Abstract
High-strength, lightweight castable refractories based on spinel were prepared by introducing porous corundum-spinel aggregate and appropriate microsilica. The effects of microsilica content on microstructure and properties of lightweight castable refractories were investigated using SEM, XRD, mercury porosimetry measurements and FactSage thermochemical software. It's found that microsilica was almost dissolved into a liquid phase at high temperature, which promoted liquid sintering. With increasing microsilica content, the matrices became denser and average pore size of matrices increased, then apparent porosity decreased, crushing strength increased and content of liquid phase in castables at 1600?C increased. The appropriate microsilica content is 0.65 to 1.95 wt%, which reaches to a compromise among apparent porosity (33-38%), crushing strength (82-125MPa) and liquid content (1.80~4.97 wt%).
Highlights
Dense alumina-magnesia castable refractories have been widely used as working linings of ladles due to their excellent properties and easy installation [1,2,3,4,5,6]
Microsilica has a beneficial effect on the sintering of the castables, but over much microsilica decreases the apparent porosity which is unfavorable for lightweight refractories
When the microsilica content is 0.65⊥1.95 wt%, a compromise is reached between apparent porosity (33⊥38 %) and crushing strength (82⊥125 MPa)
Summary
Dense alumina-magnesia (or alumina-spinel) castable refractories have been widely used as working linings of ladles due to their excellent properties and easy installation [1,2,3,4,5,6]. In order to prepare dense aggregates, the raw materials should be sintered or electrofused at a high temperature, resulting in high energy consumption and environment pollution [7]. In order to save energy and resolve some problems resulting from the high thermal conductivity and heavy weight of refractories used in ladles, introducing corundum-spinel aggregates with high strength and low density into castables may be an alternative way. We have prepared porous corundum-spinel ceramics [13]. These porous ceramics have a micro-pore size and high strength. If the porous ceramics were introduced into castables, the higher water demand for placement and the expansion from the
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
