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:
Sep. 13, 1983
Filed:
Feb. 22, 1982
Ernst Eichberger, Wels, AT;
Gerhard Lazar, Linz, AT;
Voest-Alpine Aktiengesellschaft, Linz, AT;
Abstract
In a method of recovering heavy metals from filter residues containing metal oxides, metal hydroxides or metal carbonates, the residues are dried and reduced during heat supply in the presence of carbon-containing reducing agents. The metal-containing filter residues having a water content of 30 to 80% are dried in a three-compartment rotary drier (triplex drier), wherein a product having a grain size of 0.1 to 5 mm and a packing density of 0.4 to 1.2 kg/l results, which, after the addition of the carbon-containing reducing agents, is introduced into a crucible furnace at a filling height of 0.4 to 1.5 m. It is heated to a temperature above the melting point of the metal to be recovered. The filling height is kept approximately constant during the volume reduction of the material to be reduced occurring at an increased temperature by refilling the batch.