Abstract: An improved process for the thermal defluorination of phosphate rock is provided. The process comprises adding ammonia to the phosphoric acid fed to the kiln, the amount of ammonia added being effective for forming a eutectic with the fused ring and ball materials and heating the mixture with agitation to defluorinating temperatures for a period of time sufficient to defluorinate the rock and recovering the defluorinated rock.

Abstract: A process to maintain a high iron +2/iron +3 concentration in the reductive stripping system for recovering uranium from wet-process phosphoric acid, comprises contacting partially oxidized strip acid, containing substantial amounts of iron +3, which had just previously stripped uranium values from an organic solvent, with elemental iron to reduce iron +3 to iron +2 and provide a Fe.sup.+2 /Fe.sup.o conversion ratio of from about 1.5 to 3.0.

Abstract: A process to restore solvent after the stripping step in recovering uranium from phosphoric acid, comprises passing stripped, water-immiscible organic extraction solvent, containing contaminants and having a lowered uranium extraction coefficient value, through a water scrub, to scrub contaminants from the organic solvent and raise its uranium extraction coefficient. The scrubbed solvent is then passed back to the extractor and the contaminated water is passed into at least one purification means and then back to the scrubber.

Abstract: A method for concentrating and recovering uranium material from a solution containing uranium, comprises passing the solution through at least one semipermeable membrane system capable of concentrating uranium, to provide a uranium rich product.

Abstract: Wet process phosphoric acid is oxidized with nitric acid so that uranium values therein are in the +6 state. The organic extractant which contacts the acid extracts the +6 uranium and nitrate and/or nitrite ions. Urea is added to the oxidized acid to react with the nitrate and/or nitrite ions so that the organic does not extract them. The organic is reductively stripped with an aqueous solution containing ferrous ions. The efficacy of the ferrous ions is not lost through reaction with nitrate and/or nitrite ions.

Abstract: A method of recovering liquid from an emulsion formed in a liquid-liquid contacting process, where the emulsion comprises at least one of the liquids entrapped by water-permeable membranes, comprises: admixing water and the emulsion in a volume ratio of water:emulsion of between 0.5 to 4.5:1 and raising the temperature of the admixture to between about 45.degree. C. and 99.degree. C., to cause water permeation of the membranes, causing them to disintegrate and release liquid, forming a three-phase composition consisting essentially of the two liquids and the solids.

Abstract: A metal containing acidic solution, also containing humic acid impurities and contaminants, is purified by contacting the acidic solution with a scrubbing agent consisting essentially of a metal extractant and from about 50 vol.% to about 90 vol.% of a hydrocarbon, where the scrubbing agent interacts with impurities and contaminants in the acidic solution to form a sludge phase which is removed and a purified acid phase which can be fed into a metal recovery process.

Abstract: An emulsion, formed at the interface of an acidic solution and a solvent, is removed by passing at least one continuous belt through the emulsion by floating action, where portions of the emulsion attach to the surface of the belt material.

Abstract: A method for concentrating and recovering uranium material from an aqueous solution, comprises passing a feed solution containing uranium through at least one reverse osmosis membrane system to concentrate the uranium, and then flushing the concentrated uranium solution with water in a reverse osmosis membrane system to further concentrate the uranium.