Bechtel Group, Inc.

Bechtel Corporation

Raymond Kaiser Engineers, Inc.

Bechtel Croup, Inc.

Richard B Greenwalt

A method of upgrading relatively rich, fine-grained earthy hematite iron ores is provided. The iron ore, after suitable preparation, is reduced using a solid state reduction technique. As a result of the reduction process, the iron grains undergo size enhancement while the nonmetallic oxides are unreduced and remain as refractory oxide gangue. After completion of the reduction process, the enlarged malleable metallic iron grains are crushed in such a way as to cause the iron grains to fuse together, forming large, flat iron flakes. In order to achieve maximum flake size, the crushing system applies a relatively gradual pressing force rather than a rapid, impact type of force. As the large flakes are formed, the iron grains are liberated from the refractory oxide grains resulting in an increase in density. The crushing system causes non-iron oxide bonds to be broken, resulting in the formation of residual refractory particles generally with a grain size of less than 0.05 millimeters. The shape, size, density, and ferromagnetic differences between the iron flakes and the nonmetallic oxides are used to separate the iron from the nonmetallics. A variety of different separation techniques may be used, including screens, jigs, spirals, elutriation, cyclones, magnetic, and gravity separation. The combination of solid state reduction, mechanical working, and physical/electromagnetic separation enable consistent production of super concentrates of material with metallic iron contents exceeding 92% with less than 4% oxide gangue and an iron recovery of greater than 95%.

Method for direct reduction and upgrading of fine-grained refractory and earthy iron ores and slags

The performance of a gravity separator is enhanced by providing a magnetic material on the separation surface of the gravity separator. A magnetically enhanced gravity concentration/separation apparatus is provided for enhancing separation of a target feed material from remaining feed materials in a feed mixture having a transport medium and feed materials which comprise the target feed material and the remaining feed materials. The target feed material is magnetic and generally has a higher specific gravity than any magnetic feed materials contained in the remaining feed materials. The separating apparatus comprises a gravity separator including a separation surface on which to flow the feed mixture. The separation surface includes a magnetic separator material thereon to provide a magnetic field producing a sufficiently high magnetic attraction to enhance separation of the target feed material from the remaining feed materials in the feed mixture as the feed mixture flows over the separation surface carrying the remaining materials past the separation surface. The magnetic attraction of the magnetic field provided by the magnetic separator material on the separation surface is sufficiently low to at least substantially avoid accumulating magnetic feed materials contained in the feed mixture on the separation surface.

Magnetically enhanced gravity separator

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&deg; C., and preferably of about 1490&deg; 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%.

Producing liquid iron having a low sulfur content

Method for direct reduction and upgrading of fine-grained refractory and

A method of shift conversion of CO to H.sub.2 so that the level of gas can be reduced to a level that preheating for direct reduction to 800 to 900.degree. C. can be accomplished wherein carbon deposition is not a factor.

Shift conversion for the preparation of reducing gas

Method of providing fuel for an iron making process

The disclosure describes a method of direct steel making wherein liquid iron is produced in a melter gasifier system using a solid fuel reductant, preferably petroleum coke, and low silica containing iron ore, preferably less than 2.0% by weight, and the liquid iron is transferred directly to an oxygen blown steel making reactor for steel production and refining.

Method of direct steel making from liquid iron

The present invention provides a method for processing environmentally undesirable materials including petroleum coke and the sulfur and heavy metals contained therein and agglomerated waste dust from an electric arc furnace and the zinc, cadmium, lead and iron oxides contained therein and of providing fuel and a charging material for a process of making molten iron or steel preproducts and reduction gas in a melter gasifier. Metallized arc furnace waste dust material from a reduction furnace is introduced into the melter gasifier. The petroleum coke, oxygen and metallized waste dust material are reacted to produce reduction gas and molten iron from the iron oxides in the waste dust material. The molten iron contains the metals freed from combustion of the petroleum coke. The reduction gas is removed from the melter gasifier for use in the reduction furnace to produce an top off gas containing vapors of zinc, cadmium and lead.

Method of processing waste material containing non ferrous metal oxides

The invention relates to a method for processing environmentally undesirable materials including petroleum coke and the sulfur and heavy metals contained therein and oily steel and iron ferrous waste from machine shop and steel and iron processing to provide fuel and a charging material for a process of making molten iron or steel preproducts and reduction gas in a melter gasifier.

Method of making iron from oily steel and iron ferrous waste

A method is provided to improve the production of hot direct reduced iron in a melter-gasifier; reduction furnace system. All of the reduction gas produced in the melter gasifier and the top gas produced in reduction furnace which has been stripped of CO.sub.2 are recycled to the reduction furnace. The reduction furnace is sized to process all this gas and bypassed direct reduced iron may result.

Method of making hot metals with totally recycled gas

The invention provides a method for both disposing of an environmentally undesirable material comprising petroleum coke and the sulfur and heavy metals contained therein and of providing fuel for a process of making molten iron or steel preproducts and reduction gas in a melter gasifier having an upper fuel charging end, a reduction gas discharging end, a lower molten metal and slag collection end, and means providing an entry for charging ferrous material into the melter gasifier; introducing petroleum coke into the melter gasifier at the upper fuel charging end; blowing oxygen-containing gas into the petroleum coke to form at least a first fluidized bed of coke particles from the petroleum coke; introducing ferrous material into the melter gasifier through the entry means, reacting petroleum coke, oxygen and particulate ferrous material to combust the major portion of the petroleum coke to produce reduction gas and molten iron or steel preproducts containing heavy metals freed from combustion of the petroleum coke and a slag containing sulfur freed from combustion of the petroleum coke.

The invention provides a method for both disposing of an environmentally undesirable material comprising rubber tires and the sulfur and metals contained therein and of providing fuel for a process of making molten iron or steel preproducts and reduction gas in a melter gasifier. The metals freed from combustion of the rubber tires is contained in the molten iron and sulfur freed from combustion of the rubber tires is contained in the slag.

Method of using rubber tires in an iron making process

Method of processing electric arc furnace dust and providing fuel for an

The invention relates to a method of making iron or steel preproducts and reduction gas with a low slag forming process utilizing petroleum coke as a fuel in a melter gasifier.

Growing community of inventors

Danville, CA, United States of America

Richard B Greenwalt