METHOD OF PRODUCING COLLOXYLINS FROM PYROXYLINE POWDER Russian patent published in 2013 - IPC C08B5/02 

FIELD: chemistry.

SUBSTANCE: invention relates to a method of producing colloxylin from pyroxyline powder. The method involves soaking starting powder in aqueous sodium hydroxide solution, crushing the powder, treating the powder crumbs with aqueous sodium hydroxide solution, extracting organic impurities from the pyroxyline powder with a chlorinated hydrocarbon and treating first with nitric acid solution with concentration of 8-20 wt % and then in an autoclave with nitric acid solution with concentration of 0.4-0.6 wt % and water. The starting powder is soaked at temperature of 18-20°C for 1.5-2.5 hours and treated with aqueous sodium hydroxide solution at temperature of 50°C for 2-3.5 hours. Treatment with nitric acid solution is carried out at temperature of 70-90°C, followed by treatment in an autoclave for 20-45 minutes at temperature of 130°C.

EFFECT: increase in output of the end product by an average of 10%, improved quality properties of the product and cutting duration of the process twofold.

3 cl, 1 tbl, 4 ex