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:
Mar. 06, 2001
Filed:
Mar. 15, 1999
Richard B. Greenwalt, Danville, CA (US);
Bechtel Group, Inc., San Francisco, CA (US);
Abstract
A method of liquid iron production using high sulfur fuels is provided in which the level of sulfur in the iron is maintained below 0.1%. The low sulfur content is achieved even in the presence of high sulfur concentrations in the reducing gases and without the introduction of lime or limestone. According to one aspect, liquid iron in the fusion zone of a smelting system is saturated with carbon, thereby desulfurizing the liquid iron. The carbon saturation level is at least 4.5% carbon by weight and preferably, at least 5.0% carbon by weight. According to another aspect, the desulfurization of the liquid iron is enhanced by elevating the tapping temperatures to temperatures in excess of 1465° C., and preferably of about 1490° C. According to another aspect, the desulfurization process is supplemented by the presence of significant levels of silicon and/or manganese, both of which are highly soluble in the liquid iron. In a least one embodiment, the silicon levels in the fusion zone are maintained at greater than 0.3% and preferably greater than 0.5%. Manganese can be substituted for, or used in addition to, the silicon. Preferably the manganese level in the fusion zone is maintained at a level of greater than 0.3% and more preferably greater than 0.5%.