Smelting method for melting steel slag into mineral wool material in converter steelmaking process

Abstract

The invention discloses a smelting method for melting steel slag into a mineral wool material in a converter steelmaking process. The smelting method can process steel slag in the initial stage of steelmaking into a mineral wool material with acidity and temperature satisfying the requirements through a conditioner or a reducing agent. The smelting method fully utilizes the existing converter equipment of the steel factory, fully utilizes steel slag and the thermal energy of the steel slag to produce a high value-added mineral wool material, solves the problems of steel slag thermal energy useand converter steel slag use and provides an efficient path for high value-added use of steel slag. Through use of the conditioner, the steel slag fluidity is greatly improved. After the initial stage of steelmaking, the poured phosphorus-containing steel slag is greatly increased and the burden of subsequent dephosphorization is reduced. In the later stage of tempering blowing, a gun caulking process is carried out so that the FeO content and metal iron content of the slag are greatly reduced, the steel consumption is reduced and the mineral wool quality is improved. The conditioner comprises a variety of waste slag so that waste slag use is realized and a use value of the waste slag is improved. The smelting method greatly reduces the yield of the mineral wool, reduces the coal consumption and waste gas pollution caused by the coal consumption and has enormous economic and social benefits.

Description

technical field [0001] The process relates to the field of converter steelmaking, in particular to smelting steel slag into mineral wool material while converter steel is being made. Background technique [0002] Smelting blast furnace dry slag or hot molten blast furnace slag to make slag wool is a mature process. In recent years, there has been a patent application technology for producing slag wool by using converter molten steel slag "a method for producing mineral wool by using molten steel slag in the early stage of converter" (Application No.: 201610369708.3) came out. This patent application technology uses low-alkalinity molten steel slag in the early stage of the converter to enter the slag tank, and then adds a modifier and a heating agent, that is, a silicon-iron-aluminum reducing agent to reduce heat and reduce the iron oxide in the slag. To counteract the temperature drop caused by the addition of SiO2-based materials or Al2O3-based modifiers, through stirring,...

AI Technical Summary

Problems solved by technology

To modify the initial converter slag with an alkalinity [CaO / SiO2) of 1.0-2.0 into mineral wool with an acidity (SiO2+Al2O) / (CaO+MgO) of 1.1-1.7 requires the addition of a large amount of modifiers and reducing agents. In addition to the heat generated by the reducing agent, there is no other heat source. The viscosity of the slag is already high, and the volume of the slag tank is small. Adding a large amount of modifier and reducing agent can not stir evenly, and it is difficult to reach the mineral wool Modification effect required

Using mechanical stirring, its service life and stirring effect are unsuitable for use. Using gas stirring will cause splashing and large temperature drop, and it cannot be implemented; since there is no other heat source, it is modified to the modifier and added when the acidity is greater than 1.5. The amount of reducing agent is large, the amount of reducing agent added is small, and the heat is not enough. If the amount of reducing agent added is too large, the FeO content in the slag cannot be guaranteed, so the viscosity of the slag material cannot be controlled, so it is impossible to use this patented technology to produce rock wool.

At the same time, a converter with this patented technology requires frequent lifting of 2-5 slag tanks, and the operating rate of the vehicle is not allowed; the reduced iron is difficult to completely precipitate and recover due to the thick slag layer