Understanding Sinter and Sinter Plant Operations Mar15

Understanding Sinter and Sinter Plant Operations...

Understanding Sinter and Sinter Plant Operations               Sintering is a process of agglomeration of fine mineral particles into a porous and lumpy mass by incipient fusion caused by heat produced by combustion of solid fuel within the mass itself. The sintering process is a pre-treatment step in the production of iron, where fine particles of iron ores and also secondary iron oxide wastes (collected dusts, mill scale etc.) along with fluxes (lime, limestone and dolomite) are agglomerated by combustion.  Agglomeration of the fines is necessary to enable the passage of hot gases during the blast furnace operation. Sintering has been referred to as the art of burning a fuel mixed with ore under controlled conditions. It involves the heating of fine iron ore with flux and coke fines or coal to produce a semi-molten mass that solidifies into porous pieces of sinter with the size and strength characteristics necessary for feeding into the blast furnace. Although simple in principle, sintering plant requires that a number of important factors in its design and operation be observed to attain optimum performance. A simplified schematic flow diagram of sintering process is at Fig 1.  Fig 1 Simplified flow diagram of a sintering process  There are basically the following three types of sinters. Non flux or acid sinters – In these sinters no flux is added to the iron ore in preparing the sinter mix. Non flux sinters are very rarely being produced these days. Self fluxing or basic sinters – These are the sinters where sufficient flux is added in the sinter mix for producing slags of desired basicity (CaO/SiO2) in blast furnace taking into account the acidic oxides in the blast furnace burden. Super flux sinters – These are the sinters where sufficient flux is added in...

Sinter Quality and Process of Sintering Iron Ores Nov21

Sinter Quality and Process of Sintering Iron Ores...

Sinter Quality and Process of Sintering Iron Ores Sinter is normally the major component of the blast furnace (BF) charge burden. Sinter consists of many mineral phases produced during process of sintering of iron ores. The quality and properties of sinter are dependent on the mineral structure of sinter. However, since the sintering conditions are usually not uniform throughout the sinter bed, the phase composition, and therefore the sinter quality, varies in the sinter bed. The structure of sinter is not uniform. It consists of pores (of varying sizes) and a complex aggregate of mineral phases, each with different properties. It is the combination of these pores and mineral phases, and the interaction between them that determines the sinter quality, but also makes the prediction of sinter properties very difficult. Though a large number of investigations have been carried out on sinter, still the correlation between the chemical composition and mineralogy of sinter with its properties and behaviour is still not clearly understood. Schematics of sinter mix and the product sinter are at Fig 1. Fig 1 Schematics of sinter mix and product sinter  Sintering process is a generic term that is used to describe the process of agglomeration of a green mix of iron ores, fluxes and coke and plant solid wastes having a particle size of -10 mm so as to produce sinter  which can withstand operating pressure and temperature conditions existing in a BF. Solid wastes such as dusts, sludges, slags and mill scales etc. are used for their utilization in sinter mix because of the complex chemical structure and mineral components of these materials. The process of sintering is described in detail in a separate article which is available under the link http://ispatguru.com/the-sintering-process-of-iron-ore-fines-2/ During the process of sintering, as the...