METHOD FOR REPROCESSING OF REACTION MASSES RESULTING IN LEWISITE DETOXICATION PROCESS Russian patent published in 2009 - IPC A62D3/36 A62D3/37 A62D101/40 

FIELD: chemistry.

SUBSTANCE: invention refers to the methods of chemical weapon disposal namely to the reprocessing of reaction masses resulting during alkaline hydrolysis of lewisite. The reprocessing is implemented in closed process cycle including the reaction masses treatment with chlorhydric acid up to pH less than 1, washing and removal of resulting polymer organic compounds and mechanical admixtures with filtration, merging of acid filtrate with washwater and following reduction of arsenic (V) compounds to arsenic (III) compounds which are then treated with alkaline solution, obtained precipitate of arsenic (III) oxide is separated and transformed by washing, filtration and drying to commercial-grade arsenic oxide. The alkaline filtrate and washwater are treated with alkaline solution and undergo the vacuum evaporation with forming of the sodium chloride precipitate. The latter is washed and separated with centrifugation, resulting alkaline centrate and washwater are used on the stage of arsenic (III) oxide precipitation; the precipitate of contaminated sodium chloride is solved in water and obtained solution is purified from arsenic (III) compounds by passing through the solid sorbent bed; purified solution of sodium chloride undergo the vacuum evaporation, obtained salt mass is centrifugated with obtaining of technical sodium chloride. The condensates obtained in vacuum evaporation are recycled.

EFFECT: development of effective, low-waste and environmentally safe method of chemical weapon disposal which provides processing of hydrolysed sodium arsenite to commercial-grade products - arsenic (III) oxide and technical sodium chloride

18 cl, 1 dwg