| In recent decades, domestic and foreign scholars have done a lot of research works on Cd(SxSe1-x) ceramic pigment and in various pigments, only the Cd (SxSe1-x) can produce pure bright red. But the thermal stability of Cd (SxSe1-x) is poor , it can be oxidized and decomposed easily in high temperature. So lots of research work has been focused on how to get the high-temperature standing red pigment . Too many human, financial and material resources have been invested and it is the people' s earnest dream to obtain bright red porcelain through high temperature sintering. But the results were not so satisfactory,because red ceramic pigment couldn't stand high temperature,red corlor will fade when the temperature rose to above 600℃. During this process, Cd (SxSe1-x) solid solutions turned into a mixture of CdS and CdSe and in high temperature CdS will be oxidized to CdO and SeO2, thus lost its coloring function。However, to produce high quality porcelain, the temperature is generally above 1200℃so a huge contradiction of temperature difference arises, which is a difficult scientific problem to both domestic and foreign ceramic experts. According to this problem, nano- Cd (SxSe1-x) were first prepared with wet synthesis. Then Zn2+ was added to form solid solutions, which can improve the decomposition temperature of Cd (SxSe1-x). After that, H4SiO4 sol which can form nano- SiO2 particles parceled on the Cd (SxSe1-x) was added as well, which attains the goal of standing high temperatures. Thus,high-temperature standing Cd (SxSe1-x) red ceramic pigment whose particle size is within 100-nanometer were prepared successfully.The major work of this paper includes:1,Preparation of red pigment precursorFirst ,we prepared ZrSiO4 sol using ZrOCl2 and Na2SiO4, then put the sol into a vessel which contains the pre-prepared Cd (SxSe1-x) and suspension containing Zn2+ and ster, they reacte in strictly controlled conditions. As the precipitation of both Zr(OH)4 and SiO2 is transformed by the sol and their single particles are all nanosized, the synthesis of ZrSiO4 can be completed at nanometer level,which can reduce the formation temperature of ZrSiO4.。According to the nucleation mechanism and the special characteristic of ZrSiO4 as well as experiments, if moderate Zn2+ as auxiliary reagents was added to the sol and then calcined together with the precursor , the formation temperature of ZrSiO4 can be further lowered。2,The preparation of red high-temperature ceramic pigmentThe precursor was placed into a ceramic crucible,then put it into a muffle furnace at 350℃and maintain the temperature which could make H4SiO4 dehydrate. Then the crucible was heated up to 550℃and the temperature was maintained which could make Cd (SxSe1-x) complete the crystal transition before the formation of ZrSiO4 . At the same time, Zr(OH)4 decomposed at this temperature to prepare for the synthesis of ZrSiO4. Then the product was put into the graphite crucible in the muffle furnace,heated up to 850℃and maintained the temperature in a confined environment. Solid solutions of ZrSiO4 and Cd (SxSe1-x) are formed, and the red nano-Cd (SxSe1-x) pigment can be prepared in this way. The pigment could withstand 1200℃high temperature and could exist stably in oxidizing atmosphere.By using the combination of Sol co-precipitation and Zn2+ ,we successfully synthesized the ideal red ZrSiO4 and Cd (SxSe1-x) solid solutions pigment under a lower temperature。3,The characterization of the red Cd (SxSe1-x) pigmentThe IR spectra showed that solid solutions of Cd (SxSe1-x) and ZrSiO4 have been prepared when the precursor in the muffle furnace was heated up to 850℃and this temperature was preserved for some time.Results of the XRD and SEM showed that the particle size of the red ceramic pigment prepared in this way is between 20-30nm, which suggested the product belonged to amorphous solid solutions.
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