Abstract: The invented pellet reclamation process includes forming green pellets of a mixture of steel furnace dust, a carbonaceous material such as coal, charcoal, lignite, petroleum coke, or coke, and an organic binder. The green pellets are fed over a layer of burnt pellets on a rotary hearth furnace which successively conveys the pellets first through a drying and coking zone in which the pellets are dried and any volatile matter driven out of the carbonaceous material. The pellets then travel through a reduction zone where the pellets are subjected to a higher temperature at which the contained iron oxide is reduced and remains within the pellets and the zinc, lead and cadmium oxides are reduced, volatilized, re-oxidized and carried off as oxides in the waste gases. The reduced pellets (DRI) are ultimately carried into a discharge zone where they are discharged from the rotary hearth furnace. An apparatus for performing the process is also disclosed.
Abstract: An improved furnace for heating or heat-treating of particulate materials, the furnace having an elongated body, preferably vertical, forming a triskele cylinder having a desired cross-sectional area defined by four (4) circles of identical diameter, a central circle, and three (3) tangential outer circles, the center of each tangential circle symmetrically placed 120 degrees about the central circle, each of said circles being connected by tangential arcs of about the same diameter as the circles. The furnace shell is a high performance corrosion resistant nickel-base alloy, including cobalt, chromium, and silicon, whereby the critical contents of cobalt and silicon provide improved sulfidation resistance.
Type:
Grant
Filed:
February 14, 1991
Date of Patent:
November 17, 1992
Assignee:
Zia Patent Company
Inventors:
N. Edward Bottinelli, Norman L. Kotraba
Abstract: A method and apparatus for recovering primary metals from pyrometallurgical process dust, in which a vertical shaft retort, situated in a furnace or afterburner associated with a pyrometallurgical apparatus, such as an inclined rotary reduction smelter, and preferably having a tapered cross-section with the larger end at the bottom, receives greenball pellets from a pelletizer, vaporizes volatile metal metals therein, and removes them to an associated volatile metal recovery apparatus, while reducing and recovering the major metal oxide components in the pellets in metallized form.
Type:
Grant
Filed:
March 29, 1990
Date of Patent:
July 2, 1991
Assignee:
Zia Patent Company
Inventors:
Norman G. Bishop, N. Edward Bottinelli, Norman L. Kotraba