Rohstoff‐ und energiesparende Verfahrensentwicklungen bei den Grundprodukten der anorganischen Phosphor‐Chemie

The energy crisis, and developments in the phosphorus industry for the economic production of basic products . A general shortage of power has culminated in attempts to switch over from energy intensive to energy‐saving processes. This is exemplified with reference to the field of inorganic phosphorus chemistry. Modern recrystallization processes for making wet‐processed phosphoric acid, proceed via the calcium sulfate semihydrate stage, and yield crude phosphoric acid in increased concentration. The steam normally required for concentrating the acid is thus saved. Heat of neutralization is utilized for evaporating water, for example, in a TV A process for making ammonium polyphosphate from commercial crude phosphoric acid and ammonia. Economic evaluation data reflect the economy (reduction of costs) of the above processes in comparison with those used heretofore. The purification of wet‐processed phosphoric acid by an improved precipitation method – particularly in the intermediates sector – and by modern extraction techniques are described as alternatives to the electro‐thermal production of phosphoric acid. A detailed description is given of one such process, where amyl alcohol is used as the solvent.