Patent · US Expired

Phosphor purification process

US4221676A · kind A · utility

0Cited by
9References
9Claims
0Family size

Assignee

Inventors

Key dates

Filing dateMay 4, 1979
Grant dateSep 9, 1980
Priority date—
Expiry dateMay 4, 1999

Classification

  • Technology area (CPC C)Chemistry; Metallurgy
  • CPC primaryC09K11/7442
  • WIPO fieldBasic materials chemistry
  • WIPO sectorChemistry

Abstract

A process for removing suspected heavy metal contaminants from a manganese-arsenic activated, zinc orthosilicate phosphor comprises contacting the phosphor, in an aqueous slurry, with an organic chelating agent such as an alkali metal salt of ethylenediamine tetraacetate and subsequently rinsing, filtering, drying and sieving the phosphor and baking the sieved phosphor.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.