J.r. Simplot Company

Laurence W Bierman

Samuel M Polinsky

Roger B Humberger

Gary L Long

David A Hempel

Samual M Polinsky

David K Johnson

James E Perkins, Iii

David Bortner

Michael L Lopez

Charles R Edinborough

Ores containing mineral values are separated into two slurries, one having primarily fine particles and gangue and the other having primarily coarse particles. The slurry having fine particles and gangue is adjusted to a solids content of less than about 15 percent, as necessary, and then conditioned by the addition of appropriate promoter reagents, a flotation collector, and a froth modifier. The gangue, containing a disproportionate share of impurities, is floated in a column flotation cell wherein the fine particulates are not mechanically agitated, and removed. The remaining fine particulate underflow, containing a disproportionate share of the minearl values, is then processed directly, or combined with the slurry containing the coarse particulate to yield a flow having reduced impurity content and increased recovery of the mineral values.

Process for beneficiating ores containing fine particles

A mixture of hydrophobic and hydrophilic extractants is used to separate phosphate values from impurities found in phosphoric acid. In one approach, impurities are removed from phosphoric acid and the phosphate values are recovered, by introducing polyphosphates and ammonium ions into the impure acid, and contacting the impure acid with a mixture of low and high molecular weight alcohols, one of which is hydrophilic and the other hydrophobic, in a single stage. The phosphate values segregate to the high molecular weight alcohol fraction, and the impurities segregate to the low molecular weight alcohol fraction. After separation of the alcohol solutions, the phosphate values and the impurities are separated from their respective extractant solutions, and the alcohols recirculated. Polyphosphates and ammonia are preferably provided by reacting a portion of the original feed acid with ammonia at elevated temperature in a pipe reactor.

Purification of phosphoric acid

A process and product for achieving uniform, stabilized working and setting times for phosphate-bonded magnesia cements, wherein a solid phosphate is mixed with an aqueous ammonium phosphate solution and magnesium oxide to form a cement. The solid phosphate may be provided dry or in a slurry, and may be first mixed with the ammonium phosphate solution or the magnesium oxide. Introduction of the solid phosphate into the cement stabilizes the setting time of the cement, which otherwise may vary from a few minutes to several hours, depending upon the characteristics of the ammonium phosphate solution. The ammonium phosphate solution may be supplied as a 10-34-0 composition that is readily available commercially. In one embodiment of the invention, the solid phosphate is provided as an ammonium phosphate mixture of an 18-46-0 composition, having an ammonium phosphate content above the solubility limit of ammonium phosphate in water. In another embodiment, dry phosphate is mixed with the magnesium oxide, before the ammonium phosphate solution is added.

Stabilization of setting times of phosphate-bonded magnesia cements

A process for reducing the valence state of ferrous and other ions present in phosphoric acid by heating the acid in the presence of a pressurized reducing gas, preferably hydrogen. The pressurized gas reduces the ions without an addition of metallic iron or other impurity. This process is desirably used with processes for recovering uranium from wet process phosphoric acid, wherein ferric or uranyl ions in the phosphoric acid are reduced in a pressurized reducing gas.

Gaseous reduction of phosphoric acid

A process for beneficiating phosphate containing ores, wherein promoter reagents are added to the ore slurry prior to the addition of collectors and depressants for flotation of the carbonate and silica components. The promoters aid in increasing the rejection of the magnesium present during carbonate and silica flotation steps and recovery of phosphates, so that acceptably low magnesium levels for phosphoric acid production can be achieved in a phosphate concentrate in a single rougher stage. Preferred promoters include sodium carbonate and ammonium hydroxide.

Increased reduction of magnesium content by use of inorganic promoters

A process for preparing granulated fertilizer materials, wherein urea phosphate is used as a granulating agent to assist in the agglomeration of finely divided solid particles into relatively uniformly sized granules. Urea phosphate, prepared by dissolving urea in phosphoric acid, is coated onto finely divided particles of fertilizer materials, and granulation is accomplished at a temperature within the thermoplastic range of the urea phosphate, wherein the urea phosphate plasticizes and induces adherence of the fine particles into relatively uniformly sized granules. Optionally, ammonia gas, clay, or micro nutrients may be added after granulation.

Process for granulation of fertilizer materials

A process for the selective recovery of cadmium, molybdenum, zinc, nickel and other metal values from wet process phosphoric acid and other acidic to slightly basic carrier solutions, wherein the metal-bearing solution is contacted with an organophosphene extractant to precipitate the metal values for subsequent separation from the solution. Separation may be effected by mechanical means or by scrubbing with a water-immiscible organic solvent such as kerosene for subsequent recovery of the metal values. The metal specie recovered is determined by the concentration of the organophosphene, which may be selectively adjusted to recover a series of metal values in a sequence of stages.

Process for the recovery of cadmium and other metals from solution

A two stage reductive stripping process for recovering uranium from wet process phosphoric acid, wherein the ferrous ions required for the first-stage reductive strip are supplied by heating a portion of acid raffinate phosphoric acid from the first-stage extraction in the presence of pressurized hydrogen gas. The pressurized hydrogen gas reduces the ferric ions in the raffinate to the ferrous state without any addition of metallic iron or other impurity, so that the uranium-enhanced reductive strip solution supplied to the second stage from the first stage reductive strip has a low concentration of iron impurity, and no further purification to remove iron impurity is required.

Reduction of iron in a reductive stripping process for the recovery of

An improved method and apparatus for effecting a substantial reduction in retention time of oxidation processes by the autoclave oxidation of ion species dissolved in aqueous solutions. In one embodiment, the invention provides for oxidation of dissolved reduced ion species including ferrous iron (Fe.sup.+2), uranium (U.sup.+4) and vanadium (V.sup.+3) from wet process phosphoric acids, or for conditioning of aqueous solutions for other uses, such as corrosion control, by raising the valence state of dissolved ion species. In accordance with the present invention, pure oxygen, present in quantity of at least 94% by volume, is utilized as an oxidizing agent with specified process parameters: temperature, pressure and mixing conditions in an autoclave reaction vessel. In a presently preferred embodiment, the following specified parameters have achieved optimum results with regard to a significant decrease of retention time of the aqueous solution treated in the autoclave vessel: temperature range of from about 120.degree. F. to about 160.degree. F., pressure range of from about 120 psi to about 150 psi and effecting agitation by the use of an impeller located near the interface of the liquid and gas mixture in the vessel to provide a dispersion of the liquid solution in the gaseous phase. In accordance with such embodiment, a reduction of retention time for oxidation of uranium (U.sup.+4 .fwdarw.U.sup.+6) and vandanium (V.sup.+3 .fwdarw.V.sup.+4) metals from wet process phosphoric acid has been found to be less than two minutes, whereas, prior processes for effecting the same oxidation results have taken at least one hour.

Method for autoclave oxidation of ion species aqueous solutions

Process for producing triple superphosphate by reacting dilute phosphoric acid and lime, limestone or dolomite and granulating the resultant product.

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Pocatello, ID, United States of America

Laurence W Bierman