature of the rotary kiln is 900℃.

[0100] The amount of desulfurizing agent added accounts for approximately 0.4% of the total cement raw materials.

[0101] The method for preparing a desulfurizing agent as described above:

[0102] S1: Add 160 kg of hollow glass microspheres to 1200 kg of water, add 5 kg of diaminosilane coupling agent, stir vigorously at 50 °C for 5 h, centrifuge, and dry to obtain diamino-modified hollow glass microspheres.

[0103] S2: Add 1000 kg of DMF and 128 kg of diamino-modified hollow glass microspheres to a sealed reactor, purge with nitrogen to replace the air, stir vigorously for 50 min, then add 8 kg of 1,1,3,3-tetramethylguanidine acrylate, continue the reaction at 80 °C for 60 min, then add 17 kg of linoleyl diethanolamine and 5 kg of potassium persulfate, continue the reaction for 140 min, filter, and dry to obtain the desulfurizing agent.

[0104] The diaminosilane coupling agent used is N-2-(aminoethyl)-3-aminopropyltrimethoxysilane.

[0105] The method for preparing the 1,1,3,3-tetramethylguanidine acrylate is as follows:

[0106] 20 kg of 1,1,3,3-tetramethylguanidine was added to the reactor, 14 kg of acrylic acid was added dropwise, and stirring was started. The mixture was stirred at 20°C for 60 minutes to obtain 1,1,3,3-tetramethylguanidine acrylic acid.

[0107] Comparative Example 1

[0108] A method for co-processing high-sulfur materials in a cement kiln, comprising the following steps:

[0109] S1: Pretreatment of high-sulfur waste: Mix 100 kg of high-sulfur waste with an excess of lime slurry containing 7% water until pH = 8, then stop adding lime slurry. Filter under pressure and dry until the moisture content is 1 wt% to obtain high-sulfur waste containing calcium sulfate.

[0110] S2: Cement preparation: 120kg limestone, 25kg slag powder, 5kg silicate clinker powder, 20kg high-sulfur waste containing calcium sulfate, 3kg steel slag, 5kg activator, mixed and ground into dry raw meal powder.

[0111] S3: The dry raw meal powder is sent to the homogenization silo, and after homogenization, it is sent to the preheater. After being preheated to 860°C, it enters the decomposition kiln. The decomposed raw meal then enters the rotary kiln and is calcined into clinker in 30 minutes.

[0112] The silicate clinker powder is silicate clinker with a strength of 50 MPa, ground to a specific surface area of ​​350 mm². 2 / kg.

[0113] The temperature at the top of the decomposition chamber of the rotary kiln is 870℃, and the temperature at the tail flue gas chamber is 980℃.

[0114] The thickness of the rotary kiln material layer is maintained at 350 mm.

[0115] The secondary air temperature of the rotary kiln is 1200℃.

[0116] The tertiary air temperature of the rotary kiln is 800℃.

[0117] Comparative Example 2

[0118] A method for co-processing high-sulfur materials in a cement kiln, comprising the following steps:

[0119] S1: Pretreatment of high-sulfur waste: Mix 100 kg of high-sulfur waste with an excess of lime slurry containing 7% water until pH = 8, then stop adding lime slurry. Filter under pressure and dry until the moisture content is 1 wt% to obtain high-sulfur waste containing calcium sulfate.

[0120] S2: Cement preparation: 120kg limestone, 25kg slag powder, 5kg silicate clinker powder, 20kg high-sulfur waste containing calcium sulfate, 3kg steel slag, 5kg activator, mixed and ground into dry raw meal powder.

[0121] S3: The dry raw meal powder is sent to the homogenization silo, and after homogenization, it is sent to the preheater. After preheating to 860°C, it enters the decomposition kiln. The decomposed raw meal then enters the rotary kiln and is calcined into clinker in 30 minutes.

[0122] S4: The desulfurizing agent is added to the mixing tank in the middle of the kiln tail flue gas conveying pipeline. Due to the low density of the hollow glass microspheres, they can be blown up by hot air and quickly and fully mixed with the flue gas, thereby realizing the flue gas desulfurization operation.

[0123] The silicate clinker powder is silicate clinker with a strength of 50 MPa, ground to a specific surface area of ​​350 mm². 2 / kg.

[0124] The temperature at the top of the decomposition chamber of the rotary kiln is 870℃, and the temperature at the tail flue gas chamber is 980℃.

[0125] The thickness of the rotary kiln material layer is maintained at 350 mm.

[0126] The secondary air temperature of the rotary kiln is 1200℃.

[0127] The tertiary air temperature of the rotary kiln is 800℃.

[0128] The amount of desulfurizing agent added accounts for approximately 0.02% of the total cement raw materials.

[0129] The method for preparing a desulfurizing agent as described above:

[0130] S1: Add 100 kg of hollow glass microspheres to 800 kg of water, add 2 kg of diaminosilane coupling agent, stir vigorously at 40 °C for 2 h, centrifuge, and dry to obtain diamino-modified hollow glass microspheres.

[0131] S2: Add 500 kg of DMF and 100 kg of diamino-modified hollow glass microspheres to a sealed reactor, purge with nitrogen to replace the air, stir vigorously for 20 min, continue the reaction at 70°C for 30 min, then add 13 kg of linoleyl diethanolamine and 2 kg of potassium persulfate, continue the reaction for 100 min, filter, and dry to obtain the desulfurizing agent.

[0132] The diaminosilane coupling agent used is N-2-(aminoethyl)-8-aminooctyltrimethyloxysilane.

[0133] Comparative Example 3

[0134] A method for co-processing high-sulfur materials in a cement kiln, comprising the following steps:

[0135] S1: Pretreatment of high-sulfur waste: Mix 100 kg of high-sulfur waste with an excess of lime slurry containing 7% water until pH = 8, then stop adding lime slurry. Filter under pressure and dry until the moisture content is 1 wt% to obtain high-sulfur waste containing calcium sulfate.

[0136] S2: Cement preparation: 120kg limestone, 25kg slag powder, 5kg silicate clinker powder, 20kg high-sulfur waste containing calcium sulfate, 3kg steel slag, 5kg activator, mixed and ground into dry raw meal powder.

[0137] S3: The dry raw meal powder is sent to the homogenization silo, and after homogenization, it is sent to the preheater. After preheating to 860°C, it enters the decomposition kiln. The decomposed raw meal then enters the rotary kiln and is calcined into clinker in 30 minutes.

[0138] S4: The desulfurizing agent is added to the mixing tank in the middle of the kiln tail flue gas conveying pipeline. Due to the low density of the hollow glass microspheres, they can be blown up by hot air and quickly and fully mixed with the flue gas, thereby realizing the flue gas desulfurization operation.

[0139] The silicate clinker powder is silicate clinker with a strength of 50 MPa, ground to a specific surface area of ​​350 mm². 2 / kg.

[0140] The temperature at the top of the decomposition chamber of the rotary kiln is 870℃, and the temperature at the tail flue gas chamber is 980℃.

[0141] The thickness of the rotary kiln material layer is maintained at 350 mm.

[0142] The secondary air temperature of the rotary kiln is 1200℃.

[0143] The tertiary air temperature of the rotary kiln is 800℃.

[0144] The amount of desulfurizing agent added accounts for approximately 0.02% of the total cement raw materials.

[0145] The method for preparing a desulfurizing agent as described above:

[0146] S1: Add 100 kg of hollow glass microspheres to 800 kg of water, stir vigorously at 40 °C for 2 h, centrifuge, and dry to obtain diamino-modified hollow glass microspheres;

[0147] S2: Add 500 kg of DMF and 100 kg of diamino-modified hollow glass microspheres to a sealed reactor, purge with nitrogen to replace the air, stir vigorously for 20 min, then add 5 kg of 1,1,3,3-tetramethylguanidine acrylate, continue the reaction at 70 °C for 30 min, then add 13 kg of linoleyl diethanolamine and 2 kg of potassium persulfate, continue the reaction for 100 min, filter, and dry to obtain the desulfurizing agent.

[0148] The method for preparing the 1,1,3,3-tetramethylguanidine acrylate is as follows:

[0149] 10 kg of 1,1,3,3-tetramethylguanidine was added to the reactor, 6 kg of acrylic acid was added dropwise, and stirring was started. The mixture was stirred at 10°C for 20 minutes to obtain 1,1,3,3-tetramethylguanidine acrylic acid.

[0150]

Claims

1. A method for cement kiln co-processing high-sulfur materials, the operation steps are as follows: S1: high-sulfur waste pretreatment: 100-200 parts of high-sulfur waste is mixed with excess lime milk containing 7-14% water by weight, until the pH is 8-9, then stop adding lime milk, filter and dry to obtain high-sulfur waste containing calcium sulfate, the moisture content is 1-5 wt%; S2: preparation of cement: 120-152 parts of limestone, 25-30 parts of slag powder, 5-15 parts of silicate clinker powder, 20-30 parts of high-sulfur waste containing calcium sulfate, 3-10 parts of steel slag, and 5-8 parts of active agent are mixed by weight, and then ground into dry raw meal powder; S3: the dry raw meal powder is sent to the homogenizing bin, and then sent to the preheater after homogenization, and then enters the decomposition kiln after being preheated to 860-880℃, and then enters the rotary kiln after being decomposed, and then calcined into clinker for 30-40 minutes; S4: the desulfurizing agent is added into the mixing tank in the middle of the kiln tail flue gas conveying pipeline, the hollow glass microspheres can be blown up by hot air due to their small density, and can be mixed with flue gas quickly and fully, so that the flue gas desulfurization operation is realized; The preparation method of the desulfurizing agent is as follows: S1: 100-160 parts of hollow glass microspheres are added to 800-1200 parts of water, 2-5 parts of diaminosilane coupling agent is added, and stirred at 40-50℃ for 2-5 hours, then centrifuged and dried to obtain diaminosilane modified hollow glass microspheres; 2. A method of cement kiln co-processing of high sulphur material according to claim 1, characterized in that: The silicate clinker powder is a silicate clinker with a strength of 50-60 MPa, ground to a specific surface area of 350-400 mm 2 / kg.

3. A method of cement kiln co-processing of high sulphur material according to claim 1, characterized in that: S2: 500-1000 parts of DMF, 100-128 parts of diaminosilane modified hollow glass microspheres, 5-8 parts of 1,1,3,3-tetramethyl guanidine propenoate, 70-80℃, continue to react for 30-60min, then add 13-17 parts of linoleyl diethanolamine, 2-5 parts of potassium persulfate, continue to react for 100-140min, filter and dry to obtain the desulfurizing agent.

4. A method of cement kiln co-processing of high sulphur material according to claim 1, characterized in that: The decomposition kiln of the rotary kiln has a top temperature of 870-890℃, and the kiln tail smoke chamber has a temperature of 980-1050℃.

5. A method of cement kiln co-processing of high sulphur material according to claim 1, characterized in that: The thickness of the material layer of the rotary kiln is kept at 350-400mm.

6. A method of cement kiln co-processing of high sulphur material according to claim 1, characterized in that: The temperature of the secondary air of the rotary kiln is 1200-1300℃.

7. A method of cement kiln co-processing of high sulphur material according to claim 1, characterized in that: The temperature of the tertiary air of the rotary kiln is 800-900℃.

8. A method of cement kiln co-processing of high sulphur material according to claim 1, characterized in that: The desulfurizing agent is mixed in an amount of 0.02%-0.4% of the total amount of cement clinker.

9. A method of cement kiln co-processing of high sulphur material according to claim 1, characterized in that: The diaminosilane coupling agent is N-2-(aminoethyl)-8-aminooctyltrimethoxysilane or N-2-(aminoethyl)-3-aminopropyltrimethoxysilane. The preparation method of the 1,1,3,3-tetramethyl guanidine propenoate is as follows: 10-20 parts of 1,1,3,3-tetramethyl guanidine is added to the reactor, 6-14 parts of acrylic acid is added dropwise, and stirring is started, and the mixture is stirred at 10-20℃ for 20-60 minutes to obtain 1,1,3,3-tetramethyl guanidine propenoate.

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