Preparation and application of wet spray coating
By developing a wet spray coating material, the amorphous refractory material is directly sprayed on the furnace wall or structure, the problems of high construction costs and long construction period of existing refractory materials are solved, and the effect of low-cost and rapid construction is achieved.
Patent Information
- Application Number
- CN202510171395.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-02-17
- Publication Date
- 2025-05-23
AI Technical Summary
The construction cost of existing refractory materials is high, the construction period is long, and the materials need to be purchased from outside, resulting in high costs.
Develop a wet spray coating material, which directly sprays amorphous refractory material on the furnace wall or structure through a high-pressure pump, including raw material selection and quality inspection, mixing and screening, sample preparation, adding water reducing agent, silicon micropowder and coagulation accelerator, trial spraying, and adding retarder, steel fiber and explosion-proof fiber.
It has achieved low maintenance costs, short construction period, fast solidification, less dust, low rebound rate, and fast construction speed, significantly shortening construction work time.
Smart Images
Figure CN120025179A_ABST
Abstract
Description
Technical Field
[0001] The invention relates to the technical field of wet spray coatings, and in particular to the preparation and application of wet spray coatings. Background Art
[0002] With the rapid development of the refractory industry, the requirements for the performance and construction technology of refractory materials are getting higher and higher. Because traditional furnace lining maintenance is all done by refractory brick masonry, the maintenance cost is high and the construction period is long. When the energy-saving kiln is seriously damaged or eroded by furnace lining burning, wet spraying is used to replace refractory brick masonry to repair the furnace lining. The maintenance cost is one-third lower than that of refractory brick masonry, and the construction period is shortened by two-thirds. However, the construction materials required for refractory materials are all purchased from outside, and the cost is relatively high. In order to save the cost of furnace lining maintenance, a wet spray coating is urgently needed. Summary of the invention
[0003] The purpose of the present invention is to provide a preparation and application of a wet spray coating material in view of the shortcomings and defects in the prior art. The coating material can directly use a high-pressure pump to spray amorphous refractory materials directly onto the corresponding furnace wall or structure. It has the significant advantages of low maintenance cost, short construction period, fast solidification, less dust, low rebound rate, etc. It also has the advantages of fast construction speed, which can greatly shorten the construction operation time.
[0004] To achieve the above purpose, the present invention adopts the following technical scheme: a preparation and application of a wet spray coating, a preparation of a wet spray coating, characterized in that it includes the following specific steps: selection and quality inspection of raw materials: there are many raw materials for wet spray coating, and their selection depends on the use temperature of the spray coating and the production process requirements. Quality inspection must be carried out before production to ensure that the quality meets the requirements; mixing and screening: various raw materials are added to a mixer in a certain proportion for mixing, ensuring that the proportion of the mixed raw materials is accurate, and then the mixed raw materials are screened to pick out large impurities and raw materials that are not mixed evenly, Ensure uniform particle size of the mixture; Sample preparation: According to the formula of each wet spray coating, the aggregate and powder are weighed and added into the mixer and stirred for 2-3 minutes. After stirring evenly, silicon solvent is added in a certain proportion and stirred for 3-4 minutes. The sample is vibrated and formed into 160mm×40mm×40mm by machine, and demoulded after natural curing for 24 hours. After drying at 110℃, it is heat treated at 1300℃×3h to test the linear change rate, volume density, flexural strength and compressive strength of each wet spray coating formula; Add water reducer for fluidity test; Effect of silicon micropowder addition on the performance of wet spray coating :The more silicon micropowder is added, the less silicon solvent is added. When the amount of silicon micropowder added increases from 0 to 6%, the amount of silicon solvent added decreases sharply. When the amount of silicon micropowder added is between 4% and 6%, the amount of silicon solvent added changes little. The compressive strength of the spray coating increases with the increase of silicon micropowder added. When the amount of silicon micropowder added reaches 6%, the compressive strength is the highest both at room temperature and at high temperature. When the amount of silicon micropowder added reaches 8%, the compressive strength decreases instead. Selection of coagulant: Most of the coagulants used in wet spray coatings combined with calcium aluminate cement are alkaline compounds. Calcium aluminate The bonding mechanism of cement as a binder for refractory castables is that after CaO·Al2O3(CA), CaO·2A2O3(CA2), 12CaO·7Al2O3(C12A7) in cement are mixed with water, Ca2+ and Al(OH)4 ions quickly dissolve into water to form Ca2+ and AI(OH)4 aqueous solution and quickly reach saturation. After reaching saturation, they crystallize out of the solution to form hydrates. These hydration products are interconnected to form an interlaced network structure, thereby solidifying and hardening; trial spraying: according to the formal spraying construction method; add retarders, steel fibers and explosion-proof fibers.
[0005] Furthermore, in the selection and quality inspection of the raw materials, the main raw materials are bauxite, alumina powder, silica powder, calcium aluminate cement and Vero white mud.
[0006] Furthermore, in the fluidity test, sodium hexametaphosphate, sodium tripolyphosphate and composite sodium phosphate are added as water reducers to conduct fluidity test.
[0007] Furthermore, the adding of the retarder, steel fiber and explosion-proof fiber is specifically as follows: under the same conditions, the spray material is transported to the spray gun nozzle by a high-pressure pump. Since a straight pipe and a curved pipe are connected in the middle, the material sprayed from the spray gun nozzle of the 1# formula spray material is relatively uniform, and there is no pipeline blockage, and the rebound rate is basically around 6.5%. However, after the test spray, it was found that there was some blockage at the gun head mouth; while the pipeline and the spray gun nozzle of the 2# formula and the 4# formula often have blockage during the spraying, and the rebound rate is above 10%. Therefore, the developed 1# formula is appropriately adjusted and combined with comprehensive factors and climate change, citric acid is added as a retarder in time to prevent pipeline blockage; and steel fibers are added in a certain proportion to increase the strength of the spray layer. At the same time, considering that the temperature of the kiln is not properly controlled after the kiln construction is completed, it may cause the spray layer to burst, therefore, explosion-proof fibers are added.
[0008] The invention discloses a preparation and application of a wet spray coating, characterized in that it comprises the preparation of any wet spray coating.
[0009] After adopting the above technical scheme, the beneficial effect of the present invention is: the coating can directly use a high-pressure pump to spray the amorphous refractory material directly onto the corresponding furnace wall or structure. It has the significant advantages of low maintenance cost, short construction period, fast solidification, less dust, low rebound rate, etc., and also has the advantages of fast construction speed, which can greatly shorten the construction operation time. BRIEF DESCRIPTION OF THE DRAWINGS
[0010] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.
[0011] Figure 1 This is a schematic diagram of sample preparation in the present invention. Figure 1 .
[0012] Figure 2 This is a schematic diagram of sample preparation in the present invention. Figure 2 .
[0013] Figure 3 This is a schematic diagram of sample preparation in the present invention. Figure 3 .
[0014] Figure 4 This is a schematic diagram of sample preparation in the present invention. Figure 4 .
[0015] Figure 5 This is a schematic diagram of sample preparation in the present invention. Figure 5 .
[0016] Figure 6 This is a graph showing the relationship between the amount of water reducing agent added and fluidity.
[0017] Figure 7 This is a schematic diagram of the fluidity experiment in the present invention. Figure 1 .
[0018] Figure 8 This is a schematic diagram of the fluidity experiment in the present invention. Figure 2 .
[0019] Fig. 9 This is a schematic diagram of the fluidity experiment in the present invention. Figure 3 .
[0020] Fig.10 It is a schematic diagram showing the effect of the amount of silicon micropowder added on the amount of silica sol added in the present invention.
[0021] Fig.11 It is a schematic diagram of the effect of the amount of silicon powder added on the compressive strength of the material in the present invention.
[0022] Fig.12 This is a schematic diagram of the coagulant in the present invention. Figure 1 .
[0023] Fig.13 This is a schematic diagram of the coagulant in the present invention. Figure 2 .
[0024] Fig.14 It is a schematic diagram of the test spraying construction process in the present invention. Figure 1 .
[0025] Fig.15 It is a schematic diagram of the test spraying construction process of the present invention. Figure 2 .
[0026] Fig.16 It is a schematic diagram of the test spraying construction process in the present invention. Figure 3 .
[0027] Fig.17 It is a schematic diagram of the test spraying construction process in the present invention. Figure 4 .
[0028] Fig.18 It is a schematic diagram of the burning and erosion of the kiln lining bricks in the present invention.
[0029] Fig.19 It is a schematic diagram of the spraying effect in the present invention. DETAILED DESCRIPTION
[0030] The technical solution adopted in this specific implementation method is: it includes the following specific steps:
[0031] S1, selection and quality inspection of raw materials: There are many raw materials for wet spray coatings, and their selection depends on the use temperature of the spray coating and the production process requirements. Quality inspection must be carried out before production to ensure that the quality meets the requirements. Among them, the main raw materials are bauxite, alumina powder, silica powder, calcium aluminate cement and Vero white mud. The chemical composition is shown in Table 1:
[0032]
[0033] Table 1 Main raw materials used in the experiment.
[0034] S2, mixing and screening: Add various raw materials into the mixer in a certain proportion to mix them, ensure that the proportion of the mixed raw materials is accurate, and then screen the mixed raw materials to pick out large impurities and unmixed raw materials to ensure that the mixed material has a uniform particle size.
[0035] S3, see Figure 1-Figure 5 As shown, sample preparation: according to each formula of wet spray coating, the aggregate and powder are weighed and added into the mixer and stirred for 2-3 minutes. After stirring evenly, the silicon solvent is added in a certain proportion and stirred for 3-4 minutes. The sample of 160mm×40mm×40mm is prepared by machine vibration molding, and demoulding is carried out after natural curing for 24 hours. After that, it is dried at 110℃ and then heat treated at 1300℃×3h. The linear change rate, volume density, flexural strength and compressive strength of each wet spray coating formula are tested. See Table 2:
[0036]
[0037]
[0038] Table 2 Formula and test index of wet spray coating
[0039] S4, see Figure 7-Figure 9 As shown, water reducing agent was added to conduct fluidity test; Table 2 shows that the physical and chemical indicators of formula 1# are much better than the other three, so it was decided to use formula 1# (i.e. 26% 0-1mm 83 alumina aggregate, 25% 1-3mm 83 alumina aggregate, 12% 3-5mm 85 alumina aggregate, 12% 180 mesh 85 alumina fine powder, 7% CA-68 cement fine powder, 6% 200 mesh silica powder, 9% alumina fine powder, 3% micro-white mud and 0.2% sodium hexametaphosphate) and add sodium hexametaphosphate, sodium tripolyphosphate and composite sodium phosphate as water reducing agent for fluidity test, among which, see Figure 6As shown, the optimal addition amounts of sodium hexametaphosphate, sodium tripolyphosphate, and composite sodium phosphate are 0.2%, 0.1%, and 0.2%, respectively. At this time, the corresponding viscosity of the material reaches the lowest and the fluidity is the best. By comparison, it is found that phosphate water reducer can achieve good water reduction effect at a lower addition amount. Under the conditions of this test, sodium hexametaphosphate is the most ideal dispersant, and the optimal addition amount is 0.2%.
[0040] S5, the effect of silicon powder addition on the performance of wet spray coatings: see Fig.10 As shown in the figure, the more silicon micropowder is added, the less silicon solvent is added. When the silicon micropowder addition increases from 0 to 6%, the silicon solvent addition decreases sharply. When the silicon micropowder addition is between 4% and 6%, the silicon solvent addition changes little. Fig.11 As shown, the compressive strength of the spray coating increases with the increase of the amount of silicon micropowder added. When the amount of silicon micropowder added reaches 6%, the compressive strength is the highest both at room temperature and at high temperature. When the amount of silicon micropowder added reaches 8%, the compressive strength decreases.
[0041] S6, see Figure 12-13 As shown in the figure, the selection of coagulant: the coagulants used in wet spray coatings bonded with calcium aluminate cement are mostly alkaline compounds. The bonding mechanism of calcium aluminate cement as a binder for refractory castables is that after CaO·Al2O3(CA), CaO·2A2O3(CA2), 12CaO·7Al2O3(C12A7) in cement are mixed with water, Ca2+ and Al(OH)4 ions quickly dissolve into water to form a Ca2+ and AI(OH)4 aqueous solution and quickly reach saturation. After reaching saturation, it crystallizes from the solution to form hydrates. These hydration products are interconnected to form an interlaced network structure, thereby solidifying and hardening.
[0042] S7, see Figure 14-17As shown, test spraying: follow the formal spraying construction method. From the welding of anchors, sprayer debugging and spray material stirring, the spray material uses 1# (26% 0-1mm 83 alumina aggregate, 25% 1-3mm 83 alumina aggregate, 12% 3-5mm 85 alumina aggregate, 12% 180 mesh 85 alumina fine powder, 7% CA-68 cement fine powder, 6% 200 mesh silica powder, 9% alumina powder, 3% micro-white mud and 0.2% sodium hexametaphosphate), 2# (26% 0-1mm 83 alumina aggregate, 25% 1-3mm 83 alumina aggregate, 12% 3-5mm 85 alumina aggregate, 15% 180 mesh 85 alumina fine powder, 7% CA-68 cement fine powder, 3% 200 mesh silica powder, 9% alumina powder, 3% micro clay and 0.2% sodium hexametaphosphate), 4# (26% 0-1mm 83 alumina aggregate, 25% 1-3mm 83 alumina aggregate, 12% 3-5mm 85 alumina aggregate, 13% 180 mesh 85 alumina fine powder, 8% CA-68 cement fine powder, 3% 200 mesh silica powder, 8% alumina powder, 5% micro clay and 0.2% sodium hexametaphosphate) formula and produce 2 tons of each as test spraying material.
[0043] S8, adding retarder, steel fiber and explosion-proof fiber, specifically: under the same conditions, the spray material is transported to the spray gun mouth by a high-pressure pump. Since a straight pipe and a bend pipe are connected in the middle, the material sprayed from the spray gun mouth of the 1# formula spray material is relatively uniform, and there is no pipeline blockage, and the rebound rate is basically around 6.5%. However, after the test spray, it was found that there was some blockage at the gun head mouth; while the pipeline and the spray gun mouth of the 2# formula and the 4# formula often blocked during the spraying, and the rebound rate was more than 10%. Therefore, the developed 1# formula was appropriately adjusted and combined with comprehensive factors and climate change, citric acid was added as a retarder in time to prevent pipeline blockage; and steel fiber was added in a certain proportion to improve the strength of the spray layer. At the same time, considering that the temperature of the oven is not properly controlled after the kiln construction is completed, it may cause the spray layer to burst, so explosion-proof fiber was added. The specific formula is shown in Table 3:
[0044] Raw material name Specification formula(%) 83 Alumina Aggregate 0-1(mm) 26 83 Alumina Aggregate 1-3(mm) 24 85 alumina aggregate 3-5(mm) 10 85 Alumina fine powder 180 mesh 13 Calcium aluminate cement powder 7 Silica powder 200 mesh 7 Alumina powder 10 Vero White Clay 3 Sodium Hexametaphosphate 0.2 Explosion-proof fiber 150±10℃ 0.1 Steel Fiber L = 10 mm, φ = 1.5 mm 0.6 Retarder (citric acid) 0.005
[0045] Table 3 Formula of wet spray coating
[0046] A preparation and application of a wet spray coating: characterized in that it includes the preparation of any one of claims 1-X.
[0047] The following are relevant embodiments of the present invention:
[0048] See also Fig.18As shown in the figure, it can be found that the lining bricks of the 400m3 No. 1 mixed-firing mechanized vertical kiln are seriously burned and eroded. The main reason is that the overcapacity has not been repaired in time. Fig.19 As shown, the test results of the wet spray coating were verified on site. The results show that during the construction process, the wet spray coating solidified quickly on the spray surface, no flow was found, the rebound rate was about 6.5%, the dust on the construction site was well controlled, and the high compressive strength could be identified from the knocking sound after natural drying. The total spraying construction area of this project was 328.50m2, and the construction period was 7 days, which was about 21 days shorter than the refractory brick masonry; the maintenance cost was about 1.35 million yuan, which saved about 850,000 yuan compared with the refractory brick masonry. No burning or shedding phenomenon has been found on the spray surface since its operation. It can be seen that the developed wet spray coating can replace the refractory brick masonry operations of various industrial furnace linings.
[0049] The above description is only used to illustrate the technical solution of the present invention rather than to limit it. Other modifications or equivalent substitutions made to the technical solution of the present invention by ordinary technicians in this field should be included in the scope of the claims of the present invention as long as they do not depart from the spirit and scope of the technical solution of the present invention.
Claims
1. A preparation and application of a wet spray coating, characterized in that: It includes the following specific steps: S1, Selection and quality inspection of raw materials: There are many raw materials for wet spray coatings, and their selection depends on the use temperature of the spray coating and the production process requirements. Quality inspection must be carried out before production to ensure that the quality meets the requirements; S2, mixing and screening: adding various raw materials into the mixer in a certain proportion to ensure that the proportion of the mixed raw materials is accurate, and then screening the mixed raw materials to pick out large impurities and raw materials that are not mixed evenly to ensure that the mixed material has a uniform particle size; S3, sample preparation: according to each formula of wet spray coating, the aggregate and powder are weighed and added into a mixer and stirred for 2-3 minutes. After stirring evenly, a silicon solvent is added in a certain proportion and stirred for 3-4 minutes. The sample is vibrated and formed into a 160mm×40mm×40mm sample by a machine. After natural curing for 24 hours, the sample is demoulded, dried at 110℃, and then heat treated at 1300℃×3h. The linear change rate, volume density, flexural strength and compressive strength of each wet spray coating formula are tested; S4, add water reducing agent to conduct fluidity test; S5, the effect of silicon micropowder addition on the performance of wet spray coating: the more silicon micropowder is added, the less silicon solvent is added. When the silicon micropowder addition increases from 0% to 6%, the silicon solvent addition decreases sharply. When the silicon micropowder addition is between 4% and 6%, the silicon solvent addition changes little. The compressive strength of the spray coating increases with the increase of silicon micropowder addition. When the silicon micropowder addition reaches 6%, the compressive strength is the highest both at room temperature and at high temperature. When the silicon micropowder addition reaches 8%, the compressive strength decreases instead. S6, Selection of coagulant: Most of the coagulants used in wet spray coatings bonded with calcium aluminate cement are alkaline compounds. The bonding mechanism of calcium aluminate cement as a refractory castable binder is that after CaO·Al2O3 (CA), CaO·2A2O3 (CA2), 12CaO·7Al2O3 (C12A7) in cement is mixed with water, Ca2+ and Al(OH)4 ions quickly dissolve in water to form a Ca2+ and Al(OH)4 aqueous solution and quickly reach saturation. After reaching saturation, it crystallizes from the solution to form hydrates. These hydration products are interconnected to form an interlaced network structure, thereby solidifying and hardening; S7, test spraying: according to the formal spraying construction method; S8, adding retarder, steel fiber and explosion-proof fiber.
2. The preparation and application of a wet spray coating according to claim 1, characterized in that: In the S1, the main raw materials are bauxite, alumina powder, silica powder, calcium aluminate cement and Vero white mud.
3. The preparation and application of a wet spray coating according to claim 1, characterized in that: Sodium hexametaphosphate, sodium tripolyphosphate and composite sodium phosphate were added to S4 as water reducing agents for fluidity test.
4. The preparation and application of a wet spray coating according to claim 1, characterized in that: The S8 is specifically as follows: under the same conditions, the spray material is transported to the spray gun nozzle by a high-pressure pump. Since a straight pipe and a curved pipe are connected in the middle, the material sprayed from the spray gun nozzle of the 1# formula spray material is relatively uniform, and there is no pipeline blockage, and the rebound rate is basically around 6.5%. However, after the test spray, it was found that there was some blockage at the gun head mouth; while the pipelines and spray gun nozzles of the 2# and 4# formulas are often blocked during spraying, and the rebound rate is above 10%. Therefore, the developed 1# formula is appropriately adjusted and combined with comprehensive factors and climate change, citric acid is added as a retarder in time to prevent pipeline blockage; and steel fibers are added in a certain proportion to improve the strength of the spray layer. At the same time, considering that the temperature of the kiln is not properly controlled after the kiln construction is completed, it may cause the spray layer to burst, so explosion-proof fibers are added.
5. Preparation and application of a wet spray coating: characterized by: It comprises any one of the wet spray coatings according to claims 1-4.