摘要:
A ferrous melt, e.g. of steel, is refined beneath a slag layer by blowing from above with an oxygen-containing gas through a lance and by bubbling an inert gas through the melt from the bottom. According to the invention, the consistency of the slag layer and/or its level is continuously detected on the one hand and the rate of decarburation of the bath is detected on the other hand and in response to these measurements the volume rate of flow of the bubbling gas is controlled on the one hand to maintain a predetermined spacing of the slag layer from the head of the lance and, on the other hand, a fluid consistency of the slag.
摘要:
An apparatus and method is presented for emptying metallurgical vessels, and in particular steelmaking converters containing metal and slag, whereby the slag is effectively separated from the metal during pouring. The apparatus includes at least on permeable refractory element located near the flow hole. An agitating gas is fed through the refractory element thereby creating a bubbling froth which effectively obstructs most of the slag from being carried along by the vortex which forms above the vertical flow hole.
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:
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:
Pig iron is refined by top blowing with oxygen and injecting inert gas from the bottom. The slag formation is minimized by controlled addition of lime to match the formation of slag components as they are generated by the process. This increases the capacity of the melt to receive a cold charge, e.g. of scrap.
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:
Slag is conditioned during blowing from above with oxygen of an iron melt by bubbling an inert gas into the melt from the bottom of the crucible in response to measurements made of the flowability of the slag layer and the speed of decarburization.
摘要:
A method and apparatus for accelerating solid particles entrained in a carrier gas so as to maximize the velocity of the particles at the output end of a duct is presented. This maximized or optimal acceleration is achieved by varying the cross section of the duct over at least the last 5 meters upstream from the opening thereof. Preferrably, the cross section of the duct should continuously increase i.e. diverge, towards the opening. This diverging cross section is preferrably in accordance with a nonlinear function of the length.
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:
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.