Abstract: In the electric arc furnace production of elemental phosphorus, cold phossy water is segregated from hot phossy water. The cold phossy water is discharged to a lined pond wherein solids settle to form a clarified cold water which is recycled for cooling and washing purposes. The hot phossy water is passed through a lamellar settler wherein phosphorus and solids are separated as a sludge to form a clarified hot water. The clarified hot water, without requiring additional heat, is recycled for process use. Phosphorus is recovered from the sludge to reduce to a minimum the amount of phosphorus discharged with dirt from the hot phossy water to the pond.

Abstract: Process for recovery of elemental phosphorus from phosphorus sludge produced in a phosphorus furnace by treating the sludge in a centrifugal separator and separating a fine dirt slimes fraction from a recovered heavy fraction containing the major portion of phosphorus; treating the slimes fraction in hydrocyclones not over one inch (24.4 mm) in diameter to separate two streams, a first phosphorus-poor stream containing particles smaller than 8-15 micrometers, and a second phosphorus-rich stream containing particles larger than 8-15 micrometers; recycling the second, phosphorus-rich stream to the centrifugal separator for phosphorus recovery, and discarding the first, phosphorus-poor stream.

Abstract: Process for recovery of elemental phosphorus from waste ponds by dredging the waste pond to obtain an aqueous phosphorus slurry, separating particles larger than 2 mm from the slurry, treating the remaining slurry in an initial hydrocyclone and removing an overflow of solids larger than 500 micrometers, treating the underflow from the initial hydrocyclones in smaller diameter hydrocyclones, removing a second overflow enriched in slimes and diminished in phosphorus, removing a second underflow enriched in phosphorus and diminished in slimes and heating it sufficiently to melt the phosphorus therein, treating the heated second underflow in a centrifugal separator, and separating and recovering a stream of coalesced phosphorus from a heavy fraction of impurities.

Abstract: Liquid phosphorus as produced by the reduction of a phosphate ore in an electric arc furnace while of high purity contains color-causing impurities that impart to the phosphorus a black color by reflected light. Such liquid phosphorus is polished or refined to exhibit a yellow or yellow brown cast by mixing it with hot water and subjecting the mixture to intense agitation. The refined phosphorus is separated from the water phase which retains the impurities.