摘要:
A method of and an apparatus for the refining of a molten metal overlain by a slag and in which cold solids are introduced, e.g. in the form of metal scrap. According to the invention the heat necessary to melt the scrap and prevent undue cooling of the bath is generated by directing a jet of neutral gas entraining carbon against the surface of the melt perpendicularly thereto at Mach 1.5 to Mach 2.5, while refining oxygen is directed at the surface from jets inclined to the carbon entraining jet and the melt is bottomblown by neutral gas to prevent excessive foaming of the slag.
摘要:
Process of refining of a metal bath in a crucible with oxygen blast at the top and crucible used.The invention consists essentially of providing in the bottom (15) of the crucible agitating gas injectors (15) located at least in a peripheral circular ring situated in immediate proximity to the refractory side wall. The injectors are preferably concentrated opposite the journals. Secondary injectors are, also preferably, provided in the bottom zone, intermediate between the ring and the center of the crucible.The invention makes it possible, in relation to the prior injection practice, to reduce the rate of dissolution of the agitating gas in the molten metal and then makes it possible to use a low-cost agitating gas, such as nitrogen, without risk of excessive nitridation of the bath.
摘要:
A process for refining a steel melt in a furnace in which a steel melt is formed with a slag layer thereon, the thickness of which can be controlled by passing a stream of inert gas upwardly through the melt, while directing a first stream of oxygen into the melt from a lance positioned above the melt for the top-blowing refining thereof to produce carbon monoxide above the melt and feeding a second stream of oxygen from the lance for the post-combustion of the released carbon monoxide, while monitoring continuously the thickness of the slag layer, the height of the melt, the carbon monoxide post-combustion factor (%CO.sub.2 /%CO+%CO.sub.2) and the speed of decarburization of the melt and controlling the height of the lance above the melt and the discharge rates of total blown oxygen, the second stream of oxygen and the inert gas stream at any given time in accordance with a particular relationship.
摘要:
A melt is contained in a vessel having below the level of the melt an at least gas-pervious wall portion. First the slag is removed, normally by pouring it off, from the melt. Then a finely divided treatment solids suspended in a gas is introduced through the wall portion into the melt. The melt reacts thoroughly with these solids. Immediately deslagging the melt substantially reduces its ability to pick up nitrogen or hydrogen. This can be enhanced by the further step, prior to introduction of the suspension, of adding pure lime to the melt to form a protective layer thereon. The vehicle gas for the powder of course is inert, normally argon. The vessel can also be sealed up with a tight cover after addition of pure lime to it and before introduction of the suspension. Otherwise in the subsequent desulfurizing nitrogen and hydrogen will enter into the metal matrix, especially if there is an appropriate slag present.
摘要:
A system for treating, normally refining, a metallurgical melt has a melt-containing vessel having below the level of the melt an at least gas-pervious wall portion. A finely divided treatment solids is suspended in a treatment gas and this suspension is introduced through the pervious wall portion into the melt and reacting the melt with the gas and solids. The wall portion has openings oriented so that the gases and particles can pass into the vessel through them, but the molten metal therein cannot enter them. A plurality of such gas-and particle-pervious inserts are provided in the base of the crucible. They can be individually controlled relative to respective sensors provided above the melt. Thus exothermically reacting gases and/or particles are fed in under cold spots, or endothermically reacting gases and/or particles are fed in under hot spots.
摘要:
A method of producing molten iron in which iron oxide is fed together with carbon to an oxygen-top-blown melt from below through blocks whose pores permit the particles to be entrained into the melt in a carrier gas, the pores preventing penetration of the molten metal.
摘要:
An electromagnetic stirring process for continuous casting is presented. According to the present invention, coils of inductors are supplied with a multiphase current so as to create in a molten metal at least one primary rotational movement zone which is offset with respect to a central casting axis. This primary rotational movement zone is also revolved in a secondary gyratory movement around the central casting axis by a cyclic commutation of each phase of the current.
摘要:
A composite beam especially for pile driving comprises an H-beam core whose flanges are bridged by steel sheets having inwardly bent edges engaging over outwardly projecting spurs on the flange edges. The web of the H-beam thus defines with the sheets two compartments which are internally lined with colloidal concrete, the outer steel surfaces being likewise coated with colloidal concrete.
摘要:
Molten metallurgical slags are expanded by contact with water in a liquid or vapor state by passing the molten slag along a prefoaming or expanding trough by delivering the slag to this trough via an intermediate trough which is shiftable along the prefoaming trough in order to vary the location at which the slag contacts the prefoaming trough and the expanding-agent film thereon in accordance with physical characteristics of the molten slag, especially its temperature and viscosity. From the pre-expanding or prefoaming trough, the partially expanded slag may be subjected to expansion by conventional means, e.g. a rotating drum which disperses the slag particles through the air so that they can be collected in a completely expanded, dry and solidified state.
摘要:
A refining ladle provided with a refractory lining contains a liquid-steel melt topped by a layer of slag. Wear of the lining, which is principally concentrated at the region in contact with the slag is minimized by displacing the upper surface of the melt relative to the lining of the ladle or other smelting receptacle so as to spread this wear over a greater area. This displacement is effected by providing the ladle with a plurality of throughgoing holes establishing different levels at which the melt surface is held for predetermined regular intervals. It is also possible to rotate the ladle continuously or discontinuously about its longitudinal axis. A hardenable patching material may be sprayed against a portion of the ladle lining when this portion is exposed by displacement of the melt and slag therein.