Uddeholms Aktiebolag

Allmanna Svenska Elektriska Aktiebolaget

Lars-Gunnar Norberg

Karl-Erik Oberg

Kare Folgero

Bengt Fredriksson

M K Johnsson

Rune H Lindstrom

Kare M Folgero

Per-Ake Lundstrom

A process for the production of ferro alloys containing manganese, chromium, molybdenum, and small amounts of carbon is provided. To a converter having a previous product melt and a slag rich in oxides of chromium or manganese is added a reducing agent having an excess of silicon or aluminum. Fluid is injected into the melt to create intensive agitation of the melt, slag and reducing agent, whereby the oxides in the slag are reduced. Lime is added to fix the resulting silicoc acid or aluminum oxide, and the slag with reduced chromium or manganese content is removed from the converter. Injection into the melt of a pulverulent oxide concentrate of chromium or manganese is continued, with additional lime, until the excess of silicon or aluminum in the melt, supplied by the reducing agent, reduces the injected oxide concentrate and the chromium and manganese are oxidized and go into the slag. The resulting product is partially tapped from the converter and the process is repeated.

Process for the production of ferro alloys

A metallurgical furnace vessel is provided with means for injecting fluid into a melt in a vessel, the fluid carrying materials reactive with the melt and incidentally causing rapid erosion of the vessel's wall portion above the location where the fluid is injected. This wall portion is provided with cooling means and is made so that it can be removed for repair or replacement.

Metallurgical furnace having fluid injection means for a melt in the

A metallurgical furnace has a wall contacted by molten metal and having a nozzle opening below the level of the metal, a nozzle positioned in this opening forms a passage for injecting a blast into the metal, and this nozzle has means for liquid-cooling the outer end of its blast passage to freeze the molten metal when flowing backwardly through the nozzle's passage in the event of a blast failure. In such an event, the frozen or solidified metal forms a stopper for the nozzle's passage.

Metallurgical furnace having a blast injection nozzle

A method of treating molten metal in a converter having an induction heater the heating space of which opens into the lowermost portion of the converter compartment comprises injecting a mixture of a solid treating material in powder form with a carrier gas through a sidewall of the converter at a level only slightly above the bottom wall of the converter compartment. A tuyere through which the gas-powder mixture is injected is directed slightly downward and toward the region where the heating space of the induction heater opens into the converter compartment.

Method for treating a metal melt

A process is provided for directly reducing a metal oxide to metal in a molten metal which comprises providing a body of molten metal in a converter provided with means for introducing molten metal and means for introducing metal oxide into the body of the molten metal by introducing molten metal therein, introducing said metal oxide as a powder suspended in a carrier gas, separately from said molten metal, into the body of the molten metal such that the molten metal introduced is hotter than the suspended powder and is distributed by said suspension to other parts of the mass of molten metal where the reduction can take place at the desired temperature. Preferably the molten metal is introduced into the converter via a channel in liquid communication with the converter, the channel opening into the converter at a level below the operating level of the molten metal, said metal being melted in a separate heating zone such that a temperature gradient is established between said zone and the contents of the converter, said zone having a refractory lining which is thinner than the lining of the converter, and the suspended metal oxide is injected into the body of the molten metal via a tuyere extending through the wall of the converter and terminating in the vessel at a distance from the channel, such that the suspended metal oxide does not pass through the heating zone.

Metallurgical method

Apparatus suitable for injecting fluids, particularly suspensions of solids in gases, below the surface of a molten metal, e.g. in emulsion metallurgy, comprises a converter having a tuyere for injecting the fluid below the surface of the molten metal, and a heating zone, spaced away from the converter but in liquid communication with the converter at a level below the surface of the molten metal, the heating zone having a thinner lining than the converter and being heated by electric induction heating so that a temperature gradient can be set up between the heating zone and the converter to maintain the temperature of the molten metal in the converter. The converter is dimensioned such that it can be tilted to a position where it can still contain the whole volume of molten metal to be treated but the openings of the channel and of the tuyere are exposed above the surface of the molten metal in the tilted position. The apparatus can be used for desulphurisation or decarburization of steel, the reduction of reducible metal oxides by emulsion reduction, the introduction of alloying components or the introduction of endothermally reacting gases into molten metals.

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Hagfors, Sweden

Lars-Gunnar Norberg