Process for reducing the radiotividade in sulfate containing radioactive calcium's non contamination,The process route umida type hemidrato for production of phosphoric acid and calcium sulphate, phosphate rock and dehydrate process via umida for production of phosphoric acid and calcium sulphate ROCHA phosphate

摘要

A wet process for producing phosphoric acid and phosphohemihydrate by acidulation of phosphate rock. A strong phosphoric acid is obtained with concomitant production of an improved calcium sulfate that is extremely low in radioactivity by operation in Region II for shorter time so as to produce small sized hemihydrate particles, then hydration of a substantial proportion but less than all of the hemihydrate to coarse gypsum substantially free of radioactivity in a dilute acidic aqueous slurry at a temperature and P.sub.2 O.sub.5 concentration selected so as to be within Region I of FIG. 1 and having a substantial weight proportion of coarser gypsum particles that are substantially free of radioactivity.