Supercharge Your Innovation With Domain-Expert AI Agents!

Method for recovering fluoride ions in freon by-product mixed acid

A mixed acid and freon technology, applied in the direction of calcium/strontium/barium fluoride, calcium/strontium/barium halide, chlorine/hydrogen chloride, etc., to achieve the effect of improving the quality of hydrochloric acid

Inactive Publication Date: 2014-08-20
ZHEJIANG UNIV +1
View PDF2 Cites 0 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0004] Aiming at the problem of recovering fluoride ions in the existing freon by-product mixed acid solution, the purpose of the present invention is to provide a method for recovering fluoride ions in the freon by-product mixed acid solution

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 recovering fluoride ions in freon by-product mixed acid

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0025] Add 1300 Kg of calcium chloride aqueous solution with a concentration of 40% into the reactor, heat up to 70°C under stirring; control the dropping rate for about 1 hour, add 1000 Kg of 1% hydrofluoric acid and Freon by-product mixed acid was added dropwise to the above-mentioned calcium chloride solution, and the hydrogen chloride gas produced was absorbed with 507 Kg of 3% dilute hydrochloric acid to obtain 725 Kg of 30% industrial hydrochloric acid with a hydrofluoric acid concentration of 0.021%. Continue to heat up until the temperature of the kettle reaches 120°C, and the distillate is condensed to obtain 827Kg of 3% dilute hydrochloric acid. Cool the kettle liquid to about 70°C, centrifugally filter and separate the calcium fluoride generated by the reaction, rinse the filter cake with 25Kg of water, and dry it to obtain 23Kg of calcium fluoride with a water content of 15%, and the recovery rate of fluoride ions is 98.48%. The filtrate is pumped into the reaction...

Embodiment 2

[0027] Add 2200 Kg of calcium chloride aqueous solution with a concentration of 25% into the reactor, heat up to 60°C under stirring; control the dropping rate for about 2 hours, add 1000 Kg of 5% hydrofluoric acid and Freon by-product mixed acid was added dropwise to the above-mentioned calcium chloride solution, and the hydrogen chloride gas produced was absorbed with 680 Kg of 4% dilute hydrochloric acid to obtain 971 Kg of 30% industrial hydrochloric acid with a hydrofluoric acid concentration of 0.019%. Continue to heat up until the kettle temperature reaches 108°C, and the distillate is condensed to obtain 745Kg of 4% dilute hydrochloric acid. Cool the kettle liquid to about 60°C, centrifugally filter and separate the calcium fluoride generated by the reaction, rinse the filter cake with 150Kg water, and dry it to obtain 114Kg of calcium fluoride with a water content of 15%, and the recovery rate of fluoride ions is 99.63%. The filtrate is pumped into the reactor, and 13...

Embodiment 3

[0029] Add 2500 Kg of calcium chloride aqueous solution with a concentration of 20% into the reactor, and heat up to about 50°C under stirring; control the dropping rate for about 3 hours, and add 500 Kg of 10% hydrofluoric acid and a total acid concentration of 30% The Freon by-product mixed acid is added dropwise in the above-mentioned calcium chloride solution, and the hydrogen chloride gas produced is absorbed with 446 Kg of 5% dilute hydrochloric acid to obtain 637Kg of 30% industrial hydrochloric acid with a hydrofluoric acid concentration of 0.025%. Continue to heat up until the temperature of the kettle reaches 105°C, and the distillate is condensed to obtain 345Kg of dilute hydrochloric acid with about 5%. Cool the kettle liquid to about 50°C, centrifugally filter and separate the calcium fluoride generated by the reaction, rinse the filter cake with 150Kg water, and dry it to obtain 114Kg of calcium fluoride with a water content of 15%, and the recovery rate of fluori...

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 discloses a method for recovering fluoride ions in freon by-product mixed acid. The method comprises the steps as follows: dripping 1 part by weight of mixed acid into 1.3-5.0 parts by weight of calcium chloride water solution within three hours, and absorbing produced hydrogen chloride gas with dilute hydrochloric acid to obtain 30% industrial hydrochloric acid in which the fluoride ion content is greatly reduced, wherein the total acid content of the mixed acid is 20-30%, the hydrofluoric acid content of the mixed acid is 1-15%, the calcium chloride water solution is at 50-70 DEG C, and the concentration of the calcium chloride water solution is 20-40%; after the mixed acid is dripped off, continuing to heat the mixture to 105-120 DEG C for distillation, and condensing distillate into 3-5% dilute hydrochloric acid which can be directly used for absorbing hydrogen chloride; after the distillation, cooling the mixture to 50-70 DEG C, centrifugally filtering and washing the mixture to obtain recovered calcium fluoride, adding calcium chloride into the filtrate as a supplement of calcium chloride consumed in the reaction, and adding water to adjust the filtrate to achieve the reauired concentration, so as to continue to perform next mixed acid treatment. The method has the advantages that the fluoride ion recovery ratio exceeds 98%, and the quality of obtained hydrochloric acid is greatly improved.

Description

technical field [0001] The invention relates to a method for recovering fluorine ions in a freon by-product mixed acid solution, in particular to a fluoride ion recovery method using a calcium chloride aqueous solution and a freon by-product mixed acid solution reaction method to recover fluoride ions and a freon by-product whose fluoride ion concentration is greatly reduced Production of hydrochloric acid. Background technique [0002] In the production process of Freon, the fluorination reaction will produce a mixed gas of hydrogen fluoride and hydrogen chloride, and the mixed gas will be absorbed by water to become a by-product mixed acid. Because the mixed acid contains fluoride ions, the quality of the by-product hydrochloric acid of Freon is not high, thus limiting its application field. [0003] Japanese patent JP 60027604 introduces a method for separating hydrogen fluoride from hydrogen chloride liquid. In this method, hydrogen fluoride and hydrogen chloride, the b...

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 Patents(China)
IPC IPC(8): C01F11/22C01B7/03
Inventor 尹红袁慎峰何甫长陈志荣冯华刘乘风
Owner ZHEJIANG UNIV
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