COMPOSITE BLOWING FOR CONVERTER IN STAINLESS STEEL SMELTING

摘要

PURPOSE:To widely prolong the life of a converter in the case of the composite blowing of a molten stainless steel in a converter by controlling the quantity of gas blowing from the tuyere of the hearth to be more in outside than the inside. CONSTITUTION:In the case of smelting molten stainless steel, plural gas blowing tuyeres A, B, C, D are provided on the hearth 2 of the converter 1 and a jet stream of gaseous oxygen is blown downwards from a lance 4 and executes composite blowing smelting by blowing the stirring gas from hearth by the respective lances A-D. At this time, tuyeres A, B are provided in a first section 2a which is the inside of circumference 3 on the hearth drawn by crossing point of extension line of a center of the jet stream of gaseous oxygen from the lance 4 and the hearth 2 as an center and tuyeres C, D are provided in a second section 2b which is the outside of the circumference 3. In this constitution, the flow rate of stirring gas of bottom blowing is expressed as for molten stainless steel in the furnace as 0.02-0.1Nm3/min.ton and the total gas flow rate blown from the tuyeres A, B in the first section 2a is 1/2-1/1.2 against total the gas flow rate blown from tuyeres C, D in the secondary area 2b respectively. By this means, unbalanced wearing rate of refractories for the tuyeres are corrected.