Unlock instant, AI-driven research and patent intelligence for your innovation.

Method for preparing high-purity magnesium fluoride in saturated ammonium chloride system

A pure magnesium fluoride and ammonium chloride technology, applied in magnesium fluoride, magnesium halide and other directions, can solve the problems such as hindering the complete reaction of magnesium hydroxide, difficult to meet the purity requirements, difficult to achieve the purity of magnesium fluoride, etc. Gelling phenomenon, high economic and environmental benefits, effect of changing the size of the topography

Active Publication Date: 2014-10-01
湖南有色金属投资有限公司
View PDF0 Cites 5 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, the purity of magnesium fluoride generated in the solid-liquid phase system is difficult to reach more than 99.9%. This is because the reaction of the solid-liquid phase system is a process of solid phase dissolution and new phase formation, and the newly formed magnesium fluoride crystal nuclei will cover the On the unreacted magnesium hydroxide particles, the complete reaction of magnesium hydroxide is hindered, and this hindering effect is more obvious when the reaction is enlarged; while in the liquid-liquid phase reaction system, the generated magnesium fluoride particles are extremely fine, almost in the form of Transparent colloid, difficult to separate by washing and filtration
At present, the purity of fluorides prepared by traditional synthesis processes is not good enough, and it is difficult to meet the requirements for higher and higher purity.

Method used

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0021] (1) Weigh 187.2g of ammonium chloride and add it to 120mL of deionized water, and stir until the ammonium chloride solid no longer dissolves to obtain a saturated ammonium chloride solution, which also contains undissolved ammonium chloride solid; (2 ) To the saturated ammonium chloride solution, 246.7g of ammonium fluoride solution with a mass fraction of 15% and 253.3g of a magnesium chloride solution with a mass fraction of 15% were added dropwise at the same time, the stirring speed was controlled at 250r / min, and the feeding time was 0.5h. Continue to stir and react for 1 hour to obtain a suspension solution; (3) heat it in a water bath, control the stirring speed to 250r / min, and control the temperature of the water bath to 80°C. After the solution is heated to a constant temperature, stop stirring, and then place it in the air (4) Finally, let it settle for 2 hours, take out 520mL of the supernatant, wash and filter the bottom precipitate, and burn it in a muffle ...

Embodiment 2

[0022] Example 2 (recycling of ammonium chloride solution)

[0023] (1) Take 180 mL of the turbid solution obtained after the concentration of the supernatant of Example 1, and add 4 g of ammonium chloride solid to it to obtain a saturated ammonium chloride solution, which also contains undissolved ammonium chloride solid; (2) Add 246.7g of ammonium fluoride solution with a mass fraction of 15% and 253.3g of a magnesium chloride solution with a mass fraction of 15% dropwise into the saturated ammonium chloride solution at the same time, control the stirring speed at 250r / min, and the feeding time is 0.5h, and the feeding is completed Then continue to stir and react for 1 hour to obtain a suspension solution; (3) Then heat it in a water bath, control the stirring speed to 250r / min, and control the temperature of the water bath to 80°C. After the solution is heated to a constant temperature, stop stirring, and then place Naturally cool to room temperature in the air to obtain ...

Embodiment 3

[0025] (1) Weigh 198.0g of ammonium chloride and add it to 133mL of deionized water, and stir until the ammonium chloride solid no longer dissolves to obtain a saturated ammonium chloride solution, which also contains undissolved ammonium chloride solid; (2 ) Add 185.0g of ammonium fluoride solution with a mass fraction of 20% and 199.5g of a magnesium chloride solution with a mass fraction of 20% dropwise into the saturated ammonium chloride solution at the same time, control the stirring speed at 300r / min, and feed for 1h. Stir the reaction for 1 hour to obtain a suspension solution; (3) heat it in a water bath, control the stirring speed to 250r / min, and control the temperature of the water bath to 85°C. After the solution is heated to a constant temperature, stop stirring and place it in the air Cool naturally to room temperature to obtain a turbid solution; (4) Finally, let it settle for 3 hours, take out 430 mL of the supernatant, wash and filter the bottom precipitate, a...

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

PUM

No PUM Login to View More

Abstract

The invention relates to a method for preparing high-purity magnesium fluoride in a saturated ammonium chloride system. The method comprises the following steps of adding ammonium chloride in water and dissolving to prepare a saturated solution of ammonium chloride; then simultaneously dropwise adding an ammonium fluoride solution and a magnesium chloride solution into the saturated ammonium chloride solution; then placing the mixed solution in a water bath, heating until the solution is heated to a constant temperature, then placing in air and naturally cooling to room temperature; and then standing and carrying out sedimentation for 2-3 hours, taking the supernatant out, washing the bottom precipitate, filtering, burning and crushing to obtain high-purity magnesium fluoride powder. The taken-out supernatant is evaporated and concentrated to 1 / 3-2 / 5 of original volume of the supernatant and can be recycled to the preparation of the saturated ammonium chloride solution. According to the method disclosed by the invention, problems of difficulty in sedimentation and fine particles in the preparation of magnesium fluoride are solved, the yield of magnesium fluoride is greater than 98%, the purity of the obtained high-purity magnesium fluoride product is equal to or greater than 99.9%, the contents of impurities are less, requirements on an optical coating grade material are met, and meanwhile the efficient recycling of ammonium chloride is achieved and the production cost is reduced.

Description

technical field [0001] The invention relates to a preparation process of magnesium fluoride, in particular to a method for preparing high-purity magnesium fluoride in a saturated ammonium chloride system. Background technique [0002] High-purity magnesium fluoride crystals have very good optical transmittance and low refractive index. Coating a layer of magnesium fluoride film on the optical equipment can reduce the reflection of the incident light on the lens interface and reduce halo. Improve image quality. At the same time, magnesium fluoride is also the only crystalline material with a wide spectral transmission range and birefringence properties. Therefore, magnesium fluoride crystals have been widely used in various optical components such as mirrors, lenses, windows, prisms and polarizers. [0003] The preparation of high-purity magnesium fluoride usually adopts solid-liquid phase or liquid-liquid phase reaction, that is, the solid-liquid reaction of high-purity ma...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

Application Information

Patent Timeline
no application Login to View More
Patent Type & Authority Applications(China)
IPC IPC(8): C01F5/28
Inventor 李程文王子龙廖志辉刘东晓段立山
Owner 湖南有色金属投资有限公司