The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jan. 24, 1989
Filed:
Sep. 21, 1987
Applicant:
Inventor:
Derek J Fray, Trumpington, GB;
Assignee:
National Research Development Corporation, London, GB;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
C01G / ; C01G / ; C01G / ;
U.S. Cl.
CPC ...
423 97 ; 423107 ; 75 25 ;
Abstract
Zinc and other metals are recovered form strongly bound zinc ferrite compounds in furnace dust. To the dust is added 1 weight percent of free zinc oxide unless already present. The dust is treated for 1 hour at 750C with a 20:1 air:chlorine mixture whereby the zinc, lead and cadmium are removed from the dust as volatilised chloride.