Device and method applied to thermal desorption treatment of mercury-contaminated soil

Abstract

The invention discloses a device and a method applied to thermal desorption treatment of mercury-contaminated soil. The device comprises a pretreatment unit, a charging unit, a fuel supply unit, a thermal desorption unit, a high-temperature dust removal unit, a condensate water treatment unit, a discharging unit, a tail gas cooling unit and a tail gas treatment unit, wherein the pretreatment unit is connected with the charging unit; the charging unit, the fuel supply unit, the discharging unit and the high-temperature dust removal unit are connected with the thermal desorption unit; the high-temperature dust removal unit is connected with the tail gas cooling unit; the tail gas cooling unit is connected with the tail gas treatment unit and the condensate water treatment unit; the condensate water treatment unit is connected with the discharging unit; the thermal desorption unit adopts a thermal screw conveyor. According to the device, the contaminants are indirectly heated, volatilized and separated out of the contaminated soil, so that the mercury in the mercury-contaminated soil can be effectively removed; meanwhile, the mercury in the tail gas can be recycled and desorbed by a hydrocyclone separation method; and the up-to-standard emission of the tail gas and the wastewater can be achieved.

Description

technical field [0001] The invention relates to a movable system for treating and recovering mercury by adopting a thermal desorption process for mercury-contaminated soil, belonging to the field of contaminated soil remediation. Background technique [0002] my country is the largest producer and consumer of mercury. Mercury emitted by key pollution sources such as coal burning, mercury mining and smelting, non-ferrous metal smelting enterprises, and cement plants has polluted the surrounding air, water, and soil, and the pollution is serious in some areas. According to a preliminary estimate from the data, the soil area contaminated by mercury in my country is 3.2×10 4 ha, the amount of mercury that pollutes the environment is 1.9×10 per year 8 kg. The thermal desorption process is one of the best treatment technologies for high-concentration mercury-contaminated soil. It uses direct or indirect heating to heat the contaminated soil to a high enough temperature and kee...

AI Technical Summary

Problems solved by technology

However, the above-mentioned types of equipment have problems such as being unsuitable as mobile equipment and generating a large amount of exhaust gas.

At the same time, the desorption tail gas and wastewater treatment process produced in the thermal desorption process still needs to be improved to avoid secondary pollution; on the other hand, in order to realize the resource utilization of mercury, it is also necessary to Consider Mercury Recovery

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