Polyester catalyst recovery

Abstract

Abstract A process for the recovery of germanium dioxide in a form and degree of purity suitable for catalyzing a polycondensation from an ethylene glycol solution of a reaction product of germanium dioxide and ethylene glycol, said ethylene glycol solution containing a proportion of germanium in amount less than that corresponding to a total concentration of 2 percent of germanium dioxide by weight based on the weight of solution, said process comprising the steps of removing ethylene glycol from the said solution by vaporization until the resultant concentrated solution contains a proportion of germanium corresponding to a total concentration of at least 2 percent by weight of germanium dioxide, adding to the resultant concentrated solution a quantity of water equal to at least 34 percent by weight of the germanium (expressed as dioxide) in the resultant concentrated solution, effecting hydrolysis of the compounds of germanium present in the resultant aqueous mixture to germanium dioxide by maintaining the said resultant aqueous mixture at elevated temperature for a time sufficient to effect said hydrolysis, cooling to ensure the separation in the solid state of the germanium dioxide so produced, and isolating the said germanium dioxide.

Inventors

• 👤 Gordon Edwin Head
• 👤 Kenneth Morgan Jones
• 👤 Eric Gendle

Bibliographic Details