Abstract: A multi-chamber melting furnace for melting scrap of non-ferrous metals, in particular aluminum scrap, including a first shaft furnace with a shaft for charge material, in which impurities of the charge material can be removed, and at least one furnace chamber which is connected to the shaft of the first shaft furnace and has a first heat supply device, wherein at least one second shaft furnace with a shaft for charge material, in which shaft impurities of the charge material can be removed, the furnace chamber being connected to the shaft of the second shaft furnace and being arranged between the shafts in such a manner that the furnace chamber forms a main melting chamber in which the molten bath is located during operation.

Abstract: An alloy having two constituents: a crystal structure of orderly solid iron-based solution; a non-metallic phase at least partially soluble in iron including particles which are uniformly dispersed in the volume of the first phase and are of suitable size. In a preferred embodiment, the alloy contains iron with dissolved and bonded carbon as the first phase, which forms the crystal structure, and material partially soluble in iron, for example structurally free molecular carbon, is taken as the second non-metallic phase. The alloy preferably contains the components at the following ratios, % by mass: carbon in a dissolved and in a bonded state: 0.01-1.00; free carbon: 0.01-2.24; iron: balance. The ratio of free carbon to that of carbon in a dissolved and in a bonded state ranges from 0.01 to 20. The alloy Is preferably produced by melting out low carbon semi-product, overheating the semi-product above a liquidus temperature, for example by 20-70° C.

Abstract: In order to preheat pieces of iron scrap of various sizes and shapes highly effectively while avoiding the fusion of the pieces of iron scrap, a rotary kiln type preheating furnace and a shaft type preheating furnace are arranged in parallel with each other in the front stage of a melting furnace in which iron scrap is melted, and preheated iron scrap is charged from both preheating furnaces into the melting furnace. A damper is provided between the shaft type preheating furnace and the melting furnace, so that exhaust gas discharged from the melting furnace is prevented from directly flowing into the shaft type preheating furnace and introduced into the rotary kiln type preheating furnace. Exhaust gas which has passed through the rotary kiln type preheating furnace is introduced into the shaft type preheating furnace preferably from an upper portion and discharged from a lower portion.

Abstract: A hot coke bed is established at the bottom of a vertical shaft furnace, e.g. an iron melting cupola. The cupola is then charged with alternate layers of ferrous metal and coke material, respectively. Burners burn hydrocarbon fuel in the presence of a stoichiometric excess of oxygen-enriched air and thus form a hot gas mixture including oxygen. The hot gas mixture passes upwards through the shaft of the cupola thereby providing sufficient heat to melt the ferrous metal. Molten ferrous metal flows downwards under gravity into and through the coke bed and may be removed through a tap hole. At least one jet of oxygen is injected into the hot coke bed so as to maintain it at a temperature sufficient to superheat the molten metal. Preferably a fan is operated to dilute with air the combustion gases above the level of the charge in the shaft and thereby create secondary flames. No air blast is supplied to the cupola.

Abstract: The conventional operation of a cokeless cupola furnace has a requirement for a low volume of slag to be produced, because of the fact that there is no ash from coke to remove from the charge, and the fact that flux added to the charge to form slag eats away at the furnace lining, and at the bed of refractory spheres. Running the furnace at low slag volumes makes the slag thick and can cause blockage of the slagging and tapping box. The invention adds more flux materials than is conventional, preferably including silica in the form of broken bottles, so as to deliberately increase the volume of slag, improving the flow. Care must be taken not to add too much slag-forming materials.

Abstract: The improved method of melting a metal, especially cast iron, in a cokeless cupola furnace includes the step of injecting at least one case product quality improving and stabilizing substance into a space between the grate and the burners. The quality improving and stabilizing substance can be refining substance and a nuclear-enriching substance of the type used in code-fired cupola furnaces including nitrogen-containing substances such as ammonia and hydrazine and halogen-containing substances. A suitable apparatus for performing the improved process is also described having a downwardly direct lance for injection of the quality improving and stabilizing substance with an upwardly-directed mouth portion for forming an upwardly directed jet inserted through a furnace wall in a throughgoing guideway.

Abstract: For the purpose of melting scrap iron, pelletized sponge iron in reduced condition, solid pig iron or the like, there is introduced into the melting heat from below a charge-accepting receptacle by means of burners the carbon content within the molten bath is adjusted by a sub-stoichiometric combustion of hydrocarbon. Addition of any coal to the charged material is avoided. By reducing the oxygen flow, in particular by performing the combustion with approximately 0.9-times of the stoichiometric amount of oxygen, and by optionally adding slag formers, the aggressivity of the slag in relation to the furance lining is simultaneously reduced.