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Properties of Refractory Castables Tina Stendal Svendsen Product Manager. Refractory materials are subjected to following stress factors: Thermal - by high temperatures and thermal shock Mechanical - by pressure, impact , friction and airborne particles
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Properties of RefractoryCastables Tina Stendal Svendsen Product Manager
Refractorymaterialsaresubjected to following stress factors: • Thermal- by high temperatures and thermalshock • Mechanical- by pressure, impact, friction and airborneparticles • Chemical - by gases, liquids, build-up, slag and melts The properties of castables and theirability to withstand stresses aredetermined by: • Rawmaterials • Particlesize distribution • Chemical reactionbetweenrawmaterials at various temperatures The properties of refractorycastablescanbeanalysed by a range of international test procedures
Bendingstrength; Modulus of rupture (EN 1402-6) Cold modulus of rupture Provides information on materialstructure(QC) Hot modulus of rupture Characterize the thermodynamicbehaviour of the castable
ThermalShockResistance (EN 993-11) Air quenching of 950°C hot specimens
Abrasionresistance (ASTM C 704) Temperature: 1000°C Abrasion media: SiCgrains Testing angle: 45° and 90° Results: ≤ 5cm3loss: excellent 5cm3 to 10cm3: verygood 10cm3 to 20cm3: good
Alkali resistance (CEN/TS 15418) Test media K2CO3 or K2SO4
Hot-melt slag and build-up
Open porosity (EN 933-1) Test piecesaresaturated in water under vacuum
Other tests • Particlesize distribution • Thermalexpansion/ creep • Chemical and structural analyses; SEM and XRD • Thermalconductivity • Refractoriness / refractoriness under load • CO-resistance
Temperature Thermal property Application
Summary • Castablesaresubjected to thermal, mechanical and chemical stresses • Wide range of international test standards to measure properties • Some tests aretargeted for qualitycontrol • Other tests simulate operation conditions (temperature, chemicals) • Test of corrosive slags canbothstatic and dynamic • Test slags at relevant temperatures • There is a closerelationshipbetweenporosity and the physical and chemical properties of castables • Whencomparingdatasheets: Be aware of test-temperature and of to which temperature has the test specimensbeenprefired prior to test