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Preparation Of Powder Quartz/TiO2 Composite Particles By Mechano-chemical Method

Posted on:2011-12-11Degree:MasterType:Thesis
Country:ChinaCandidate:H HeFull Text:PDF
GTID:2181360302493043Subject:Materials Science and Engineering
Abstract/Summary:PDF Full Text Request
At present,titanium dioxide is the best white inorganic pigment in the world,and has a wide range of use,which leads to a strong demand for its production,and the price of titanium dioxide is increasing continuously.However,the excessive consumption of resources,serious environmental pollution and high costs exist in its production.To produce the substitute of titanium dioxide which is low in cost and similar to titanium dioxide in properties is the most effective way to solve the problem,because the substitute of titanium dioxide can replace all or a large proportion of titanium dioxide.The mineral/TiO2 composite particles,material non-metallic mineral as core material and crystallized TiO2 as coating material,is newly developed white pigment in recent years.It has been widely used as substitute for titanium white in paints,rubber,plastics,paper making and other industries.The particle size and lattice distortion of powder quartz are decreased and formed through the wet extra-fine-grinding,respectively.The hydroxylation has occurred on the surface of powder quartz particles.And the powder quartz is activated.In this paper,powder quartz/TiO2 composite particles(PQ/TCP),a core(powder quartz)-shell(TiO2) type composite powder,were prepared by mechano-chemical method and the pigment properties of PQ/TCP and the mechanism of the mechano-chemical reaction between powder quartz and TiO2 were investigated. Results show that the pigment characteristics of PQ/TCP,i.e.the whiteness=94.0, the hiding power=20.06 g/m2 and the oil absorption=31.0 ml/100g,prepared under conditions of grind(activation) time of powder quartz=4h,mix grind speed=1000r/min,mix grind time=1h,slurry concentration of powder quartz=60% and dosage of dispersant=0.4%are similar to that of TiO2,i.e.the whiteness=94.4, the hiding power=17.30 g/m2 and the oil absorption=31.0 ml/100g.Mechanism analysis indicated that powder quartz is evenly coated by TiO2 and Si-O-Ti bond is formed between powder quartz and TiO2 in PQ/TCP.So the complex reaction results from the dehydroxylation between powder quartz and TiO2.The powder quartz/TiO2 composite particles material is used as pigment in the interior building coatings,and testing different affects on its way to coating property. When substituting some of the titanium dioxide pigment by 80%,we can get a similar contrast ratio of the coating.So this method can significantly reduce production costs of coatings to create a good economic benefit and ease the imbalance between supply and demand of titanium dioxide...
Keywords/Search Tags:powder quartz, titanium dioxide pigments, composite particles, mechano-chemistry, wet extra-fine-grinding
PDF Full Text Request
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