Process and apparatus for mixing sulphuric acid and returned phosphoric acid

摘要

In a process for mixing sulphuric acid and returned phosphoric acid in the context of the preparation of wet phosphoric acid by sulphuric acid digestion of raw phosphate in a reactor, a hollow cone of returned phosphoric acid spray is allowed to fall over the sulphuric acid present in the form of a high surface area conical spray from a nozzle, in the gas space of the reactor above the reaction paste. Here the mixing of the two acids over large surfaces has to be complete before they reach the reaction paste. An apparatus for carrying out this process comprises a sulphuric acid pipe (1) which is partly surrounded concentrically by a returned phosphoric acid pipe (4) to form an annular space (5). A hollow cone nozzle (3) is set into the lower end of the sulphuric acid pipe (1). The returned phosphoric acid pipe (4) has a lateral widening (6) in its upper region. A guide ring (8) is fixed close to the lower end of the sulphuric acid pipe (1). The returned phosphoric acid pipe (4) ends in a conical widening (flaring) (9). <IMAGE>