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The United States of America As Represented by the Secretary of

William K Tolley

William C Laughlin

John C Stauter

Beckay J Nelson

Peter Urban

William Rostoker

Alton B Whitehead

Francisco J Corral

Pieter D Rademaker

Process of using supercritical fluid to selectively separate, purify and recover metal halides.

Supercritical fluid metal halide separation process

Titanium metal values may be recovered from a metal-bearing source containing titanium and iron by subjecting the source to an oxidation treatment and a reductive roast. After having crushed the source to a desired particle size, the reduced source is then leached by treatment with a halogen-containing compound to form soluble halides, following which the soluble titanium halide is precipitated as titanium dioxide by treatment with an iron oxide such as ferric oxide and recovered. The amount of titanium dioxide which is recovered may be optimized by utilizing a reductant such as hydrogen or carbon monoxide in an amount in the range of from about 1.5 to about 4.5 times the stoichiometric amount required to reduce the iron oxide to metallic oxide during the reductive roast.

Recovery of titanium metal values

The recovery of metal values such as cobalt may be improved in a hydrometallurgical recovery of metal values from metal-bearing sources such as ores and the like. The hydrometallurgical recovery process involves subjecting a metal-bearing source to a reductive roast in a reducing atmosphere after having treated said source with at least one additive. Thereafter, the reduced metal-bearing source is cooled and extracted by a leaching operation such as treatment with an ammoniacal ammonium salt solution. The leaching step is followed by a separation of various metal values by adding a solid adsorbent to the leach solution whereby selective metal ions are adsorbed thereon. The improvement of the process involves subjecting the solid adsorbent to a stripping operation with a stripping agent such as steam or a gas at an elevated temperature prior to recovery of the adsorbed metal ions from the solid adsorbent by conventional means such as acid-stripping.

Recovery of cobalt values by absorption from ammoniacal solution

In a hydrometallurgical process for the recovery of metal values from a metal bearing source in which a metal bearing source is treated at a temperature in the range of from about 300.degree. to about 900.degree. C. in a reducing atmosphere in contact with an additive such as a hydrogen halide and sulfur followed by cooling and extracting the source with a basic or acidic solution, the recovery of the desired metal value may be improved by adding the hydrogen halide to the source at a temperature below about 500.degree. C.

Ammoniacal nickel leach of laterites

Desired metal values are recovered from metal-bearing sources by subjecting said metal-bearing sources to a reduction step which is effected in an aqueous solution of an ammoniacal ammonium salt containing a reducing reagent such as hydrazine, hydroxylamine hydrochloride, etc., or by treatment with carbon monoxide in the presence of a metal chelate such as that formed from cobalt sulfate and dimethyl glyoxime, and thereafter subjecting the reduced source to an oxidative leach by treatment wth an oxygen-containing gas such as air or oxygen. The reducing step is effected at ambient temperatures and pressures and the oxidative step is effected at ambient temperatures and pressures ranging from about 5 to about 500 psig. Desired metal values such as nickel and cobalt may be recovered in commercially attractive yields.

Hydrometallurgical recovery of copper, cobalt nickel with reductive and

The present process involves an improvement in the hydrometallurgical recovery of metal values from metal bearing sources such as ores and the like. The metal values are obtained by subjecting a metal bearing source to a reductive roast at an elevated temperature followed by cooling the reduced metal bearing source, extracting the cooled source and recovering the resultant metal values. An improvement in this process is effected by adding a compound containing a metal of Group IA or IIA of the Periodic Table to the source before subjecting the source to the reductive roast. Following the roast the ore is quenched in an aqueous solution and thereafter subjected to an extraction step.

Enhanced hydrometallurgical recovery of cobalt and nickel from laterites

Metal values may be recovered from metal bearing sources which contain at least two metals, at least one of which is in the form of a sulfide, by treating the aforesaid source with an oxidant at an elevated temperature in the range of from about 600.degree. to about 1500.degree. C. and in the presence of an added promoter comprising a sulfur-containing compound. The treatment will convert at least one metal value to an oxide and at least one metal value is converted to the elemental state which contains a relatively minor amount of a subsulfide. The addition of the sulfur-containing compound will result in an increase in the particle size of the elemental metal, thus permitting the recovery of said metal more readily.

Recovery of metal values from a metal bearing source of nickel and

Metal values may be recovered from metal bearing sources which contain at least two metals, at least one of which is in the form of a sulfide, by treating the aforesaid source with a mild oxidant at an elevated temperature in the range of from about 600.degree. to about 1500.degree. C. whereby at least one metal value is converted to an oxide and at least one metal value is converted to the elemental state which contains a relatively minor amount of sulfur. Thereafter the metal compounds may be separated and recovered by conventional means.

Titanium metal values may be recovered from a titanium bearing source such as an ilmenite ore by subjecting the source to a reductive roast and leaching the reduced source with a halogen containing compound such as hydrochloric acid. The soluble titanium halide is then extracted from the leach liquor by utilizing an organophosphoric acid such as mono-2-ethylhexylphosphoric acid. The extracted titanium may then be stripped from the loaded organic acid solution by treating the solution with a mixture of hydrogen peroxide and an inorganic acid. Thereafter the desired titanium metal value may be recovered from the acid solution by any means known in the art such as hydrolysis.

Recovery in titanium metal values by solvent extraction

A process for removing, by absorption, sulfur dioxide from a gaseous mixture such as a flue gas by scrubbing said mixture with an aqueous scrubbing liquor to which a solution of an alkaline reagent such as sodium carbonate is added to maintain alkalinity of the scrubbing liquor. The solution also has dissolved in it a quantity of silica which tends to precipitate when solution is added to the scrubbing liquor. The silica precipitated in this manner tends to form extremely hard solid deposits in the scrubbing device and associated equipment. If a water soluble acid salt such as ferrous or ferric sulfate is added to the alkaline reagent solution prior to its use in the process, the precipitate formed has a minimum deleterious effect.

Flue gas treatment for sulfur dioxide removal

Rutile, which has been obtained by precipitation from a hydrogen chloride solution will contain a relatively large amount of residual chlorine containing compounds such as the various forms of titanium chloride. These residual chlorine containing compounds may be removed in an economical way by treating the rutile with hydrogen peroxide in an acidic solution at relatively low temperatures to substantially reduce the chloride content of the product.

Purification of rutile

In a process for recovering titanium metal values from a titanium bearing source which also contains iron, the source is subjected to a reductive roast followed by a leach of the reduced source with hydrogen chloride. The suppression of the dissolution of titanium during the leaching step of the process will be effected by the addition of a phosphoric acid to the leaching solution.

Separation of iron metal values from titanium metal values

Titanium metal values may be recovered from iron and titanium bearing sources such as an ilmenite ore by subjecting the source to a reductive roast after having crushed the source to a desired particle size. The reduced source is then leached by treatment with a halogen-containing compound to form soluble titanium halides and iron halides. Thereafter, the soluble titanium halide is precipitated as titanium dioxide by treatment with an iron oxide such as ferric oxide. The desired titanium dioxide or rutile may be recovered without an appreciable loss by effecting the leach step of the process in such a manner so that the solution potential is not greater than about +150 millivolts.

Iron metal values and titanium metal values may be recovered from iron and titanium bearing sources such as ilmenite by subjecting the source to a reductive roast followed by leaching of the reduced source with a halogen-containing compound. Thereafter, the iron halide is crystallized and separated from the soluble titanium halides. One portion of the iron halides is subjected to a reducing step to form metallic iron while a second portion is oxidized, the iron oxides being used to precipitate the titanium as titanium dioxide. The titanium dioxide may then be separated and recovered while the liquid portion is recycled to the leaching zone.

Recovery of iron and titanium metal values

Iron metal values and titanium metal values may be recovered from iron and titanium bearing sources such as an ilmenite ore by subjecting the source to a reductive roast after crushing the source to a desired particle size. The reduced source is then leached by treatment with a halogen-containing compound to form soluble titanium halides and iron halides. Thereafter the soluble titanium halide is precipitated by treatment with iron oxides such as ferric oxide and after separation from the soluble iron halides is recovered as titanium dioxide. The soluble iron halides are then crystallized by reducing the temperature of the solution and one portion of the crystals are subjected to a reduction step to form metallic iron. The other portion of the iron halide crystals is oxidized to form ferric oxide which is used to precipitate the titanium compound.

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Arlington Heights, IL, United States of America

William K Tolley