Popular Science On The Preparation Method Of Lightweight Refractory Bricks Made Of Cordierite

Popular science on the preparation method of lightweight refractory bricks made of cordierite
A method for preparing lightweight refractory bricks made of cordierite, characterized in that 40-85wt% of porous cordierite ceramic particles, 3-12wt% of magnesite fine powder, 6-24wt% of Al (OH) 3 fine powder, and 6-24wt% of silica fine powder are used as raw materials, and 3-10wt% of the binder is added to the raw materials. The mixture is stirred evenly and pressed into shape; Dry the formed body at 110 ℃ for 8-36 hours, and then keep it at 1300-1410 ℃ for 2-10 hours to obtain lightweight refractory bricks made of cordierite; The preparation method of porous cordierite ceramic particles is as follows: mix 8-12wt% coal gangue powder, 33-37wt% Al (OH) 3 powder, 8-12wt% talc powder, 13-17wt% magnesite powder, and 28-32wt% silica powder, and add 3-12wt% water to stir evenly and form the mixture; Dry the formed body at 110 ℃ for 8-36 hours, and then keep it at 1300-1400 ℃ for 1-6 hours to obtain porous cordierite ceramics; ***Crush porous cordierite ceramics into particles smaller than 8mm to produce porous cordierite ceramic particles.
The following provides a further description of the present invention in conjunction with specific embodiments, without limiting the scope of protection: To avoid repetition, the preparation method of porous cordierite ceramic particles in this specific embodiment is described as follows, which will not be repeated in the embodiments: the preparation method of porous cordierite ceramic particles is to mix 8-12 wt% of coal gangue powder, 33-37 wt% of Al (OH) 3 powder, 8-12 wt% of talc powder, 13-17 wt% of magnesite powder, and 28-32 wt% of silica powder, and add 3-12 wt% of water to the above mixture, stir evenly, and shape; Dry the formed body at 110 ℃ for 8-36 hours, and then keep it at 1300-1400 ℃ for 1-6 hours to obtain porous cordierite ceramics. ***Crush porous cordierite ceramics into particles smaller than 8mm to produce porous cordierite ceramic particles.
Example 1: A lightweight refractory brick made of cordierite and its preparation method. Firstly, use 50-76wt% porous cordierite ceramic particles, 6-10wt% magnesite fine powder, 12-20wt% Al (OH) 3 fine powder, and 12-20wt% silica fine powder as raw materials, and add 3-8wt% * * * pulp waste liquid of the raw materials. Stir evenly and press them into shape under a pressure of 50-100MPa; Dry the formed body at 110 ℃ for 8-16 hours, and then keep it at 1340~1380 ℃ for 3-6 hours to obtain lightweight refractory bricks made of cordierite. In this embodiment, the particle size of magnesite fine powder is less than 50 μ m; The particle size of Al (OH) 3 fine powder is less than 50 μ m; The particle size of silica fine powder is less than 25 μ m; The apparent porosity of porous cordierite ceramic particles is 35-40%, with an average pore size of 10-20 μ m; The particle size ratio of porous cordierite ceramic particles is: 8~5mm, accounting for 6~12wt% of the raw material; 5-3mm accounts for 18-24wt% of the raw material; 3-1mm accounts for 18-24wt% of the raw material; Less than 1mm accounts for 8-16wt% of the raw material. The lightweight refractory brick of cordierite prepared in this example has a visible porosity of 30-38%; The average pore size is 10-20 μ m; The bulk density is 1.56-1.65g/cm3; The compressive strength at room temperature is 60-80MPa.
Example 2: A lightweight refractory brick made of cordierite and its preparation method. Firstly, use 50-76wt% porous cordierite ceramic particles, 6-10wt% magnesite fine powder, 12-20wt% Al (OH) 3 fine powder, and 12-20wt% silica fine powder as raw materials, and add 5-10wt% silica sol to the raw materials. Stir evenly and press them into shape under a pressure of 80-120MPa; Dry the formed body at 110 ℃ for 12-20 hours, and then keep it at 1370-1410 ℃ for 4-8 hours to obtain lightweight refractory bricks made of cordierite. In this embodiment, the particle size of magnesite fine powder is less than 74 μ m; The particle size of Al (OH) 3 fine powder is less than 88 μ m; The particle size of silica fine powder is less than 44 μ m; The concentration of silica sol is 25-30wt%; The apparent porosity of porous cordierite ceramic particles is 38-46%, with an average pore size of 20-30 μ m; The particle size ratio of porous cordierite ceramic particles is: 8~5mm, accounting for 6~12wt% of the raw material; 5-3mm accounts for 18-24wt% of the raw material; 3-1mm accounts for 18-24wt% of the raw material; Less than 1mm accounts for 8-16wt% of the raw material. The lightweight refractory brick of cordierite prepared in this example has a visible porosity of 38-46%; The average pore size is 20-30 μ m; The bulk density is 1.40-1.56g/cm3; The compressive strength at room temperature is 40-60MPa.
Example 3: A lightweight refractory brick made of cordierite and its preparation method. Firstly, using 40-60wt% porous cordierite ceramic particles, 8-12wt% magnesite fine powder, 16-24wt% Al (OH) 3 fine powder, and 16-24wt% silica fine powder as raw materials, in addition to 3-5 wt% silica sol and 3-5 wt% * * * pulp waste liquid, stir evenly and machine press them into a shape under a pressure of 50-80MPa; Dry the formed body at 110 ℃ for 24-36 hours, and then keep it at 1320-1380 ℃ for 5-10 hours to obtain lightweight refractory bricks made of cordierite. In this embodiment, the particle size of magnesite fine powder is less than 88 μ m; The particle size of Al (OH) 3 fine powder is less than 88 μ m; The particle size of silica fine powder is less than 88 μ m; The concentration of silica sol is 20-25wt%; The apparent porosity of porous cordierite ceramic particles is 45-55%, with an average pore size of 15-25 μ m; The particle size ratio of porous cordierite ceramic particles is: 5-3mm, accounting for 15-22wt% of the raw material; 3-1mm accounts for 15-22wt% of the raw material; Less than 1mm accounts for 10-16wt% of the raw material. The lightweight refractory brick of cordierite prepared in this example has a visible porosity of 46-54%; The average pore size is 15-25 μ m; The bulk density is 1.29-1.40g/cm3; The compressive strength at room temperature is 25~55MPa.
Example 4: A lightweight refractory brick made of cordierite and its preparation method. First, use 65-85wt% porous cordierite ceramic particles, 3-7wt% magnesite fine powder, 6-14wt% Al (OH) 3 fine powder, and 6-14wt% silica fine powder as raw materials, and add 5-10wt% * * * pulp waste liquid of the raw materials. Stir evenly and press it into shape under a pressure of 80-120MPa; Dry the formed body at 110 ℃ for 12-20 hours, and then keep it at 1300-1350 ℃ for 4-8 hours to obtain lightweight refractory bricks made of cordierite. In this embodiment, the particle size of magnesite fine powder is less than 44 μ m; The particle size of Al (OH) 3 fine powder is less than 74 μ m; The particle size of silica fine powder is less than 44 μ m; The apparent porosity of porous cordierite ceramic particles is 35-42%, with an average pore size of 10-20 μ m; The particle size ratio of porous cordierite ceramic particles is: 5-3mm, accounting for 20-30 wt% of the raw material; 3-1mm accounts for 25-30wt% of the raw material; Less than 1mm accounts for 20-25wt% of the raw material. The cordierite lightweight refractory brick prepared in this example has a visible porosity of 34-44%; The average pore size is 10-20 μ m; The bulk density is 1.40-1.60g/cm3; The compressive strength at room temperature is 50~70MPa.
Example 5: A lightweight refractory brick made of cordierite and its preparation method. First, use 65-85wt% porous cordierite ceramic particles, 3-7wt% magnesite fine powder, 6-14wt% Al (OH) 3 fine powder, and 6-14wt% silica fine powder as raw materials, and add 6-10wt% silica sol of the raw materials. Stir evenly and press them into shape under a pressure of 50-80MPa; Dry the formed body at 110 ℃ for 16-24 hours, and then keep it at 1300-1350 ℃ for 2-6 hours to obtain lightweight refractory bricks made of cordierite. In this embodiment, the particle size of magnesite fine powder is less than 88 μ m; The particle size of Al (OH) 3 fine powder is less than 88 μ m; The particle size of silica fine powder is less than 74 μ m; The concentration of silica sol is 30-35wt%; The apparent porosity of porous cordierite ceramic particles is 48-55%, with an average pore size of 20-30 μ m; The particle size ratio of porous cordierite ceramic particles is: 3-1mm accounts for 45-60wt% of the raw material, and less than 1mm accounts for 20-25wt% of the raw material. The lightweight refractory brick of cordierite prepared in this example has a visible porosity of 46-55%; The average pore size is 20-30 μ m; The bulk density is 1.28-1.34g/cm3; The compressive strength at room temperature is 20~40MPa.
Example 6: A lightweight refractory brick made of cordierite and its preparation method. Firstly, use 50-76wt% porous cordierite ceramic particles, 6-10wt% magnesite fine powder, 12-20wt% Al (OH) 3 fine powder, and 12-20wt% silica fine powder as raw materials, and add 3-8wt% silica sol of the raw materials. Stir evenly and press them into shape under a pressure of 100-150MPa; Dry the formed body at 110 ℃ for 8-16 hours, and then keep it at 1360-1410 ℃ for 6-10 hours to obtain lightweight refractory bricks made of cordierite. In this embodiment, the particle size of magnesite fine powder is less than 74 μ m; The particle size of Al (OH) 3 fine powder is less than 44 μ m; The particle size of silica fine powder is less than 60 μ m; The concentration of silica sol is 35-40wt%; The apparent porosity of porous cordierite ceramic particles is 35-40%, with an average pore size of 10-20 μ m; The particle size ratio of porous cordierite ceramic particles is: 8~5mm, accounting for 6~12wt% of the raw material; 5-3mm accounts for 18-24wt% of the raw material; 3-1mm accounts for 18-24wt% of the raw material; Less than 1mm accounts for 8-16wt% of the raw material. The lightweight refractory brick of cordierite prepared in this example has a visible porosity of 30-35%; The average pore size is 10-20 μ m; The bulk density is 1.60-1.65g/cm3; The compressive strength at room temperature is 70~100MPa. This specific implementation method adopts the "A Porous Cordierite Ceramic Material and Its Preparation Method (CN201110038289.2)" * * * technology applied by the applicant to prepare porous cordierite ceramic particles. The obtained porous cordierite ceramic particles are used as aggregates, and magnesite, Al (OH) 3, and silica fine powder are used as matrices. Magnesite and Al (OH) 3 self decompose in the matrix to form a porous structure. MgO and Al2O3 produced by the decomposition of magnesite and Al (OH) 3 are in situ combined with silica to form high-purity porous cordierite, and a lightweight refractory brick of cordierite is prepared by combining high-purity porous cordierite with porous cordierite ceramic aggregates.
By using this method, the prepared material not only has high strength and insulation performance, but also has good thermal shock stability and resistance to medium erosion. The main chemical components of the lightweight refractory brick made of cordierite prepared in this specific embodiment are MgO, Al2O3, and SiO2. The main crystal phase is cordierite, with a visible porosity of 30-55%, an average pore size of 10-30 μ m, a bulk density of 1.28-1.65 g/cm3, and a room temperature compressive strength of 20-100 MPa. Therefore, this specific implementation method has the characteristics of controllable visible porosity and pore size of aggregate and matrix, environmental friendliness, and small volume change after firing. The prepared lightweight refractory brick of cordierite has the advantages of high visible porosity, small average pore size, high strength, low thermal conductivity, good thermal shock stability, and strong resistance to medium erosion. This lightweight refractory brick is suitable for the * * * layer and working layer of high-temperature kilns or containers with working temperatures below 1380 ℃.