A method of starting a molten bath-based process for smelting a metalliferous material is disclosed. The method includes using the heat flux of water-cooled elements in lower parts of a smelting vessel to provide an indication of molten bath temperature during at least an early part of the start-up method and adjusting injection rates of oxygen-containing gas and/or carbonaceous material into the smelting vessel to control the molten bath temperature during start-up without exceeding critical heat flux levels and tripping the start-up method.

A lance (1) for blowing oxygen onto a bath of molten steel including a tip (15) provided with first oxygen ejector (16) and a distributor (17) provided with second ejector (18).

A molten iron refining method having, an auxiliary material, and an oxidizing gas supplied through a top-blowing lance, to a cold iron source and molten pig iron that are contained/fed in a converter-type vessel, and molten iron is subjected to a refining process. A pre-charged cold iron source is charged into the converter-type vessel at an amount not larger than 0.15 times. A furnace-top-added cold iron source that's part or all of the cold iron source and added from a furnace top is fed during the refining process. A burner at a leading end of the top-blowing lance that spray holes through which a fuel and a combustion-supporting gas are ejected. During the refining process, a powdery auxiliary material processed into powder that's part of the auxiliary material is blown in, to pass through a flame formed by the burner.

The instant invention relates to a blow lance assembly for metal manufacturing and refining, developed so as to control slag formation and oxidation, as well as the heat capacity of the reactor, and the conservation of the operational conditions during charging and blowing, having, in its lower part, two groups of gas outlets which determine two blowing conditions, the first group consisting of oxygen passage nozzles having a converging-diverging shape, main responsible for the oxidation reactions and for the conveyance of the basic solid material, mainly calcium oxide, for initial slag formation, and dephosphorization at the final stages during batch refining; the second group consisting of secondary jets with various functions during each blowing stage, the first function, at the beginning of the process as an afterburning agent, through the reaction of oxygen with carbon monoxide generated by the main jets, and the second function being that of accelerating the reaction with carbon by increasing oxygen jet speed, accelerating scrap melting in the early stages and, finally, incrementing the oxidation of the elements of the metal bath, iron, in order to reduce the phosphorus content in the final stages of batch refining.

Provided is a lance and an operation method using the same, in which a suction hole allowing source gas to be injected into a container, in which a reaction gas is generated, is included. The suction hole is formed in a source gas passage where the reaction gas is introduced into the passage. Thus the temperature of the gas injected into the container may be easily increased without using any separate heating device, and secondary combustion efficiency may be increased. In addition, the gas sprayed at a high temperature is provided, and thus additional heat may be supplied into the container. Thus, excessive use of fuel used to increase the temperature of the container may be avoided, and thus operation costs may be reduced and operation efficiency and productivity may be increased.