| Abstrakt: |
Trails were performed for the recovery of group trace elements, including the radioactive elements, partitioned with the phosphogypsum (PG) stockpiled in around 12 million tones at Al-Qaim in Akashat Phosphate Fertilizer State Company. The method utilizes the concept of the preferential solubility of phosphogypsum in water over other metal sulfates, phosphates, silicates and others may exist with phosphogypsum. At the limit of PG solubility a colloid is formed due to the in-soluble and partially soluble constituents including various trace elements which are settled down after 20-45 minutes. Shorter time settlement was achieved in the presence of polyacrylamide as coagulant. The dissolution process of PG in water has been studied using conductivity technique. De-ionized water show better solvation power for PG and better separation properties compared with potable water. The efficiency of separation and settling of the suspended colloidal particles was studied as function of pH, temperature, time and the presence of flocculent polyvinyl acrylamide. The abundance of the trace elements in PG was determined using x-ray fluorescence, atomic absorption and induced plasma emission spectroscopy. Radioactivity accumulated by the 238U and 232Th decay schemes were measured for 226Ra-228Ra and 222Rn gamma and Alfa spectrometry. Due to their low solubility, it is anticipated that appreciable percentage recovery for the alkaline earth elements Sr, Ba and 226Ra,228Ra, while partial recovery is expected for the other elements i.e., Cu, Zn, Pb, Fe, R.E, uranium and thorium. Phospgogypsum was finally purified with acceptable properties for industrial and agricultural applications. [ABSTRACT FROM AUTHOR] |
