Lump lime as the most common flux and iron ore as a coolant are used in basic oxygen steel making. However, high melting point, poor dissolution property, fines generation tendency and hygroscopic nature of lump lime ...Lump lime as the most common flux and iron ore as a coolant are used in basic oxygen steel making. However, high melting point, poor dissolution property, fines generation tendency and hygroscopic nature of lump lime often create problems in operation. As the combination of both iron oxide （Fe2O3） and CaO shows eutectic at 1 230 ℃, a combined mass of iron oxide and lime melts at lower temperature and dissolves faster in a molten bath. A partially pre-fused synthetic flux （PSF） was prepared through an innovative way in combination of iron oxide fines viz. Linz Donawitz converter sludge and blast furnace flue dust and lime fines by micro-pelletization of the mix followed by coke breeze free sintering. The developed PSF shows good cold handling strength, low melting point （1 180 ℃）, good thermal shock resistance, etc. As a low melting synthetic flux, its performance was assessed through dissolution/melting study in hot metal bath and refining of hot metal in a simulated bottom blown converter using （i） PSF, （ii） only lump lime and （iii） lump lime with iron ore when keeping other conditions identical. Very fast dissolution （27 80 s for 1-3 g lumps）, enhanced removal of C and P （11-12 min）, controlled slag foaming, and reduced oxygen consumption was obtained for using PSF.展开更多
We propose a theoretical scheme to realize nonreciprocal transition between two energy levels that can not coupled directly.Suppose they are coupled indirectly by two auxiliary levels with a cyclic four-level configur...We propose a theoretical scheme to realize nonreciprocal transition between two energy levels that can not coupled directly.Suppose they are coupled indirectly by two auxiliary levels with a cyclic four-level configuration,and the four transitions in the cyclic configuration are controlled by external fields.The indirectly transition become nonreciprocal when the time reversal symmetry of the system is broken by the synthetic magnetic flux,i.e.,the total phase of the external driving fields through the cyclic four-level configuration.The nonreciprocal transition can be identified by the elimination of a spectral line in the spontaneous emission spectrum.Our work introduces a feasible way to observe nonreciprocal transition in a wide range of multi-level systems,including natural atoms or ions with parity symmetry.展开更多
基金the financial assistance received from Ministry of Steel(Government of India) under Steel Development Fund to carry out this investigation
文摘Lump lime as the most common flux and iron ore as a coolant are used in basic oxygen steel making. However, high melting point, poor dissolution property, fines generation tendency and hygroscopic nature of lump lime often create problems in operation. As the combination of both iron oxide （Fe2O3） and CaO shows eutectic at 1 230 ℃, a combined mass of iron oxide and lime melts at lower temperature and dissolves faster in a molten bath. A partially pre-fused synthetic flux （PSF） was prepared through an innovative way in combination of iron oxide fines viz. Linz Donawitz converter sludge and blast furnace flue dust and lime fines by micro-pelletization of the mix followed by coke breeze free sintering. The developed PSF shows good cold handling strength, low melting point （1 180 ℃）, good thermal shock resistance, etc. As a low melting synthetic flux, its performance was assessed through dissolution/melting study in hot metal bath and refining of hot metal in a simulated bottom blown converter using （i） PSF, （ii） only lump lime and （iii） lump lime with iron ore when keeping other conditions identical. Very fast dissolution （27 80 s for 1-3 g lumps）, enhanced removal of C and P （11-12 min）, controlled slag foaming, and reduced oxygen consumption was obtained for using PSF.
基金supported by the National Natural Science Foundation of China(NSFC)under Grant No.12064010the Natural Science Foundation of Hunan Province of China under Grant No.2021JJ20036,and the Natural Science Foundation of Jiangxi Province of China under Grant No.20192ACB21002.A.-X.C.is supported by NSFC under Grant No.11775190.
文摘We propose a theoretical scheme to realize nonreciprocal transition between two energy levels that can not coupled directly.Suppose they are coupled indirectly by two auxiliary levels with a cyclic four-level configuration,and the four transitions in the cyclic configuration are controlled by external fields.The indirectly transition become nonreciprocal when the time reversal symmetry of the system is broken by the synthetic magnetic flux,i.e.,the total phase of the external driving fields through the cyclic four-level configuration.The nonreciprocal transition can be identified by the elimination of a spectral line in the spontaneous emission spectrum.Our work introduces a feasible way to observe nonreciprocal transition in a wide range of multi-level systems,including natural atoms or ions with parity symmetry.
