高配比磁铁精矿烧结技术的研究进展

随着传统高品位铁矿石资源的日趋枯竭,烧结用铁矿石资源已经从赤铁矿类型逐渐转变为复杂综合的铁矿类型。但某些铁矿石的杂质和烧损较高,细粒级比例较多,严重影响了烧结性能和烧结矿质量,如烧结矿品位、强度和固体燃耗等。磁铁精矿具有含铁品位高、杂质低的特点,而且在氧化时能够释放出大量的热量。配加磁铁精矿不仅可以改善烧结矿质量,而且还具有减少烧结燃料消耗的潜力。然而,大多数磁铁精矿是经过处理后的铁矿粉,其粒度非常细,会对烧结料层透气性产生很大的负面影响,从而影响烧结过程,不利于烧结生产率的提高。在调查了磁铁精矿烧结特性的基础上,回顾和评论了高配比磁铁精矿烧结技术的最新进展,包括添加剂技术、原料预处理技术、预造块技术、复合烧结技术、气体燃料喷吹技术、双层预烧结技术等。通过分析烧结料层的透气性和控制烧结过程中的化学反应,论证这些新技术在高配比磁铁精矿烧结中的潜力,期望充分发挥磁铁精矿的优点,改善100%磁铁精矿或高配比磁铁精矿烧结混合料的烧结性能,为高生产效率条件下生产出优质低耗的烧结矿提供理论依据和技术方案。

Development on sintering technologies with high proportion of magnetite concentrates

Due to the depletion of reserves of traditional high-grade iron ore,the ore resources have changed drastically from hematite to complicated and comprehensive ore types. However,the level of impurities and the loss on ignition in some kinds of iron ores are relatively higher,and more iron ore fines in the ores,which have significant impacts on the sinter quality and sintering performance,including Fe-grade,sinter strength,and solid fuel consumption. Magnetite concentrate is typically high in Fe grade and releases extra heat when oxidized to hematite. This will not only improve the sinter quality but also have a beneficial impact on the fuel consumption of the sintering process. But,most of the concentrates available are very fine,which will negatively impact the green bed permeability and consequently the productivity of the sintering process. The sintering characteristics of magnetite concentrates was discussed firstly,and then reviews and comments on the recent technological advances in sintering with high proportions of magnetite concentrate,including additive technology,pre-treatment technology,multi-sintering technology,gas fuel injection technology,double layers of pre-sintering technology,etc. In order to obtain the full advantage of magnetite,the permeability and chemical reactions in the sintering bed were reviewed,which can give theoretical guidance and technology support for the application of 100% and high proportion magnetite in the sintering process.