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:
Oct. 19, 1993
Filed:
Dec. 17, 1991
Applicant:
Inventor:
Rolf E Malmstrom, Helsinki, FI;
Assignee:
A. Ahlstrom Corporation, Noormarkku, FI;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
C01G / ; C01G / ; C01G / ; C01G / ;
U.S. Cl.
CPC ...
423 28 ; 423 23 ; 423 29 ; 423 47 ; 4235611 ;
Abstract
A method for roasting sulphide ores or ore concentrates containing precious metals is practiced in a furnace, typically in a fluidized bed. The ore and a sulphur-binding lime-containing material are supplied to a roasting furnace in which the ore is roasted with the emission of heat and sulphur dioxide. The lime-containing material--such as calcium hydroxide--is mixed into the cooling water for the roasting furnace and sprayed into the furnace as a lime-containing aqueous slurry. Roasting occurs at about 600-850.degree. C. (e.g. 650-750.degree. C.). Roasted material is discharged from the furnace and acted upon to recover gold, silver and copper metal.