Sequential chemical extraction for a phosphogypsum environmental impact evaluation

Abstract

Phosphogypsum (PG) is gypsum generated during phosphoric acid production. PG is stocked in large stacks or accumulated in lakes; it contains heavy metals and naturally occurring radioactive elements. The metal contamination may affect the functionality, sustainability and biodiversity of ecosystems. In this work, PG samples were analyzed by Plasma Spectrometry. Total metal content and in the extractable fraction of chemical elements were determined. For K, Ni, Zn, Cr, Cd, Ba, Pb and U, the results obtained are lower than those obtained in a Idaho plant are including and also lower than those found in the soil, indicating this PG sample analyzed probably will not cause any additional metal neither natural radiation contamination.

Study of phosphogypsum conversion from Kyzylkum phosphorites with soda ash solution

“…The top ten countries in terms of mining and production of phosphate ores, such as the United States, have piled up more than 200 million tons of PG with an annual dumping of 11 million tons, China more than 500 million tons with an annual dumping of 50 million tons, Russia about 500 million tons with an annual dumping of 11 million tons, Kazakhstan more than 30 million tons, Brazil more than 150 million tons with an annual dumping of 5 million tons, Morocco produces about 15 million tons of PG, most of which is dumped into the sea, Tunisia 52 million tons, where more than 10 million tons of FG is dumped per year near the enterprise [8][9][10][11][12]. Only 15% of the world production of PG is processed into building materials (ɑ, β forms of gypsum, cement), sulfuric acid, used for paving, as a fertilizer, reclamation of saline (saline) soils, as well as raw materials for the extraction of rare earth elements (REE) and a medium to fix CO2 and improve drainage [13][14][15][16].…”

Research Perspectives on the Use of Phosphogypsum in the Brazilian Cerrado

“…6 Mg[10]. Out of this total, 1.7 106 Mg yr -1 have been used as soil amendment, 0.7 10 6 Mg yr -1 in cement industry, and the remaining 2.1 10 6 Mg yr -1…”