Abstract: Provided is a method for recovering a valuable metal sulfide, the method including: (a) adding limestone to a residual solution including a valuable metal to remove iron and aluminum; (b) adding sulfuric acid and a sulfide to the solution from which the iron and aluminum are removed to recover the valuable metal sulfide; and (c) adding air or sulfuric acid to the solution from which the valuable metal sulfide is recovered to remove sulfur.

Abstract: Provided is a method for producing solutions, by which two solutions, namely a high-purity nickel sulfate solution and a mixed solution of nickel sulfate and cobalt sulfate are able to be obtained at the same time from a sulfuric acid solution containing nickel, cobalt and calcium. A method for producing solutions according to the present invention uses a sulfuric acid solution containing nickel, cobalt and calcium and performs a first step S1 for producing a mixed solution of nickel sulfate and cobalt sulfate from the sulfuric acid solution and a second step S2 for producing a solution of nickel sulfate from the sulfuric acid solution in parallel. In the first step, the sulfuric acid solution is subjected to solvent extraction by an extractant, thereby obtaining a first organic solvent after extraction. In the second step, the sulfuric acid solution is subjected to solvent extraction by means of an extractant.

Abstract: A novel process for treating and recovering valuable metals and other components from pickling acid residue (PAR) has been developed. The metals and other components are recovered by neutralizing the pickling acid residue using a magnesium compound or a mixture of magnesium compounds, and separating components of the resulting mixture (metals and sulfates) into products that can be reused, such as magnesium sulfate, nickel sulfate, iron and chromium phosphate, or various metal hydroxides or oxides.

Abstract: A process is provided for removing metal salt co-constituents from an iron-containing solution comprising: (a) decreasing the free acidity of the solution to produce a slurry; (b) optionally heating the solution or the slurry to a temperature at least 30° C.; (c) optionally aging the slurry; (d) adding one or more cationic polyelectrolyte flocculants to the slurry; and (e) separating a solid-containing portion from a liquid portion of the slurry.

Abstract: The present invention relates to a method for preparing magnetite nanoparticles from low-grade iron ore using solvent extraction and magnetite nanoparticles prepared by the same. According to the method for magnetite nanoparticles from low-grade iron ore of the present invention, it is possible to prepare high-purity magnetite nanoparticles having a purity of 99% or higher by solvent extraction using low-grade iron ore as a starting material, and thus it is possible to reduce the processing cost and the amount of energy used, thus supplying a high-efficiency magnetite nanoparticle adsorbent, which can be industrially applied to wastewater treatment or desalination plant, in large quantities at low cost. In particular, it is possible to effectively treat livestock wastewater, heavy metal wastewater, oil discharged into rivers, etc. at low cost, thus significantly contributing to the prevention of environmental pollution.

Abstract: Methods of enhancing recovery of value sulfide and/or precious-metal minerals from an ore containing said minerals and a Mg-silicate, slime forming mineral, and/or clay, and which is subjected to a froth flotation process, by adding to one or more stage of the froth flotation process a froth phase modifier having a polymer containing one or more functional groups, and optionally a monovalent ion modifier enhancing agent, thereby enhancing recovery of a value sulfide mineral and/or a precious metal-bearing mineral.

Abstract: Nickel compositions for use in manufacturing nickel metal compositions, and specifically to methods of making basic nickel carbonates used to produce nickel metal compositions are disclosed. By varying the molar ratios of carbonates and bicarbonates to nickel salts, the methods provide basic nickel carbonates that produce superior nickel-containing solids that react more effectively with phosphorous-containing ligands. The phosphorous containing ligands can be both monodentate and bidentate phosphorous-containing ligands.

Abstract: Non-spherical siliceous particles having a plurality of porous branches are disclosed and claimed. The porous branches are randomly oriented and elongated, ring-like, and/or aggregated. An additive introduced during synthesis of the particles modifies pore volume and morphology. The tunability of the pore volume includes an inner diameter ranging from about 2 ? to about 50,000 ?. Synthesizing the particles includes mixing under constant or intermittent stirring in a reaction vessel an aqueous silicic acid solution with an acidic heel solution to form a mixture. The stirring may optionally be performed at a variable speed. An additive is introduced into the mixture at a controlled rate, wherein the additive imposes a pH change from a lower pH to a higher pH to the mixture to induce siliceous particle precipitation.

Abstract: The invention enables processing waste sludge after galvanic treatment of metals, and particularly recycling spent pickling acids after pickling. Provided is an environmentally friendly process, which yields acids for reuse, and pure nano-sized iron pigments as a side product.

Abstract: Methods for regenerating amorphous iron oxide hydroxide after being used as desulfurizer by (1) grinding a waste mixture into waste powder, wherein the waste mixture results from use of the composition comprising amorphous iron oxide hydroxide as desulfurizer; (2) preparing the waste powder into a suspension and charging the suspension with a gas containing oxygen to obtain a slurry comprising amorphous iron oxide hydroxide and elemental sulfur; and (3) placing the slurry or a solid resulting from filtering the slurry into a container and charging the slurry or the solid with air so that the elemental sulfur floats and the amorphous iron oxide hydroxide precipitates.

Abstract: The present invention provides a method for preparing magnetite nanoparticles from low-grade iron ore and magnetite nanoparticles prepared by the same. According to the method of the present invention, in which iron ore leachate is obtained by adding low-grade iron ore powder to an acidic solution, Si and Mg that inhibit the formation of magnetite nanoparticles present in the leachate are selectively removed, iron hydroxide (Fe(OH)3) is allowed to be precipitated from a supernatant containing Fe2+ ions and Fe3+ ions, a mixed iron solution containing Fe2+ ions and Fe3+ ions is prepared using the iron hydroxide (Fe(OH)3), and the mixed iron solution is added to an alkaline solution to react, thereby preparing magnetite nanoparticles.

Abstract: Process for the treatment of a lateritic nickel/cobalt ore consisting of a mixture (2) of limonite and saprolite, characterized in that: the mixture (2) in the presence of an iron-precipitating agent is made into a pulp (1), having a solids content of between 10 and 40% by weight; the pulp undergoes a leaching operation (4) with sulphuric acid (5), at a temperature between 70° C. and the boiling point and at atmospheric pressure; and a solid-liquid separation (8) is carried out so as to obtain an iron-containing solid residue (9) and a solution containing nickel and cobalt ions. Process for producing nickel and/or cobalt intermediate concentrates or commercial products using the above process.

Abstract: There are provided processes for extracting aluminum ions from aluminous ores. Such processes can be used with various types of aluminous ores such as aluminous ores comprising various types of metals such as Fe, K, Mg, Na, Ca, Mn, Ba, Zn, Li, Sr, V, Ni, Cr, Pb, Cu, Co, Sb, As, B, Sn, Be, Mo, or mixtures thereof.

Abstract: Uses for a composition comprising a polymer derived from at least two monomers: acrylic-x and an alkylamine, wherein said polymer is modified to contain a functional group capable of scavenging one or more compositions containing one or more metals are disclosed. These polymers have many uses in various mediums, including wastewater systems.

Abstract: The present invention relates to a process for the conversion of cobalt(II)hydroxide into cobalt(III)oxidehydroxide (CoOOH) by reaction of the cobalt(II)hydroxide with oxygen in the presence of certain metal compounds. The invention further relates to the use of cobalt(III)oxidehydroxide thus prepared in the preparation of catalysts or catalysts precursors, especially catalysts or catalyst precursors for the conversion of synthesis gas into normally liquid and normally solid hydrocarbons and to normally liquid or solid hydrocarbons, optionally after additional hydrotreatment, obtained in such a conversion process.

Abstract: Disclosed is a method of manufacturing a metal oxide nano powder comprising preparing a first dispersed solution by adding a nano-sized metal powder to water and dispersing the metal powder within the water, performing a hydration reaction of the first dispersed solution at a temperature of about 30 to about 70° C. to generate a precipitation, and filtering and drying the precipitation to prepare a metal oxide powder. Also, disclosed is a metal oxide nano powder manufactured by the method described above, and having any one of a bar-form, a cube-form, and a fiber-form.

Abstract: A method of preparation of spherical tricobalt tetraoxide, including at least oxidizing a bivalent cobalt salt in a wet environment and in the presence of a precipitant, a complexing agent, and an oxidant to yield spherical cobalt oxyhydroxide.cobalt hydroxide according to the following equation Co2++3OH?+O?CoOOH.Co(OH)2; oxidizing the spherical hydroxy cobalt oxyhydroxide.cobalt hydroxide to yield spherical tricobalt tetraoxide according to the following equation 6CoOOH.Co(OH)2+O?4Co3O4+9H2O; and roasting the spherical tricobalt tetraoxide at low or intermediate temperature to yield a black powder. The method is easily practiced and suitable for mass production, and the resultant spherical tricobalt tetraoxide has stable structure, reliable properties, and high activity.

Abstract: The separation method for zinc sulfide, in the hydrometallurgical process by a High Pressure Acid Leach for nickel oxide ore comprising leaching and solid/liquid separation step, neutralization step, zinc removal step, and nickel recovery step, which can inhibit clogging of a filter cloth and reduce a frequency of washing operation and replacement operation of a filter cloth by improving filtration performance of zinc sulfide, and inhibit decrease of nickel recovery ratio, in the zinc removal step in which zinc sulfide is formed by adding a sulfurizing agent to the neutralization final liquid containing zinc as well as nickel and cobalt and zinc sulfide is separated to obtain a mother liquid for nickel recovery containing nickel and cobalt. The separation method for zinc sulfide of the present invention is characterized in that in the above-described neutralization step, the leach residue is added to the leach liquor, and pH of the neutralization final liquid is adjusted so as to fall to the range from 3.

Abstract: Porous, ferro- or ferrimagnetic, glass particles are described that selectively bind molecules of interest, especially nucleic acid molecules, under appropriate conditions. Methods of preparing the porous, ferro- or ferrimagnetic, glass particles and their use for identifying or separating molecules of interest are also described. Kits comprising the porous, ferro- or ferrimagnetic, glass particles are also provided.

Abstract: A method of treating alkaline industrial by-products, such as red mud generated by Bayer process bauxite refining, is described. Embodiments of the method comprise treating the alkaline industrial by-products with salts of divalent and/or polyvalent cations, thereby lowering pH of the alkaline industrial by-products. The method involves replacement reactions in which relatively insoluble hydroxide salts form precipitates, thereby removing hydroxide ions from solution.

Abstract: The process for production of iron oxyhydroxide particles according to the invention is characterized by comprising a step (A) in which a suspension containing iron(II) is prepared, and a step (B) in which fine bubbles with diameters of 0.05-500 ?m are generated in the suspension to form a reaction mixture, and the iron(II) in the reaction mixture is oxidized by the bubbles to produce iron oxyhydroxide particles.

Abstract: A process for the recovery of nickel and cobalt from nickel and cobalt containing ores, including the steps of first leaching a laterite ore and/or a partially oxidized sulfide ore with an acid solution to produce a pregnant leach solution containing at least dissolved nickel, cobalt and ferric ions, and subsequently leaching a sulfide ore or concentrate with the pregnant leach solution to produce a product liquor. Alternatively, the laterite ore and/or partially oxidized sulfide ore can be leached in a combined leach with the sulfide ore or concentrate. The ferric ion content in the pregnant leach solution or in the combined leach is sufficient to maintain the oxidation and reduction potential in the sulfide leach high enough to assist in leaching nickel from the sulfide ore or concentrate.

Abstract: There are provided processes for extracting aluminum ions from aluminous ores. Such processes can be used with various types of aluminous ores such as aluminous ores comprising various types of metals such as Fe, K, Mg, Na, Ca, Mn, Ba, Zn, Li, Sr, V, Ni, Cr, Pb, Cu, Co, Sb, As, B, Sn, Be, Mo, or mixtures thereof.

Abstract: A process for the recovery of nickel and/or cobalt from an impure nickel, cobalt or mixed nickel/cobalt material including the steps of: a) providing a nickel, cobalt or mixed nickel/cobalt material; and b) contacting the nickel, cobalt or mixed nickel/cobalt material with a feed ammoniacal ammonium carbonate solution and a reductant in a leach step.

Abstract: The invention relates to a process for purifying inorganic materials by treating the materials with a solution of hydrogen fluoride in aqueous hydrofluorosilicic acid. The process involves treating an inorganic material containing at least two species, to at least partially separate a first species contained in the material from a second species contained in the material, and comprises treating the material with a fluorine acid solution comprising aqueous hydrofluorosilicic acid and hydrofluoric acid (HF), such that the first species is converted to a product selected from the group consisting of a fluoride, a fluorosilicate and mixtures thereof, and such that the second species is at least partly unreacted, and separating the second species from the product.

Abstract: A hydrometallurgical process based on pressure leaching at elevated temperature for recovering nickel from nickel oxide ores, characterized by a simplified and efficient process as a whole, realizing a simplified leaching stage, reduced neutralizer consumption and precipitate production in the neutralization stage, and efficient use of recycled water. The hydrometallurgical process of the present invention, comprising a leaching stage which stirs the slurried ore in the presence of sulfuric acid at 220 to 280° C.

Abstract: Decomposition of methane to produce carbon monoxide-free hydrogen is accomplished using un-supported, nanometer sized, hydrogen reduced, nickel oxide particles made by a precipitation process. A nickel compound, such as NiCl2 or Ni(NO3) is dissolved in water and suitably precipitated as nickel hydroxide. The precipitate is separated, dried and calcined to form the NiO catalyst precursor particles.

Abstract: This invention relates to a method for the removal of iron as hematite from a zinc sulphate solution in atmospheric conditions during the electrolytic preparation of zinc. According to the method, the pH of the iron-containing solution is adjusted to a value of at least 2.7, oxygen-containing gas is fed into the solution and part of the hematite thus formed is recirculated to the precipitation stage.

Abstract: Described is a method for the manufacture of iron hydroxide, iron oxide hydrate or iron oxide from filter salts from thin acid recovery, in which the filter salts are dissolved in water, the solution is adjusted to a pH of <1, then a pH of 2 to 4 is established by the addition of a strong base, with stirring, the substances precipitating are separated in a known manner, the remanent solution is adjusted to a pH of 6 to 8 by the addition of a strong base, the precipitating iron hydroxide is separated from the solution, washed, dried, and, if desired, dried and/or calcined to form iron oxide.

Abstract: This invention provides a method for preparing cerium oxide nanoparticles with a narrow size distribution. The cerium oxide nanoparticles obtained by the method of the invention are nearly all crystalline. The method comprises providing a first aqueous solution comprising cerium nitrate and providing a second aqueous solution comprising hexamethylenetetramine. The first and second aqueous solutions are mixed to form a mixture, and the mixture is maintained at a temperature no higher than about 320° K to form nanoparticles. The nanoparticles that are formed are then separated from the mixture. A further aspect of the present invention is an apparatus for preparing cerium oxide nanoparticles. The apparatus comprises a mixing vessel having a first compartment for holding a first aqueous solution comprising cerium nitrate and a second compartment for holding a second aqueous solution comprising hexamethylenetetramine. The mixing vessel has a retractable partition separating the first and second compartments.

Abstract: There is provided an improvement in a process for producing cobalt (III) hexammine sulphate which process comprises oxidatively pressure leaching nickel cobalt sulphides in an ammoniacal ammonium sulphate solution. The nickel and cobalt sulphides are oxidized to sulphates, and an ammoniacal leach liquor in which dissolved cobalt is predominantly in the (III) oxidation state is produced. The ammoniacal leach liquor is combined with ammonia to precipitate the triple salt of cobalt (III) hexammine sulphate, nickel (II) hexammine and ammonium sulphate which is further treated to produce a crystalline cobalt (III) hexammine sulphate and a nickel enriched leach liquor. The improvement involves the provision of a second oxidative pressure treatment effective to maximize the formation of the desired cobalt (III) hexammine ion, prior to the triple salt precipitation step.

Abstract: The present invention relates to a process for inducing homogeneous precipitation of a metal oxide, wherein said metal is capable of existing in at least two cationic oxidation states, which process comprises the steps of: i) providing an aqueous solution of a metal in a lower cationic oxidation state; and ii) adding an oxidant capable of oxidising said metal to a higher cationic oxidation state under conditions such that the mixing of said aqueous solution and said oxidant is substantially complete before precipitation of an oxide of said metal in its higher oxidation state occurs.

Abstract: Processes for treating iron containing waste streams are provided. According to these processes, metal-containing compounds, particularly iron oxides are produced. These methods may, for example, be used in the processing of the waste streams from the chlorination of titanium-bearing raw materials and involve the use of certain combinations of neutralization and precipitation steps.

Abstract: A nickel hydroxide for rechargeable batteries which is provided with a cobalt hydroxide coating which is stable to oxidation is described. The stability to oxidation is achieved by covering the surface of the cobalt hydroxide layer with anions of weak inorganic oxygen acids.

Abstract: This invention relates to a process for producing magnetite particles having a coercivity of 6.366 kA/m to 10.345 kA/m (=80 to 130 Oe) and an octahedral particle shape, comprising heating an alkaline component and an iron(II) component in the form of an aqueous solution to a temperature of 50° C. to 100° C., whereby the molar ratio of iron(II) component to one equivalent of alkaline component is 0.38 to 0.45, and treating the suspension with an oxidizing agent at a rate of oxidation of 20 to 50 mol. % Fe(II)/h until the iron compound has an Fe(III) content of more than 65 mol. %, and then again adding an Fe(II) component in the form of an aqueous solution at a molar ratio of Fe(II) to one equivalent of total alkaline component used is 0.47 to 0.49, and treating the suspension with an oxidizing agent, at a rate of oxidation is 20 to 50 mol. % Fe(II)/h until the iron compound has an Fe(III) content of more than 65 mol.

Abstract: A hydrometallurgical process is provided for leaching nickeliferous laterite ores at temperatures below the boiling point of the pulp and at atmospheric pressure. The high iron fraction of the laterite, referred to as limonite, is first contacted with concentrated sulfuric acid to partially or completely dissolve the iron and nickel into solution. A reducing agent is used to keep the redox potential in solution below 1000 mV to enhance cobalt dissolution and more advantageously between 1000 and 900 mV to avoid reduction of ferric iron. Further mixing of the leach slurry in the presence of sodium, potassium, or ammonium allows formation of iron jarosite at ambient pressure. The resulting acid from iron hydrolysis is neutralized with the low iron fraction of the laterite ore (saprolite), thereby dissolving nickel into solution. The resulting final leach slurry can then be treated with conventional methods to recover nickel and cobalt from solution.

Abstract: Stable copper hydroxide is prepared by removing ferrous ion from the beginning cupric solution. The ferrous ion is oxidized to ferric ion, and the ferric ion is precipitated by raising the pH of the solution to 3-4. The utilization of phosphate ion both increases the efficiency of oxidation and simultaneously precipitates ferric ion. A second raising the pH of the purified solution precipitates highly pure copper hydroxide that can be harvested.

Abstract: A process for decreasing the crystallinity of nickel hydroxide by generating and supplying large numbers of heteronuclei into the nickel hydroxide producing reaction system. Nickel sulfate and sodium hydroxide are initially forcefully and intimately combined to form a supersaturated solution of heteronuclei. These heteronuclei are introduced into a nickel powder containing slurry wherein nickel hydroxide having a crystallinity FWHM value of greater than about 0.5° is generated.

Abstract: A method for preparing a CdS photocatalyst represented by general formula (I): m(a)/Cd[M(b)]S, comprising the steps of: dissolving Cd-containing and M-containing compounds in water in such an amount that the mol % of M ranges from 0.001 to. 20.00; adding one H2S or Na2S as a reactant in the solution with stirring to precipitate Cd[M]S; washing the precipitate with water and vacuum-drying the precipitate in a nitrogen environment at a temperature of 105˜150° C. for 1.5˜3.0 hours; doping a liquid m-containing compound to this precipitate in such an amount that the % by weight of m ranges from 0.10 to 5.00. In the formula, m represents a doped metal element as an electron acceptor selected from the group of Ni, Pd, Pt, Fe, Ru, Co or an oxidized compound of these metals; a represents a percentage by weight of m, ranging from 0.10 to 5.00; M is a promoter selected from the group consisting of V, Cr, Al, P, As, Sb and Pb; b represents mol % of M/(M+Cd), ranging from 0.

Abstract: The present invention provides an atmospheric acid leaching process for leaching nickel and cobalt from highly-serpentinized saprolitic fractions of nickel laterite deposits that are generally too low in nickel to support economical extraction of their nickel contents by pyrometallurgical processing except under special circumstances, and generally too high in magnesium to be suitable for processing by modern high pressure acid leaching processes employed for treating predominantly limonitic nickel laterites. The process involves leaching the highly-serpentinized saprolitic portion of the nickel laterite ore profile in strong sulphuric acid solutions at atmospheric pressure and temperatures between 80° C. and 100° C., essentially autogenously, to extract at least 90% of its contained nickel content and a large proportion of its cobalt content after leaching reaction times of about one hour or less.

Abstract: The invention relates to a process for preparing a usable product, in particular a water treatment solution which contains ferric iron, from an impure ferric sulfate solution which contains as an impurity at least one other metal, the process comprising a first precipitation step in which a base is added to the said impure ferric sulfate solution in order to raise the pH to approx. 2-5, preferably approx. 3-4, whereupon ferric hydroxide precipitates; following the first precipitation step, a second precipitation step in which there are added to the solution an oxidant and a base to raise the pH to approx. 6-10, preferably approx. 8-9, whereupon the said impurity metal precipitates; and one or more separation steps to separate from the sulfate solution the solids precipitated in the first and the second precipitation steps; as well as possibly an additional step in which the said separated solids, or a portion thereof, are treated further in order to form a usable product.

Abstract: The present invention relates to a method of treatment of acid waste waters or acid drainage waters containing metals comprising ferrous and ferric ions, the method comprising increasing the pH of the acid waste to at least 7.5 by addition of an alkaline reagent under conditions such that ferrous ions are stable with respect to oxidation to ferric ions, to form a precipitate and collecting the precipitate.

Abstract: A method of producing ferrate is disclosed, in which Fe.sup.3+ is oxidized with monoperoxosulfate (HSO.sub.5.sup.-) to form K.sub.2 FeO.sub.4 /K.sub.2 SO.sub.4. The isolation of the potassium ferrate (K.sub.2 FeO.sub.4) product in a sulfate matrix (K.sub.2 SO.sub.4) stabilizes the ferrate against decomposition and inhibits clumping of the solid product by inhibiting moisture adsorption. The method is a safe, simple process for the production of ferrate that is reliable, fast, and inexpensive, and that avoids the use of chlorine or chlorinated products, thus avoiding their harmful side effects. The improved ferrate product of this method is particularly useful for water and wastewater treatment, especially in the treatment of sulfides and hydrazines, and in other applications.

Abstract: A process for recycling a zinc phosphating system sludge comprising forming a mixture of the sludge with water and phosphoric acid. The mixture is formed at an elevated temperature and a pH of between 1.5 and 2.4. The sludge substantially dissolves in the mixture and iron phosphate precipitates out. The resultant liquid comprises a substantially zinc ion and phosphate ion solution suitable for use as a make-up feed in zinc phosphating system.

Abstract: A process for separately removing zinc and iron from acidic wastewater. The process involves adding alkali metal hydroxide to the acidic wastewater (below about pH 4) to achieve a first pH of about 4.8 to at most about 5.4 and precipitate an iron hydroxide-containing precipitate at this pH. The precipitate from the wastewater is separated and then additional alkali metal hydroxide is added to achieve a second pH in the range from about 8.8 to about 9.4. A zinc hydroxide containing precipitate forms at this second pH and is then recovered by filtration.

Abstract: A method for producing a powdered iron oxide comprises the steps of adjusting the pH of a crude iron chloride solution to 2.5-4.5; reducing the P content of the solution by mechanical stirring or air bubbling and filtering; and oxidizing the solution into a powdered iron oxide having a maximum P content of 0.005 wt. %. The P content of the solution may also be reduced by ultrafilter treatment. The soft ferrite made by using the powdered iron oxide by this process shows excellent magnetic properties.

Abstract: In a method of preparing high-purity manganese compounds, wherein the method comprises adding a member selected from ferromanganese and metallic manganeses to an aqueous electrolyte-containing solution, dissolving said member while stirring and maintaining a pH of 2 to 9, and then removing insolubles by filtration and recovering solubles by precipitation, heavy metal elements as well as non-metllic elements, such as P, Si, etc. can be removed efficiently, and high-purity manganese compounds of stable quality can be prepared.

Abstract: A method of processing manganese ore by adding the ore to an aqueous solution of acid and H.sub.2 O.sub.2 to form a leach pulp. The leach pulp is agitated for a predetermined time period at predetermined temperatures. The leach pulp is then separated into a solid fraction and a liquid fraction containing solubilized metals. The solubilized metals are then recovered from the liquid fraction.

Abstract: A metal stripping system and an operation process therefor which includes the following elements and steps. A main part of this system is a crystallization apparatus for metal stripping comprising a mixing zone of organic solvent and fluoride series stripping solution, a settling zone for organic solvent, a settling zone for stripping solution, a separation zone for fluorinated metal complex crystal and a stripping solution cooling zone. In the operation of the system wherein the organic solvent containing extracted metal ions is contacted with the fluoride series stripping solution to deposit the fluorinated metal complex crystal and then the crystal is recovered as metal or metal oxide, the stripping solution is circularly used by supplying NH.sub.4 HF.sub.

Abstract: A process is disclosed for recovering cobalt in a relatively pure form from an impure cobalt bearing material. The process involves digesting the material in hydrochloric acid to form a solution essentially all of the cobalt and some impurities and insoluble material containing the remainder of the impurities, separating the solution from the insolubles, adding an oxalate producing compound in an amount sufficient to subsequently convert essentially all of the cobalt to cobalt oxalate to the solution, adjusting the pH of the oxalate treated solution to from about 1.5 to about 2.0 with a base to precipitate the cobalt, and finally separating the precipitate from the resulting mother liquor.