New method for processing fluorine-containing tail gas in production of calcium superphosphate

A technology of calcium superphosphate and a new method is applied in the new field of treating fluorine-containing tail gas in the production of calcium superphosphate, which can solve the problems of increasing pollutants such as ammonia, nitrogen emission, easy escape of ammonium fluorosilicate, etc., and achieve an environment-friendly environment. Effect

Inactive Publication Date: 2012-03-21
云南氟业化工股份有限公司
View PDF4 Cites 5 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, although this method can eliminate the secondary pollution caused by waste water, since ammonium fluoride is used as the absorption liquid and there is some free ammonia in the ammonium fluoride, the temperature of the absorption liquid reaches 40-- 80°C

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
  • New method for processing fluorine-containing tail gas in production of calcium superphosphate
  • New method for processing fluorine-containing tail gas in production of calcium superphosphate
  • New method for processing fluorine-containing tail gas in production of calcium superphosphate

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0030] Embodiment 1: produce 1000Kg ammonium fluorosilicate product, by weight percentage

[0031]1. The silicon tetrafluoride gaseous waste gas escaped in the superphosphate production process is absorbed by the ammonium fluoride solution of 18%-20% with a concentration (the first two stages of absorption process), and the temperature of the first absorption tower 1 is controlled to be 80°C, The temperature in the second absorption tower 2 is 60°C, when the pH value of the solution in the first absorption tower 1 and the second absorption tower 2 reaches 3.0-3.5, react ammonium fluoride with silicon tetrafluoride gas to generate fluorosilicic acid 4000Kg of ammonium is discharged from the bottom of the first absorption tower (1) into the cooling crystallization tank, under continuous stirring, to prevent the crystals from blocking the pipeline, and naturally cool to room temperature in the crystallization tank, at this time, a large amount of ammonium fluorosilicate crystals a...

Embodiment 2

[0038] Taking the calcium superphosphate plant with an annual output of 300,000 tons as the implementation plan, put 6 tons of ammonium fluoride solution with a concentration of 20.5% into the first absorption tower 1 and the second absorption tower 2 of the tail gas absorption system respectively, The third absorption tower 3 still uses water as the absorption washing liquid. At this time, send the fluorine-containing waste gas generated in the production process of superphosphate to the first absorption tower 1, control the temperature of the first absorption tower 1 to 60°C, and the inside of the second absorption tower to 80°C, and the pH value in the first absorption tower 1 When reaching 3.5, more than 99% of ammonium fluoride has been converted into ammonium fluorosilicate. From the first absorption tower 1, this solution is all put into the tank with stirring paddles, and allowed to cool naturally. When the ammonium fluorosilicate solution discharged from the first ab...

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 mew method for processing a fluorine-containing tail gas in the production of calcium superphosphate, which considers practical cases of the production of calcium superphosphate and needs of the environmental protection processing of the tail gas and adopts a tail gas segment absorption mode to process wastewater and waste gases. The method of the invention is characterized in that: the fluorine-containing tail gas generated in the production process of calcium superphosphate is processed in a three-segment absorption mode; ammonium fluoride is adopted as an absorption liquid in the first segment and the second segment, and water is adopted as an absorption liquid in the third segment; ammonium fluorosilicate which is well absorbed in the first segment and the second segment is cooled and crystallized to obtain an ammonium fluorosilicate product, and can also be directly ammonified as needed to obtain an over 40% ammonium fluoride solution which can be evaporated and concentrated to obtain an ammonium fluoride product or can be used to prepare other fluorine chemical engineering products; and water is used as an absorption washing liquid in the third segment, and an obtained mixed solution is added with a mother solution (a dilute ammonium fluorosilicate solution) according to the needed concentration amount when the fluorine-containing tail gas which is not completely absorbed in a first absorbing tower and a second absorbing tower or ammonia, or volatilized ammonium fluoride and an ammonium fluorosilicate liquid foam which escape because of the over high temperature of the first absorbing tower and the second absorbing tower is absorbed and washed by water.

Description

technical field [0001] The invention discloses a new method for treating fluorine-containing tail gas in calcium superphosphate production. Considering the actual situation of calcium superphosphate production and the need for environmental protection treatment of tail gas, the tail gas can be absorbed in stages to treat both waste water and waste gas. Background technique [0002] In the past production process of calcium superphosphate, when sulfuric acid decomposes phosphate rock to produce calcium superphosphate, the fluorine in the phosphate rock will escape in the form of silicon tetrafluoride. For a long time, various manufacturers have used water to absorb this Fluorine-containing tail gas is used to produce low-concentration fluosilicic acid, which is then further processed into sodium fluosilicate products for sale. When this treatment method produces sodium fluorosilicate, a large amount of waste water will be generated, forming secondary pollution. [0003] Chin...

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): B01D53/78B01D53/68C01B33/10C01B15/16
Inventor 李志林陈建敏
Owner 云南氟业化工股份有限公司
Who we serve
  • R&D Engineer
  • R&D Manager
  • IP Professional
Why Eureka
  • Industry Leading Data Capabilities
  • Powerful AI technology
  • Patent DNA Extraction
Social media
Try Eureka
PatSnap group products

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

© 2024 PatSnap. All rights reserved.Legal|Privacy policy|Modern Slavery Act Transparency Statement|Sitemap