Method and system for co-processing waste incineration fly ash and zinc-containing dust mud of steel plant

Abstract

The invention discloses a method and a system for co-processing waste incineration fly ash and zinc-containing dust mud of a steel mill. The method comprises the following steps: 1, adding 1.5% of lime and pulverized coal into the fly ash and the dust mud according to the slagging alkalinity of 1.1-1.3, the total carbon content of 2-8% and the binder ratio of 2-5% for proportioning, wherein the fly ash accounts for 5-20% of the dust mud; 2, adding water into the mixture, extruding into blocks or pelletizing, and curing until the strength meets the requirement; 3, adding the agglomerates or pellets into a rotary kiln, and introducing high-temperature coal gas to pre-reduce the agglomerates or pellets in the kiln; 4, continuously adding the pre-reduced agglomerates or pellets into a smeltingreduction furnace, and meanwhile distributing main fuel such as nut coke within the range of the material surface radius of the smelting reduction furnace; blowing hot air with the oxygen concentration of 35% from a tuyere of a reduction furnace, and spraying pulverized coal through the tuyere; and carrying out further indirect reduction, softening melting and FeO-C final reduction on the pre-reduced pellets in a coke bed in the reduction furnace to generate molten iron and furnace slag. According to the main purpose, the fly ash is cooperatively treated and utilized by combining the advantages of a metallurgical furnace for treating zinc-containing dust according to the chemical components of the fly ash.

Description

technical field [0001] The invention belongs to the technical field of environmental protection, and in particular relates to a method and a system for co-processing and utilizing waste incineration fly ash and steel plant zinc-containing solid waste. Background technique [0002] Waste incineration is the process of converting waste into heat energy, waste gas and residue through thermal decomposition, combustion and other reactions. During the incineration process of garbage, flue gas will be produced, and fly ash is the dust removal ash produced by dust removal and purification of flue gas, including bag filter fly ash and flue gas purification absorption tower fly ash. Waste incineration fly ash is classified as double hazardous waste because it is rich in heavy metals such as Pb, Cr, Cd, Zn, Hg, Cu, Ni, As, and highly toxic organic compounds dioxins and furans (PCDD / DFs). In addition, fly ash also contains more than 20% of Ca, Na, and K chlorides. Because the main com...

AI Technical Summary

Problems solved by technology

Disadvantages: The addition of curing agent just increases the final treatment capacity and takes up a lot of land; secondly, the strength of the cured body is low, the long-term stability of heavy metals is poor, and the purpose of volume reduction and resource utilization cannot be achieved at the same time

Advantages: simple treatment process, low investment in equipment; Disadvantages: wastewater with high concentration of inorganic salts will be produced, which needs further treatment; secondly, the price of chemical stabilizers is high, and the treatment of heavy metals is not thorough

Disadvantages: high energy consumption

The main purpose of this technology is to utilize the valuable components in fly ash, such as CaO, Fe 2 o 3 , MgO, Al 2 o 3 However, the alkali metals, heavy metals and chlorides in the fly ash will enter the blast furnace with the sinter, which will have a significant adverse effect on the smooth production of the blast furnace and the life of the lining

Images