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

Combined treatment method for rear earth smelting/separating wastewater

A joint treatment, rare earth technology, applied in neutralization water/sewage treatment, water/sewage multi-stage treatment, water/sludge/sewage treatment, etc. Effect of Economic Benefit and Resource Recovery Benefit

Inactive Publication Date: 2013-09-11
北方稀土(全南)科技有限公司 +1
View PDF4 Cites 13 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, due to the small amount of wastewater absorbed by the tail gas of electrolytic redox extraction, simple and direct addition cannot completely treat high-concentration COD sewage

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
  • Combined treatment method for rear earth smelting/separating wastewater
  • Combined treatment method for rear earth smelting/separating wastewater
  • Combined treatment method for rear earth smelting/separating wastewater

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0022] The used saponification waste water is produced by extracting and separating rare earth with sodium hydroxide as a saponification agent, and the oxalic acid precipitation waste water is used as precipitation to prepare lanthanum oxalate mother liquor. At room temperature, the acidic oxalic acid precipitation wastewater is mixed according to the set ratio to adjust the acidity of the saponification wastewater. After clarification and phase separation, the residual oxalic acid and rare earth crystals in the wastewater are precipitated, and the amount of recovered rare earth and the COD concentration in the wastewater are measured. The water phase separated from the oil phase and solid phase is further neutralized with lime slurry to a pH value of 10-11, and is filtered through clarification to remove heavy metals Pb, Cr and most of the remaining organic extractant and solvent. Add electrolytic redox extraction tail gas to absorb wastewater for oxidation, so as to reduce th...

Embodiment 2

[0025] Determination of ultrasound-assisted demulsification time. Mix 500ml of saponification wastewater and quantitative oxalic acid precipitation wastewater with the above-mentioned optimal ratio, and measure the COD concentration of the wastewater by ultrasonication for different times and static clarification for 5 hours. The results are as follows Figure 5 , Ultrasonic assistance has a significant effect on reducing COD in wastewater, which is beneficial to the recovery of organic extractants and solvents. The ultrasonic time is controlled at 20-28 minutes. The COD concentration in the wastewater is low. With the extension of the ultrasonic time, the COD concentration tends to increase.

[0026]

Embodiment 3

[0028] Determination of the final pH value of lime slurry neutralization and precipitation of a class of pollutants Pb and adsorption of organic substances. Use the above conditions to recover 500ml of wastewater after rare earth and organic extractant, adjust the pH value to 9, 10, 11, 11.5, 12, etc. with lime slurry, stir and react for 30 minutes, and measure the concentrations of Pb and COD in the wastewater after clarification and filtration. Such as Image 6 As shown, it shows that with the increase of pH value, both Pb and COD of the first class of pollutants are significantly reduced. When the pH rises to 10-11, the concentration of Pb is between 0.1-0.2 mg / l, reaching the level of "Rare Earth Industrial Pollution According to the most stringent standard requirements (less than 0.2mg / l), the COD is stable between 500-600mg / l. It shows that the best control point of pH value of lime slurry to neutralize and precipitate a kind of pollutant Pb and adsorb organic substance...

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 provides a combined treatment method for rear earth smelting / separating wastewater. The combined treatment method comprises the following steps of: precipitating the wastewater by using acidic oxalic acid to regulate the acidity of the saponified wastewater, so that most of oxalic acid and rare earths in the wastewater are separated out in the form of precipitate; demulsifying the emulsified organic phase under assistance of ultrasonic waves, and the recovering the organic phase and rare earth oxalates through clarification and phase separation; continuously neutralizing the water phase, from which the oil phase and the solid phase are separated, by using lime slurry until the pH value is in the range from 10 to 11; and then performing clarification and filtering so that heavy metals Pb and Cr and most of residual organic extracting agent and solvent are removed, then introducing electrolytic oxidation-reduction extracting tail gas to absorb the wastewater, and oxidizing the residual reducing substances (including oxalic acid, ammonium and organic substances) in the wastewater by using ClO<->, Cl2 and the like in the tail gas, thereby achieving the purposes of reducing ammonia nitrogen, organophosphorus and COD (Chemical Oxygen Demand) concentration in the wastewater. According to the method provided by the invention, the reactivity among the effective components in the wastewater is effectively utilized so that valuable materials are recovered and harmful materials are removed; and therefore, dual goals of resource recovery and environmental protection are achieved.

Description

[0001] technical field [0002] The invention relates to a joint treatment method of saponification wastewater, oxalic acid precipitation acid wastewater, and electrolysis redox tail gas absorption wastewater in the rare earth smelting and separation process, and belongs to the technical field of rare earth smelting separation and water treatment. Background technique [0003] Rare earth extraction and separation is the main method to produce high-purity rare earth compounds and metals, and has been widely used in industry. At present, my country's rare earth separation technology and industrialization level are in the leading position in the world, but the corresponding environmental protection has not been well resolved. In 2014, my country's rare earth industry will implement more stringent industrial pollutant discharge standards, which not only put forward higher requirements for the concentration of pollutants in the discharged water, but also have strict requirements...

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): C02F9/04C02F9/08C22B59/00C02F1/66
Inventor 鲍永平王悦宋丽莎李永绣蔡立宁徐欣邬元旭钟月明梁少锋
Owner 北方稀土(全南)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