Unlock instant, AI-driven research and patent intelligence for your innovation.

Method for purifying phosphoric acid waste liquid

A purification method and phosphoric acid solution technology, applied in chemical instruments and methods, phosphorus compounds, inorganic chemistry, etc., can solve problems such as ineffective application, achieve the effects of reducing processing load, avoiding secondary pollution, and simple process methods

Active Publication Date: 2021-03-16
江苏电科环保有限公司
View PDF7 Cites 1 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0004] Aiming at the problem that the traditional phosphoric acid waste liquid treatment method cannot be effectively applied to the recycling and treatment of semiconductor phosphoric acid waste liquid, the present invention provides a purification method for phosphoric acid waste liquid. The process method is simple, can avoid secondary pollution, and does not require additional investment Add solvent or do further regeneration and stripping treatment to effectively use phosphoric acid waste liquid and recover industrial grade phosphoric acid

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 purifying phosphoric acid waste liquid
  • Method for purifying phosphoric acid waste liquid
  • Method for purifying phosphoric acid waste liquid

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0033] S1 electrodialysis: the phosphoric acid mass concentration is 85%, the impurity mass fraction is 2%, and the impurity is H 2 SO 4 , HCl, HNO 3 , AlPO 4 、Cu 3 (PO 4 ) 2 、Ni 3 (PO 4 ) 2 、FePO 4 The phosphoric acid waste liquid was preheated to 35°C and then passed into the electrodialysis device with a current density of 50mA / cm 2 A constant current reaction of 3h, each compartment in the electrodialysis device is set to circulate backflow, to obtain a phosphoric acid solution for removing aluminum, copper, nickel, and iron metal ions;

[0034] S2 Distillation: Use low-pressure saturated steam with a pressure of 0.3Mpa and a temperature of 155°C to carry out vacuum distillation and concentration of the phosphoric acid solution. The distillation temperature is 100°C and the pressure is controlled at -0.08MPa to obtain a phosphoric acid concentrate; after distillation, the low-pressure saturated steam becomes Condensed water at 80°C is reused in S1 to preheat phos...

Embodiment 2

[0038] S1 electrodialysis: the phosphoric acid mass concentration is 85%, the impurity mass fraction is 2%, and the impurity is H 2 SO 4 , HCl, HNO 3 , AlPO 4 、Cu 3 (PO 4 ) 2 、Ni 3 (PO 4 ) 2 、FePO 4 The phosphoric acid waste liquid was preheated to 40°C and then passed into the electrodialysis device with a current density of 60mA / cm 2 The constant current reaction of 5h, each compartment in the electrodialysis device is set to circulate backflow, obtains the phosphoric acid solution that removes aluminum, copper, nickel, iron metal ion;

[0039] S2 Distillation: Use low-pressure saturated steam with a pressure of 0.3Mpa and a temperature of 155°C to carry out vacuum distillation and concentration of the phosphoric acid solution. The distillation temperature is 100°C and the pressure is controlled at -0.1MPa to obtain a phosphoric acid concentrate; after distillation, the low-pressure saturated steam becomes Condensed water at 80°C is reused in S1 to preheat phosphor...

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 method for purifying phosphoric acid waste liquid, and the method is simple in process method, can avoid secondary pollution, and can effectively utilize the phosphoric acid waste liquid and recover industrial-grade phosphoric acid without additionally adding a solvent or carrying out further regeneration and reverse extraction treatment. The method comprises the followingsteps: S1, electrodialysis: preheating the phosphoric acid waste liquid, introducing the preheated phosphoric acid waste liquid into an electrodialysis device, and carrying out sufficient reaction byadopting constant current to obtain a phosphoric acid solution without metal ions; s2, distillation: carrying out reduced pressure distillation concentration on the phosphoric acid solution by adopting low-pressure saturated steam to obtain a phosphoric acid concentrated solution; S3, melt crystallization: conveying the phosphoric acid concentrated solution to a cooling crystallizer, cooling, then adding seed crystals, stirring for crystallization, separating out phosphoric acid crystals, then conveying crystal mush containing the phosphoric acid crystals to a melter, sweating and melting toobtain a phosphoric acid solution with the mass fraction of 98%-99.5%; S4, diluting: diluting the phosphoric acid solution obtained in the S3 into industrial-grade phosphoric acid with the mass fraction of 85% by adopting distilled water in a blending tank.

Description

technical field [0001] The invention relates to the technical field of industrial wastewater treatment, in particular to a method for purifying phosphoric acid waste liquid. Background technique [0002] According to the content of impurities, phosphoric acid is divided into fertilizer grade, industrial grade, food grade, pharmaceutical grade and high-purity grade. Different grades of phosphoric acid are used in different fields; the content of industrial grade phosphoric acid is mostly 85%, which is colorless, transparent or slightly Light-colored, viscous liquid, mainly used in electroplating industry, pharmaceutical industry, phosphate industry and metallurgical industry, etc. [0003] Phosphoric acid waste liquid produced in the semiconductor industry is mainly aluminum, copper, nickel, iron phosphate and a small amount of hydrochloric acid, nitric acid and sulfuric acid, so it contains a relatively high concentration of phosphoric acid. If it is directly discharged, it ...

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): C01B25/234C01B25/237
CPCC01B25/2346C01B25/2377C01B25/2372
Inventor 朱玲慧刘晓雨刘围王颜
Owner 江苏电科环保有限公司