Recovery of the nitration acid mixtures from nitration processes

Removing and recovering nitrating acid mixtures of nitric acid, sulphuric acid and oxides of nitrogen, from the nitrated crude products occurring in the nitration of nitratable aromatic compounds, after the nitrating acid has been separated off, by a multistage extraction process involves one stage of a cross-flow extraction and another stage of a countercurrent extraction. An independent claim is also included for production plant for nitrating nitratable aromatic compounds with subsequent purification of the nitrated products, including removal and recovery of nitrating acid mixtures of sulphuric acid, nitric acid and oxides of nitrogen, comprises: (a) a nitrating unit for nitrating nitratable aromatic compounds, having at least one appropriate reaction containers for carrying out the nitration reactions; and (b) arranged in the production line downstream of the nitrating unit, a unit for carrying out acidic scrubbing by units of extraction and is comprising a cross-flow extraction unit for carrying out acidic scrubbing of nitrated crude products by units of cross-flow extraction, and in the production line downstream of the cross-flow extraction unit, a countercurrent extraction unit for carrying out acidic scrubbing of the nitrated crude products, scrubbed beforehand by units of cross-flow extraction, by units of countercurrent extraction.