Bismuth Zinc Oxide Pigments Synthesis And Relevant Research

Bismuth zinc oxide system pigments were prepared as new ecological colorant pigments.The synthesis parameters were determined by DTA method. The synthesized powders were evaluated by X-ray diffraction analysis (XRD), Scanning electron microscope (SEM). and Spectrum photometer.ln terms of the thermodynamic analysis,the phase diagram was obtained.With the help of kinetic analysis,the reaction mechanisms were discussed.According to the experimental results evaluations, thermodynamic calculation and kinetic analysis, the following conclusions were obtained:1 .Both routes, ceramic method and aqueous solution route, can yield a fine bismuth zinc oxide powder.but the powders synthesized by the latter were better with finer mean particle size (15 μm) and without agglomeration.2. The model of substitutional solution was used to optimize the phase diagram of the ZnO-Bi₂O₃ system, which proved the existence of the 24Bi₂O₃·ZnO compound and ZnO solid solution .And the full region phase diagram for ZnO-Bi₂O₃ system was obtained for the first time.3. The reaction of ZnO +24Bi₂O₃=24Bi₂O₃-ZnO was a very complex process, which included many steps.The kinetics equation for different steps were evaluated by two different model.At the beginning steps, it could be described by Jander model, and later Carter model.4. The ceramic method and aqueous solution route were conducted to prepare Bismuth zinc oxide.The three most important processing factors were temperature, size of the starting powder, and homogeneity of the mixing.5. By the crystalline field theory ,the color of 24Bi₂O₃·ZnO and ZnO(ss) resulted from the change of their crystalline field split energy.By controling the ratio of the starting powder, the products with different colors could be prepared.