Limonite treatment system and application of limonite treatment system to limonite treatment

Abstract

The invention discloses a limonite treatment system and the application of the limonite treatment system to limonite treatment. The limonite treatment system comprises a magnetic separation device, a pellet pressing and forming device and a rotary hearth furnace direct reduction system. A material outlet of the magnetic separation device communicates with a material inlet of the pellet pressing and forming device. A material outlet of the pellet pressing and forming device communicates with a feeding channel of the rotary hearth furnace direct reduction system. When the special limonite treatment system is applied to limonite treatment, limonite green pellets containing water can be dried and preheated in a rotary hearth furnace, the limonite green pellets containing water can be directly fed into a furnace, a drying process conducted in advance is omitted, investment is saved, and the energy consumption is also reduced; the temperature of the limonite green pellets is slowly raised from the bottom so as to preheat the limonite green pellets, the water content in the limonite green pellets is slowly reduced, it is avoided that the pellets burst suddenly in the reduction process, and meanwhile metalized pellets higher in metallization rate can be obtained.

Description

technical field [0001] The invention relates to a system for processing limonite, and further relates to the application of the system in processing limonite, which belongs to the field of limonite processing. Background technique [0002] The direct reduction process of the rotary hearth furnace mostly adopts the process of material forming (briquetting or pelletizing)-drying-direct reduction. The formed pellets need to be dried before they can be placed in the rotary hearth furnace. Therefore, a separate drying equipment must be set up for In addition, the reduction product directly reduced by the rotary hearth furnace needs to be cooled before being discharged out of the rotary hearth furnace, and is cooled by the water wall installed on the cooling section of the rotary hearth furnace, which also causes the reduction product heat waste. [0003] Although China's iron ore resource reserves are very rich, a considerable amount of iron ore is complex and difficult to selec...

AI Technical Summary

Problems solved by technology

This equipment cannot handle undried pellets, and needs to add a drying process in the pelletizing stage, which increases the energy consumption of the process; at the same time, it cannot directly use the heat carried by the flue gas, which increases heat loss

[0005] The Chinese invention patent with application number 201510648755.7 discloses a method for synchronizing cooling and drying in a rotary hearth furnace. On the lower chain plate at the feed end A2, the raw balls of the rotary hearth furnace are evenly dropped on the upper chain plate at the feed end B1 through the first distributor at the same time; secondly, by adjusting the upper chain plate and the lower chain The rotating speed of the plate ensures that the two rotate in opposite directions; then, the cold air rises and passes through the red ball on the lower chain plate to cool down the red ball, and at the same time, the temperature of the cold air rises and turns into preheated air; then , the preheated air continues to rise, and then passes through the green balls on the upper chain plate to dry and preheat the green balls. At the same time, the temperature of the preheated air drops and turns into hot air with a certain amount of heat; finally, The hot air is drawn out, enters the dust-fall chamber, and then enters the dust-removing chamber from the dust-fall chamber, and is transferred to the air preheating system in the rotary hearth furnace through the dust-removing chamber for use; The cooling treatment can only be carried out after being discharged from the rotary hearth furnace, which not only requires a separate cooling device, but also causes heat loss; in addition, the use of air cooling for the reduced products of the rotary hearth furnace is likely to cause oxidation of the rotary hearth furnace products, which will reduce the metal content of the products. rate, affecting product quality

[0006] The Chinese invention patent with application number 201510649237.7 discloses a high-efficiency device for synchronous cooling and drying in a rotary hearth furnace, which includes: bearing housing, first bearing, second bearing, upper chain / chain plate, lower net chain / Chain plate, exhaust fan, casing, upper partition wall, middle partition wall, lower partition wall, inspection door, bellows, material baffle, support frame, reducer and drive motor; the two ends of the upper chain plate are respectively installed and The first bearing is connected, the lower chain plate is respectively installed and connected to the second bearing, and the first bearing and the second bearing are fixed on the bearing seat in an up-and-down positional relationship; the casing is placed on the support frame , the inspection door is opened on the casing, and the inspection door is placed on the support frame, the air box is located above the casing, and the exhaust fan is located above the air box; inside the casing, the upper partition wall is located Above the upper chain plate; the middle partition wall is located between the upper chain / chain plate and the lower chain plate; the lower partition wall is located below the lower chain plate; the reduction products of the rotary hearth furnace in this method must be discharged from the rotary hearth furnace Cooling treatment can only be carried out outside the furnace, which not only requires a separate cooling device, but also causes heat loss; in addition, the use of air cooling for the reduction products of the rotary hearth furnace is likely to cause oxidation of the rotary hearth furnace products, which will reduce the metallization rate of the products and affect product quality

[0007] To sum up, in the current rotary hearth furnace process, the drying of green pellets and the cooling of reduced products are processed by different equipment and processes, which occupy a large area, have a long process flow, and have low heat utilization efficiency, which not only increases the construction cost , will also cause problems such as high energy consumption indicators and high production costs, which need to be improved urgently

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