Dense corundum-mullite brick for blast furnace ceramic pad was prepared using white fused corundum and tabular corundum as aggregates,andalusite fine powder,sillimanite fine powder,zircon sand powder and Guangxi soil ...Dense corundum-mullite brick for blast furnace ceramic pad was prepared using white fused corundum and tabular corundum as aggregates,andalusite fine powder,sillimanite fine powder,zircon sand powder and Guangxi soil as the matrix,and phosphate as the binder,introducing different amounts ofα-alumina micropowder,tabular corundum fine powder and fused corundum powder.The properties of the prepared brick were studied.The results show that,the brick with 10 mass%of tabular corundum fine powder fired at 1560℃for 3 h in a tunnel kiln has the bulk density of 3.08 g·cm^(-3),the apparent porosity of 13.2%,the cold compressive strength of 178 MPa,the molten iron corrosion rate of 0.6%,the slag corrosion rate of 6.4%,the alkali resistance strength decreasing rate of 7.5%,and the thermal shock resistance of 32 cycles,which is both dense and of good thermal shock resistance.The slag resistance simulation test was performed,which proved that the prepared corundum-mullite brick is better than those currently supplied in the market.展开更多
The paper presents a new method to synthesize β-Sialon bonded corundum brick (β-SBCB) from Al-Si alloy directly and easily under 1430℃ , the volume expansion of reaction between Al powder and Nitrogen can help to e...The paper presents a new method to synthesize β-Sialon bonded corundum brick (β-SBCB) from Al-Si alloy directly and easily under 1430℃ , the volume expansion of reaction between Al powder and Nitrogen can help to establish the fast diffusion channel in Al-Si alloy; the suitable crystal seed of Si3N4 is helpful to the fast synthesis of β-Sialon.展开更多
MgO -ZrO2 unfired bricks with ZrO2 content up to 8% at the interval of 2% were prepared, using fused magnesia ( MgO : 97% ) and fused MgO - ZrO2 clinker ( ZrO2 : 14. 33% ) as starting materials and phenolic resi...MgO -ZrO2 unfired bricks with ZrO2 content up to 8% at the interval of 2% were prepared, using fused magnesia ( MgO : 97% ) and fused MgO - ZrO2 clinker ( ZrO2 : 14. 33% ) as starting materials and phenolic resin as binder. The effects of ZrO2 content on thermal shock resistance (TSR) and other properties such as cold and hot modulus of rupture have been investigated. Re- sidual cold modulus of rupture ratio after heating at 1 000 ℃ and quenching by air blowing was adopted to characterize TSR. Addition of the MgO -ZrO2 clinker improves TSR, attributing to the microcrack toughening effect by thermal expansion mismatch between different phases. When ZrO2 content goes above 4%. the impro- ving effect tends to be moderate. The introduction of MgO- ZrO2 clinker can also improve the HMOR at 1 500 ℃, while the increased ZrO2 content reduces CMOR of the bricks prefired at 1 600 ℃, due to the thermal expansion mismatch effect. Compromising the overall properties, the optimal ZrO2 content for such magnesia based unfired brick is suggested to be 4%.展开更多
The paper aims at investigating whether corundum bricks can be used for the bottom, of the direct reduction furnace of high phosphorus oolitic hematite. The reducing materials including high phosphorus oolitic hemati...The paper aims at investigating whether corundum bricks can be used for the bottom, of the direct reduction furnace of high phosphorus oolitic hematite. The reducing materials including high phosphorus oolitic hematite, bitumite, Ca(OH) 2 and Na2CO3 at a mass ratio of 1:0. 15:0. 15:0. 03 were mixed and pressed into carbon containing cylindrical specimens with the size of Ф15 mm × 20 mm. The specimens were placed on the corundum bricks and reduced in a high temperature tube furnace at 1 200 ℃ for 40, 60, 80, 140 and 220 min, respective- ly. The corrosion and penetration resistance of corundum. bricks to high phosphorus oolitic hematite reducing materials were analyzed with XRD, SEM and EDS. It shows that the reducing slag formed in the reduction process corrodes the surface of corundum bricks to form a product layer of anorthite and hercynite, retarding the further corrosion of the reducing slag; the reducing slag which has penetrated into the interior of the brick goes through the gaps between the particles and generates anorthite and hercynite, filling the gaps and hindering the reducing slag penetration.展开更多
The corundum - spinel castables were prepared by six kinds of tabular corundum, as aggregates, respective- ly, and their linear change rate on heating, apparent porosity, bulk density, cold modulus of rupture, coht cr...The corundum - spinel castables were prepared by six kinds of tabular corundum, as aggregates, respective- ly, and their linear change rate on heating, apparent porosity, bulk density, cold modulus of rupture, coht crushing strength, hot modulus of rupture and thermal shock resistance were compared and studied. The results show that: 1) the six tabular corundum materials have similar main chemical composition but their physical properties vary for the different technical procedures which result in different properties of castables ; 2 ) the optimal properties of corundum - spinel castables corre- spotut to different tabular corundum types, so the corundum type shall be selected according to the application of the castables.展开更多
Resins PFG-4 , PFG-8 and a reference resin (resin A) were used as binders of MgO - C bricks, effects of the resins with different molecular structures on wettability of magnesia, on physical properties, mechanical p...Resins PFG-4 , PFG-8 and a reference resin (resin A) were used as binders of MgO - C bricks, effects of the resins with different molecular structures on wettability of magnesia, on physical properties, mechanical properties, oxidation resistance and thermal expansion properties of MgO- C bricks were researched. The results show that the microstructures of solidified resins with different mo- lecular structures are different, which have obvious effect on the cold mechanical properties of MgO - C brick, but little effect on the oxidation resistance, thermal perform- ance and expansion properties.展开更多
Five lightweight castables containing different TiO2 additions were prepared by using porous corundum - spinel ( MgAl2O4 ) ceramics as aggregate. Corrosion of the lightweight cstables by ladle slag was conducted u...Five lightweight castables containing different TiO2 additions were prepared by using porous corundum - spinel ( MgAl2O4 ) ceramics as aggregate. Corrosion of the lightweight cstables by ladle slag was conducted using a static crucible test. The effect of the TiO2 addition on the slag resistances of the lightweight corundum -spinel castables was investigated through SEM, EDS and Fact- Sage@ software, etc. h was found that TiO2 additi,ve t,vmoted the sintering degree of the castables, deereased the average pore .size, the apparent porosity, and the contact area between the casmbles and slag, and then en- hanced the corrosion resistance. However, TiO2 additive decreased the viscosity of the penetrated .slag simultane- ously, and then deteriorated the penetration resistance.展开更多
SiC- mullite brick is widely used in the upper and lower transitional zones of cement rotary kilns, due to excellent thermal shock resistance, and abrasion resist- ance. The investigation of different bauxites was mad...SiC- mullite brick is widely used in the upper and lower transitional zones of cement rotary kilns, due to excellent thermal shock resistance, and abrasion resist- ance. The investigation of different bauxites was made on the performance and micro-structure of SiC - mullite brick, especially thermal shock resistance. In two batches of bricks ( G1 and G2 ) , and two grades of bauxites ( L1 and I_2 ), samples' physical and chemical properties were tested, and microstructure and phase composition were studied by SEM and XRD. The results show that raw material I2, containing large numbers of micro- pores smaller than 4 μm, has well developed mullite phase. While using L2 as aggregates and flues, SiC- mullite brick G2 has excellent thermal shock resistance. Therefore, for manufacture of SiC - mullite brick, not only chemical composition, bulk density and open porosi- ty of bauxite are important, but also its microstructure has to be considered, such as phase composition, crystal size and pore size distribution.展开更多
Effects of FeO content (0, 5%, 10%, and 15% in mass, respectively ) in lab-synthesized smelting redttc- tion slag with iron bath and test temperature (1 450, 1 500, 1550, anti 1 600 ℃ ) on corrosion am,amount and...Effects of FeO content (0, 5%, 10%, and 15% in mass, respectively ) in lab-synthesized smelting redttc- tion slag with iron bath and test temperature (1 450, 1 500, 1550, anti 1 600 ℃ ) on corrosion am,amount and microstructure of fused rebonded magnesia - chrome brick with 26.02 massqc of Cr2O3 were researched by rotary cylinder method. The results show that : ( 1 ) the corro- sion amolult of magnesia -chrome brick by slag without FeO is higher than that by the slag with 5% FeO, and the vorrosion amount increases when FeO content increa- ses from 5% to 15% ; (2) the test temperature is one of the important factors affecting the slag corrosion resist- ance of magnesia - chrome brick, and the corrosion of smelting reduction slag to brick increases with the temperature rising.展开更多
The effect of Ti ( C, N) on properties of low-carbon MgO - C bricks was investigated. The phase composition and the microstructure of the matrix of low-carbon MgO - C brick containing Ti ( C, N) were studied by XR...The effect of Ti ( C, N) on properties of low-carbon MgO - C bricks was investigated. The phase composition and the microstructure of the matrix of low-carbon MgO - C brick containing Ti ( C, N) were studied by XRD and SEM analysis together with EDS. The results showed that Ti ( C, N) distributed in the matrix of lowcarbon MgO - C brick uniformly after being treated at 1 600 ~C for 3 h in coke powder bed, and Ti (C, N) and MgO formed a solid solution. After the treatment at 1 600 ℃ for 3 h in coke powder bed, the bulk density and cold crushing strength of low-carbon MgO - C brick with Ti ( C, N) decreased, and the apparent porosity and linear change rate of specimens increased. The oxidation resistance of low-carbon MgO - C brick with Ti( C, N) was superior to that of low-carbon MgO - C brick with no additives, but inferior to that of low-car- bon MgO - C brick with Al powder. The slag resistance of the specimen with Ti ( C, N) was excellent as well.展开更多
1 Scope This standard specifies the classifcation, technical requirements, test methods, quality appraisal procedure, packing, marking, transportation, storage and quality certificate of silica bricks.
1 Scope This standard specifies the definition, classifica- tion, technical requirements, test methods, quality appraisal procedures, packing, marking, transportation, storage, and quality certificate of silicon nitri...1 Scope This standard specifies the definition, classifica- tion, technical requirements, test methods, quality appraisal procedures, packing, marking, transportation, storage, and quality certificate of silicon nitride bonded silicon carbide bricks.展开更多
为了满足生产低碳钢和超低碳钢的技术要求,以棕刚玉、板状刚玉、电熔镁铝尖晶石粉为原料,电熔镁砂粉和α-氧化铝微粉为添加剂,络合镁铝溶胶为结合剂,研制出了机压成型免烧刚玉-尖晶石无碳砖,并进行了实验。试验结果表明:当电熔镁砂粉和...为了满足生产低碳钢和超低碳钢的技术要求,以棕刚玉、板状刚玉、电熔镁铝尖晶石粉为原料,电熔镁砂粉和α-氧化铝微粉为添加剂,络合镁铝溶胶为结合剂,研制出了机压成型免烧刚玉-尖晶石无碳砖,并进行了实验。试验结果表明:当电熔镁砂粉和α-氧化铝微粉加入量分别为3%和8%时,试验砖的性能最佳。该砖在太钢90 t LF钢包熔池及包底部位使用,其寿命达到105炉。展开更多
文摘Dense corundum-mullite brick for blast furnace ceramic pad was prepared using white fused corundum and tabular corundum as aggregates,andalusite fine powder,sillimanite fine powder,zircon sand powder and Guangxi soil as the matrix,and phosphate as the binder,introducing different amounts ofα-alumina micropowder,tabular corundum fine powder and fused corundum powder.The properties of the prepared brick were studied.The results show that,the brick with 10 mass%of tabular corundum fine powder fired at 1560℃for 3 h in a tunnel kiln has the bulk density of 3.08 g·cm^(-3),the apparent porosity of 13.2%,the cold compressive strength of 178 MPa,the molten iron corrosion rate of 0.6%,the slag corrosion rate of 6.4%,the alkali resistance strength decreasing rate of 7.5%,and the thermal shock resistance of 32 cycles,which is both dense and of good thermal shock resistance.The slag resistance simulation test was performed,which proved that the prepared corundum-mullite brick is better than those currently supplied in the market.
文摘The paper presents a new method to synthesize β-Sialon bonded corundum brick (β-SBCB) from Al-Si alloy directly and easily under 1430℃ , the volume expansion of reaction between Al powder and Nitrogen can help to establish the fast diffusion channel in Al-Si alloy; the suitable crystal seed of Si3N4 is helpful to the fast synthesis of β-Sialon.
文摘MgO -ZrO2 unfired bricks with ZrO2 content up to 8% at the interval of 2% were prepared, using fused magnesia ( MgO : 97% ) and fused MgO - ZrO2 clinker ( ZrO2 : 14. 33% ) as starting materials and phenolic resin as binder. The effects of ZrO2 content on thermal shock resistance (TSR) and other properties such as cold and hot modulus of rupture have been investigated. Re- sidual cold modulus of rupture ratio after heating at 1 000 ℃ and quenching by air blowing was adopted to characterize TSR. Addition of the MgO -ZrO2 clinker improves TSR, attributing to the microcrack toughening effect by thermal expansion mismatch between different phases. When ZrO2 content goes above 4%. the impro- ving effect tends to be moderate. The introduction of MgO- ZrO2 clinker can also improve the HMOR at 1 500 ℃, while the increased ZrO2 content reduces CMOR of the bricks prefired at 1 600 ℃, due to the thermal expansion mismatch effect. Compromising the overall properties, the optimal ZrO2 content for such magnesia based unfired brick is suggested to be 4%.
文摘The paper aims at investigating whether corundum bricks can be used for the bottom, of the direct reduction furnace of high phosphorus oolitic hematite. The reducing materials including high phosphorus oolitic hematite, bitumite, Ca(OH) 2 and Na2CO3 at a mass ratio of 1:0. 15:0. 15:0. 03 were mixed and pressed into carbon containing cylindrical specimens with the size of Ф15 mm × 20 mm. The specimens were placed on the corundum bricks and reduced in a high temperature tube furnace at 1 200 ℃ for 40, 60, 80, 140 and 220 min, respective- ly. The corrosion and penetration resistance of corundum. bricks to high phosphorus oolitic hematite reducing materials were analyzed with XRD, SEM and EDS. It shows that the reducing slag formed in the reduction process corrodes the surface of corundum bricks to form a product layer of anorthite and hercynite, retarding the further corrosion of the reducing slag; the reducing slag which has penetrated into the interior of the brick goes through the gaps between the particles and generates anorthite and hercynite, filling the gaps and hindering the reducing slag penetration.
文摘The corundum - spinel castables were prepared by six kinds of tabular corundum, as aggregates, respective- ly, and their linear change rate on heating, apparent porosity, bulk density, cold modulus of rupture, coht crushing strength, hot modulus of rupture and thermal shock resistance were compared and studied. The results show that: 1) the six tabular corundum materials have similar main chemical composition but their physical properties vary for the different technical procedures which result in different properties of castables ; 2 ) the optimal properties of corundum - spinel castables corre- spotut to different tabular corundum types, so the corundum type shall be selected according to the application of the castables.
文摘Resins PFG-4 , PFG-8 and a reference resin (resin A) were used as binders of MgO - C bricks, effects of the resins with different molecular structures on wettability of magnesia, on physical properties, mechanical properties, oxidation resistance and thermal expansion properties of MgO- C bricks were researched. The results show that the microstructures of solidified resins with different mo- lecular structures are different, which have obvious effect on the cold mechanical properties of MgO - C brick, but little effect on the oxidation resistance, thermal perform- ance and expansion properties.
基金The National Natural Science Foundation of China(Grant No.51302201)
文摘Five lightweight castables containing different TiO2 additions were prepared by using porous corundum - spinel ( MgAl2O4 ) ceramics as aggregate. Corrosion of the lightweight cstables by ladle slag was conducted using a static crucible test. The effect of the TiO2 addition on the slag resistances of the lightweight corundum -spinel castables was investigated through SEM, EDS and Fact- Sage@ software, etc. h was found that TiO2 additi,ve t,vmoted the sintering degree of the castables, deereased the average pore .size, the apparent porosity, and the contact area between the casmbles and slag, and then en- hanced the corrosion resistance. However, TiO2 additive decreased the viscosity of the penetrated .slag simultane- ously, and then deteriorated the penetration resistance.
文摘SiC- mullite brick is widely used in the upper and lower transitional zones of cement rotary kilns, due to excellent thermal shock resistance, and abrasion resist- ance. The investigation of different bauxites was made on the performance and micro-structure of SiC - mullite brick, especially thermal shock resistance. In two batches of bricks ( G1 and G2 ) , and two grades of bauxites ( L1 and I_2 ), samples' physical and chemical properties were tested, and microstructure and phase composition were studied by SEM and XRD. The results show that raw material I2, containing large numbers of micro- pores smaller than 4 μm, has well developed mullite phase. While using L2 as aggregates and flues, SiC- mullite brick G2 has excellent thermal shock resistance. Therefore, for manufacture of SiC - mullite brick, not only chemical composition, bulk density and open porosi- ty of bauxite are important, but also its microstructure has to be considered, such as phase composition, crystal size and pore size distribution.
文摘Effects of FeO content (0, 5%, 10%, and 15% in mass, respectively ) in lab-synthesized smelting redttc- tion slag with iron bath and test temperature (1 450, 1 500, 1550, anti 1 600 ℃ ) on corrosion am,amount and microstructure of fused rebonded magnesia - chrome brick with 26.02 massqc of Cr2O3 were researched by rotary cylinder method. The results show that : ( 1 ) the corro- sion amolult of magnesia -chrome brick by slag without FeO is higher than that by the slag with 5% FeO, and the vorrosion amount increases when FeO content increa- ses from 5% to 15% ; (2) the test temperature is one of the important factors affecting the slag corrosion resist- ance of magnesia - chrome brick, and the corrosion of smelting reduction slag to brick increases with the temperature rising.
文摘The effect of Ti ( C, N) on properties of low-carbon MgO - C bricks was investigated. The phase composition and the microstructure of the matrix of low-carbon MgO - C brick containing Ti ( C, N) were studied by XRD and SEM analysis together with EDS. The results showed that Ti ( C, N) distributed in the matrix of lowcarbon MgO - C brick uniformly after being treated at 1 600 ~C for 3 h in coke powder bed, and Ti (C, N) and MgO formed a solid solution. After the treatment at 1 600 ℃ for 3 h in coke powder bed, the bulk density and cold crushing strength of low-carbon MgO - C brick with Ti ( C, N) decreased, and the apparent porosity and linear change rate of specimens increased. The oxidation resistance of low-carbon MgO - C brick with Ti( C, N) was superior to that of low-carbon MgO - C brick with no additives, but inferior to that of low-car- bon MgO - C brick with Al powder. The slag resistance of the specimen with Ti ( C, N) was excellent as well.
文摘1 Scope This standard specifies the classifcation, technical requirements, test methods, quality appraisal procedure, packing, marking, transportation, storage and quality certificate of silica bricks.
文摘1 Scope This standard specifies the definition, classifica- tion, technical requirements, test methods, quality appraisal procedures, packing, marking, transportation, storage, and quality certificate of silicon nitride bonded silicon carbide bricks.
文摘为了满足生产低碳钢和超低碳钢的技术要求,以棕刚玉、板状刚玉、电熔镁铝尖晶石粉为原料,电熔镁砂粉和α-氧化铝微粉为添加剂,络合镁铝溶胶为结合剂,研制出了机压成型免烧刚玉-尖晶石无碳砖,并进行了实验。试验结果表明:当电熔镁砂粉和α-氧化铝微粉加入量分别为3%和8%时,试验砖的性能最佳。该砖在太钢90 t LF钢包熔池及包底部位使用,其寿命达到105炉。