铁矿粉液相流动性的主要液相生成特征因素解析

烧结矿是我国高炉炼铁的主要原料,烧结矿质量将直接影响高炉冶炼及炼铁工序的经济技术指标.因此,基于铁矿粉的高温特性进行优化配矿从而改善烧结矿的产质量对于炼铁工序节能增效具有十分重要的现实意义.铁矿粉的液相流动性是非常重要的烧结高温特性指标,适宜的液相流动性可以使烧结矿获得较高的固结强度.本文模拟实际烧结黏附粉层中铁矿粉颗粒与钙质熔剂质点的接触状态,采用FastSage热力学计算和微型烧结可视化试验方法研究了固定CaO配比条件下铁矿粉的液相流动性及其主要的热力学液相生成特征影响因素.研究结果表明,采用固定CaO配比与固定碱度的熔剂配加方式下,铁矿粉的液相流动性规律明显不同.铁矿粉的液相生成量是影响其液相流动性的最主要液相生成特征因素,液相生成量越多则铁矿粉的液相流动性指数越大.铁矿粉液相流动性的配合性机制是基于其液相生成量的线性叠加原则.脉石矿物含量将在一定程度上影响铁矿粉的液相流动性,随着SiO2含量的升高铁矿粉的液相生成量减少,从而导致液相流动性指数显著降低;而Al2 O3含量增加,液相流动性指数略有升高.

Major melt formation characteristic factor analysis of iron ore liquid phase fluidity during the sintering process

Sinter ore is one of the main materials of blast furnaces in China, and the productivity of the blast furnace and the economic and technical indicators of the ironmaking process are directly influenced by sinter yield and quality. Therefore, the ore-blending process should be optimized based on the high-temperature characteristics of iron ore to improve the sinter yield and quality and the energy efficiency of the ironmaking process. The liquid phase fluidity of iron ore is a vital characteristic of high-temperature sintering, since a suitable liquid phase fluidity of blended ores produces a sintered body with a stronger bonding strength. In this paper, by simulating the contact state of the iron ore particles and the calcareous flux particles in the actual sintering adhering fines, the FactSage thermodynamic calculation and the visible micro-sintering tests were conducted to study the liquid phase fluidity indexes of different iron ores and the major melt formation characteristic factors that influenced the liquid phase fluidity of iron ore under fixed CaO ratio conditions. The results show that the rule of liquid phase fluidity of iron ores under a fixed CaO ratio is different from the rule of liquid phase fluidity of iron ores with fixed alkalinity. According to the fitting relationship between the calculation results by Factsage software and the testing results of liquid phase fluidity index of the 9 kinds of iron ores, the formed melt content of iron ore is the most important melt formation characteristic factor that affects liquid phase fluidity. The formed melt content and the liquid phase fluidity index are directly related, and the coordination mechanism of liquid phase fluidity of iron ore is based on the principle of linear superposition of the formed melt content. Furthermore, the content of gangue minerals affects the liquid phase fluidity of iron ore to some extent. The liquid fluidity index decreases greatly with increased SiO2 content, leading to lower formed melt content, while the liquid fluidity index slightly increases with increased Al2 O3 content.