Thermal desorption method for contaminated soil

A technology for thermal desorption and polluted soil, which is applied in the field of incineration to treat flue gas containing gasification pollutants and purify polluted soil. It can solve the problems of secondary pollution, long biological treatment cycle, expensive landfill and incineration, etc., and achieve Maintain the inherent characteristics and eliminate the effect of secondary pollution

CN102218446BActive Publication Date: 2013-07-24BEIJING ECO ISLAND SCI & TECH +1
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Patent Information

Authority / Receiving Office
CN · China
Patent Type
Patents(China)
Current Assignee / Owner
Publication Date
2013-07-24

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Abstract

The invention discloses a thermal desorption method for contaminated soil, which comprises the following steps of: performing thermal desorption on the contaminated soil at the temperature of between 400 and 650 DEG C; incinerating gaseous contaminant-containing flue gas which is discharged by the thermal desorption step at the temperature of between 750 and 1,200DEG C; and performing afterheat utilization and tail gas treatment on the incinerated flue gas. When the thermal desorption method is used for treating the contaminated soil, the destruction and removal efficiency for the organic contaminants in the contaminated soil is over 99 percent, the tail gas meets the emission standard, and the possible secondary pollution in the process of treating the contaminated soil is stopped, so that the effective innocent treatment is realized and the original reutilization property of the soil is maintained.
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Description

technical field

[0001] The invention relates to a thermal desorption method for polluted soil, in particular to a method for purifying polluted soil by thermally desorbing pollutants in polluted soil and incinerating flue gas containing gasified pollutants. Background technique

[0002] In recent years, with the rapid development of my country's economy, soil environment has been increasingly polluted by volatile organic compounds (VOC) and semi-volatile organic compounds (SVOC). At present, the treatment of VOC and SVOC polluted soil is usually to excavate the polluted soil and carry out landfill, incineration and biological treatment. However, these methods have their own shortcomings. Landfill and incineration are expensive, and secondary pollution will occur; the biological treatment cycle is long, and the treatment effect is not ideal, and secondary pollution will also occur. Therefore, it is of great environmental and economic significance to provide an economical and...

Examples

Embodiment

[0030] Contaminated soil sieved by a 50mm screen is conveyed to the feed inlet of the desorption chamber of the horizontal rotary kiln by a grab bucket, and then pushed into the desorption chamber by a hydraulic push rod device at a feed rate of 1 ton / hour. The temperature of the desorption chamber is 450°C-600°C, the rotation speed is 0.6-1.5r / min, the desorption time is 40-17 minutes, and the negative pressure in the kiln is -15Pa. During operation, natural gas (natural gas is used as combustion-supporting fuel to prevent secondary pollution to the soil) and primary air are sent from the kiln head by the blower after combustion, and the downstream operation is adopted, that is, the heat source and the polluted soil flow in the same direction. The soil after thermal desorption is discharged into the storage tank through the sealed pipeline through the high-temperature chain plate slag discharger, and a certain proportion of the storage tank is immersed in the cooling water tan...