Sinter strand

The capacity of a sintering strand is related direcdy to the rate at which the burning zone moves downward through the bed (78). This rate is... 

The produrtive capacity of a sintering strand is related directly to the rate at which the burning zone moves downward through the bed. This rate, which is of the order of 2.5 cm/min (1 in/min), is controlled by the air rate through the bed, with the air functioning as the heat-transfer medium. 

Sinter strand Crushing Hot screening Cooling and cold screening — ( blast... 

Thermal methods Sinter formation Feed of ore fines, pulverized fuel, waste dusts and flux is moistened, mixed to a nodular texture and ignited on a horizontal grate to form an agglomerated sinter cake. Sintering Continuous sinter strand (travelling grate)... 

Sinter strand feed conditioning premixing for balling... 

Section 8.2). The advantage of using a sinter strand for the agglomeration by heat is that the machine can be easily used for the manufacture of additives to building materials tvith different compositions and qualities (Fig. 6.7-44 [6.3.7.1]). 

Fig. 6.7-44 Sinter strand operating on the production of light-weight building material from fly ash [6.7.3.1]...

Iron is produced by the reduction of iron ore (oxides of iron), by coke in blast furnaces. Limestone is used as a fluxing agent. It dissociates into quicklime in the blast furnace, and helps to remove impurities in the iron ore (mainly silica and alumina) by reacting with them to form a molten slag. The slag also assists in the removal of other impurities. Traditionally, all of the limestone was charged with the other raw materials into the blast furnace. In current practice, limestone is also used as a component of the feed to sinter strands, which are used to agglomerate finely divided iron ore before it is fed into the blast furnace. 

The pellets are then fed onto the sinter strand and are heated by burning blast furnace gas. This ignites the coke and raises the temperature of the solids to about 1280 °C. The limestone is calcined and reacts with silica and alumina in the ore to produce a molten calcium silicate-aluminate-ferrite system, which bonds the iron ore particles and produces strong pellets. 

Some producers add 1 to 2 % of quicklime to the raw mix, to improve agglomeration and produce stronger green pellets. This increases the output of the sinter strand and reduces heat usage (see section 27.2). 

The sinter strand process, which transforms finely divided iron oxide into sintered agglomerates, suitable for charging into the blast furnace, is described in section 11.1.2. 

Some steel works add small amounts of quicklime (e.g. 1 kg/t of sinter) to bind smaller particles of ore (0.5 to 2 mm) into larger agglomerates and produce stronger green pellets. This helps to increase the porosity of the bed on the sinter strand and increases the potential output per unit area [27.4]. Larger amounts of quicklime (10 to 20 kg/t), are used by some producers to increase the output of the... 

Heat generated by the roasting reactions is lost from the hood of the machine and in sinter gases from which heat is not recovered as steam. Otherwise energy input is in the form of electric power to a wide range of fans to supply combustion air and handle sinter plant gases, as well as miscellaneous pumps, conveyors, the drive motors for the sinter strand and product sinter crushers, and feed conditioning equipment. Total electrical power input is related to the sulfur burned, which defines the gas flow and size of the sinter hearth area and is 300 kWh/t of sulfur burned or 90 kWh/t of product lead. 

Conventional up-draught sinter plant including feed mixing with return sinter, feed conditioning and moisture control, sinter strand, product sinter crushing and screening, sinter storage. 

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