Process for producing high purity magnesia

Abstract

The invention discloses a method for producing high-purity magnesium oxide products with simple equipment, easy operation, continuous production and low production cost. The present invention uses sea and lake brine containing magnesium chloride or crude magnesium chloride hexahydrate as raw material, uses vacuum crystallization method to purify the brine, removes boron, sulfate radical, calcium ion and other soluble impurities in the raw material, and then performs dynamic calcination Process technology for producing high-purity magnesium oxide (MgO>99%) series products and hydrochloric acid (30%). The method has the characteristics of short technical route, less investment, simple equipment, easy operation, continuous production, low cost, high-purity magnesium oxide series products and hydrochloric acid, and the like. This process implements closed-loop production, which is clean and environmentally friendly.

Description

technical field [0001] The invention relates to the technical field of marine chemical engineering in inorganic chemical engineering, and more specifically relates to a method for producing high-purity magnesium oxide, high-purity active magnesium oxide, high-purity magnesia and hydrochloric acid by using brine containing magnesium chloride in oceans and salt lakes as raw materials. Background technique [0002] High-purity magnesium oxide series products are magnesium salt fine chemical products, widely used in steel industry, rubber, high-grade cables, high-grade plastics, paint, ceramics, high-grade papermaking and pharmaceutical industries. More than 99% of high-purity magnesium oxide is used in the production of oriented silicon steel Tablet of the best chemical raw materials. High-purity magnesia is the main raw material for high-grade refractory carbon-magnesia bricks used in metallurgy and cement industries [0003] At present, the raw ma...

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Problems solved by technology

[0006] At present, our traditional craftsmanship is difficult to participate in international competition due to its low technological content.

The lime (or dolomite) method and carbonization method currently being used in China not only consume high energy consumption, but also are difficult to solve the problem of excessive calcium content; the more advanced ammonia method and carbon ammonia method in China, although these methods can produce high-grade oxidation Magnesium products, but there are still several problems: that is, magnesium oxide and magnesium carbonate must be dissolved in ammonia solution, and to maintain this balance, ammonia must be continuously supplemented, and there is a pollution problem. Magnesia is produced by magnesium hydroxide and magnesium carbonate At the same time, it is necessary to press the ball or die after molding, which leads to high energy consumption and difficult operation, which is difficult for the cost.

This method needs to be calcined three times. When the intermediate product magnesium hydroxide is dead-burned, dust is easy to fly, causing loss and pollution. Therefore, ball pressing or molding is required, which increases equipment investment and production cycle.