In order to improve the performance of Al_(2)O_(3)-SiC-C castables for iron trough,samples were prepared using brown corundum,dense corundum,activated alumina micropowder,ball pitch,and silicon as main raw materials,c...In order to improve the performance of Al_(2)O_(3)-SiC-C castables for iron trough,samples were prepared using brown corundum,dense corundum,activated alumina micropowder,ball pitch,and silicon as main raw materials,calcium aluminate cement as the binder.Several kinds of silica fumes(93SiO_(2),96SiO_(2),and 99SiO_(2))with different particle size distributions and chemical composition were added to research the effects on the properties of castables.The results show that the sample with 99SiO_(2) fume has high water requirement for molding,but the bulk density is the lowest,the apparent porosity is the highest,the oxidation resistance is the worst,and the permanent linear change on heating is low after firing at 1 450 ℃ for 3 h.The bulk density and the apparent porosity of the sample with 93SiO_(2) fume or 96SiO_(2) fume are equivalent,the hot modulus of rupture of the sample with 93SiO_(2) fume is the lowest,and the slag resistance of the sample with 96SiO_(2) fume is the best.The comprehensive performance of the sample with 96SiO_(2) fume is the best.展开更多
Thermal behavior and physical properties of castables during curing and drying-out are associated with their binding system. In this work, five alumina based （ Al2O3 〉 87% ） castables with different combinations of...Thermal behavior and physical properties of castables during curing and drying-out are associated with their binding system. In this work, five alumina based （ Al2O3 〉 87% ） castables with different combinations of binding materials, i. e. , （ 1 ） CA cement （CA） ＋ Reactive alumina （ RA ） ＋ H2O ; （ 2 ） high level addi- tion of CA ＋ Microsilica （MS） ＋ H2O ; （ 3 ） low level addition of CA ＋ MS ＋ H2O ; （4） MS ＋ Hydratable alumina ＋ H20 and （ 5 ） MS ＋ Magnesia ＋ H2O, respectively, have been investigated on the flowability and thermal behavior during curing at room temperature, drying at 110% and heating from 200℃ to 1000℃ at an interval of 100℃ , in terms of water addition, vibration flow value, porosity, dehydration, explosion resistance, cold and hot bending strengths. Differences in dehydrating behavior and the mentioned properties have been revealed and correlated to the binding system.展开更多
采用自产大孔球形氧化铝载体和专有技术研制出新型蒽醌加氢制过氧化氢(双氧水)催化剂EK-Ⅲ。制备的EK-Ⅲ催化剂比表面积为170 m 2 g以上,堆密度为0.42 g mL左右,有大比表面积、低堆密度的特性;其钯分布更广泛也更富集,载钯厚度仅为60~70...采用自产大孔球形氧化铝载体和专有技术研制出新型蒽醌加氢制过氧化氢(双氧水)催化剂EK-Ⅲ。制备的EK-Ⅲ催化剂比表面积为170 m 2 g以上,堆密度为0.42 g mL左右,有大比表面积、低堆密度的特性;其钯分布更广泛也更富集,载钯厚度仅为60~70μm。催化剂EK-Ⅲ在吉林市双欧化工有限公司进行了工业应用,结果表明:与国内某工业产品催化剂R相比,EK-Ⅲ催化剂在装填量少30%的情况下,每吨催化剂的双氧水产能仍高出20%以上;EK-Ⅲ催化剂活性较高、选择性较好、稳定运行周期较长。展开更多
Inner vapor pressure and temperature of vulnerable explosive spalling positions in refractory castables during rapid drying were measured by embedding pressure transmitting pipes and thermocouples during casting. The ...Inner vapor pressure and temperature of vulnerable explosive spalling positions in refractory castables during rapid drying were measured by embedding pressure transmitting pipes and thermocouples during casting. The measured vapor pressure, temperature, and tensile strength of the castables were analyzed and discussed. A hollow sphere shell model was used to analyze the stress induced by the vapor pressure based on the structure of refractory castables. The mechanism of refractory castables explosive spalling caused by vapor-induced pore split was proposed. By comparing the vapor-induced stress and the tensile strength of the castables, the explosive spalling mechanism was validated quantitatively.展开更多
Status and state-of-the-art progress on research,development and application of refractories for aluminum smelting furnaces and holding furnaces were reviewed and discussed in the present paper.The main types of alumi...Status and state-of-the-art progress on research,development and application of refractories for aluminum smelting furnaces and holding furnaces were reviewed and discussed in the present paper.The main types of aluminum smelting furnaces and smelting processes,and the service conditions of refractories and the requirements for refractory lining were also described and discussed.展开更多
Al2O3 - SiC - C castables with pelletized graphite addition of 0. 2%, 4% or 6% （by mass, the same hereinafter ） were prepared using brown fused corundum （8 - 5, 5 - 3 and 3 - 1 mm ） , dense fused corundum （ ≤1 a...Al2O3 - SiC - C castables with pelletized graphite addition of 0. 2%, 4% or 6% （by mass, the same hereinafter ） were prepared using brown fused corundum （8 - 5, 5 - 3 and 3 - 1 mm ） , dense fused corundum （ ≤1 and 0. 045 mm） and SiC （ ≤1 and ≤0. 064 mm） its main starting materials with mass ratio of aggregate： matrix = 71： 29, 2% silicon powder and 0. 4% B4C as antioxidants, and pelletized graphite as carbon source, Effect of pelletized graphite addition on physical properties, oxidation resistance, slag resistance arid thermal shock resistance of Al2O3 -SiC- C eastables was researched. The results show that： with the in.crease of pelletized graphite addition, the required water amount of castables increases, the bulk density and strength reduce; with 4% pelletized graphite, the eastable performs the best oxidation resistance; the increase of graphite is beneficial to the improvement of slag penetration resistance and corrosion resistance; with 6% pelletized graphite, the thermal shock resistance is the best.展开更多
Laboratory study; was carried out on deep desulfurization of molten steel by CaO-Al2O3 based refining slag containing BaO at 1873K to achieve lower sulphur level in steel. A mathematical model of desulfurization was e...Laboratory study; was carried out on deep desulfurization of molten steel by CaO-Al2O3 based refining slag containing BaO at 1873K to achieve lower sulphur level in steel. A mathematical model of desulfurization was established with the methodology of quadratic orthogohal regression. According to the modle, the influence of AlO3/CaO, MgO, CaF2, BaO in slag on desulfurization rate was analyzed. The results showed that the desulfurization rate almost linearly decreased with the increase of Al2O3/CaO and it increased firstly then decreased when MgO and BaO content increased respectixely, yet the trend is on the contrary as CaF2 content increased. Based on the comprehensive analysis, the optimum composition of the refining slag was achieved under the experimental conditions.展开更多
文摘In order to improve the performance of Al_(2)O_(3)-SiC-C castables for iron trough,samples were prepared using brown corundum,dense corundum,activated alumina micropowder,ball pitch,and silicon as main raw materials,calcium aluminate cement as the binder.Several kinds of silica fumes(93SiO_(2),96SiO_(2),and 99SiO_(2))with different particle size distributions and chemical composition were added to research the effects on the properties of castables.The results show that the sample with 99SiO_(2) fume has high water requirement for molding,but the bulk density is the lowest,the apparent porosity is the highest,the oxidation resistance is the worst,and the permanent linear change on heating is low after firing at 1 450 ℃ for 3 h.The bulk density and the apparent porosity of the sample with 93SiO_(2) fume or 96SiO_(2) fume are equivalent,the hot modulus of rupture of the sample with 93SiO_(2) fume is the lowest,and the slag resistance of the sample with 96SiO_(2) fume is the best.The comprehensive performance of the sample with 96SiO_(2) fume is the best.
文摘Thermal behavior and physical properties of castables during curing and drying-out are associated with their binding system. In this work, five alumina based （ Al2O3 〉 87% ） castables with different combinations of binding materials, i. e. , （ 1 ） CA cement （CA） ＋ Reactive alumina （ RA ） ＋ H2O ; （ 2 ） high level addi- tion of CA ＋ Microsilica （MS） ＋ H2O ; （ 3 ） low level addition of CA ＋ MS ＋ H2O ; （4） MS ＋ Hydratable alumina ＋ H20 and （ 5 ） MS ＋ Magnesia ＋ H2O, respectively, have been investigated on the flowability and thermal behavior during curing at room temperature, drying at 110% and heating from 200℃ to 1000℃ at an interval of 100℃ , in terms of water addition, vibration flow value, porosity, dehydration, explosion resistance, cold and hot bending strengths. Differences in dehydrating behavior and the mentioned properties have been revealed and correlated to the binding system.
文摘采用自产大孔球形氧化铝载体和专有技术研制出新型蒽醌加氢制过氧化氢(双氧水)催化剂EK-Ⅲ。制备的EK-Ⅲ催化剂比表面积为170 m 2 g以上,堆密度为0.42 g mL左右,有大比表面积、低堆密度的特性;其钯分布更广泛也更富集,载钯厚度仅为60~70μm。催化剂EK-Ⅲ在吉林市双欧化工有限公司进行了工业应用,结果表明:与国内某工业产品催化剂R相比,EK-Ⅲ催化剂在装填量少30%的情况下,每吨催化剂的双氧水产能仍高出20%以上;EK-Ⅲ催化剂活性较高、选择性较好、稳定运行周期较长。
文摘Inner vapor pressure and temperature of vulnerable explosive spalling positions in refractory castables during rapid drying were measured by embedding pressure transmitting pipes and thermocouples during casting. The measured vapor pressure, temperature, and tensile strength of the castables were analyzed and discussed. A hollow sphere shell model was used to analyze the stress induced by the vapor pressure based on the structure of refractory castables. The mechanism of refractory castables explosive spalling caused by vapor-induced pore split was proposed. By comparing the vapor-induced stress and the tensile strength of the castables, the explosive spalling mechanism was validated quantitatively.
文摘Status and state-of-the-art progress on research,development and application of refractories for aluminum smelting furnaces and holding furnaces were reviewed and discussed in the present paper.The main types of aluminum smelting furnaces and smelting processes,and the service conditions of refractories and the requirements for refractory lining were also described and discussed.
文摘Al2O3 - SiC - C castables with pelletized graphite addition of 0. 2%, 4% or 6% （by mass, the same hereinafter ） were prepared using brown fused corundum （8 - 5, 5 - 3 and 3 - 1 mm ） , dense fused corundum （ ≤1 and 0. 045 mm） and SiC （ ≤1 and ≤0. 064 mm） its main starting materials with mass ratio of aggregate： matrix = 71： 29, 2% silicon powder and 0. 4% B4C as antioxidants, and pelletized graphite as carbon source, Effect of pelletized graphite addition on physical properties, oxidation resistance, slag resistance arid thermal shock resistance of Al2O3 -SiC- C eastables was researched. The results show that： with the in.crease of pelletized graphite addition, the required water amount of castables increases, the bulk density and strength reduce; with 4% pelletized graphite, the eastable performs the best oxidation resistance; the increase of graphite is beneficial to the improvement of slag penetration resistance and corrosion resistance; with 6% pelletized graphite, the thermal shock resistance is the best.
文摘Laboratory study; was carried out on deep desulfurization of molten steel by CaO-Al2O3 based refining slag containing BaO at 1873K to achieve lower sulphur level in steel. A mathematical model of desulfurization was established with the methodology of quadratic orthogohal regression. According to the modle, the influence of AlO3/CaO, MgO, CaF2, BaO in slag on desulfurization rate was analyzed. The results showed that the desulfurization rate almost linearly decreased with the increase of Al2O3/CaO and it increased firstly then decreased when MgO and BaO content increased respectixely, yet the trend is on the contrary as CaF2 content increased. Based on the comprehensive analysis, the optimum composition of the refining slag was achieved under the experimental conditions.
