Daido Tokushuko Kabushiki Kaisha

Daido Steel Co., Ltd.

Daido Ecomet Kabushiki Kaisha

Tetsuo Okamoto

Noboru Demukai

Saburo Sugiura

Kenji Kanada

Motoshi Shinkai

Hajime Amano

Kiyohide Hayashi

Yasuaki Ikitsu

Nobuyuki Kamei

Yoshio Inagaki

Senji Fujita

Sabro Sugiura

Hiroya Nakata

Toshiki Watanabe

Keiichi Mizuguchi

Atsushi Ishii

Wataru Sato

Hideharu Sakai

A powder body melting burner which injects a powder body, fuel and oxygen into a furnace individually from a burner head and melts the powder body in flames in which the fuel is burned under oxygen support. The burner includes a single powder body injection hole provided in the center of the burner head, a plurality of fuel injection holes disposed at a predetermined central angle in the radial direction centered on the powder body injection hole, a single primary oxygen injection bole provided concentrically which each of the fuel injection holes, a plurality of second oxygen injection holes ranged in large numbers at a predetermined interval so as to enclose each of the powder injection boles and the fuel injection holes with the plurality of secondary oxygen injection holes forming a ring shape as a whole and a cooling chamber provided on the back side of the burner head.

Powder body melting burner

A process for producing metals in the reduced state from their oxides using a simple and less expensive facility with lower running cost. A metal oxide in the form of particles is supplied into a high temperature flame from an oxygen burner in a reactor furnace to heat and melt the metal oxide. A reducing agent is also supplied into the flame to cause a reducing reaction of the molten metal oxide with the reducing agent. The resulting metal is recovered.

Process for obtaining metal from metal oxide

A melting furnace for reforming steel-making slag so as to be available, for example, to roadbed ballast by mixing steel-making dust with the slag in molten states, which is provided with a fuel oxygen burner for melting the slag and the dust, a slag charging port for charging the slag in molten state into the furnace, a dust feeder for supplying the dust into the furnace, a slag feeder for supplying the slag in powdered state into the furnace, a storage portion for storing a molten mixture of the slag and the dust in a quantity corresponding to a tilting angle of the furnace body and an outlet port for discharging the molten mixture, and is possible to dispose the slag efficiently whether the slag is in the powdered or molten state.

Method and furnace for disposal of steel-making waste, and operating

A new electrode is joined to a consumed electrode of the electric furnace according to a method comprising the steps of lifting and transporting the new electrode suspended from a joining apparatus by a crane, aligning both electrodes by throwing a laser beam from a projector disposed to the crane on a positioning marker disposed on a deck plate provided in the vicinity of the electric furnace, screwing a screw thread of the new electrode into a threaded hole of the consumed electrode by actuating an electric motor disposed in the joining apparatus, and tightening both electrodes at desired tightening torque by operating the motor in a stalled state with a small electric current of low frequency.

Method and apparatus for joining new electrode to consumed electrode of

Disclosed are an improved method of refining steel and an apparatus for practicing the method. The refining method comprises, basically, carrying out the refining, particularly, decarburization, while stirring molten steel in the refining furnace by injecting gas thereinto, while supplying heat with a burner installed at the top of the furnace to the molten steel. According to this method, it is possible to start at an initial carbon content of the moltend steel lower than that of known AOD process, and complete the refining in a curtailed period of time and with a decreased oxidation loss of Cr. Thus, damage of refractory materials of the furnace is reduced, and the amount of Si necessary for reducing Cr-oxides in the latter stage of the refining is also reduced. Oxygen for the decarburization is supplied usually in the form of gas, but can be supplied from a solid oxygen source. In an alternative of the present method, powdery metal oxide, which is reducable equally to or more easily than Cr-oxides, is shot into the furnace through the burner or injected into the molten steel through a tuyere or an immersed lance. Preferably, the burner is of a type of variable flame length. Use of the burner disclosed here makes it possible to lengthened the flame at the former stage of the refining so that not only heat but also oxygen may be supplied to the molten steel surface of promoting the decarburization, and to shorten the flame at the latter stage of the refining so that only heat may be supplied.

Method and apparatus for refining steel

An improvement to a scrap melting method employing an electric arc furnace, which comprises the step of heating the scrap by a powdered coal burner prior to the step of heating the scrap by the electric arc. The burning conditions are controlled so as to reduce the amount of oxidized Fe as well as the amount of NO.sub.x contained in the exhaust gases. In preferred embodiments, a pair of furnaces are employed to heat the scrap alternately by the powdered coal burner and by the electric arc.

Scrap melting method

A powdered coal burner used for directly heating an object to be heated, particularly iron scrap, in a heating vessel. The burner is composed of an oxygen nozzle, a powdered coal nozzle, an air nozzle, disposed concentrically from the center, and a cone which is provided at the end of the opening part of the oxygen nozzle in such a way as to disperse oxygen in a radial direction and burn powdered coal. The burner burns with shortened length of flame, and temperature of the flame is not excessively high.

Powdered coal burner

During the heating of scrap in a container using sulfur-containing fuels for combustion, CaO, Ca(CO).sub.2, or CaCO.sub.3 powder is injected into the container to fix sulfur oxides generated during the combustion mainly as CaSO.sub.4. There is no need for special exhaust gas desulfurization, and, at the same time, slag formation is possible.

Growing community of inventors

Chita, Japan

Tetsuo Okamoto