Study of production conditions of arsenic selenide(III) from arsenious sodium and sodium hydroselenide

The paper presents results of a study of the reaction occurring between the arse-nious sodium and sodium hydroselenide. It is revealed that when medium pH is 6-8 and a temperature is 323-343 K arsenic selenide(III) precipitates almost completely out of solution. A chemical analysis of the sediment composition is carried out after filtration and drying. Arsenic and selenium are determined by known gravimetric methods. Thermographic analysis of arsenic selenide sample synthesized in water medium is carried out by the device of NETZSCH STA 449F3. It is ascertained that up to the temperature of 250°C weight loss doesn't occur. However, in the temperature range of 300-550°C weight loss is 100%. This is due to the complete oxidation of arsenic sulfide and volatilization of corresponding resulting oxides. The morphology of nano- and microparticles of arsenic selenide obtained in water medium is studied by Hitachi electron microscope TM-3000 (SEEM). It is ascertained that on crystallization the precipitate forms certain form of nano- and microparticles. Particle sizes vary in the range of600-900 nm. The melting temperature of arsenic selenide is taken by the device of NTR (362°C). X-ray diffraction analysis is carried out on the powder dif-fractometer D2 PHASER of the Bruker company (Germany). The results of X-ray analysis showed that the size of peaks comply enough with the standard (PDF 01-0750739 As ₂Se ₃ Laphamite. syn). This once again confirms the composition of the precipitate As2Se3.

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