A method and product for improving the microstructure and mercury removal performance of magnetic beads in fly ash

Abstract

The invention discloses a method for improving a magnetic-bead micro structure and demercuration performance of fly ash. The method comprises the following steps of utilizing a magnetic separation machine to choose magnetic-bead particles from coal ash; utilizing X-ray fluorescent spectroscopy (XRF) to test chemical components of magnetic beads and determining the content m of silicon and aluminum (Si and Al) in the magnetic beads; arranging the magnetic-bead particles in a polytetrafluoroethylene container, adding HF solution and mechanically stirring; filtering the magnetic-bead particles varnished by the HF solution out and washing the magnetic-bead particles with deionized water for several times until the magnetic-bead particles become a neutral state; drying the magnetic-bead particles to obtain the magnetic beads with the improved micro structure. The invention further discloses corresponding magnetic beads. According to the method, the HF solution is utilized to process the surfaces of the magnetic beads to peel aluminosilicate covering the surfaces of the magnetic beads, the covered hercynite-phase substances can be fully exposed, and the micro structure of the magnetic bead is improved, the specific surface area of the magnetic beads is improved, a hole structure of the magnetic beads is improved, and the catalysis and adsorption performance of the magnetic beads is greatly improved.

Description

technical field [0001] The invention belongs to the fields of refined utilization of magnetic beads in coal-fired solid waste fly ash and mercury removal in coal-fired power plants, and specifically relates to a method and product for improving the microstructure and mercury removal performance of fly ash magnetic beads. Background technique [0002] Fly ash magnetic beads have strong magnetism and a special iron spinel structure, so they have high resource utilization value. It is predicted that the annual output of fly ash in my country will reach 570 million tons by the end of the "Twelfth Five-Year Plan" period, and the yield of magnetic beads in the fly ash of typical coal-fired power plants in my country will be 1.5% to 11.5%, so the annual output of magnetic beads will reach at least 28.5 million tons (Magnetic bead yield is based on 5%), and has a good resource utilization prospect. [0003] Magnetic beads are mainly derived from iron-containing minerals in coal (pyr...

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Problems solved by technology

[0006] However, in this scheme, the adsorption performance of the magnetic beads is only optimized by loading catalytically active substances on the surface of the magnetic beads. Due to the small specific surface area of ​​the magnetic beads, the amount of active substances loaded on the surface is limited, and the amount of active substances loaded on the surface is limited. Active substances are prone to agglomeration, resulting in lower catalytic activity

In addition, when the magnetic beads loaded with active substances are sprayed into the flue gas to remove mercury, they will rub and collide with the fly ash particles in the flue gas, resulting in the peeling off of the active substances loaded on the surface of the magnetic beads, which greatly reduces their catalytic activity.

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