Looking for breakthrough ideas for innovation challenges? Try Patsnap Eureka!

Method for recycling fluorides in preparation process of silicon-containing compound

A technology of silicon compounds and fluorides, applied in the direction of silicon halide compounds, silicon oxide, silicon dioxide, etc., can solve problems such as the inability to achieve the recycling of fluorides

Active Publication Date: 2014-04-23
贵州天合国润高新材料科技有限公司
View PDF4 Cites 12 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

It can be said that fluoride is widely used in various chemical productions, but these applications will generate a lot of fluorine-containing waste products, and the recycling of fluoride cannot be achieved.

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 recycling fluorides in preparation process of silicon-containing compound
  • Method for recycling fluorides in preparation process of silicon-containing compound
  • Method for recycling fluorides in preparation process of silicon-containing compound

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0057] Embodiment 1: Preparation of high-purity SiF 4 CaF 2 recycling

[0058] Will contain SiO 2 waste with CaF 2 Mix well to get a mixture, SiO 2 with CaF 2 The particle size is below 3mm, the CaF in the resulting mixture 2 The mass percentage is 80%. Calcinate the mixture at a temperature of 900-1100°C for 1 hour to generate CaO and SiF 4 , SiF 4 It is gaseous at high temperature and escapes from solid reactants. SiF that will escape 4 Introduce into another reactor and hydrolyze at a temperature of 810-1000°C to form SiO 2 and HF gas. Introduce the HF gas produced by hydrolysis into the reactor, and react with the reaction product CaO at 300-600°C for 2.5 hours to obtain CaF again 2 , thus realizing CaF 2 of reuse. The reaction equation is as follows:

[0059] SiO 2 +2CaF 2 →2CaO+SiF 4 (4)

[0060] SiF 4 +2H 2 O→SiO 2 +4HF (5)

[0061] CaO+2HF→CaF 2 +H 2 O (6)

Embodiment 2

[0062] Embodiment 2: Preparation of high-purity SiF 4 Process AlF 3 recycling

[0063] Bauxite ((Al 2 o 3 ) m (TiO 2 ) nSiO 2 ) with AlF 3 Mix well to get a mixture, bauxite and AlF 3 The particle size is below 5mm, and the AlF in the resulting mixture 3 The mass percentage is 60%. Calcinate the mixture at a temperature of 1100-1350°C for 3 hours to generate Al 2 o 3 、H 2 O and SiF 4 . SiF 4 Escape from solid reactant. SiF that will escape 4 Introduce into another reactor and hydrolyze at a temperature above 1000-1200°C to form SiO 2 and HF gas. The HF gas produced by hydrolysis is introduced into the reactor, and the reaction product Al 2 o 3 After reacting at 100°C for 5 hours, AlF was recovered 3 , thus achieving AlF 3 of reuse. The reaction equation is as follows:

[0064] 3SiO 2 +4AlF 3 ·3H 2 O→2Al 2 o 3 +3SiF 4 +12H 2 O (7)

[0065] SiF 4 +2H 2 O→SiO 2 +4HF (8)

[0066] al 2 o 3 +6HF→2AlF 3 +3H 2 O (9)

Embodiment 3

[0067] Embodiment 3: Preparation of nano-SiO 2 NH in process 4 HF 2 efficient use of

[0068] SiO 2 Coarse particles and NH 4 HF 2 Mix well, SiO 2 with NH 4 HF 2 The particle size is below 7mm, and the NH in the resulting mixture 4 HF 2 The mass percentage is 40%. Calcinate the mixture at a temperature of 600-700°C for 5 hours to generate NH 3 、H 2 O and SiF 4 , SiF 4 escaped from the solid. SiF that will escape 4 Introduce into another reactor and hydrolyze at a temperature of 1200-1300°C to form SiO 2 and HF gas. The HF gas produced by hydrolysis is introduced into the reactor, and the reaction product NH 3 and H 2 O was reacted at 150°C for 4.5 hours to regain NH 4 HF 2 , thus achieving NH 4 HF 2 of reuse. The reaction equation is as follows:

[0069] SiO 2 +2NH 4 HF 2 →SiF 4 +2NH 3 +2H 2 O (10)

[0070] SiF 4 +2H 2 O→SiO 2 +4HF (11)

[0071] NH 3 ·H 2 O+2HF→NH 4 HF 2 +H 2 O (12)

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

PropertyMeasurementUnit
Particle sizeaaaaaaaaaa
Login to View More

Abstract

The invention relates to the field of chemical industry, and particularly relates to a method for recycling fluorides in a preparation process of a silicon-containing compound. The method comprises the steps of: mixing a silicon-containing substance with fluoride to generate fluoridation to obtain silicon tetrafluoride gas and oxides of cations in the fluoride; carrying out pyrohydrolysis on the silicon tetrafluoride gas to obtain nanoscale silicon dioxide and hydrogen fluoride gas; reacting the hydrogen fluoride gas with the oxides of cations in the fluoride to obtain fluorides again. In the method for recycling the fluorides, during the whole reaction, fluorine element basically does not have any loss; as reactants, the fluorides are obtained again in the final reaction; and in the preparation of the silicon-containing compound, the fluorides are recycled.

Description

technical field [0001] The invention relates to the field of chemical industry, in particular to a method for recycling fluoride in the process of preparing silicon-containing compounds. Background technique [0002] The fluorine in fluorine chemical products mainly comes from fluorspar, which is a non-renewable resource and a strategic resource at the same time. Efficient utilization of existing fluorine resources and conservation of existing fluorspar resources have become an important direction for the sustainable development of the fluorine chemical industry. During the use of fluoride, a variety of wastes will be generated, such as ammonium fluoride and ammonium bifluoride used as the etchant, ammonium fluoroaluminate waste residue, and fluorine-containing carbon residue produced by the electrolytic aluminum production process, etc., which are stored as waste for a long time; The electrolysis process produces a large amount of gas such as hydrofluoric acid and silicon ...

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
IPC IPC(8): C01B33/12C01B33/107
Inventor 杨先金刘瑞李丹阳龚亚云林乐洪章林
Owner 贵州天合国润高新材料科技有限公司
Who we serve
  • R&D Engineer
  • R&D Manager
  • IP Professional
Why Patsnap Eureka
  • Industry Leading Data Capabilities
  • Powerful AI technology
  • Patent DNA Extraction
Social media
Patsnap Eureka Blog
Learn More
PatSnap group products

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

© 2024 PatSnap. All rights reserved.Legal|Privacy policy|Modern Slavery Act Transparency Statement|Sitemap|About US| Contact US: help@patsnap.com