METHOD OF REMOVING AND RECOVERING MIXTURES OF NITRATING ACIDS FROM NITRATION PROCESSES AND INDUSTRIAL NITRATION INSTALLATION Russian patent published in 2009 - IPC C07C201/16 C07C201/08 C07C205/06 B01D11/04 

FIELD: chemistry.

SUBSTANCE: present invention relates to the method of removing and recovering mixtures of nitrating acids, mainly nitric acid, sulphuric acid and nitrogen oxide, from nitrated aromatic compounds obtained from nitration, after removal of nitrating acid from crude nitration products through washing with acid in a multiple-stage method of extraction processing. This method involves crossflow extraction processing with subsequent counterflow extraction processing. The invention also relates to the industrial installation for nitrating aromatic compounds with subsequent purification of the products, including removal from them and recovery of mixtures of nitrating acids, mainly nitric acid, sulphuric acid and nitrogen oxide. The industrial installation has a nitrating unit and an acid washing unit, placed after it, consisting of a crossflow extraction processing unit.

EFFECT: practically complete recovery in high concentration of the above mentioned acids, including nitrogen oxide, which allows for returning them into the nitration process and thereby significantly reduce their contamination of sewage water.

10 cl, 2 dwg, 1 ex