Skip to main content
Industrial Research And Consultancy Centre
Patent
Method for Recovering Yttrium Oxide from Phosphor
Abstract

The invention presents a method and electrochemical cell designed to recover Yttrium Oxide from phosphor. The process begins with leaching a phosphor sample using a specific acid in a controlled quantity under predefined conditions to produce a leach liquor. This leach liquor is then diluted with deionized water (DI water) to form an electrolyte solution containing a yttrium compound. Next, the electrolyte solution is utilized in an electrochemical cell for electrodeposition, depositing yttrium hydroxide onto a cathodic stainless-steel substrate. The yttrium hydroxide forms through a reaction between the yttrium compound and the cathodic substrate. Subsequently, the yttrium hydroxide undergoes calcination at a predetermined temperature and for a specified duration to yield Yttrium Oxide.

Uniqueness of the Solution
  • Does not require treatment at higher temperature 
  • Does not use expensive molten salts 
  • Uses a combination of both hydrometallurgical and electrometallurgical approaches 
  • Uses hydrochloric acid for the effluent of red phosphor in solution 
  • Employed leach liquor as electrolytic solution for the recovery of yttrium using cathodic electrodeposition 
  • Economically feasible for the large-scale production of pure Y2O3 from WFL phosphor 
  • Recovered Y2O3 has purity > 90% which can be reused for several applications
Prototype Details

The electrochemical cell includes a cathode substrate made of stainless steel, with specified dimensions: a length ranging from 50 mm to 1.0 m, a width ranging from 25 mm to 0.5 m, and a thickness ranging from 0.01 mm to 1.0 mm. Surrounding the cathode substrate are at least two parallel counter electrodes, each consisting of a graphite electrode with a length between 60 mm and 1 m, and a width between 3 mm and 30 mm. The cell also contains an electrolyte solution containing Yttrium Chloride.

Current Status of Technology

The components of the invention have been validated in lab environment. Purity of the Yttrium Oxide recovery through the method was shown to lie in a range of 85% to 95%.

Technology readiness level

4

Societal Impact

The invention has environmental benefits as it recycles WFL phosphors to give REE’s which can be used in various places. The recycled WFL is also prevented from going to landfill and causing soil pollution.

Relevant Industries, Domains and Applications

Electronics industry, Chemical industry, Metallurgical industry, Medical industry, Defense and aerospace industry

Applications or Domain

WFL Phosphor is recycled to recover REE’s which have application in many domains. The REE’s recovered from the defined method can be used in various industries such as electronics, defense and aerospace, metallurgical, chemical and so on.

Geography of IP

Type of IP

Application Number

201821038649

Filing Date
Grant Number

398773

Grant Date
Assignee(s)
Indian Institute of Technology Bombay