铁矿石高温烧结基础特性评价方法的国外研究进展

 随着全球优质铁矿石日益减少、资源禀赋变差,国内外钢厂普遍面临着烧结原料供应不稳定、铁矿石性质波动大、原料结构频繁变化等问题,对烧结生产、高炉冶炼和产品质量产生了极大的不利影响。因此,开展铁矿石烧结性能评价研究具有重要的现实意义。铁矿石烧结基础特性可分为冷态特性和高温特性两大类,前者主要包括铁矿石的化学成分、粒度组成、矿物学特性等常温性质,后者主要包括铁矿石的同化性能、液相生成特性等高温成矿行为及实际烧结性能。概述了国外关于铁矿石高温烧结基础特性评价方法的研究进展,系统归纳了不同研究机构提出的评价指标和试验方法。已有研究表明,现有基于团块烧结法的评价方法虽然对铁矿石不同的烧结行为分别进行了深入研究,但未能在其与铁矿石的实际烧结性能之间建立起准确可靠的关系,主要原因在于,对影响铁矿石实际烧结性能的最关键因素把握不准,同时对烧结过程的模拟性有待提高。因此,揭示铁矿石基础特性与其烧结性能的内在联系,首要前提在于必须深入研究和把握“铁矿石-制粒物料-烧结矿”不同阶段物料性质的传递规律,查明影响铁矿粉烧结过程的主要因素,这对找准高温烧结基础特性研究的切入点具有十分重要的意义。

Overseas research advances in evaluation methods of high-temperature fundamental sintering characteristics of iron ores

Due to the increasing depletion of high-grade iron ore resources and the diminishing quality of iron ore sinter feeds, the steel mills at home and abroad are facing with problems that sintering raw material supply is unstable, iron ore property fluctuates greatly and raw material structure changes frequently, which has great adverse effect on sintering production, blast furnace smelting and product quality. Therefore, it's of great significance to conduct evaluations of fundamental sintering characteristics of iron ores. The basic properties of iron ores can be classified into two categories, i.e., cold and high-temperature characteristics. The former mainly includes the chemical composition, particle size distribution and mineralogical characteristics, etc., while the latter generally includes high-temperature mineralization behavior, such as assimilation, liquid phase formation characteristics of iron ores as well as the real sintering performance. This article mainly summarizes the overseas research advances in the evaluation of high-temperature fundamental sintering characteristics of iron ores. Meanwhile, the evaluation indexes and experimental methods proposed by various research institutions are summarized systematically. The previous studies show that, although the existing evaluation methods based on compact sintering provide deep insight into different sintering behavior of iron ores, it's still difficult to build accurate and reliable relationship with the real sintering performance. The main reason is that the key factors affecting the actual sintering performance of iron ore are not well understood, and the evaluation methods needs to be improved to simulate the real sintering conditions as much as possible. Therefore, to reveal the internal relations between fundamental sintering characteristics and its sintering performance of iron ore, the first premise is to develop deep understanding about the transfer law of the properties for materials derived from different operational stages, notably “iron ores-granules-sinter”. It is of great significance to find out the main factors influencing the iron ore sintering process, which can provide a proper breakthrough point for the evaluation of high-temperature fundamental sintering characteristics of iron ores.