Skw Trostberg Aktiengesellschaft

Thyssen Stahl Ag

Metallgesellschaft Aktiengesellschaft

Suddeutsche Kalkstickstoff-werke Aktiengesellschaft

Werner Gmohling

Walter Meichsner

Alfred Freissmuth

Heinrich Rock

Karl-Heinz Peters

Manfred Tutte

Heinrich Rellermeyer

Friedrich Wolfsgruber

Karl J Reifferscheid

Helmut Lischka

Jochen Hintermayer

Ernst A Weiser

Georg Schroll

Ernst Graf

Gerd Hieber

Wolfgang Kobler

Hans Kern

The present invention provides a process for the production of silicon nitride by the reaction of silicon and nitrogen, wherein, in one reaction step, silicon powder is reacted with nitrogen which continuously rotates at a temperature of from 1000.degree. to 1800.degree. C. and at a pressure of from 1.01 to 1.8 bar up to a nitrogen content of 1 to 39.5% by weight. The present invention also provides a silicon nitride produced by this process wherein it is obtained in porous form and has the following properties.

Process for the production of silicon nitride and product made according

The present invention provides an agent for desulphurizing iron containing calcium carbide and a metallic component, wherein the calcium carbide and the metallic component are present in such a form that the bulk densities and grain sizes thereof lie in the same range. The present invention also provides a process for producing this agent, as well as a process for desulphurizing iron using this agent.

Agent for desulphurizing iron melts, a process for the production

A process for desulfurizing molten iron using a fine-grain agent consisting essentially of industrial calcium carbide, a dried coal, the coal containing at least 15% by weight of volatile components, and fine-grained magnesium and which agent is injected in fluidized form into an iron melt by means of a gas, comprising separately storing fine-grained magnesium and a calcium carbide/coal mixture, separately fluidizing the fine-grained magnesium and calcium carbide/coal mixture, combining the fluidized fine-grained magnesium and calcium carbide/coal mixture in a conveying line or lance and injecting the resultant combined fluidized mixture into an iron melt. A process for desulfurizing molten iron using a fine-grain agent consisting essentially of industrial calcium carbide, a dried coal, the coal containing at least 15% by weight of volatile components, and fine-grained magnesium and which agent is injected in fluidized form into an iron melt by means of a gas, comprising separately storing fine-grained magnesium, calcium carbide and coal, separately fluidizing the fine-grained magnesium, the calcium carbide and the coal, combining the fluidized fine-grained magnesium, the calicum carbide and the coal in a conveying line or lance and injecting the resultant combined fluidized mixture into an iron melt.

Process for desulfurizing molten iron

A fine-grained agent for desulfurizing molten iron comprising industrial calcium carbide, dried coal which contains at least 15% by weight of volatile constituents and which, immediately after being passed into the molten iron, releases at least 80 standard liters of gas per kg of coal, and optionally contains fine-grained magnesium. The coals used are lignites, flame coal, gas-flame coal, gas coal or coking coal. The agent is prepared by addition of the dried coal to the calcium carbide, if appropriate, pre-crushed, and common comminuted to a grain size of 90% &lt;200 .mu.m. The fine-grained magnesium is present in the agent either in uniform distribution, or it is stored and fluidized separately from the carbide/coal mixture and added to the carbide/coal mixture in the transport line or in the lance, if appropriate, with variation during injection.

Fine-grained agent for desulfurizing molten iron

A method and composition for desulfurization of hot metal is disclosed. To the hot metal there is added a composition comprising calcium carbide, a hydrogen releasing compound and magnesium.

Method, process and composition for desulfurizing pig-iron melts

The present invention provides a treatment agent for cast iron melts based upon ferrosilicon magnesium with a silicon content of from 40 to 80% by weight and a magnesium content of from 0.5 to 15% by weight, said agent being in the form of granules with a specific surface area of from 0.2 to 0.8 m.sup.2 /g. according to BET. The present invention also provides a process for the production of this treatment agent, wherein a jet of molten ferrosilicon magnesium alloy is directed on to a bounce plate made of fire-resistant material and the melt droplets which bounce back from bounce plate are allowed to solidify in a liquid-filled collection receiver.

Treatment agent for cast iron melts and a process for the production

The present invention provides a desulphurizing agent, especially for iron melts, based upon calcium carbide and diamide lime, wherein it contains a diamide lime which has been post-treated by flotation or air sifting. The diamide lime used preferably contains 18 to 40% of free carbon.

Desulfurization agent

Process and composition for desulfurizing pig iron in which the desulfurization agent consists essentially of calcium carbide, a gas-evolving component and fluorspar; the advantage of the process and composition is that it reduces dust pollution and danger of flaming in the handling of the slag after the desulfurization of pig iron.

Desulfurization mixture and process for desulfurizing pig iron

Improved desulfurization of ferrous melts is obtained by injecting into the melt a readily-flowable desulfurization composition composed of a desulfurization agent, such as calcium carbide or the like and, if desired, an additional component in which the particles are finely ground with about 3 to 20% by weight of carbon for at least about five minutes to coat the particles with a solid, lubricating coating of carbon.

Desulfurizing composition, process for producing them and

Improved desulfurization of ferrous melts is obtained by injecting into the melt in finely divided form a mixture by weight 48% to 95% calcium carbide, 2% to 40% of carbon-containing calcium carbonate and from about 1% to 12% of high volatile, bituminous coal dust.

Desulfurization agent for ferrous melts and method of using the same

Finely granular desulfurizing agents for iron melts, consisting of at least one alkaline earth metal carbonate and at least one reducing metal carbide and optionally a reducing metal or an alloy thereof, are outstandingly effective in desulfurizing action and, based on the high degree of utilization of said agent, increase the amount of slag formed only to a negligible degree.

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Hufschlag, Germany

Werner Gmohling