engleski

WASTE PHOSPHOGYPSUM CHARACTERIZATION – TOWARD SUSTAINABLE REUSE

The Croatian fertilizer plant Petrokemija d.d. - Kutina produces phosphoric acid by the wet process natural phosphate rock sulfuric acid digestion. Phosphoric acid librated from apatite mineral is further used in fertilizer formulation. Unfortunately, large quantities of the phosphogypsum (PG) are produced by this process as an unwanted by product. The usual plant operation generates 4.9 ton of phosphogypsum per 1 ton of phosphoric acid (calculated as 100% P2O5). Since 1983, when the phosphogypsum pond has been formed and wet stacking has been applied, 8.4 million tons of PG had been disposed. PG tailing facility is located about 5 km from the plant at the very edge of the Natural Protected area Lonjsko Polje. Most favorable improvements, from the point of environmental protection and sustainability, should bring about any possible reuse of phosphogypsum. In order to evaluate reuse potential of phosphogypsum we investigated its chemical and mineralogical composition and physical properties of the as collected wet slurry and dried phosphogypsum. Radioactive nuclide content of the PG is of special concern and limits its possible applications. In this work an overview of PG pond present state and near future projection along with recent legislative changes in Croatia is given. It is concluded that comprehensive characterization is necessary for safe waste management and several material recovery routes proposed.

phosphogypsum; chemical characterization; waste management; reuse of phosphogypsum

nije evidentirano