Study On The Development And Application Of White Pigment Based On Calcium Carbonate

In the current social context of more and more shortage of energy,resources,titanium dioxide industry has already more and more obviously exposure such as titanium iron ore resources tension,prices,the problems of pollution,which restricted the development of the industry to continue.The inorganic mineral rich reserves such as calcium carbonate,kaolin,have been used in plastic,rubber,paint and chemical industries.But these powders are almost used as a physical packing,the price is low,and have not transform into economic advantage from resources advantages.So it is very necessary and urgent to do the deep processing of these inorganic mineral,broadening the application industry and to create greater added value.In this research,we prepared a new,white pigment based on GCC/TiO2 through mechano-chemical method.In the end,the optimum technical conditions are:compounding mass of GCC/TiO2 being 6:4,surface modifier A 5g,dry milling 2 h,200 r/min.Under these conditions,the obtained composite powders'whiteness(98.6),oil absorption(18.6g/100g),hiding power(25.8 g/m2)are all close to the pure titanium dioxide,and can be used as substitutes of titanium dioxide in some applications.We research modification agent,milling time and speed's influence of coated effect.SEM and infrared research show that,calcium carbonate-TiO2 composite pigment is calcium carbonate particles surface coated TiO2 particles.The TiO2 coating surface of calcium carbonate is evenly and complete.Then explore the mechanism.Then we continue use the mechano-chemical method to do the surface modification again of early white pigment,choose a variety of modification agent.The brightness,oil absorption and sediment time and volume are used to evaluated the effect of surface modification.We discuss the influence of various process conditions.The results show that in many modifiers,silicone fluid and aluminum acid ester the modified effects of the most prominent,and both can significantly reduce oil absorption quantity.Along with the increase of the modified agents content,oil absorption quantity declining,but silicone fluid is always better than aluminum acid ester;The brightness also have some degree of decline,but aluminum acid ester down less than silicone fluid.At last coatings properties contrast test with composite powder and titanium dioxide is finished.We found it is almost equal in the application of alkyd coatings.