RU1807354C - Process of finding organic impurities in sulphur - Google Patents

Abstract

SUMMARY OF THE INVENTION: a sample is heated in oleum to a temperature not exceeding 100 ° C, followed by photometric measurement of the sulfonated product.

Description

The invention relates to methods for the determination of organic compounds in natural sulfur and can be used to determine organic impurities in gas and fused sulfur after filtration.

The purpose of the invention is to increase the accuracy of determination, eliminating the use of toxic substances, reducing the complexity and increasing the expressness of the method.

In the method, the goal is achieved by dissolving sulfur when heated (not higher than 100 ° C) in oleum and sulfonation to completely remove sulfur from the solution in the form of sulfur dioxide (within 30 min) and subsequent photometric measurements of the sulfonated product on an FEC-56 or FEC photocalorimeter -60 in the visible region of the spectrum.

The essence of the method consists in the interaction of sulfur with oleum sulfur trioxide, the resulting sulfur dioxide is removed from the solution (the disappearance of intermediate sulfur compounds, colored blue), and organic impurities are sulfonated to form compounds of different coloring intensities.

depending on the concentration of organic substances in sulfur.

The method is carried out as follows: two sulfur standards were taken to construct a calibration curve. 1-content of organic impurities 0.1% - in terms of carbon (Sample GIGHS) and II- content of organic impurities O., 02% (Sumy sample Khimprom PO).

About 5 g of sulfur of I and H samples were decomposed to sulfur dioxide in 25 cm of oleum with heating for 30 minutes. The temperature did not exceed 100 ° C in order to avoid sulfur melting. The solutions were transferred to volumetric flasks with a capacity of 100 cm3 sulfuric acid 1: 2, cooled, mixed.

In volumetric flasks with a capacity of 50 cm3, I solution O, I was taken; 0.2; 0.5; 1.0; 1.2 cm3, which corresponds to 0.05; 05. 0.01; 0.25; .05 and 0.06 mg of carbon and solution II - 0.2; 0.5; 1.0; 2.0 and 5.0 cm, which corresponds to 0.002; 0.005; 0.01; 0.02 and 0.05 mg of carbon.

The solution in the flasks was brought to the mark with distilled water, mixed and the optical density of the solutions was measured relative to the optical density of distilled water on a photocalorimeter

ate

with

With

about VI with

Joint venture

b.

FEK-56, using a red filter No. 8 in a cuvette with a thickness of 50 mm light-absorbing layer.

The relative density of the solutions was obtained:

I - 0.03; 0.05; 0,118,0,226; 0.270

II - 0.015; 0.03; 0.05; 0.095; 0.228.

According to the data obtained, a calibration graph was constructed, plotting the carbon content in milligrams on the abscissa axis, and the corresponding values of optical densities on the ordinate axis.

The direct dependence of optical densities on the content of organic impurities was obtained. The points of two reference samples coincided or served as a continuation of the straight line, which indicates the reproducibility of the results and the high sensitivity of the method.

Example 1. A sample of lump sulfur.

Samples of sulfur: 1) 408528 and 2) 4.1526. Sulfur was dissolved in 25 cm3 of oleum and decomposed to sulfur dioxide for 30 minutes at 80 ° C.

The solutions were transferred to volumetric flasks per 100 cm3 with sulfuric acid 1: 2, cooled, mixed. 5 cm of solution was taken from the flasks and transferred to 50 cm3 volumetric flasks, brought to the mark with distilled water, mixed, cooled. The optical density of the resulting solutions: 1) 0.23 and 2) 40.19, which corresponds to 0.052 and 0.0415 mg of carbon, respectively.

The content of organic impurities in sulfur in terms of carbon (X) is calculated as a percentage:

. „0.052 -100 -100 - 002P.

 4.8528-1000-.

2) X

0.0415 100 100

0.02%.

4.1526 1000 5

Two samples of the same sulfur sample were analyzed by determining the content of bitumen with the dissolution of sulfur in sodium sulfide and subsequent extraction in carbon tetrachloride. The bitumen content is 0.018 and 0.016%. 5.5 hours were spent on determination ....

Example 2. A sulfur sample after filtration.

Samples of sulfur 4.2152 and 5.0816. Sulfur was dissolved in 25 cm of oleum and decomposed to sulfur dioxide for 25 and 30 minutes, respectively, until the blue colored intermediate sulfur disappeared. The solutions were transferred to volumetric flasks with a capacity of 100 cm3 sulfuric acid 1: 2, brought to the mark, cooled, mixed. 10 cm3 of the solution was transferred into volumetric flasks with a capacity of 50 cm, brought to the mark with distilled water, mixed. The optical density of the solutions is 0.079 and 0.095, which corresponds to 0.0168 and 0.02 mg of carbon. The content of organic impurities in sulfur in terms of carbon (X) is calculated by the formula;

iw- 0.0168 100 100 ppb. 1) X 1000-10-4-2152 ° 00398% ax-0.02 -100-100 OPP4 „, 1000 10 5.0816 ° 004%

Time spent on determination 1.0 h.

Two parallel samples of the same sulfur sample after filtration were analyzed by determining bitumen in sulfur by dissolving sulfur samples in a solution of sodium sulfide and subsequent extraction in chloroform.

Bitumen in sulfur was found: 1) -0.001% and 2) -otts.

Thus, as shown in the examples, the proposed method for the determination of organic impurities in sulfur is characterized by increased accuracy, rapidity, does not require the use of toxic substances in execution, and is available for any plant laboratory and research institutes.

Formula A method for determining organic impurities in sulfur, comprising treating a sample with a chemical reagent when heated, characterized in that, in order to increase the accuracy and simplify the method; Oleum is used as a chemical reagent, heating is carried out to a temperature not exceeding 100 ° C, after processing, the resulting mixture is dissolved in water and photometric.