Types of Castable Refractories
Types of Refractory Castables
- Conventional, High Cement
- Low Cement
- Ultra-Low Cement
- No Cement (Colloidal Silica, Phosphate Bonded)
- Basic Castables (Magnesite – Chrome)
- Insulating (20pcf to 90 pcf categories)
Castable Refractory Classifications
- Conventional / Regular Castable =>2.5% CaO
- Low Cement = 1.0% to 2.5% CaO
- Ultra-Low Cement = 0.2% to 1.0% CaO
- No Cement Castables = up to 0.2% CaO
- Castables and gun mixes based on colloidal silica and phosphate-based binders
No Cement Castable (Chemically Bonded)
No-Cement Castables, also known as chemically bonded castables contains no cement improving resistances to alkali and other attacks. The most common binders for no-cement castables include colloidal silica and phosphate. High alumina chem-bonded castables can be installed through casting, pumping, gunning, coating, and hand-packing. EZ EST (Colloidal Silica Bonded) and Rescobond (Phosphate Bonded)
Extreme Service Castables - Rescobond AA-22S
Extreme Service Castables are a complete line of specialty castables blended for specific application and performance needs. Formulations are available for hydrogen and/or carbon monoxide-rich reducing atmospheres, for low thermal conductivity and high resistance to thermal shock spalling, for critical wear areas in high-erosion applications, for exceptional erosion resistance, and wherever higher strength and greater insulation properties are required.
The castable which sets the standards for performance, ease of application, and long life throughout its full range of applications is Resco's premium, abrasion/erosion-resistant castable, Rescobond AA-22S. Particularly effective in thin, metal-anchored, and metal-reinforced linings, Rescobond AA-22S offers all the benefits of air setting. Because it readily bonds to other refractory surfaces it is ideal as a quick and easy patch -- a permanent patch -- for worn linings.
The Rescobond, family of castables are easy-to-mix castables that adhere permanently to all refractory surfaces with heat curing. This line of specialty products offers exceptional physical properties for all applications and can be used for patching or for a full lining.
Low Cement Castable
Characteristics of low cement castables include:
- Low Thermal Conductivity
- Excellent Strength
- High Thermal Shock Resistance
- High Mechanical Strength
- Easy Installation
Basic Monolithics or basic castables have chemistry of magnesia (MgO) caustic, sintered, or fused. Basic castable refractory products provide great resistance to basic slags most commonly found in basic steelmaking processes. Basic brick can also be found in glass, lime, and cement applications.
Resco Product’s magnesia-chrome ramming mixes are highly resistant to basic slags. Basic refractory products provide high strength and excellent corrosion resistance throughout a wide variety of high-temperature applications. Our most well known basic monolithic is Permanente 165-AF with its nonchromatic bonding system and installation methods of vibration, casting, or ramming.
- 95 to 97% MgO-based; Dead Burned Magnesia
- Chrome Ore-Based
- Fused magnesia-Chrome Grain-Based
- Chemically Bonded
- Phosphate Bonded
- Silicate Bonded
Conventional castables are ideal for high-temperature applications where high mechanical strength, good thermal shock, abrasion, and corrosion resistance are crucial. Highly revered calcium alumina or CA gunning mixes like HM 70 are ideal for general purpose repairs. Ideal for high temperatures and erosion applications. Rescocast 17EG is ideal for erosion resistance and is excellent alumina cement-bonded gunning mixes. View a full list of conventional refractory castable comparisons.
Conventional refractory castables also are known as general-purpose castables have a lime (CaO) content higher than 2.5%. The binder, calcium aluminate, and the 8-20% water content ensure significant strength at low and moderate temperatures. Conventional castables ease of installation, casting, makes it ideal for a wide range of applications. Conventional castables are commonly utilized in power plants, furnaces, aluminum production, rotary kilns, and more.
Alumina Silica Conventional Castable
The Rescocast family is alumina-silica based castable. For more extreme applications Resco offers an alumina-silica conventional castable with abrasion resistance.
Our extensive and on-going R&D efforts have resulted in an unparalleled selection of specialty insulating castables. These products range in density from 25 to 95 pounds per cubic foot and are well suited for use in difficult application areas including reducing atmospheres. Most can be installed by gunning, casting, hand-packing, troweling or pump-casting without the need to order special formulations
- Can be cast, gunned, or pumped
- Cement bonded
- Contain lightweight aggregate
- Densities range 20 pcf to 90 pcf
- Gunned densities higher than cast density