JPS5857702B2 - Mercury measurement method in SO↓2 containing gas - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for accurately measuring mercury in SO2-containing gas with simple operations.

The method for measuring mercury in gases usually involves directly absorbing the mercury in a strongly oxidizing liquid such as aqua regia or sulfuric acid KMnO4 solution.
This is analyzed and measured using atomic absorption, but SO2 gas coexists in non-ferrous metal smelting gas, and the inside of this SO□-containing gas is a reducing atmosphere.
When measuring mercury using the above method, the strongly oxidizing liquid does not absorb all the mercury, and the measured value is only a little below the actual concentration.

Although most of the mercury in the gas is in the form of metallic mercury vapor, it also contains a small amount of Hg5e03 and the like.

The present inventors have already proposed a method using a combination of H2O2 and aqua regia as a mercury absorbent in SO2-containing gas, but this method is difficult to use since aqua regia is edible. The disadvantages include that the equipment is easily damaged, the strong odor of aqua regia makes it difficult to handle, and there may be differences between individuals.

The present invention solves the above-mentioned drawbacks of the conventional methods and proposes a method that can accurately measure mercury in SO2-containing gas with simple operations and without interference with the SO2 gas. In the method for measuring mercury in a gas containing SO2 gas and mercury, the gas containing SO2 gas and mercury is mixed with KOH2, 2CO3, NaOH
and Na2CO3, and then absorb the gas with the alkaline solution into sulfuric acid acid KMn04.
After absorption treatment with a solution, two types of absorption liquids, the alkaline solution and the sulfuric acid acidic KMnO4 solution, are connected to the conduits between the two types of absorption treatment vessels and the two types of absorption treatment bath vessels, respectively. There is a method for measuring mercury in a gas containing SO2 gas, which is characterized by measuring mercury in a solution containing a washing solution sequentially washed with concentrated sulfuric acid and water, or aqua regia and water, by atomic absorption spectrometry.

Next, the present invention will be explained with reference to the drawings.

FIG. 1 is a mercury absorption device comprising a plurality of absorption bottles used in the practice of the present invention, and FIG. 2 is a graph showing the relationship between the number of absorption bottles in FIG. 1 and the cumulative amount of mercury collected.

Here, the cumulative amount of mercury collected is a value obtained by converting the total amount of mercury collected in each absorption bottle into 1 mercury per N'm3 of gas sucked.

Furthermore, in FIG. 1 ρ, two absorption bottles for the sulfuric acid acidic KMnO4 solution are connected in series, but this does not mean two-stage absorption, and the number of the absorption bottles may be one.

On the first night, the mercury absorber was filled with KOHm in absorption bottle 1.
Add LOOml of solution and add sulfuric acid acid K to absorption bottles 2 and 3.
1OOrrll of MnO4 solution was put into each tank, and a suction air pump 4 and a wet gas meter 5 were connected thereto.

The concentration of KOH in absorption bottle 1 is 300 gyl, and the concentration of KOH in absorption bottle 2 is 300 gyl.
The concentration of the sulfuric acid acidic KMnO4 solution of ,3 is KMnO410
”/l and 100 volumes of sulfuric acid solution.

Using this absorption device, a measurement gas of known concentration (1,4-
1m9/Nm') by suction air pump 4 from 1 to 21/f
601 nm was aspirated.

In this absorption operation, the entire amount of SO2 gas in the measurement gas is absorbed by the K O:E (solution) in absorption bottle 1,
The sulfuric acid acidic KMnO4 solution in absorption bottles 2 and 3 absorbs all the mercury in the gas.

Mercury measurement was performed using the above KOH solution after absorption and sulfuric acid acid KMnO.
Collect the two absorption solutions of the 4 solutions and the cleaning solution obtained by washing the absorption bottles 1.2 and 3 and the conduit with aqua regia and water, respectively, or the washing solution obtained by sequentially washing them with concentrated sulfuric acid and water, and perform atomic absorption using a conventional method. Analytical measurements were carried out over the period.

This analytical measurement result is shown in Figure 2 as a relationship between the absorption bottle number and the cumulative amount of mercury collected, and the analytical measurement value is in good agreement with the concentration value of the measured gas used in the actual demonstration. It was confirmed that the invented method is an extremely reliable measurement method.

Furthermore, the method of the present invention is economical as there is no damage to equipment.

In the above, the case where KOH was used as the alkaline solution was described, but K2CO3, NaOH2Na2
Of course, the same effect can be obtained using any of CO3.

As described above, the present invention provides a method for accurately measuring mercury in SO2-containing gas without being interfered with by the SO2, and has great industrial value.

[Brief explanation of drawings]

FIG. 1 is a mercury absorption device comprising absorption bottles used in the practice of the present invention, and FIG. 2 is a graph showing the relationship between the number of absorption bottles in FIG. 1 and the cumulative amount of mercury collected. In FIG. 1, 1...absorption bottle (KOH solution) 2.3...absorption bottle (sulfuric acid acidic KMnO4 solution) 4...suction air pump.

Claims (1)

[Claims] 1. In a method for measuring mercury in a gas containing SO2 gas and mercury, the gas containing SO2 gas and mercury is added to KOH2 with a type of compound selected from the group consisting of 2CO3, NaOH and NaCO3. The gas absorbed with the alkaline solution is then absorbed with a sulfuric acid acidic KMnO4 solution, and the alkaline solution after the absorption treatment and the sulfuric acid acidic KMnO4
The mercury in the solution is added to the two types of absorption liquid with the two types of absorption treatment vessels and the cleaning liquid that is obtained by sequentially cleaning the conduit between the two types of absorption treatment vessels with concentrated sulfuric acid and water or aqua regia and water. A method for measuring mercury in a gas containing SO2 gas, which is characterized by measuring by atomic absorption method.