Preparation method and application of magnetic renewable mercury removal agent

Abstract

The invention discloses a preparation method and application of a magnetic renewable mercury removal agent. According to the method, natural iron minerals are subjected to high-temperature roasting to remove part of sulfur and then are converted into magnetic iron minerals, copper chloride is added for modification treatment, and the magnetic renewable mercury removal agent with excellent mercury removal performance is obtained after mechanical grinding and activation. The magnetic mercury removal agent is placed in a fixed bed, a fluidized bed and a wet flue gas purification system or sprayed into flue gas to be in contact with mercury in the flue gas,converts gaseous mercury into a stable compound, and achieves curing removal of the gaseous mercury; the mercury-loaded mercury removal agent is separated out after magnetic separation, and the magnetic mercury removal agent can be recycled after being subjected to high-temperature mercury desorption. The raw materials of the magnetic renewable mercury removal agent are natural and easily available and have abundant reserves; the preparation method of the magnetic renewable mercury removal agent is simple; and the magnetic renewable mercury removal agent has large mercury adsorption capacity and fast adsorption rate, can be recycled, substantially reduces the mercury removal cost, and has good practical value.

Description

technical field [0001] The invention belongs to the technical field of environmental pollution prevention and purification, in particular to a preparation method and application of a magnetic regenerable mercury removal agent. Background technique [0002] Mercury is a heavy metal pollutant that exists in the environment for a long time and has global migration and diffusion. It is highly toxic, persistent, highly corrosive, and volatile, and poses serious harm to human health and the ecological environment of water and land. On October 10, 2013, the Minamata Convention on Mercury was signed in Kumamoto, Japan. In 2017, the Minamata Convention on Mercury came into force in more than 100 countries around the world, marking that mercury pollution control has not only become the focus of domestic environmental pollution control , will also be bound by international environmental conventions and assume corresponding performance responsibilities. [0003] At present, the commonl...

AI Technical Summary

Problems solved by technology

At present, the adsorbents that have been studied mainly include activated carbon, metal sulfides, metal oxides, modified fly ash, calcium adsorbents, precious metals, etc. Activated carbon has been used in the field of mercury removal from coal-fired flue gas, but its mercury removal effect is limited. Working conditions have a great impact, and the amount of use is large, the cost is high, and the activated carbon after adsorbing mercury is difficult to separate from the fly ash, so it cannot be recycled and reused, and the mixing of activated carbon seriously reduces the resource utilization of fly ash; metal oxides, Cheap adsorbents such as modified fly ash and calcium adsorbent have limited adsorption capacity and low mercury removal efficiency, so they are not suitable for the purification of flue gas with high mercury concentration; metal sulfides have superior mercury removal activity and are considered to be a class of It has the greatest potential to replace traditional activated carbon adsorbents, but natural metal sulfide minerals have almost no ability to remove mercury, and metal sulfide adsorbents with high mercury removal efficiency need to be synthesized precisely and precisely by complex precursors and additives. Complex, high cost, and generally cannot be recycled and reused, which greatly increases the cost, increases the operating cost, and hinders its industrial production and application