Abstract: A process for purifying elemental phosphorus that contains antimony using an oxidizer, such as hydrogen peroxide, peroxymonosulfate, peroxydisulfate, or a hypochlorite, in a two phase system containing water and phosphorus as the two liquids. A purified elemental phosphorus having 200 ppb or less antimony content.

Abstract: Aqueous phosphorus wastes from the electric furnace production of phosphors and containing heavy metal bearing particulates are treated with lime whereby the phosphorus is converted into useful phosphorus compounds and the heavy metals rendered sufficiently non-leachable to permit their release into the environment. The treatment is conducted above about 60.degree. C. at a pH of between about 11.0 to 12.5.

Abstract: A process is described for the separation and recovery of phosphorus from phosphorus-dirt mixtures by adding a quaternary ammonium compound to the mixture, while it is under an aqueous cover, agitating same, and separating a lower phosphorus phase from an upper dirt phase. The mixtures are treated prior to addition of the quaternary ammonium compound, where required, by lowering their dirt to phosphorus levels sufficiently low to permit them to be destabilized.

Abstract: The excessive wear and formation of ring-like cavities in carbon crucibles used to contain iron-based compositions that are heated in a plasma furnace to a temperature of from about 2000.degree. C. to aboout 2700.degree. C. are reduced or eliminated by adding carbon particles to the crucible in amounts of at least about 6 weight percent of the melt, and preferably in amounts exceeding the solubility of carbon in the heated melt.

Abstract: Ferrophos is treated in a plasma furnace by maintaining an electric arc between a cathode and at least one point on the surface of the ferrophos which serves as the anode in the presence of an inert plasma gas, maintaining the average temperature of the ferrophos at about 2,000.degree. C. to about 2,700.degree. C., evolving gaseous phosphorus from the ferrophos until it contains less than about 7% by weight phosphorus, removing a purified phosphorus gas as one product and a metal concentrate having a reduced phosphorus content as a coproduct.

Abstract: In the production of SALP tetrahydrate wherein sodium carbonate and aluminum hydroxide are added to aqueous phosphoric acid, the viscous reactive mixture is agitated with water to free the SALP tetrahydrate crystals from the gelatinous matrix. The crystals are recovered by filtration or centrifugation.

Abstract: A method for removing small concentrations of phosphine contained in a carbon monoxide gas mixture by preferentially oxidizing the phosphine, in which the phosphine is oxidized with air at a temperature of from 500.degree. C. to 800.degree. C. to form phosphorus pentoxide, which is recovered from the gas mixture preferably as phosphoric acid.

Abstract: Off gases from electric furnace production of phosphorus, consisting essentially of carbon monoxide and phosphine, are heated to 700.degree.-800.degree. C. to decompose the phosphine to red phosphorus and hydrogen; the red phosphorus is separated from the gas--most desirably by passing the gas through aqueous hydrogen peroxide which oxidizes the phosphorus to phosphoric acid,--to obtain a clean gas which can be used as a fuel.