Mixing process for nitric and sulphuric acids

摘要

A mixture of concentrated H2SO4 and HNO3 is obtained by feeding separate streams of HNO3 and H2SO4 or oleum into a stream of the mixed acids circulating through a heat exchanger. 4-10 parts of the mixed acid per part by wt. of the total incoming acids may be recirculated. Product is withdrawn from the circuit after the heat exchanger, and acid fumes may be drawn off and passed into an absorption column in the H2SO4 feed line.ALSO:A continuous discharge mixing apparatus comprises a circuit (including a heat exchanger and a centrifugal pump) into which separate streams of sulphuric and nitric acids are metered and from which the mixed acid is removed. 4-10 parts of the mixed acid per part by wt. of the total incoming acids may be recirculated. The mixed acid is withdrawn after the heat exchanger, and acid fumes may be drawn off and passed into an absorption column in the sulphuric acid feed line.