Sintering dust treatment system and method

Abstract

The invention belongs to the field of solid waste in the metallurgical industry and particularly relates to a sintering dust treatment system and method. The sintering dust treatment system comprisesan acid leaching device, a primary filtering device, a crystallization device, a secondary filtering device, a drying device and an evaporation device, wherein the primary filtering device is connected with the acid leaching device and is used for filtering leachate obtained through reaction of sintering dust and hydrochloric acid in the acid leaching device to obtain acid leaching solution; the crystallization device is connected with the primary filtering device and is used for crystallizing the acid leaching solution to obtain precipitation solution; the secondary filtering device is connected with the crystallization device and is used for filtering and separating the precipitation solution to obtain iron oxide red filter residue and sylvite solution; the drying device is connected with the filter residue outlet of the secondary filtering device; and the evaporation device is connected with the filtering solution outlet of the secondary filtering device. The sintering dust treatment system recycles potassium and iron in sintering dust step by step and has the characteristics of being low in energy consumption of the flow, simple and easy to operate and environmentally-friendly.

Description

technical field [0001] The invention belongs to the field of solid waste in the metallurgical industry, and in particular relates to a system and method for processing sintering dust. Background technique [0002] The amount of sintering dust accounts for about 2% to 4% of the output of sintering ore, and the annual production of sintering dust in the country is tens of millions of tons. At present, the domestic utilization method is mainly realized by directly adding sintered materials for reuse. Due to the different sources of iron ore, some ore raw materials contain relatively high alkali metal elements such as K. The compounds formed by these alkali metal elements have low boiling points and are directly volatilized into the flue gas during high-temperature sintering or reduced by coke. The corresponding elemental metal gas escapes, condenses and oxidizes in the electrostatic precipitator system, and is trapped into the dust removal ash. Repeated direct re-batching and...

AI Technical Summary

Problems solved by technology

Repeated direct re-batching and recycling of sinter ash, the gradual enrichment of alkali metal elements such as K, makes sinter dust and sinter ore contain higher alkali metal elements such as K, which significantly affects the dust removal efficiency and operational stability of sintered electrostatic precipitators , resulting in excessive dust concentration in the flue gas emitted by electrostatic precipitator and increased energy consumption during device operation. When sintered ore with high content of alkali metal elements such as K enters the blast furnace, it will corrode the furnace lining and affect the long-life operation of the blast furnace. Moreover, the K element in the sintering dust has not been recovered. waste

At the same time, in the prior art, most of the processing has problems such as complicated process or low recovery rate. For example, the patent document with the application number 200910227173.6 provides a comprehensive treatment method for sintering ash in iron and steel plants. , the ESP ash produced by the primary power plant is directly sent to the sintering plant (raw material field or distribution room) for sintering batching utilization, and the ESP ash produced by the subsequent power plant is mixed, and after mixing, stirring pulping, gradient magnetic separation, and flotation Carbon selection, solid-liquid separation; after solid-liquid separation, the obtained potassium solution is used to make potassium fertilizer, and lead products are extracted from the obtained tailings; the process is long and complicated, requiring hydrochloric acid leaching, and the corrosion resistance of equipment is strictly required

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