Preparation method of high-purity magnesium fluoride

Abstract

The present invention relates to process of preparing high purity magnesium fluoride with fluorosilicic acid and magnesia as material. The process includes the following steps: 1. reacting fluorosilicic acid solution and magnesia for 10-60 min, filtering to obtain solid magnesium fluorosilicate solution, and concentrating to obtain crystal magnesium fluorosilicate hexahydrate; 2. decomposing magnesium fluorosilicate at 100-500 deg.c for 1-5 hr to produce solid magnesium fluoride product, silicon tetrafluoride gas and water vapor; and 3. absorbing silicon tetrafluoride gas and water vapor with water and hydrolyzing, filtering to obtain fluorosilicic acid solution to be returned to the step 1 and solid silica, and washing and drying silica to obtain carbon white. The process utilizes fluorosilicic acid as one side product of phosphate fertilizer production as one main material, and has low cost and environment friendship.

Description

technical field

[0001] The invention relates to a method for preparing high-purity magnesium fluoride, in particular to a method for preparing high-purity magnesium fluoride by using fluosilicic acid and magnesium oxide as raw materials. Background technique

[0002] Magnesium fluoride is mainly used for smelting metal aluminum, flux for manufacturing ceramics and glass, coatings for lenses and filters in optical instruments, fluorescent materials for cathode ray screens, antireflective agents and soldering agents for optical lenses, and titanium pigments paints, etc. The traditional production method of magnesium fluoride is the reaction between hydrofluoric acid and magnesium oxide. Hydrofluoric acid is used as raw material, and the production cost is high. Contents of the invention

[0003] The purpose of the invention is to provide a method for preparing high-purity magnesium fluoride, so as to greatly reduce the production cost and turn waste into wealth.

[0004] I...

Images