Gfe Gesellschaft Fur Elektrometallurgie Mbh

Gfe Gesellschaft Fur Elektrometallurgie MIT Beschrankter Haftung

Gesellschaft Fur Elektrometallurgie Mbh

Rudolf Fichte

Hans-Joachim Retelsdorf

Friedrich Breuer

Reinhard Hahn

Gunter Duderstadt

Karl Brotzmann

Siegfried Sattelberger

Fritz Stadler

Gerd Nassauer

Richard Jervis

Peter Kunert

Gunter Radel

Werner Dresler

Peter K Kunert

Process for the recovery of vanadium from vanadium-containing source materials under the addition of additives, especially alkali metal compounds, particularly the carbonates, chlorides, sulfates as well as nitrates and/or mixtures of these compounds, whereby the source material is ground and roasted. The roasted material is leached and whereby the withdrawn leach solution is hydrometallurgically treated for the recovery of vanadium compounds. The source materials are first roasted without the addition of alkali additives and subsequently are leached in a first leaching step. To the residues of the first leaching step are added alkali additives and the mixture is roasted in a second roasting step. The roasting products are again leached.

Method of recovering vanadium from vanadium-containing materials with at

Titanium-containing hydrogen storage alloys with a Laves phase composition AB.sub.2 are made in which the A component is titanium and possibly an element from the start of the transition metal groups of the Periodic Table. According to the invention a titanium-free prealloy is first formed and this prealloy is comminuted and smelted again with addition of titanium and possibly zirconium in a second vacuum furnace stage. The latter melt is then deoxidized with cerium mischmetal. Hydrogen storage capacities of about 2% by weight and above that conventionally obtained can be made.

Method of making a titanium-containing hydrogen storage alloy

A method of making cobalt-boron and/or nickel-boron alloys in a low-shaft electrical furnace wherein the burden or charge has a height of at least 500 mm and at least a portion of its carbon carrier consists of wood chips which are carbonized to wood charcoal during the process so that the wood charcoal which is produced can adsorb volatilized boron compounds and tap them so that they do not escape. The volatilized boron compounds thus tapped are carried to the reduction zone by the wood charcoal so that a high yield is obtained and the product has a low aluminum content.

Carbothermal method of producing cobalt-boron and/or nickel-boron

A method of making ferroboron or ferroborosilicon alloys in a low-shaft electrical furnace wherein the burden or charge has at least as a major portion of its carbon carrier, wood chips or particles which are carbonized to wood charcoal during the process and thus the charge has a porosity which permits adsorption action to prevent loss of volatile boron compounds. The charge also contains iron oxide and boron oxide, the electrodes of the furnace effecting a reduction of the boron oxide at a reduction zone just above the floor of the furnace.

Method of making ferroboron and ferroborosilicon alloys and the alloys

A workpiece of alloy steel is produced by sintering under a nonoxidizing atmosphere a mass of malleable-iron powder admixed with a comminuted complex ferroalloy. The latter, obtained from a molten mixture of several simple high-carbon ferroalloys saturated with graphite, is a blend of at least three nonferrous metals and iron in carbide form, including a complex carbide of formula M.sub.7 C.sub.3 containing iron and manganese with the possible addition of chromium and another carbide of formula M'.sub.2 C/M'C containing molybdenum with the possible addition of vanadium and/or niobium. The carbidically bound carbon amounts to at least 4%, by weight, of the ferroalloy composition and may constitute between 10% and 60% of the carbon of the sinterable powder mixture to which elemental carbon may be added as graphite. As the mass of iron and ferroalloy particles compacted under high pressure is sintered at temperatures between about 1150.degree. and 1300.degree. C., the carbides lose their identity as their metals diffuse into the soft iron along with the carbon.

Sinterable mass for producing workpieces of alloy steel

The invention relates to a method of rapidly decarburizing a high-carbon ro-alloy with oxygen for avoiding an undesirable oxidation of the principal alloying elements, especially chromium or manganese, comprising blowing an oxidizing gas under the surface of a bath of molten ferro-alloy from one or more gas-jacketed nozzles in an amount ranging between substantially 3 and 15 m.sup.3 S.T.P. per metric ton of ferro-alloy with reduction of the carbon content of the ferro-alloy at a rate of about 0.2% to 1%. Comminuted solids, especially particles of oxides of alkaline-earth metals such as powdered lime, may be admixed with the oxidizing gas to prevent the ejection of molten metal from the bath.

Method of rapidly decarburizing ferro- alloys with oxygen

A ferro-alloy, namely ferrochrome or ferromanganese, is refined by being heated to at least 100.degree. C above its melting point to form a bath whereupon oxygen is blown into the melt, below the bath surface, within a protective gas envelope. The rate of oxygen blowing is so chosen that 1% of carbon is oxidized within a period not to exceed about ten minutes, preferably not more than five minutes.

Method of refining ferro-alloys

A hign-carbon ferro-alloy, specifically ferrochrome or ferromanganese, is carburized in a converter in which oxygen or air is blown from below into the melt together with a surrounding protective gas. With the bath preheated to a temperature somewhat higher than the melting point of the ferro-alloy, the oxygen is introduced at such a rate that its reaction with the chromium or the manganese locally superheats the bath, in a region well below the surface and spaced from the converter walls, to a temperature high enough to let the resulting oxides react endothermically with the carbon. This reaction takes place in combustion zones believed to be localized in gas bubbles formed above the injection nozzles, the oxidation of the ferrous and nonferrous constitutents occurring at the interface between the gas and the melt with formation of a very thin and highly reactive oxide skin around each bubble. Some high-melting oxides of chromium or manganese may remain after the oxygen blow but can be reduced by blowing in powdered lime, after and possibly also with the oxygen, and by the deposition of solid or liquid reducing agents on the bath surface. A minor fraction of the ferro-alloy may be added in solid form to hold down the bath temperature.

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Nuremberg, Germany

Rudolf Fichte