Method for producing metallic iron nuggets

Abstract

A method of producing metallic iron nuggets includes providing a hearth with refractory material, and providing a reducible mixture above at least a portion of the hearth, where the reducible mixture includes reducible iron bearing material, reducing material such that the reducible mixture has a quantity of reducible iron bearing material and between about 65% and about 90% of a stoichiometric amount of reducing material necessary for complete iron reduction of the reducible iron material, between about 1% and 4% by weight manganese oxide, between about 1% and 3% by weight fluorspar, and additives providing a slag basicity ratio of CaO/SiO2 between 1.2 and 1.7. Then the method includes thermally treating the reducible mixture in the presence of other carbonaceous material separate from the reducible mixture forming one or more metallic iron nuggets by melting.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS[0001]This application is a continuation-in-part of and claims the benefit of U.S. application Ser. No. 12 / 639,584, filed on Dec. 16, 2009, which is a divisional of application Ser. No. 11 / 296,198, filed on Dec. 7, 2005, which claims priority to provisional patent application Ser. No. 60 / 633,886, filed Dec. 7, 2004, the disclosures of which are incorporated herein by reference.BACKGROUND OF THE INVENTION[0002]The present invention relates to the reduction of metal bearing material (e.g., the reduction of iron bearing material such as iron ore).[0003]Many different iron ore reduction processes have been described and / or used in the past. The processes may be traditionally classified into direct reduction processes and smelting reduction processes. Generally, direct reduction processes convert iron ores into a solid state metallic form with, for example, use of shaft furnaces (e.g., natural gas-based shaft furnaces), whereas smelting reduction co...

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