Abstract
Abstract Plant alumina trihydrate (ATH, Al(OH) 3 ) from Korea Alumina (KC) Ltd's Bayer alumina plant was used to synthesize boehmite, a new product used as fire retarding fillers or laminating materials. The hydrothermal treatment conditions were optimized from tests conducted with ATH-water slurries (30, 40 and 50 w/v%) at different temperatures (160–220 °C), reaction time (10–80 min) and mean feed sizes D 50 (1.5–50 μm). Well crystalline boehmite was formed at a temperature > 200 °C after 60-minute treatment. The reaction pressure (1.0–2.0 MPa) has no effect on the process. The hexagonal crystal of the starting gibbsite changes to plate-like shape as boehmite is formed. After the treatment, the boehmite mean particle size (4–25 μm) is generally smaller than the original gibbsite feed (8–50 μm). For finer ATH feed (1.5–2.5 μm) there is no change in particle size after the hydrothermal treatment. The highly crystalline boehmite product containing 2 O and 2 O 3 has higher purity and whiteness than the ATH feed.
Sign-in/Register to access full text options 
Free) 
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 call
