What Are the Different Raw Materials for Steel?

Refers to raw materials for smelting steel and iron. Mainly iron ore, manganese ore, iron-containing waste and flux. Iron and steel smelting, a general term for steel and iron metallurgy.

With the development of the steel industry,

Anything that can be used economically

An important slagging material in iron and steel metallurgy raw materials. Continuous steel casting | In the process of ironmaking, it forms fusible slag with impurities in iron ore or molten iron, and separates impurities from iron, thereby improving the quality of pig iron. In the steelmaking process, the flux is an indispensable slag-forming material for desulfurization, dephosphorization, deoxidation, and removal of various non-metallic inclusions to improve the purity of the molten steel and reduce heat loss. Fluxes can be divided into 3 types: alkaline flux, acid flux and neutral flux. ^[3]

Principles of iron and steel metallurgy raw materials

The choice of flux is controlled by the high-temperature physical and chemical reaction law of the smelting process, the most important of which is the principle of slag formed by the interaction of acidic and alkaline substances. Generally speaking, the melting point of the slag phase compound or mixture is lower than the melting point of the reactant, so the high melting point impurities become fusible after slag formation, thereby achieving the purpose of separating the metal from the slag. During the iron and steel smelting and refining process, the ore itself brings acidic or alkaline impurities. A corresponding strongly alkaline or strongly acidic flux must be selected to form a low melting point slag with the impurities in the ore in order to separate the impurities from the metal and The purpose of smelting. In addition, some neutral substances can also be used as a flux to lower the melting point of the slag and improve its fluidity, which should be explained from the ionic structure of the slag.

Classification of iron and steel metallurgy raw materials

The main chemical components of alkaline flux are alkaline substances such as CaO and MgO. Commonly used are limestone, dolomite, lime and slaked lime. The requirements for alkaline fluxes for iron and steel smelting are: high alkali oxides (CaO and MgO), low acid oxides (SiO ₂ and Al ₂ O ₃ ) and harmful impurities (S, P). Certain strength and granularity. The basic flux used directly into the blast furnace is mainly limestone; in order to increase the MgO content in the blast furnace slag to improve the slag fluidity and desulfurization ability, dolomite is added to the furnace charge, and it is best to use dolomite-based limestone. In order to save the heat consumption of the decomposition of the flux in the blast furnace, avoid direct introduction of alkaline flux into the furnace as much as possible. Instead, mix the flux that needs to be fed into the sintering material or pellets to make a flux sintered ore or self-melting pellets. mine. In order to strengthen the sintering production, a part of lime or slaked lime is added to the sintering material. The alkaline flux used for steelmaking is mainly lime, which requires CaO to have high CaO and high activity, and its block size is related to the process requirements and the length of the smelting time. Limestone is also used in the slag-making of the alkaline open furnace and in the melting and oxidation stages of the electric furnace. The limestone is mainly used to decompose CO ₂ gas to activate the molten pool, exhaust gas and impurities in the steel, and reduce sulfur content. In order to make the slag contain a certain amount of MgO to protect the furnace lining, a small amount of roasted dolomite is added during the steelmaking process.