Wet process phosphoric acid concn. - by absorption and condensation, using a surface condenser, of fluorine cpds. vaporised from at least 48 per cent acid

摘要

Process for the concn. of wet process phosphoric acid, obtd by decompsn. of phosphate minerals with sulphuric acid, and recovery of fluorine cpds. is effected by condensation of the vapours which are emitted from the section for the recovery of fluorine cpds. using a surface condenser, while the fluorine recovery section is fed with the emitted vapours from a soln. of phosphoric acid having a concn. >48 (>50) wt % P2O5. Economies are obtd. in the amt. of water used to efficiently recover the fluorine cpds. emitted during the concn. and redn. of effluent and environmental pollution problems. The use of phosphoric acid of >48 wt % P2O3 avoids decomposition of silica on the condenser surfaces.