Supercharge Your Innovation With Domain-Expert AI Agents!

Method for preparing SiF4 and anhydrous hydrogen fluoride from fluosilicic acid

An anhydrous hydrogen fluoride and fluosilicic acid technology, applied in fluorine/hydrogen fluoride, hydrogen fluoride, chemical instruments and methods, etc., can solve the problems of difficulty in obtaining purity, low concentration of fluosilicic acid, difficult liquid transportation, etc., and achieve added value of products The effect of high, high technical content and low cost of raw materials

Inactive Publication Date: 2019-04-05
贵州开磷氟硅化工有限责任公司
View PDF5 Cites 2 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0003] Due to the low concentration of fluosilicic acid by-product of phosphate fertilizer and the difficulty in liquid transportation, this technology is greatly limited. At present, most phosphate fertilizer enterprises turn fluosilicic acid into solid sodium fluosilicate for easy transportation. A lot of research has been done on the preparation of anhydrous hydrogen fluoride by sodium fluorosilicate, such as the method for preparing silicon tetrafluoride and anhydrous hydrogen fluoride from acidified sodium fluorosilicate disclosed in patent CN2010105042483, by reacting excess sulfuric acid with sodium fluorosilicate at low temperature, First collect silicon tetrafluoride gas, and then heat up to obtain hydrogen fluoride; this method has two disadvantages, one is two-stage temperature rise, the process is more complicated, and the other is excessive sulfuric acid, it is difficult to obtain high-purity hydrogen fluoride

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

Image

Smart Image Click on the blue labels to locate them in the text.
Viewing Examples
Smart Image
  • Method for preparing SiF4 and anhydrous hydrogen fluoride from fluosilicic acid
  • Method for preparing SiF4 and anhydrous hydrogen fluoride from fluosilicic acid
  • Method for preparing SiF4 and anhydrous hydrogen fluoride from fluosilicic acid

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0027] A kind of preparation SiF with fluosilicic acid as raw material 4 and the method for anhydrous hydrogen fluoride, comprising the following steps:

[0028] (1) Preparation of ammonium fluorosilicate: add liquid ammonia to fluorosilicic acid, neutralize until the pH is 3.2, filter, concentrate and crystallize the filtrate, and dry to obtain ammonium fluorosilicate;

[0029] (2) The first pyrolysis: After grinding the ammonium fluorosilicate, add concentrated sulfuric acid, stir evenly, the liquid phase enters the airtight container for pyrolysis reaction, the temperature is 80°C, the time is 30min, the escaped gas phase is treated with concentrated sulfuric acid Carry out washing, the washing temperature is 30°C, the washed gas is cooled to -10°C, and the alumina and silica gel packing columns are used for secondary adsorption, and the adsorption time of each level is 2min to obtain SiF 4 The gas is frozen at -90°C to produce the SiF gas for the electronic industry that ...

Embodiment 2

[0038] A kind of preparation SiF with fluosilicic acid as raw material 4 and the method for anhydrous hydrogen fluoride, comprising the following steps:

[0039] (1) Preparation of ammonium fluorosilicate: add liquid ammonia to fluorosilicic acid, neutralize until the pH is 3.5, filter, concentrate and crystallize the filtrate, and dry to obtain ammonium fluorosilicate;

[0040] (2) The first pyrolysis: After grinding the ammonium fluorosilicate, add concentrated sulfuric acid, stir evenly, the liquid phase enters the airtight container for pyrolysis reaction, the temperature is 100°C, the time is 60min, and the escaped gas phase is treated with concentrated sulfuric acid Carry out washing, the washing temperature is 50°C, the gas after washing is cooled to 0°C, and the alumina and silica gel packing column is used for secondary adsorption, and the adsorption time of each level is 5min to obtain SiF 4 Gas, compressed and liquefied to produce high-purity SIF 4 gas;

[0041] ...

Embodiment 3

[0049] A kind of preparation SiF with fluosilicic acid as raw material 4 and the method for anhydrous hydrogen fluoride, comprising the following steps:

[0050] (1) Preparation of ammonium fluorosilicate: add liquid ammonia to fluorosilicic acid, neutralize to pH 3.4, filter, concentrate and crystallize the filtrate, and dry to obtain ammonium fluorosilicate;

[0051] (2) The first pyrolysis: After grinding the ammonium fluorosilicate, add concentrated sulfuric acid, stir evenly, the liquid phase enters the airtight container for pyrolysis reaction, the temperature is 90°C, the time is 45min, the escaped gas phase is treated with concentrated sulfuric acid Carry out washing, the washing temperature is 40°C, the washed gas is cooled to -5°C, and the alumina and silica gel packing columns are used for secondary adsorption, and the adsorption time of each level is 3min to obtain SiF 4 The gas is frozen at -70°C to produce the SiF gas used in the electronics industry that meets th...

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 belongs to the technical field of the chemical industry and particularly relates to a method for preparing SiF4 and anhydrous hydrogen fluoride from fluosilicic acid. The method includes: taking fluosilicic acid as a raw material, adding liquid ammonia to prepare ammonium fluosilicate, and performing two-stage heating treatment at different temperatures to obtain SiF4 and anhydrous hydrogen fluoride. A whole process realizes clean production and zero emission of waste gas and wastewater, the method is a technically-advanced environmental-friendly production process high in technical content and benefit, and the process is low in raw material cost, high in product quality and high in product benefit. In addition, a system is available for production of products in various specifications, and regulation according to the market and devices is realized.

Description

technical field [0001] The invention belongs to the technical field of chemical industry, in particular to a SiF 4 and the method of anhydrous hydrogen fluoride. Background technique [0002] In nature, the minerals that can be used as fluorine resources are mainly fluorite, natural cryolite and phosphate rock. Fluorite contains high fluorine, but its reserves are limited. From 2001 to 2007, the global price of fluorite increased from US$135 / t increased to 270 US dollars / t; the reserves of natural cryolite are very small, which is far from meeting the needs of industry, while the reserves of phosphate rock are large, which is an important fluorine resource; and the production of wet process using phosphate rock as raw material Phosphoric acid and phosphate fertilizers will emit a large amount of fluorine-containing gas, which will be absorbed and treated by water to obtain fluorosilicic acid. Therefore, the recycling of fluorosilicic acid by-product of phosphate fertilizer...

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): C01B33/107C01B7/19
CPCC01B7/193C01B7/195C01B33/10705
Inventor 张伟娄火松杨秀国田维强孙昌红
Owner 贵州开磷氟硅化工有限责任公司
Features
  • R&D
  • Intellectual Property
  • Life Sciences
  • Materials
  • Tech Scout
Why Patsnap Eureka
  • Unparalleled Data Quality
  • Higher Quality Content
  • 60% Fewer Hallucinations
Social media
Patsnap Eureka Blog
Learn More

Browse by: Latest US Patents, China's latest patents, Technical Efficacy Thesaurus, Application Domain, Technology Topic, Popular Technical Reports.

© 2025 PatSnap. All rights reserved.Legal|Privacy policy|Modern Slavery Act Transparency Statement|Sitemap|About US| Contact US: help@patsnap.com