Study on Preparation of High-purity Magnesium Oxide from Serpentine
|School||Huazhong University of Science and Technology|
|Keywords||High purity magnesium oxide Serpentine Impurity Shen magnesium Precipitating agent|
Magnesium oxide is a very versatile chemical raw materials , industrial magnesia production based on the initial raw materials ( magnesite , dolomite , brucite , serpentine, brine , etc.) , different production methods . Serpentine its resource-rich , high magnesium content and their own special structure , in recent years the use of its preparation of magnesium oxide , silica and other ancillary products get attention. However using serpentine prepared taken magnesia process complexity, larger raw material consumption , high cost , and difficult to recycle tail liquid , cause environmental pollution , Shen magnesium rate is not high , the impurity ions, particularly sodium ions double teams in the basic magnesium carbonate difficult to wash away the problem. Thus serpentine acid leaching filtrate of refined impurity Shen magnesium conditions to do a more comprehensive discussion , aimed at improving the purity magnesia , increase rate of Shen magnesium , thereby enhancing economic efficiency . Using air oxidation acid leaching filtrate divalent iron in the acid leach filtrate purified impurity , to reduce the hydrogen peroxide dosage . Simplifying the refining process, using NaOH to adjust pH, precipitation the of Fe 3 < / sup > , Al 3 < / sup> , Na 2 sub > S precipitation of Ni 2 < / sup> and other heavy metal ions, once impurity try divisible various impurities , ammonium persulfate secondary oxidation further purify ( Mn 2 sup > , the excess the of Na 2 sub > S ) and as an insurance measure to control impurity quality . In Shen magnesium , more comprehensive comparison of the effect of different the precipitating agents Shen magnesium . From the Shen magnesium rate , consumption of raw materials , consider filtration ability compared by experiment , to determine the best of the precipitating agent is sodium hydroxide - soda ash , the which nNaOH ︰ nNa 2 < / sub > CO 3 < / sub> 2:1 8 . Also explore the use of sodium hydroxide or soda ash Shen magnesium sodium double teams magnesium carbonate , and by optimizing the process conditions to reduce the sodium double teams , to further improve the purity of the magnesium oxide . These studies taken serpentine system magnesium oxide , particularly in high purity magnesium oxide production process improvement and process conditions are selected to provide a certain reference .