Fabrication of colored CaCO3 compacts by hydrothermal hot-pressing method

Abstract
Hydrothermal hot-pressing (HHP) technique was used to solidify shell powder dyed. Shell powder was mixed with dye with a ratio of 0.25 wt%, and was treated by HHP at 130 to 170° C, 45 MPa for 2 hours. It is showed that the powder can be dyed well by some basic dyes at 60° C, and can maintain the color of dyes after HHP process. The resulting compactness with a beautiful color appearance has high hardness and apparent density. Possible mechanisms for solidification and coloration were also discussed.