The ultrafine copper chromite black pigment(CuCr2O4)with spinel structure was prepared from chromium and copper nitrates by the chemical coprecipitation method

using sodium dodecyl benzene sulfonate(SDBS)as surface active agent and urea as precipitation agent.The effect of processing parameters

such as precipitation agent

calcination temperature and surface active agent on crystal structure

grain size and morphology of the CuCr2O4 was investigated

and the effect of processing parameters on its tinting strength was discussed.The results showed that urea and SDBS could effectively control grain size

morphology and crystal structure of the pigment.Ultrafine CuCr2O4 300 nm in size and with hexagonal structure was synthesized under the conditions of 400% theoretical amount of urea

5% SDBS and 800℃ of calcination temperature

and exhibited excellent tinting strength compared with commercial samples.