JP3058748B2 - Sulfur moisture determination method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for determining moisture in sulfur.
About the moisture method of quantifying because of sulfur.

[0002]

2. Description of the Related Art Conventionally, as a method of measuring the water content of a solid, there is a method of measuring by a gravimetric method. This method is a method in which a solid sample is heated in a dryer, and then the weight loss is determined as moisture. In the Karl Fischer coulometric titration method, a solid sample, for example, sulfur is put into a solvent for extracting water, the extracted water is reacted with iodine, iodide is electrolytically oxidized to generate iodine, and coulometric titration is performed.

[0003]

However, this is not the case.
According to conventional methods for determining the water content of solids such as
In the case, according to the weight loss method, the heating temperature is 60 ° C.
And the moisture in the sulfur may not be completely removed.
You. Further, when the temperature is further increased, sulfur itself becomes SO2. _Two age
The problem that accurate quantification is difficult because
is there.

According to the Karl Fischer coulometric titration method, when sulfur is in a lump, it is difficult to extract water inside the lump. Further, when sulfur is a powder, there is a problem that the affinity for the solvent is poor and the solid floats on the solvent, making the measurement operation difficult. Further, it is not possible to determine a trace amount of water of about several tens ppm by any of the above methods.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and has as its object to provide a high-precision method for quantitatively determining the water content of sulfur , which has good operability and can determine a small amount of water.

[0006]

Water metering method of sulfur according to the present invention for solving the above problems SUMMARY OF THE INVENTION, the solid sulfur is heated in an inert gas stream, to remove water in the molten state,
It is characterized by quantifying this moisture. Heating the sulfur ,
The temperature for melting is in the range of 120 ° C to 200 ° C.

[0007] At least one of argon, nitrogen and helium is used as the inert gas.

[0008]

[Function] Solid sulfur is heated in an inert gas at a temperature of 120 ° C to 2 ° C.
By heating to 00 ° C and bringing it to a molten state, the water adsorbed on the surface of the sulfur mass and the moisture present in the mass can be completely extracted into the solvent, and the accurate and accurate determination of the moisture content Can be performed. According to the present invention, completely expel moisture inside surface and sulfur of sulfur, it is possible to accurately measure the moisture ppm levels of trace.

[0009]

Embodiments of the present invention will be described below with reference to the drawings. First, FIG. 1 shows a sulfur moisture determination device. FIG.
Indicates a water extraction device 1. In FIG. 1, reference numeral 1 denotes a heating vaporizer. Sulfur is introduced into the sample boat 3 and inserted into the heating furnace 2. The temperature inside the heating furnace 2 is 1
The mixture is heated to 20 ° C. to 200 ° C. to bring sulfur into a molten state, vaporize moisture, and extract the solvent in the titration cell 5 through the pipe 4.

Details of the titration cell 5 are shown in FIG. 2 and FIG. In the titration cell 5, a commercially available solvent such as methanol, chloroform, pyridine or the like is introduced in advance from the sample stopper 6. Then, water is introduced into the solvent in the container 8 from the inlet pipe 7 connected to the pipe 4 shown in FIG. Next, the quantitative operation is as follows. The water in the titration cell 5 is previously titrated to zero. The solid is put into the sample boat 3 in the heating vaporizer 1 and heated to a temperature of 140 ° C. while purging with nitrogen, and the solid is brought into a molten state, kept for about 10 minutes, and water is extracted into the solvent. Titrate the extracted water. The water content of the solid is calculated from the obtained titration value.

Experimental Example 1 Experimental Example 1 is an example of analysis by the above-described quantitative operation. The analysis conditions are as follows: sample amount: 2 to 6 g, heating temperature: 140 ° C., inert gas: nitrogen. The results of this analysis are shown in Table 1.

[0012]

[Table 1] Experimental Example 2 Experimental example 2 is an example in which the amount of water in sulfur that has absorbed water is determined. The method for preparing the sample in this case is as follows. 20 μl of distilled water was added to 20 g of the sulfur sample, and the mixture was pulverized and mixed in a mortar, and 1 g of the pulverized mixed product was taken.
It was prepared by grinding and mixing again with a 9 g sulfur sample.

Table 2 shows the results of the analysis by the above quantitative operation.

[0014]

[Table 2] In Table 2, the measured values of the water content indicated by n 1 to 5 vary, but are within an error range when considered from the sample preparation method. Next, the coulometric titration method used in the examples of the present invention will be described. 3 and 4 show an example of a coulometric titrator and a coulometric cell used in an embodiment of the present invention.

The coulometric titration cell comprises two chambers, an anolyte chamber 11 and a catholyte chamber 12, both chambers 11 and 12 being separated by a diaphragm 13 made of ceramic or ion exchange resin.
As the diaphragm 13, a material which does not mix the anolyte and the catholyte during electrolysis and has a small electric resistance is used. The anolyte compartment 11 and the catholyte compartment 12 each have an electrolytic electrode 15 and an indicator electrode for determining the end point of the titration. In the open air section,
It has a drying tube 18 filled with silica gel or the like.

Each section shown in FIG. 4 has the following functions. Polarization current detection unit 20: A constant voltage or constant current is applied to the indicator electrode from a DC or AC power supply, and the minute current or minute voltage change of the indicator electrode tube is amplified to detect the end point. Current control unit 21: Controlling the electrolysis by intermittently or gradually decreasing the electrolysis current near the end point in response to the signal from the detection amplification unit.

Electrolytic current power supply 22: constant current (107.1 m
A or its multiple) or variable current (0-500 mA)
Power supply. End point detection display unit 23: When the polarization voltage or current reaches the set end point value in response to the signal from the detection amplification unit, the end of measurement is displayed. Current integration unit 24: integrates the current required for titration and displays the amount of electricity or the amount of water (μg H ₂ O).

[0018]

As described above, according to the method for determining the moisture content of sulfur according to the present invention, there is an effect that the minute moisture content in solid sulfur can be accurately detected.

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing a heating vaporizer of the present invention.

FIG. 2 is a schematic perspective view showing a titration cell.

FIG. 3 is a schematic configuration diagram showing a titration cell.

FIG. 4 is a schematic configuration diagram showing a titrator.

──────────────────────────────────────────────────続 き Continued on the front page (58) Fields surveyed (Int.Cl. ⁷ , DB name) G01N 25/56 G01N 1/22 G01N 31/00 G01N 31/12

Claims (2)

(57) [Claims] 1. A method for producing solid sulfur in an inert gas stream at 120
Heat to ℃ ~ 200 ℃ to make the molten state to expel moisture
And determine the moisture content of the sulfur.
Quantity method. 2. An inert gas, such as argon or nitrogen.
Or at least one of helium
The method for quantifying the water content of sulfur according to claim 1, wherein: