Iron ore powder liquid phase fluidity detection method based on sintering actual production conditions

Abstract

The invention discloses an iron ore powder liquid phase fluidity detection method based on sintering actual production conditions, and belongs to the technical field of ironmaking sintering. The method comprises the following steps: taking the actual industrial analysis CaO mass fraction of sinter as a constant target value; selecting calcium ash in a sintering production field as a flux, and determining that the mass fraction of CaO in a mixture is a batching structure with a set constant target value according to the mass fractions of the calcium ash, iron ore powder SiO2 and CaO; pressing a sample with a fixed specification by using a grinding tool, and simulating a sintering temperature rise curve to sinter the sample; utilizing organic glass with equidistant grids to calculate the vertical projection area of the fused sample by applying a differential method and a cutting compensation method; characterizing the ratio of the vertical projection area of the sample after melting to the vertical projection area of the sample before melting as a liquid phase fluidity index; taking an index mean value of a plurality of groups of samples of a single iron ore powder as the liquid phase fluidity of the iron ore powder under the actual sintering production condition, and guiding the sintering ore blending according to the complementation principle.

Description

technical field [0001] The invention belongs to the technical field of ironmaking and sintering, and relates to a detection method based on the liquid phase fluidity of iron ore powder under actual sintering production conditions. Background technique [0002] Sinter is the most important iron-containing raw material for blast furnaces in my country, and its quality is directly related to the straightness of the blast furnace and the technical and economic indicators. During the sinter production process, the iron ore powder is mixed with a certain proportion of materials such as flux, fuel, returned ore, and solid waste inside the iron and steel enterprise. At the sintering temperature, part of the mixture is melted and liquefied to form a liquid phase and spread around. Adhere to the surrounding fine powder particles, and form liquid phase consolidation under cooling to form sinter. If the fluidity of the sintering liquid phase is too large or too small, the strength of t...

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Problems solved by technology

[0004] However, the above detection methods do not fully consider the actual sintering production situation, and all have the following disadvantages: First, in the actual sintering production, the sintering ore blending is based on the balanced SiO2. The actual control level is also different, but under the premise that the SiO2 control is relatively stable, the binary alkalinity of the sintered finished ore is generally controlled between 2.0-2.2, and the CaO mass fraction is also basically stable at a certain level. Using a fixed binary alkalinity of 4.0 as the basis for the determination of the liquid phase fluidity of a single iron ore powder, artificial factors have increased the effective component of CaO in iron ore powder; the second is that calcium ash is used as a flux in sintering production, and CaO in calcium ash Mass fraction of 77%-80%, SiO2 mass fraction of 3.5%-4.5%, and MgO mass fraction of 1.5%-2.0%, the SiO2 and MgO components will interfere with the liquid phase formation and flow ductility of the iron ore powder itself, but The above method uses analytically pure CaO reagent, and its CaO mass fraction is as high as 99.9% or more; the third is that no detailed calculation method is given for the vertical projected area of ​​the irregularly shaped melt formed after the reaction

The above detection method, especially for the high-silicon iron ore powder mixed with an excessive amount of pure CaO with better dispersion, artificially increases the effective contact area between CaO and SiO2, Fe2O3 and other components, which cannot be consistent with the actual production process of sintering. There is a certain deviation between the test results of the liquid phase fluidity of iron ore powder and the liquid phase formation and flow characteristics in the actual production process, which cannot completely and effectively characterize the sintering production process. There will be a certain deviation when mixing ore

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