Synthesis Of Sphene By Solid Shase Method And Application As Ceramic Opacifier

The sphene is mainly composed of titanium dioxide?TiO₂?as the ceramic opacifier firing the main emulsion phase material,in addition to the TiO₂ as an opacifier directly added to the glaze,preparing sphene in advance,and use it as a ceramic opacifier for application,it will be expected to solve the problems existing in the direct application process of TiO₂.In this dissertation,the solid phase method was used to systematically study the preparation of sphene and sphene by the use of mineral raw materials containing TiO₂,CaO and SiO₂,and sphene firing for sanitary ceramic glazes.?1?The effects of various raw material combinations,proportions and calcination conditions used to make sphene on the product phase were studied.According to the raw material TiO₂?SiO₂?CaO?molar ratio?=1?1?1?the proportion of sphene,TiO₂ mass fraction 40.8%?combination,calcined at a temperature of 1200?can be made sphene as the main component of the product.Among them,calcium carbonate,silica,and metatitanic acid are the raw materials for the calcining of the single sphene,and the remaining combined products also contain a small amount of impurities.The proportion of TiO₂ in the raw materials increased to 46.2%and 50.7%,and the calcined product phase was the same as 40.8%of TiO₂.The combination of raw materials also has an important impact on the formation of sphene intermediate reaction,in which lime,silica,metatitanic acid as raw materials,less intermediates,it is easy to form sphene;?2?The particle morphology and micro-morphology of the prepared sphene product were studied.The sphene particles in the sphene product of each raw material combination are regular blocks,and there are differences in the particle size and the dispersion degree of the sphene particles in each product.Among them,the calcium carbonate,silica and metatitanic acid are the smallest raw material particles,and are about 0.8?m.High degree of dispersion.The grinding of the sphene product by agitating and grinding by wet grinding can reduce the agglomeration of the particles.After the vermiculite product is ground,the D90 is reduced from about 70?m before milling to 7-9?m,the D50 is reduced from about 5-10?m to about 2.5?m,and the specific surface area is increased by more than double.?3?sphene prepared by the solid phase method was used as an opacifier for the firing of sanitary ceramics.The use of sphene opacifier glaze effect is basically positively correlated with opacifying agent content and TiO2 content in the glaze.Among them,the raw materials containing TiO₂46.2%and 50.7%of the lanthanum glaze have the maximum L*value of 89.39 and 84.86,respectively,and the b*value is at least 5,which is comparable to the zirconium silicate opacifier glaze.The calcined temperature of glaze containing emulsifier opaque has a significant effect on glazed surface properties.The glaze at 1100?has the best performance,L*value is between 90⁹2,and a*is between-1.0⁰,b*is between 4 and 6.The firing temperature is 1000?,the glaze does not become porcelain on the surface of the specimen;the firing temperature increases to 1250?,the glaze is transparent,and the emulsion disappears;?4?The phase and morphology of glazed glaze layer of sphene opacifier were studied.The firing temperature is 1000?.The glaze layer phase is mainly composed of quartz and a small amount of sphene.The firing temperature is 1100?.The glaze layer phase is amorphous and sphene.The 1250?glaze layer phase is amorphous and quartz shows that sphene is an opaque phase material.The phase of the glaze layer reflects the reason for the formation of the respective glaze properties.