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...

Iron Ore Sinter

Iron Ore Sinter  Iron ore sinter or simply called sinter is usually the major component of a blast furnace iron bearing burden material. Sinter normally consists of various mineral phases produced by sintering of iron ore fines with fluxes, metallurgical wastes and a solid fuel. Coke breeze is normally used as fuel in the sinter mix since it supplies necessary heat energy for sintering of sinter mix. Fig 1 shows a piece of sinter. Fig 1 A piece of sinter  In sintering, a shallow bed of fine particles is agglomerated by heat exchange and partial fusion of the still mass. Heat is generated by combustion of coke breeze admixed with the bed of iron ore fines, fluxes, and metallurgical wastes (sinter mix) being agglomerated. The combustion is initiated by igniting the fuel exposed at the surface of the bed, after which a narrow, high temperature zone is caused to move through the bed by an induced draft applied at the bottom of the bed. Within this narrow zone, the surfaces of adjacent particles reach fusion temperature, and gangue constituents form a semi liquid slag. The bonding is affected by a combination of fusion, grain growth and slag liquidation. The generation of volatiles from the fuel and flux materials creates a frothy condition and the incoming air quenches and solidifies the rear edge of the advancing fusion zone. The product sinter consists of a cellular mass of sinter mix materials bonded in a slag matrix. Important factors that affect the granulation efficiency and permeability of the sinter mix are water addition, particle size distribution, ore porosity, surface properties of the iron ore and the wettability of the iron ore. During sintering process, coke breeze increases the temperature of the sinter mix within the sinter bed...