Method and device for recognizing mercury forms

Abstract

The invention discloses a method for recognizing the mercury forms. The method comprises the following steps that 1, a sample is heated to be decomposed, a first curve that the mercury concentration changes along with temperature changes is obtained, and then the decomposing temperatures of various mercury compounds are obtained; 2, the decomposing temperatures of various mercury compounds in the step 1 are compared with the decomposing temperature of a standard mercury compound, and then the forms of part of mercury in the sample are recognized; 3, the mercury compounds which are not recognized in the step 2 are recognized through a step-by-step chemical extraction method. The invention further discloses a corresponding device. According to the method, the forms of most mercury in the mercury-containing solid sample can be recognized through temperature increasing desorption, and meanwhile the forms of the mercury compounds of which the decomposing temperatures overlap in the sample can be further recognized by combining the step-by-step chemical extraction method; in addition, by means of a constant-temperature thermal decomposition unit in the device, it can be guaranteed that mercury in all forms can be completely decomposed, and then mercury form recognition is more accurate.

Description

technical field [0001] The invention belongs to the technical field of coal-fired mercury emission control, and in particular relates to a method and device for identifying mercury forms. Background technique [0002] Mercury is a kind of nerve poison, which is highly cumulative and irreversible, and poses a great threat to human health. Coal-fired power plants are one of the most important sources of anthropogenic mercury pollution. In order to protect the environment and achieve sustainable development, the Ministry of Environmental Protection of my country promulgated the latest "Emission Standards of Air Pollutants for Thermal Power Plants" (GB13223-2011) in 2011. From January 1, 2015, coal-fired boilers are required to remove mercury and Its compound emission is controlled at 0.03mg / m 3 the following. [0003] In the process of coal combustion, there are three main forms of mercury in the flue gas: elemental mercury (Hg 0 ), divalent mercury compounds (Hg 2 + ) and...

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Problems solved by technology

[0005] However, the composition of coal combustion flue gas and combustion products is complex, and the form of mercury in combustion products will also be very complicated.

The decomposition temperature difference of some mercury compounds is small, and the characteristic peaks of the decomposition temperature overlap each other during the temperature-programmed desorption process, which will bring great interference to the identification of mercury species. Therefore, the temperature-programmed desorption method is used to detect coal The speciation of mercury in the product is more difficult

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