Mechano-chemical Preparation Of Dolomite / Tio <sub> 2 </ Sub> Composites Technology And Research

At present, titanium dioxide is the best white pigment in the world, and been used by many fields. However, both the serious environmental pollution during the production and the high cost of pollution_treated binging on the high price, which are important bottle-neck for its development. Producing the substitute of titanium dioxide is the most effective way to solve the problem, which is the economic way. The properties of substitute of titanium dioxide is similar to the titanium dioxide, however, the cost is too low. The substitute of titanium dioxide can replace all or most proportion of titanium dioxide, which can be extended the range of TiO₂. Because of high brightness, rich resources and low price of dolomite, the composite particles of dolomite/TiO₂ material is prepared by mechano-chemical method, which can replace a proportion of titanium dioxide. The dolomite/TiO₂ not only reduce the serious environmental pollution in its production, but also enhance the use of dolomite.The raw materials of dolomite and titanium dioxide are mixed in this experiment by mechano-chemical method to research the technical parameters in the preparation of dolomite/TiO₂ composite material. On these base, the action mechanism between dolomite and titanium dioxide is discussed lastly.The optimized technical parameters is got by the single factor experiment, the groped experiment and the orthogonal experiment, which can help to prepare the dolomite/TiO₂ composite particles material. The wet grinding time of fine quartz is 3 hours; the ratio of the ball to the powder is 4:1; the slurry concentration is 60%; the dosage of dispersant is 0.5%; the grinding speed is 1200r/min. The dosage of TiO₂ is 45%, which is dispersed for 1.5 hours in the water with 60% slurry concentration and 0.5% dispersant. At the reaction stage, the grinding speed is 1100r/min, the ratio of the ball to the powder is 4:1, the reaction time is 90 minutes. The whiteness of the composite particles material prepared under the optimum condition is 94.0%, the hiding power is 20.06 g/m2 and the oil absorption is 34.0 ml/100g.Showing as the X-ray Diffraction, TiO₂ is covered by the dolomite effectively. Although there are some reunions in the composite metial which can be found from the scanning electron microscope, TiO₂ particles have already covered on the dolomite surface and the particle size is suitable. The hydroxylation has occurred on the surface of dolomite, whose structure has also been activated.