Cr2O3 can be sintered well at 1500℃ in carbonembedded condition or H2 atmosphere. But the high chrome bearing refractories can not reach densification when sintered at 1 700℃ .for 10 h in weak reducing atmosphere fo...Cr2O3 can be sintered well at 1500℃ in carbonembedded condition or H2 atmosphere. But the high chrome bearing refractories can not reach densification when sintered at 1 700℃ .for 10 h in weak reducing atmosphere formed by the combustion of fuel, and its ap- parent porosity is about 18%. The high chrome bearing refractories are mainly used in coal gasifiers. The temperature in the furnace is about 1 500℃ and the products are H2 and CO, which are just the sintering conditions of the dense chrome refractories with apparent porosity less than 10%. The high chrome bearing refractories used in coal gasifiers may be sintered again and then shrink, destroying the gasifier lining. The thermodynamic calculation shows that it is safe about the high chrome bearing refractories used in gasifiers. It is also explained that the high chrome bearing refractories can＇t be sintered densely in weak reducing atmosphere formed by the combustion of fuel. The new sintering technologies can be used to improve the bulk density of the high chrome bearing refractories.展开更多
Pure Cr2O3 refractories and high Cr2O3 bearing refractories are difficult to sinter in oxidizing atmosphere, but they can be sintered easily in carbon embedded conditions. In the latter case it is attributed to the fo...Pure Cr2O3 refractories and high Cr2O3 bearing refractories are difficult to sinter in oxidizing atmosphere, but they can be sintered easily in carbon embedded conditions. In the latter case it is attributed to the formation of liquid CrO in reducing atmosphere. The thermodynamic calculation shows that the Cr2O3 is reduced by CO at 1 550 ℃ to chromium carbides, which disproves the existence of liquid CrO. This is confirmed by further sintering experiment of the Cr2O3 refractories. Effect of atmosphere on sintering of high Cr2O3 bearing refractories and measures to accelerate the sintering process are discussed based on the experiment and thermodynamic calculation.展开更多
文摘Cr2O3 can be sintered well at 1500℃ in carbonembedded condition or H2 atmosphere. But the high chrome bearing refractories can not reach densification when sintered at 1 700℃ .for 10 h in weak reducing atmosphere formed by the combustion of fuel, and its ap- parent porosity is about 18%. The high chrome bearing refractories are mainly used in coal gasifiers. The temperature in the furnace is about 1 500℃ and the products are H2 and CO, which are just the sintering conditions of the dense chrome refractories with apparent porosity less than 10%. The high chrome bearing refractories used in coal gasifiers may be sintered again and then shrink, destroying the gasifier lining. The thermodynamic calculation shows that it is safe about the high chrome bearing refractories used in gasifiers. It is also explained that the high chrome bearing refractories can＇t be sintered densely in weak reducing atmosphere formed by the combustion of fuel. The new sintering technologies can be used to improve the bulk density of the high chrome bearing refractories.
文摘Pure Cr2O3 refractories and high Cr2O3 bearing refractories are difficult to sinter in oxidizing atmosphere, but they can be sintered easily in carbon embedded conditions. In the latter case it is attributed to the formation of liquid CrO in reducing atmosphere. The thermodynamic calculation shows that the Cr2O3 is reduced by CO at 1 550 ℃ to chromium carbides, which disproves the existence of liquid CrO. This is confirmed by further sintering experiment of the Cr2O3 refractories. Effect of atmosphere on sintering of high Cr2O3 bearing refractories and measures to accelerate the sintering process are discussed based on the experiment and thermodynamic calculation.
