Abstract: Zircon encapsulated carbon black powders were synthesized by a co-precipitation method using TEOS and zirconium oxychloride as starting materials. X-ray diffraction (XRD), scanning electronic microscope (SEM), colorimeter and laser grain size analyzer were used to investigate the phase structure, morphology, thermal stability and size distribution of the prepared composite powders, respectively. The effect of experimental conditions including the pH of the precursor solution, the calcination temperature, the type and amount of mineralizers on their thermal stability was studied by orthogonal test. The optimal conditions were accordingly determined as follows: precursor solution pH=5, calcination temperature 1150℃ and 5% LiF mineralizer. Under these conditions, zircon encapsulated carbon black with embedded structures can be obtained. The composite powder has high thermal stability and adequate size distribution, and thus it is a good candidate material for black ceramic pigment. When calcined at 1000℃ in the frit glaze, the powder shows considerable tilting strength.

Key words: encapsulated carbon black, zircon, co-precipitation, thermal stability