Mitsubishi Heavy Industries Limited

Primetals Technologies Japan, Ltd.

Mitsubishi Jukogyo Kabushiki Kaisha

Mitsubishi-Hitachi Metals Machinery, Inc.

Susumu Kamikawa

Keiichi Sato

Hideki Ito

Hironori Fujioka

Hideaki Mizuki

Kouichi Hirata

Khanhson Pham

Hiroshi Nakajima

Shigeo Itano

Hisao Teramoto

Yoshimitsu Onaka

Toshio Taguchi

Koichi Hirata

Takashi Yamane

Hiromi Osaka

Shigeki Sueda

Tetsumasa Kawamoto

Kenichi Yanagi

Heizaburo Furukawa

Hiroko Kitamoto

Toshiro Kobayashi

Minoru Sueda

Kozo Wada

Atsushi Oda

Hajime Okita

Hideki Itou

Younosuke Hoshi

Akihiro Santo

Provided is a device for producing partially reduced iron, with which partially reduced iron having a prescribed reduction ratio can be produced efficiently. The present invention is equipped with: CO sensors that detect the carbon monoxide concentration in an exhaust gas; an Osensor that detects the oxygen concentration in an exhaust gas; an exhaust gas circulation device that adjusts the circulating amount of the exhaust gas supplied to a reduction furnace main body, and an air feed device that adjusts the amount of air that being fed; and a control device that controls these devices. The control devices on the basis of the carbon monoxide concentration in the exhaust gas as detected by the CO sensor and the oxygen concentration in the exhaust gas as detected by the Osensor.

Device for producing partially reduced iron

Provided is a green pellet () which comprises: an inner core layer () containing an iron oxide-containing starting material, a carbonaceous material for reduction, and a slag-forming agent; and a coating layer () disposed so as to encapsulate the surface of the inner core layer (), wherein the coating layer () is formed from a protective layer (), which is disposed so as to encapsulate the surface of the inner core layer () and which contains an inorganic compound (includes an alkali metal oxide) having a melting point that is 750&#xb0;C. or greater but less than 1100&#xb0;C., and a combustion layer (), which is disposed so as to encapsulate the surface of the protective layer () and which contains the carbonaceous material.

Green pellet

A partially-reduced iron producing apparatus includes: an exhaust gas circulating device which supplies an oxygen-containing gas to raw-material pellets to be heated by a heat of ignition raw-material pellets, the oxygen-containing gas made by circulating part of an exhaust gas discharged from the raw-material pellets by use of the heat of the ignition raw-material pellets heated in a heating furnace and mixing the discharged exhaust gas with air; and a liquid-tar separating device which is provided in the exhaust gas circulating device and which separates a tar component in the exhaust gas from the exhaust gas as a liquid tar.

Partially-reduced iron producing apparatus

A partially-reduced iron producing apparatus includes: a supplying device laying ignition raw-material pellets on an endless-grate; a heating furnace heating the ignition raw-material pellets; another supplying device laying the raw material pellets on the ignition raw-material pellets; and an exhaust gas circulation device supplying an oxygen-containing gas to the raw-material pellets. The oxygen containing gas is made by circulating part of an exhaust gas discharged from the raw-material pellets and mixing it with air. A partially-reduced iron is produced by thermally reducing the raw-material pellets in a bed height direction thereof through separate combustion and heating regions. The combustion region formed on an upstream side in a travelling direction of the endless grate by supplying the oxygen-containing gas having a high oxygen concentration. The heating region formed downstream of the combustion region in the travelling direction of the endless grate by supplying the oxygen-containing gas having a low oxygen concentration.

Partially-reduced iron producing apparatus and partially-reduced iron producing method

A reduction furnace includes a pellet material supplying device forming on a grate an ignition carbon material layer having a predetermined height; an ignition device; and an exhaust gas circulation device supplying an oxygen-containing gas comprising circulated exhaust gas mixed with air, to a packed bed of the pellets heated by a combustion heat of the ignition carbon material layer. A partially-reduced iron is produced by thermally reducing the pellets through a combustion region for the ignition carbon material layer and a heating region, the combustion region formed upstream in a travelling direction of the grate by supplying a gas having a high oxygen concentration, the heating region formed downstream of the combustion region by supplying a gas having a low oxygen concentration.

Partially-reduced iron producing method and partially-reduced iron producing apparatus

An evaporation source having a nozzle structure that makes the distribution of film thickness uniform in the width direction of a substrate and a vacuum evaporator using the same are provided. A vapor produced by evaporation or sublimation by heating to evaporation material is discharged from a long nozzle opening like a band. A deposited substrate is transferred in a direction perpendicular to the longitudinal direction of the nozzle opening while facing the nozzle opening. A discharge flow rate of vapor per unit area in the longitudinal direction of the nozzle opening is made to be maximum in a portion at a nozzle width direction position corresponding to a substrate edge position rather than a central part of the nozzle opening and a plurality of partition plates providing directivity to the flow of vapor are arranged inside the nozzle opening.

Evaporation source and vacuum evaporator using the same

A method of producing reduced iron pellets including reducing raw material pellets to obtain reduced iron pellets, and rolling the reduced iron pellets at a temperature ranging between 800 and 1200&#xb0; C. sufficiently such that the reduced iron pellets undergo sintering.

Method of producing reduced iron and production facilities therefor

A reduced iron discharger in a rotary hearth reducing furnace scoops up reduced iron on a rotary hearth from a front side with the use of an impeller enough long to cover the entire width of the rotary hearth, drops the reduced iron onto a vibrating conveyor mounted in the impeller, and discharges it from an outlet to the outside of the reducing furnace. The reduced iron discharger involves minimal structural waste, and gives a satisfactory yield.

Reduced iron discharger in rotary hearth reducing furnace

A pretreatment apparatus for raw materials for production of reduced iron pretreats the raw materials, comprising an iron material, such as iron ore, and other raw materials, such as coal and flux, by a dryer, classifiers, a roll press, and a vertical mill, and feeds the pretreated raw materials to a pelletizer via a feed bin. At least two fluidized mixers for mixing the classified raw materials, one of the fluidized mixers for storage and the other fluidized mixer for supply, are provided for batch treatment. The pretreatment apparatus can uniformize the crushed particle sizes of iron ore, coal, etc. different in hardness, stably supply homogeneously mixed raw materials, and simplify pelletization-side facilities.

Pretreatment apparatus for raw materials for production of reduced iron

An apparatus for producing reduced iron, and a compact drying method for application to the apparatus are disclosed. The apparatus comprises a pelletizer or a briquetter for mixing and agglomerating coal as a reducing agent and iron ore as iron oxide to form compacts, a dryer for drying the compacts, a circular rotary hearth type reducing furnace for reducing the dried compacts in a high temperature atmosphere, a first heat exchanger for performing heat exchange between a hot off-gas discharged from the reducing furnace and combustion air to be supplied to the reducing furnace, and coolers for cooling the hot off-gas. A second heat exchanger for heating drying air is disposed on an exit side of the first heat exchanger. The drying air heated by the second heat exchanger is supplied to the dryer to dry the compacts with the drying air which is scant in moisture. Consequently, highly efficient, stable drying in the dryer can be performed, and high quality reduced iron can be produced stably.

Apparatus for producing reduced iron and compact drying

An apparatus for producing reduced iron dries agglomerates, pelletized from a powdery mixture of an iron oxide powder and a reducing agent, in a drying chamber, preheats the dried agglomerates in a preheating chamber, and then reduces the preheated agglomerates in a high temperature atmosphere of a reducing furnace. In the preheating chamber, an off-gas from the reducing furnace is convected to preheat the dried agglomerates. A decrease in the fuel cost, and downsizing of the equipment can be achieved by effective use of the sensible heat of the off-gas discharged from the reducing furnace. Moreover, a downsized, simplified system for treatment of the off-gas is realized by decreasing the amount of the off-gas.

Apparatus for producing reduced iron

In the production of reduced iron by agglomerating a mixed powder of an iron material and a reducing agent to form compacts like briquettes or pellets, and reducing the compacts in a high temperature atmosphere, when the temperature of reduced compacts is 900&deg; C. or higher, the oxide content in the reduced compacts is set at 11% or more, and the basicity of the reduced compacts is set at 0.5 or higher.

Method for producing reduced iron

An apparatus for producing reduced iron by agglomerating a mixed powder of an iron material and a reducing agent to form compacts like briquettes or pellets, and reducing the compacts in a high temperature atmosphere is disclosed. In the apparatus, a rotary hearth in an annular form is rotatably supported. Right and left furnace walls and a ceiling are provided to cover an area above the rotary hearth, thereby forming a space portion in a high temperature atmosphere. A compact supply portion, and a compact discharge portion are provided adjacently in the ceiling. Partitioning members are provided as partitions between the compact supply portion, the compact discharge portion, and the high temperature atmosphere space portion.

An apparatus for producing reduced iron, and a compact drying method for application to the apparatus are disclosed. The apparatus comprises a pelletizer or a briquetter for mixing and agglomerating coal as a reducing agent and iron ore as iron oxide to form compacts, a dryer for drying the compacts, a circular rotary hearth type reducing furnace for reducing the dried compacts in a high temperature atmosphere, a first heat exchanger for performing heat exchange between a hot off-gas discharged from the reducing furnace and combustion air to be supplied to the reducing furnace, and coolers for cooling the hot off-gas. A second heat exchanger for heating drying air is disposed on an exit side of the first heat exchanger. The drying air heated by the second heat exchanger is supplied to the dryer to dry the compacts with the drying air scant in moisture. Consequently, highly efficient, stable drying in the dryer can be performed, and high quality reduced iron can be produced stably.

Method for drying compacts

A method of producing raw material pellets, including forming pellets from a mixture of an iron oxide powder, a coal powder and a binder material after adding adjusting water to the mixture, and drying the pellets, wherein the binder material comprises at least one of tar and at least one of carboxymethylcellulose and polyvinylalcohol.

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Hiroshima, Japan

Susumu Kamikawa