Nkk Corporation

Nippon Kokan Kabushiki Kaisha

Jfe Steel Corporation

Katsuhiro Iwasaki

Masahiro Kawakami

Haruyoshi Tanabe

Kenji Takahashi

Shigeru Inoue

Kenzo Yamada

Toshio Takaoka

Chihiro Taki

Ichiro Kikuchi

Takeshi Sekiguchi

Masayuki Watanabe

Yasuo Nagashima

Osamu Terada

Akichika Ozeki

Shinichi Isozaki

Koichi Nushiro

Haruo Ito

Hitoshi Kawata

Yuji Iwami

Nobuyuki Oyama

Terutoshi Sawada

Mitsuru Ohtsuki

Junichi Fukumi

Hiroshi Tako

Hideki Kadoya

Apparatus for supplying diluted gaseous fuel to not more than a lower limit combustion concentration at downstream of suction type sintering machine including a hood having similar width as a circularly-moving pallet and arranged above charged layer to surround the pallet in all directions, pipes disposed at upper position of charged layer in the hood and supplying the fuel air inside the hood, baffle plates formed by arranging plate materials having dog-leg shaped cross-section in plural rows and steps at intervals in the widthwise and height directions, respectively, of the hood to make each interval formed between adjacent plate materials in widthwise direction of the hood in each steps vertically alternate; fences having a void and arranged on both sides upper ends of the hood; vortex suppressing plates formed between fences at intervals having a void ratio, 20&#x2dc;80%; whereby the gaseous fuel leakage supplied to the outside is prevented.

Gaseous fuel supply apparatus for sintering machine

A smelting reduction method comprising (a) charging a carbonaceous material and an ore into a reacting furnace to directly contact the carbonaceous material and the ore; (b) reducing the ore until at least a part of the ore is metallized, the resultant reduced ore containing at least a part of metallized metal being produced; (c) charging the carbonaceous material and the ore containing at least a part of the metallized metal from step (b) into a smelting furnace having a metal bath; and (d) blowing a gas containing 20% or more of oxygen into the metal bath in the smelting furnace to produce molten iron.

Smelting reduction method

The invention provides an apparatus for smelting reduction of iron ore which contains (1) at least one preheat and prereduction furnace which preheats and prereduces iron ore to a prereduction degree of less than 30%; (2) a smelting reduction furnace into which the preheated and prereduced iron ore, carbonaceous material and flux are charged and in which the preheated and prereduced iron ore is reduced; and (3) a top blow oxygen lance having first nozzles for decarburization and second nozzles for post-combustion, oxygen gas being blown through the first nozzles and the second nozzles into the smelting reduction furnace. At least one side tuyere is placed in a side wall of the smelting reduction furnace and at least one bottom tuyere is placed in a bottom wall of the smelting reduction furnace for blowing a stirring gas through the at least one side tuyere and the at least one bottom tuyere into the smelting reduction furnace.

Apparatus for smelting reduction of iron ore

An apparatus for a smelting reduction of iron ore comprising a preheat and prereduction furnace which preheats and prereduces iron ore, a smelting reduction furance into which said preheated and prereduced iron ore, carbonaceous material and fluxes are charged and in which said preheated and prereduced iron ore are smelted and reduced, a top blow oxygen lance having decarburizing nozzles and post-combustion nozzles and blowing oxygen into said smelting reduction furance, and at least one side tuyere placed at a side wall of the smelting reduction furnace and at least one bottom tuyere placed at a bottom of the smelting reduction furnace through which a stirring gas is respectively blown so that at least a part of said stirring gas introduced through said at least one side tuyere hits a swollen portion of the molten metal by said stirring gas introduced through said at least one bottom tuyere.

Method for smelting reduction of iron ore and apparatus therefor

A method for smelting reduction of Ni ore comprises charging Ni ore and carbonaceous material into a converter type smelting reduction furnace having bottom-blow tuyeres and a top-blow lance, the smelting reduction furnace holding a molten metal, blowing oxygen gas from the top-blow lance and a stirring gas from the bottom-blow tuyeres into the furnace, and discharging slag so that a relation represented with a formula

Method for smelting reduction of Ni ore

Method of decarburizing high chromium molten metal

A method for manufacturing molten metal containing Ni and Cr comprises a process of smelting and reducing Ni ore, and a process of smelting and reducing Cr ore. The process of smelting and reducing Ni ore comprises the steps of charging molten iron into a smelting reduction furnace having a top-blow oxygen lance and tuyeres for blowing stirring gas, charging Ni ore, carbonaceous material and flux into the smelting reduction furnace, blowing decarbonization oxygen and post-combustion oxygen from the top-blow oxygen lance into the smelting reduction furnace, blowing stirring gas for stirring the molten metal and slag inside the smelting reduction furnace from the tuyeres, and controlling post-combustion ratio [(H.sub.2 O+CO.sub.2)/(H.sub.2 +H.sub.2 O+CO+CO.sub.2)] at 0.3 or more. The process of smelting and reducing said Cr ore comprises charging Cr ore, carbonaceous material and flux into the smelting reduction furnace holding the molten metal containing Ni, blowing decarbonization oxygen and post-combustion oxygen from the top-blow oxygen lance into the smelting reduction furnace, blowing stirring gas for stirring the molten metal and slag inside the smelting reduction furnace from the tuyeres, and controlling post-combustion ratio [(H.sub.2 O+CO.sub.2)/(H.sub.2 +H.sub.2 O+CO+CO.sub.2)] at 0.3 or more.

Method for manufacturing molten metal containing Ni and Cr

A method for smelting reduction of Ni ore comprises charging Ni ore, carbonaceous material and flux into a converter type smelting reduction furnace holding molten iron therein and controlling a post-combustion ratio [(H.sub.2 O+CO.sub.2)/(H.sub.2 +H.sub.2 O+CO+CO.sub.2)] inside the smelting reduction furnace at 0.3 or more by blowing oxygen from a top-blow oxygen lance and stirring gas from a bottom-blow tuyere arranged in the bottom of the smelting reduction furnace into the smelting reduction furnace. A relation between a content of carbon [C] (%) in molten metal and an amount of slag produced per ton of molten metal is represented with a formula:

A method for smelting reduction of iron ore comprises the steps of: preheating and prereducing iron ore; charging said preheated and prereduced iron ore, carbonaceous material and flux into a smelting reduction furnace; blowing oxygen gas through a top blow oxygen lance having decarburizing nozzles and post-combustion nozzles into said smelting reduction furnace, an end of said top blow oxygen lance being arranged between an upper side level of a slag layer and a lower side level of said slag layer; blowing a stirring gas through at least one side tuyere placed in side wall of said smelting furnace and at least one bottom tuyer placed in bottom wall of said reduction furnace so that at least part of said stirring gas introduced through at least one said side tuyere hits a swollen portion of the molten metal by said stirring gas introduced through at least one said bottom tuyere; and controlling a flow rate of said oxygen gas and said stirring gas blown in said smelting reduction furnace so that an OD of infurnace gas of said smelting furnace ranges 0.5 to 1.0, where said OD is represented by the following formula: OD=(H.sub.2 O+CO.sub.2 )/(H.sub.2 +H.sub.2 O+CO+CO.sub.2). And, further, an apparatus used in the above-mentioned method.

Method for smelting reduction of iron ore

A method for smelting reduction of iron ore, comprises the steps of: introducing iron ore into a preheat and prereduction furnace and preheating and prereducing the iron ore, a prereduction degree being less than 30%; charging the iron ore, carbonaceous material and flux into a smelting reduction furnace; blowing oxygen gas, through decarburization nozzles and post-combustion nozzles placed in a top end of an oxygen lance, into the smelting reduction furnace, the top end of the oxygen lance being located so as to be between a top level and a bottom level of a slag layer; blowing a stirring gas through side tuyeres placed in a side wall and bottom tuyeres placed in a bottom wall of the smelting reduction furnace; and controlling a flow amount of the oxygen gas and the stirring gas so that an oxidation degree of an exhaust gas generated in the smelting reduction furnace ranges 0.4 to 0.9 and still a temperature of the exhaust gas ranges 300.degree. to 1300.degree. C. when the exhaust gas is introduced into the preheat and prereduction furnace. Furthermore, an apparatus for smelting reduction of iron ore comprises: a preheat and prereduction furnace; a smelting reduction furnace; a top blow oxygen lance with decarburization nozzles and post-combustion nozzles; side tuyeres and bottom tuyeres.

An apparatus for smelting reduction comprising a preheat and prereduction furnace for preheating and prereducing iron ores; a smelting reduction furnace into which iron ores, carbonaceous material and fluxing material are charged and in which the iron ores are smelted and reduced; a top-blow oxygen lance through which oxygen gas is blown into the smelting reduction furnace, having decarbonizing nozzles and post combustion nozzles; and the smelting reduction furnace having bottom and side tuyeres built respectively in a side wall and a bottom thereof.

Apparatus for smelting and reducing iron ores

Method of smelting reduction of chromium raw materials and a smelting

Method of producing stainless molten steel by smelting reduction

A method for smelting and reducing iron ores comprises the steps of: the step of preheating and prereducing iron ores; the step of charging the preheated and prereduced iron ores into a smelting reduction furnace; the step of charging carbonaceous material and fluxing material into the smelting reduction furnace; the step of blowing in oxygen gas into the smelting reduction furnace through a top-blow oxygen lance having decarbonizing nozzles and post combustion nozzles; and the step of blowing in stirring gas through side and bottom tuyeres set respectively in a side wall and a bottom of the smelting reduction furnace. Furthermore, an apparatus for smelting reduction fitted for the method comprising: a preheat and prereduction furnace preheating and prereducing iron ores; a smelting reduction furnace into which iron ores, carbonaceous material and fluxing material are charged and in which the iron ores are smelted and reduced; a top-blow oxygen lance through which oxygen gas is blown in into the smelting reduction furnace, having decarbonizing nozzles and post combustion nozzles; and the smelting reduction furnace having bottom and side tuyeres built respectively in a side wall and a bottom thereof.

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Tokyo, Japan

Katsuhiro Iwasaki