Suggestions for Sintering Technologies of High Cr_2O_3 Bearing Refractories Based on Thermodynamic Calculation

摘要

Cr2O3 can be sintered well at 1 500 ℃ in carbon-embedded 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 apparent 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.