The drying behavior for various calcium aluminate cement and hydratable alumina‐bonded refractory castables was investigated in the first‐drying temperature range (100°C‐300°C). Using a specialized high‐temperature Nuclear Magnetic Resonance setup, we were able to directly and nondestructively measure the spatially and temporally resolved moisture distribution, while simultaneously measuring the temperature distribution as well. These measurements show that the drying front position is a linear function of time, which can be explained on the basis of a simplified model where only vapor transport is considered. Based on the measurements and the model, one can directly determine the permeability at high temperatures. Moreover, the results demonstrate that the drying front speed and temperature strongly correlates with the control of key material parameters (eg, water demand, binder content, etc). In particular, microsilica fume‐containing low‐cement castables displayed the highest vapor pressures, while regular castables generated the lowest vapor pressures reflecting the permeability of these materials.

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The article contains sections titled: 1. Introduction 2. Historical Aspects 3. General Classification and Nomenclature 4. Raw Materials 5. Production 5.1. Production of Coarse‐Grained Refractory Products 5.1.1. Preparation 5.1.2. Shaping 5.1.3. Drying 5.1.4. Thermal Treatment (Tempering) 5.1.4.1. Firing 5.1.4.2. Aftertreatment 5.2. Production of Insulating Refractory Products and Other Porous Refractory Ceramics 5.3. Production of Fine‐Grained Refractory Ceramics 5.4. Brick Dimensions and Dimensional Tolerances 5.5. Packaging, Storage, and Storage Time 5.6. Quality Assurance 6. General Composition, Properties, and Testing 6.1. Tests that Measure Properties Under Mechanical Load 6.2. Tests that Measure Properties Under Thermal Load 6.3. Thermal and Electrical Properties 6.4. Tests that Measure Properties Under Chemical and Physical Load 6.5. Tests that Measure the Interference of Thermal and Mechanical Load 6.6. Tests that Measure the Interference of Thermal, Mechanical, and Chemical/Physical Load 6.6.1. Interaction with Gas—CO Resistance 6.6.2. Interaction with Gas—H 2 Resistance 6.6.3. Interaction with Volatiles—Alkalies 6.6.4. Attack by Slag, Melts, and Other Fluid Media 6.6.5. Interaction with Accelerated Particles in the Furnace Aerosol 6.6.6. Tribomechanic Interaction 7. Types of Refractory Ceramics 7.1. Dense Shaped Refractory Products 7.1.1. Alumina–Silica Products (ISO 10081‐1) 7.1.1.1. High‐Alumina Products (HA) 7.1.1.2. Fireclay Products (FC) 7.1.1.3. Low‐Alumina Fireclay Products (LF) 7.1.1.4. Siliceous Products (SS) 7.1.1.5. Silica Products (SL) 7.1.2. Basic Products Containing Less than 7 mass% Residual Carbon (ISO 10081‐2) 7.1.2.1. Magnesia Products (M) 7.1.2.2. Doloma Products (D) 7.1.2.3. Magnesia Lime Products (ML) and Magnesia–Doloma Products (MD) 7.1.2.4. Lime Products (L) 7.1.2.5. Magnesia Spinel Products (MSp) 7.1.2.6. Forsterite Products (F) 7.1.2.7. Magnesia Chromite Products (MCr) 7.1.2.8. Chromite Products (Cr) 7.1.2.9. Magnesia–Zirconia Products (MZ) 7.1.2.10. Magnesia–Zirconia–Silica Products (MZS) 7.1.3. Basic Products Containing 7–50 mass% Residual Carbon (ISO 10081‐3) 7.1.3.1. Magnesia–Carbon Products (MC) 7.1.3.2. Magnesia–Lime–Carbon Products (MLC) Magnesia–Doloma–Carbon Products (MD) 7.1.4. Special Products (ISO 10081‐4) 7.1.4.1. Alumina–Chromia (ACr) and Chromia products (Cr) 7.1.4.2. Alumina–Chromia–Zirconia (ACrZ) and Alumina–Chromia–Zirconia–Silica Products (ACrZS) 7.1.4.3. Zirconia (Z) and Zirconia–Silica Products (ZS) 7.1.4.4. Alumina–Zirconia–Silica Products (AZS) 7.1.4.5. Alumina–Carbon Products (AC) 7.1.4.6. Alumina–Magnesia–Carbon Products (AMC) 7.1.4.7. Alumina–Fused Silica–Carbon Products (AFC) 7.1.4.8. Alumina–Silicon Carbide–Carbon Products (ASC) 7.1.4.9. Zirconia–Carbon Products (ZC) 7.1.4.10. Silicon Carbide–Carbon Products (SiC) 7.1.4.11. Carbon Products (C) 7.2. Monolithic or Unshaped Refractory Materials 7.2.1. Product Types 7.2.1.1. Refractory Castables 7.2.1.2. Refractory Ramming Materials 7.2.1.3. Tap‐Hole Mixes 7.2.1.4. Refractory Gunning Materials 7.2.1.5. Dry (Vibratable) Mixes 7.2.1.6. Refractory Jointing Materials 7.2.1.7. Carbon‐Containing Monolithic (Unshaped) Products 7.2.2. Classification of Monolithic (Unshaped) Refractory Materials 7.2.3. Application of Monolithic (Unshaped) Refractory Materials 7.3. Insulating Refractory Materials 7.3.1. Shaped and Unshaped Insulating Refractory Materials 7.3.1.1. Insulating Materials 7.3.1.2. Insulating Firebricks (IFB) 7.3.1.3. Unshaped Insulating Refractory Products 7.3.1.4. Microporous Insulating (Refractory) Products 7.3.2. High‐Temperature Insulation Wools (HTIW) 7.3.2.1. Amorphous Alkaline‐Earth Silicate Wools (AESW) 7.3.2.2. Amorphous Aluminosilicate Wools (ASW) 7.3.2.3. Polycrystalline Wools (PCW) 7.3.2.4. Applications of HTIW 8. Selection, Use, and Industry‐Specific Consumption of Refractory Ceramics 9. Toxicology and Occupational Health 10. Economic Aspects

In service, refractory linings experience thermal stresses typically exceeding their mechanical strength. However, this does not lead to the catastrophic failure of modern well-designed refractory linings. They rather undergo a more or less stepwise wear process and typically retain their structural stability despite existing substantial damage. Classic mechanical tests, such as modulus of rupture measurements that solely consider the maximum strength right before catastrophic fracture occurs are thereby inappropriate to quantify the resistance to damage of refractory products. Despite significant advancements in the theoretical description of fracture process and resistance to damages of refractory materials, there is still a lack of empirical data and scientific studies regarding the fracture behavior of typical refractory materials, especially at high temperature. Wedge splitting measurements, which proved very efficient to investigate the fracture behavior of refractory materials, were performed up to 1500 • C on four typical refractory materials and supported by microscopic investigations.All investigated refractory materials display a rather brittle behavior below 900 • C. While the high alumina brick almost remains in this state up to at least 1500 • C but gets mechanically weakened above 1400 • C, the cement bonded high alumina castable displays a drastic increase of its specific fracture energy above 1100 • C and no substantial loss of strength. This strongly suggests a brittle-toductile transition. The andalusite and silica bricks also seem to experience a brittle-to-ductile transition, even at lower temperature than for the high alumina castable; however as the andalusite brick gets dramatically weakened by the formation of liquid phase, its specific fracture energy collapses as well above 1100 • C. Much more surprisingly, silica bricks see their specific fracture energy strongly rising at about 1000 • C, but falling again above 1100 • C while retaining substantial strength, hence coming back to a rather brittle state.