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Comprehensive Utilization Of Magnesite And The Preparation And Application Of Nano-magnesia

Posted on:2011-09-05Degree:MasterType:Thesis
Country:ChinaCandidate:X J WangFull Text:PDF
GTID:2121360305499385Subject:Analytical Chemistry
Abstract/Summary:PDF Full Text Request
Consisting of Magnesium carbonate, Magnesite is a main source of Magnesium, ranking first across the world. Its products have been widely used in the field of metallurgy, chemistry and construction and so on. Although our country is rich in magnesite reserves, the resource of high gride magnesite is more and more absent. with the growing demand of magnesium salt's products, improving the rate of resources utilization has become an urgent problem in Magnesite products field. It is clearly that the major development directions of magnesia are functional and fine.Nano-magnesia is a new kind of inorganic matierial which has different special properties from its body material.For its broad application in some fields, people pay more and more attention to it. By superficial modification,the compatibility of nano-magnesia with the base materials has been improved. What is more, developing magnesia with high activity is very significant to improve market competitiveness and the added value.In view of utilizing the magnesite resource effectively, the article studyed the preparation of nano-magnasia,activity,modification,etc.the primary contents are:1. Nano-magnesia is prepared by the direct precipitation method,using magnesite as raw material and NaCO3 as precipitant. The effect of modification is characterized by lipophilic degree. In order to obtain the best process conditions,the paper discussed influence factors:the modifiers types, temperature, the modification time and the modifier content.Under the optimized condition the dispersivity improves obviously in organic solvent and the chemical binding is formed between nano-magnesia ang the modifier.2. The active magnesia were prepared by controlling calcining temperature,the soaking time and the heating rate using non-crystal magnesite as raw material.Their activity was measured by the citrate route.The influence factors,such as calcining temperature,soaking time and the heating rate were studied in this paper,the ratio surface of the magnesia and the rate of dissociation of the raw material has been determined as well.It was found that high active magnesia could be prepared under certain conditions.3. Nano-magnesia particles were prepared by ultrasonic- alcohol-water and chelate -precipitation method using magnesium chloride and ammonium tartrate as raw materials, and studied by DTA-TQ XRD and SEM.The influence factors, such as concentration of reactants, different alcohol, different alcohol-water ratio, ultrasonic time and frequency on nano-magnesia particle size were studied in this paper. It was found that magnesia uniformly dispersed with particle size about 50nm could be prepared by controlling a certain process conditions.
Keywords/Search Tags:magnesite, nano-magnesia, surface modification, activity, ultrasonic, chelate -precipitation method, optimal technology
PDF Full Text Request
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