Iron ore sintering method and device without quicklime digester

Abstract

An iron ore sintering method comprises the steps of mixing iron ore powder, dolomite powder and the like, adding to a motion belt of a belt conveyor (9) according to a mixture calculation result, conveying the material on the belt into a primary mixer (10) for wetting with water and primary mixing, then conveying to a primary mixing bunker (12) for storage, conveying the stored material to a secondary mixer (11) for pelletizing or granulating, and finally allowing the material to enter a sintering machine trolley in a distribution manner for sintering. The method is characterized in that a plough-shaped device (13) is mounted between a limestone ore bin (3) and a quicklime ore bin (4) and above the belt conveyor (9) and plows a groove in a material layer of the belt conveyor; quicklime in the quicklime ore bin (4) is added into the plowed groove through a corresponding electronic batching belt weigher; in addition, digestion water or a high water content material is added onto a quicklime layer in the groove on the belt of the belt conveyor (9) to allow the quicklime to perform digestion reaction.

Description

technical field [0001] The invention relates to a method and a sintering device for eliminating a quicklime digester in an iron ore sintering process. Background technique [0002] In the iron ore sintering production process, it is necessary to add 3% to 5% quicklime to improve the spheroidization of the mixture and improve the air permeability of the sintered layer, and the digested slaked lime has a large specific surface area, which is helpful for iron ore sintering. The formation of calcium acid can lead to faster solid-liquid phase reaction and easy formation of low-melting point compounds, ultimately achieving the purpose of reducing fuel consumption and reducing combustion zone resistance. [0003] Lime digestion is the process in which calcium oxide, the main component of quicklime, reacts with water to form calcium hydroxide. This reaction process is called the hydration reaction of CaO. The thermodynamic reaction equation of the main digestion reaction is: [00...

AI Technical Summary

Problems solved by technology

The disadvantages of this process are: water is added too early at the entrance, water is added to quicklime without mixing, the viscosity of quicklime in digestion increases, the mixing effect is poor, slaked lime is easy to stick to the wall of the cylinder, and a large amount of steam generated by digestion carries dust It emerges from the entrance and pollutes the environment; adding water at the exit is late, so that the quicklime flows out of the mixer without time to digest after absorbing water, and can only be digested slowly or incompletely in the subsequent transportation process, and cannot maximize the role and function of quicklime. This quicklime addition method has been used in some sinter plants with backward production conditions, but it does not meet the existing industrial production standards with strict environmental protection requirements

The traditional quicklime digestion process is realized in the digester, which is prone to the following problems: the heat released during the digestion process forms steam and carries dust from the digester and subsequent transportation equipment, resulting in environmental pollution and waste of heat. Dust and steam permeate everywhere, causing frequent damage to the sensor of the batching scale and interrupting production; once the quicklime is not fully digested in the digester, it will stick to a block after digestion, resulting in poor feeding, blocked pipes, unstable quicklime batching, etc. Phenomenon, which affects the stable production of sintering; setting up a special quicklime digester and its auxiliary equipment will bring a huge load to the dust removal system in the batching room, and the production environment around the batching room is poor, which does not conform to the existing concept of green steel production

[0010] For some low-grade iron ores, such as pyrite, sulfuric acid slag is produced after sulfuric acid production, and the water content is high. Generally, it needs to be pretreated (filtered and dried) to reduce the water before it can be used, which increases the cost; especially the iron and steel plant sludge. The mixed sludge in the pond is generally treated as "waste" and not used as a resource, which not only increases environmental pollution, but also causes a waste of resources

[0011] The existing quicklime digestion process in the sintering production process, especially the mainstream quicklime digestion process in which a digester is specially installed in the batching room, has a long process (an additional special process integrating sealed transportation, water-added digestion and bag dust removal is required), and the equipment is complicated. (For example, it includes the quicklime digester body, gas collecting hood, exhaust pipe, porous atomizing nozzle, quicklime inlet and quicklime outlet, etc.), the equipment is easy to block and the unsmooth feeding will directly affect the sintering production rate, resulting in The working environment in the ingredient room is poor, etc.

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