JP2008527164A - Method for recovering nickel and cobalt from resin eluate stream - Google Patents

Abstract

  The present invention is a method for recovering nickel and cobalt from an acidic resin eluate containing at least nickel and cobalt, wherein (a) most of the cobalt present in the eluate and one of copper, zinc and magnesium are present. Treating the eluate with an immiscible organic reagent to selectively absorb the part, leaving the raffinate containing nickel and minor impurities, and (b) A method comprising: neutralizing the raffinate to precipitate the nickel as nickel hydroxide; (c) removing the cobalt from the organic reagent; and (d) recovering the cobalt. .

Description

  In general, the present invention relates to a nickel hydroxide product and a process for producing a cobalt product from an acidic resin eluate containing nickel and cobalt. Cobalt will generally be recovered as a mixed cobalt sulfide product. The present invention is particularly suitable for the treatment of eluents containing nickel and cobalt. This leachate is removed from the resin used in the resin-in-pulp process to extract nickel and cobalt from the slurry of the laterite acid leaching process.

  Laterite nickel and cobalt ore deposits typically include limonite, an oxidation-type ore, and corrosive rock, a silicate-type ore, as two layers within the same deposit, separated by a transition. In order to minimize the size of equipment for treating eroded rock or limonite by commercial processing, high quality limonite and eroded rock are desired.

  Corrosion rocks with higher nickel content tend to be processed by high temperature metallurgical methods that require roasting and electrorefining techniques to produce ferronickel. The power requirement and the high iron ore to nickel ore ratio in the low nickel content limonite, corrosive rocks, and limonite / corrosion rock mixtures in the transition region make this treatment route very expensive.

  Limonite with high nickel and cobalt content is usually produced by high pressure metallurgy and wet processes such as by high pressure acid leaching (HPAL) or by the Caron reduction roast-ammonium carbonate leach process. Commercially and hydrometallurgically processed by a combination of metallurgical methods. This HPAL method usually requires less capital than the Caron method and is not energy intensive.

  Other non-commercial hydrometallurgical processes combine nickel laterite ore with acid at atmospheric pressure to extract nickel and cobalt into solution, or combine high pressure autoclave leaching and atmospheric pressure leaching Is described in the literature.

  One such method is described in US Pat. No. 6,379,636 (BHP Minerals International Inc.) under the title “Method for Leaching Nickeliferous Laterite Ores”. The laterite ore limonite debris is provided for high pressure acid leaching, and the high magnesium corrosion rock debris is added to the autoclave discharge slurry in the atmospheric leach stage. This atmospheric leaching stage recovers nickel from the corroding rock in addition to partially neutralizing excess acid from this pressure leaching. After further partial neutralization, iron is deposited as jarosite.

  International patent application WO / 2003AU / 00309 (QNI Technology Pty Ltd) titled “Atmospheric acid leach process for lateritic nickel ore” describes another method in which limonite fragments of ore are leached with sulfuric acid at atmospheric pressure. Yes. The leached slurry is then mixed with the high magnesium corrosion rock slurry in a second atmospheric pressure leaching stage. After substantial completion of this stage, iron is deposited as goethite. The final leached solid is substantially free of jarosite.

  A problem with atmospheric acid leaching processes is that the leaching slurry produced contains a large amount of precipitated iron oxide and a variety of other dissolved impurities in addition to the targeted dissolved nickel and cobalt values. . Purification of similar aqueous nickel solutions obtained from commercial laterite acid leaching methods can be accomplished by neutralization of acid components, solid / liquid separation, nickel / cobalt intermediate production, re-generation to produce commercially available nickel and cobalt. Requires a dissolution step, a complex solvent extraction step. This purification step is usually aimed at complete removal of iron and other impurities.

  Although ion exchange (IX) treatment is not used commercially, solid / liquid separation of leachate from beneficiation waste through a neutralization stage, an iron precipitation stage, and counter current decantation (CCD) Later, it has been disclosed for the extraction of both nickel and cobalt from nickel leachate. Major impurities remain in the raffinate. The high concentration ratio of iron to nickel in the laterite ore results in a large amount of precipitated ions and consequently requires large CCD processing.

  International patent application WO / 1995 US / 16118 (BHP Minerals International Inc.) entitled “Recovery of Nickel and Cobalt from lateritic ores” is an IX method for separating nickel from leachate obtained by processing of laterite by this pressure acid leaching process. Is described. Nickel is extracted by the resin at a pH of approximately 2 and stripped with sulfuric acid in subsequent electrowinning. Cobalt remains in the raffinate along with other impurities and is deposited as sulfide after solution neutralization.

  Patent WO 00/053820 (BHP Minerals International Inc.) discloses IX extraction of nickel and cobalt onto an acidic sulfate leaching solution and subsequent acid stripping of the metal from the resin and electrowinning. Describes their separation by solvent extraction in the production of high purity nickel and cobalt.

  In a further improvement to this process, US Pat. No. 6,350,420 (BHP Minerals International Inc.) teaches the use of an ion exchange resin in an in-pulp resin process to extract nickel and cobalt onto the resin from an acidic leaching slurry. . This leach slurry is in contact with an ion exchange resin that selectively packs nickel and cobalt from the pulp. The resin is separated from the leach slurry by screening and removed from the metal with acidic solution. Here, the metal consumable slurry can be performed following waste treatment and disposal, which is typically a large and capital intensive process that is required for acid leaching to extract the product solution from the solid residue. This eliminates the need for solid / liquid separators.

  All the above documents aim to produce relatively pure nickel solutions or nickel and cobalt strip solutions from IX resin. The present invention is aimed at economically producing nickel products with low levels of important impurities such as copper, zinc and manganese, such as the production of ferronickel or other wet metallurgy processes. Suitable for further processing in nickel refining process. Cobalt is generally recovered as cobalt sulfide. Again, it is a sufficient grade for further processing.

  The above discussion of literature, papers, etc. is merely included herein for the purpose of providing a context for the present invention. Some or all of these matters form part of the prior art base, or suggest or represent that they were general knowledge of the field related to the present invention prior to the priority date. It is not a thing.

  The present invention seeks to provide a novel method of overcoming or mitigating one or more problems associated with the prior art.

  In general, the present invention relates to a method for producing a nickel hydroxide product and a cobalt product from an acidic resin eluate containing nickel and cobalt. Cobalt is preferably recovered as a mixed cobalt sulfide product. In particular, the present invention is suitable for the treatment of nickel and cobalt containing eluates removed from the resin used in the in-pulp resin process for extracting nickel and cobalt metals from the later slurry of the lateritic acid leaching process.

  Accordingly, in the first embodiment, the present invention is a method for recovering nickel and cobalt from an acidic resin eluate containing at least nickel and cobalt, and (a) most of the cobalt present in the eluate. Treating the eluate with an immiscible organic reagent to selectively absorb and a portion of copper, zinc and magnesium, leaving the raffinate containing nickel and minor impurities A step of neutralizing the raffinate to precipitate the nickel as nickel hydroxide, a step of removing the cobalt from the organic reagent, and a step of recovering the cobalt. And a method comprising:

  In general, this process forms part of the overall process in nickel and cobalt recovery utilizing an in-pulp resin circuit to extract nickel and cobalt. In general, while the cobalt is recovered as an impure cobalt sulfide product, the recovered nickel hydroxide is low in significant impurities and is particularly suitable for further processing, such as the formation of ferronickel.

  In general, cobalt sulfide is recovered by precipitating cobalt sulfide by removing the cobalt from the organic reagent with sulfuric acid to produce an acidic solution and adding the sulfide to the acidic solution. In general, the sulfide is sodium hydrosulfide, hydrogen sulfide or potassium hydrosulfide.

  The treatment of the present invention is particularly applicable to recovering nickel and cobalt from nickel and cobalt-containing acidic resin eluate, and this eluate acid-peeled the ion exchange resin of the resin circuit in the pulp in the nickel and cobalt recovery treatment. It is a result. In general, the resin is removed by treating the resin with concentrated acid, preferably sulfuric acid or hydrochloric acid, to produce an acidic eluate.

  Preferably, the ion exchange resin is iminodiacetic acid which yields nickel, cobalt, copper, zinc, aluminum, ferrous and chromium almost completely present, along with a large amount of manganese and a small amount of magnesium in the in-pulp resin process. It is a resin having a functional group. Alternatively, a resin having a bis-picolylamine functional group such as Dowex 4195 may be used.

  Preferably, the nickel and cobalt recovery process is atmospheric acid leaching of nickel-containing laterite ore, but may be high pressure acid leaching or a combination of high pressure acid leaching and atmospheric acid leaching of laterite ore. In other embodiments, the eluate is a slurry of product obtained from oxidative leaching of nickel sulfide ore or concentrate, or a product slurry obtained from acid leaching of a combination of laterite and sulfide ore. It may be produced by an acidic treatment of the treatment resin.

  In other embodiments, the eluate may be obtained from resin treatment of a product solution containing at least nickel and cobalt, and obtained from acid leaching of laterite or sulfide ore after separation of the leach residue of the solution. Also good.

  In a process where the terlite ore is treated with an acid leaching process, the laterite ore may be treated by first separating the laterite ore into its less magnesium-containing limonite debris and its higher magnesium-containing corrosive rock fragments, Leaching limonite fragments and corroded rock fragments continuously. This limonite debris may be treated with acid in the first leaching stage to produce a first leaching slurry. This eroded rock fragment may then be added to the first leaching slurry that initiates the precipitation of iron as goethite and produces a second leaching slurry containing at least nickel and cobalt ions. This results in a higher amount of acid than is utilized in the leaching process, as acid is produced by iron precipitation.

  Next, the obtained second leaching slurry is sent to an in-pulp resin circuit in which at least nickel and cobalt ions are packed into the resin. Accordingly, the laterite ore is treated here under acid leaching conditions, the treatment comprising: (a) separating the laterite ore into low magnesium limonite debris and high magnesium corrosive rock debris; and (b) first leaching step. Treating the limonite debris with an acid to produce a first leaching slurry; and (c) adding the corrosive rock debris to the first leaching slurry in the second leaching stage and utilizing it in the second leaching stage. Initiating iron precipitation as goethite that provides the highest possible acid level to produce a second leaching slurry containing nickel and cobalt ions, the second leaching slurry comprising at least the nickel and Cobalt is sent to the resin circuit in the pulp where the resin is packed.

  Preferably, the pH of the second leaching slurry is partially neutralized to a pH of approximately 2 to substantially complete iron precipitation as goethite. The second leach slurry is then neutralized and maintained at its pH up to at least 4, more preferably from 4 to 5, and any ferric ions that may be present before or simultaneously to the in-pulp resin circuit. And other impurities are deposited or reduced.

  In an in-pulp resin circuit, this resin will absorb at least nickel, cobalt, and some other minor impurities from the second leaching slurry. The resin may be pre-eluted with weak sulfuric acid to substantially remove all or some of the magnesium, calcium and manganese before removing the resin with strong sulfuric acid. The resin may be washed with fine water before removing nickel and cobalt from the resin.

  The packed resin is then treated with a strong acid to remove the metal from the resin, producing an acidic eluate containing nickel and cobalt. Although hydrochloric acid may be used, it is most preferred that the acid be strong sulfuric acid.

  The acidic resin eluate containing nickel and cobalt is then neutralized with a neutralizing agent to a pH of about 4.5 to 5 prior to separation of nickel and cobalt. More preferably, the neutralizing agent is sodium hydroxide, sodium carbonate, magnesium carbonate or calcium carbonate. The eluate itself contains about 10 to 80 g / L of nickel after elution from the resin.

  The immiscible organic reagent used to selectively absorb most of the cobalt present and some of copper, zinc and manganese is preferably Cyanex 272. Cyanex 272 is selective in cobalt over nickel and as such separates nickel and cobalt in acidic resin eluate. The sulfuric acid is then used to remove cobalt from the immiscible organic reagent to produce a cobalt-containing sulfuric acid solution. The sulfide product is then added to the sulfuric acid solution to precipitate the cobalt as impure cobalt sulfide. Preferably, the sulfide product is sodium hydrosulfide, hydrogen sulfide or potassium hydrosulfide, but any suitable sulfided product will precipitate as long as it deposits cobalt as cobalt sulfide.

  In order to deposit nickel as nickel hydroxide, the pH of the raffinate is first raised to a pH greater than 7.5 by addition of a neutralizing agent, preferably a magnesium oxide slurry, to deposit nickel as nickel hydroxide. . The nickel hydroxide is then filtered and washed for nickel product recovery. The nickel hydroxide product produced is low in significant impurities such as copper, zinc and manganese and may be useful for use in further nickel processing.

  The process of the present invention is particularly advantageous for recovering nickel and cobalt from an acidic eluate stream where nickel and cobalt are transported and recovered in a form ready for further processing.

  In combination with the atmospheric leaching treatment of laterite ore and the resin circuit in the pulp, this treatment is beneficial in that it easily removes impurities, especially residual ferric ions that precipitate as goethite during the leaching treatment. This leaching process results in the recovery of nickel and cobalt products, which is a suitable form for use in further purification processes. The removal of such impurities in the resin circuit in the pulp can eliminate the need to employ fairly large settling tanks used to remove large amounts of iron impurities and can significantly reduce capital investment. it can.

  In a preferred treatment, the laterite ore is treated as shown in FIG. 1, which is convenient to describe the method with reference to the treatment of nickel-containing laterite ore. It should be understood that FIG. 1 illustrates a preferred embodiment of the present invention, and for convenience, the preferred embodiment of the present invention will be described with reference to FIG. However, the present invention should not be considered limited to the features described in FIG.

  The nickel-containing laterite ore is preferably separated into a low-magnesium-containing ore fragment (1) and a high-magnesium ore fragment (2) by selective mining or classification after mining. Limonite (low magnesium) fragment (1) of nickel laterite ore is treated with concentrated sulfuric acid (30) in atmospheric pressure in the first leaching stage (3). The eroded rock (high magnesium) fragments of the ore (2) are added to the product slurry obtained from the first leaching in a second leaching stage (4), along with iron deposited as goethite.

  The iron that is put into the solution is further precipitated as goethite (5) or FeO (OH), followed by the addition of limestone slurry (31). This results in a greater amount of acid utilized in the second leaching stage than the iron precipitates as eg jarosite.

  Most preferably, the first leaching (3) is carried out at a temperature up to 105 ° C. and is high enough to achieve rapid leaching at atmospheric pressure. The dosage of sulfuric acid is preferably 100 to 140% of the theoretical value for dissolving 90% or more of nickel, cobalt, iron, magnesium, aluminum and manganese in the ore.

Metabisulfite or sulfite free from reducing agents, such as sulfur dioxide gas, or sodium, to free the cobalt content of asbolane or other similar manganese (III or IV) minerals The salt is preferably injected into the resulting slurry obtained from the first leaching, and the redox potential is preferably controlled below 1000 mV (SHE), more preferably below 900 mV (SHE). Completion of reduction and leaching is indicated by the formation of 0.5 to 1.0 g / L of ferrous ions (Fe ²⁺ ) and stable acid concentrations in these reaction conditions. Low magnesium limonite weight loss is typically over 80% and nickel and cobalt extraction is over 90%.

  The second leaching stage (4), preferably carried out at atmospheric pressure, involves the leaching of corrosive rocks and the precipitation of iron, preferably as goethite or a relatively low sulfate-containing form of iron oxide or iron hydroxide. At the same time. No acid is added during the second leaching stage.

  The second leaching stage (4) is carried out at atmospheric pressure, preferably at a temperature up to 105 ° C., more preferably at a sufficiently high temperature so that rapid leaching and iron precipitation reactions can be realized. The dosage of high magnesium content corrosion rock added to the first leaching slurry depends on the free acid remaining in the first leaching stage, the acid released during the precipitation of iron as goethite, and the nickel in the ore Determined by unit stoichiometric acid consumption of high magnesium content corrosive rocks in a given extraction of cobalt, iron, magnesium, aluminum and manganese.

  With this introduction of corrosive rock, iron precipitation as goethite will usually occur. This corrosive rock typically contains some iron as goethite along with other fine particles that act as seeds that can initiate goethite precipitation. However, the addition of seeds helps with the concurrent erosion of eroded rocks and the precipitation of iron as goethite or other relatively low sulfate-containing forms of iron oxide or iron hydroxide. Immediately afterwards, a “seed” containing mainly goethite or jarosite may be added to the reactor to be required.

  The rich second leaching slurry containing nickel and cobalt is then neutralized with a limestone slurry at 80 ° C. to substantially complete the iron deposition as goethite (5). The end of the goethite precipitation has a pH of about 2.0.

  The rich (pregnant) slurry is further neutralized to at least pH 4 with additional limestone slurry (6), aerated (32), residual ferric ions and copper, aluminum, chromium, and additional Precipitate other impurities such as iron, especially ferric iron. This slurry then passes through the trash screen (7) and is sent to the resin circuit in the pulp. Excess material from the trash screen is sent to the beneficiation waste disposal section (9). A neutralizing agent such as limestone or lime is added to maintain the pH at about 4 in the resin circuit in the pulp. The beneficiation waste is neutralized with slaked lime and then goes through the thickening stage (10), undergoing beneficiation waste recovery (11) and then poured for disposal (12).

  The rich slurry (8) is then treated using an in-pulp resin method in which the nickel and cobalt and other impurities are extracted by the resin. The resin-in-pulp process typically consists of countercurrent contacting the leach slurry with the resin in a series of air agitation or mechanical agitation in a continuous agitation tank reactor (13). In each of these stages, the resin is separated from the slurry by screening and advanced to the next stage by pumping. The slurry itself is advanced from one tank to the next, typically by gravity. Typically, ion exchange resins having iminodiacetic acid functional groups are used in the in-pulp resin process, for example, using iminodiacetic acid Amberlite IRC718 (Amberlite IRC718) or Amberlite IRC748 (Amberlite IRC748). It is done. It is almost completely stuffed with nickel, cobalt, copper, zinc, aluminum, ferrous iron and chromium, and stuffs about half manganese and a small amount of magnesium. Other suitable resins with different functional groups may be selected if they extract the appropriate elements from the solution, such as Dowex 4195. Limestone slurry is added to control the pH from 4 to 5 during the resin packing phase.

  A thorough cleaning of the final resin is required to ensure that all entrained solids are removed prior to stripping. Before moving to the weak sulfuric acid elution stage (15), the resin is washed with good quality water. This step uses dilute acid to remove almost all of the magnesium, calcium, and some manganese from the resin prior to removal. The weak acid elution solution is returned to the wash stage as wash water.

  A high concentration sulfuric acid strip container (16) is used to remove metal from the resin and produces an eluate containing 10 to 80 g / l nickel as well as cobalt. This resin is provided to a weak acid wash (17) after stripping to minimize nickel recycling and returned to the in-pulp resin reactor.

  The strongly acidic eluate containing nickel and cobalt is preferably partially neutralized to about pH 5 using sodium hydroxide to prepare an “eluent” to separate nickel and cobalt. .

  The cobalt is separated from the eluent nickel in the solvent extraction step (18) by contacting the eluate with an immiscible organic solvent, preferably containing an extractant Cyanex 272. Cyanex 272 is selective in cobalt over nickel, and after separation of the extractant, the extractant removes the remaining zinc, copper and manganese, leaving a nickel-containing raffinate.

  The raffinate (25) is neutralized with magnesium oxide slurry (27) to a pH greater than 7.5, depositing nickel as nickel hydroxide (19), and nickel hydroxide is available for direct sale. Filtered and washed (20). The nickel hydroxide produced contains about 40% nickel and low levels of iron (21).

  It is a suitable direct feed for the production of ferronickel in an electric arc furnace or supply to other wet metallurgy nickel recovery processes.

  The cobalt-containing organic extractant produced from the solvent extraction stage (18) is not only cobalt but also sulfuric acid diluted to produce a strip solution containing nickel, zinc, iron, manganese, copper extracted therewith. Preferably removed using (28). In a preferred embodiment of the invention, cobalt is deposited as a mixture of cobalt sulfide (22) by treatment with a strip solution having a sodium hydrogen sulfide solution with sodium hydroxide (29). This temperature is maintained at 60-80 ° C. to ensure that the resulting sulfurized product is crystalline. The impure cobalt sulfide solid is then filter washed (23) and dried for direct sale (24).

  In other embodiments of the invention, the cobalt may be recovered by well known techniques such as solvent extraction or electrolytic deposition.

  This new method has advantages over current wet metallurgy methods in that it has a method that does not require complex and large capital to convert the ore to the final metallic organism ferronickel. Have. There is no need for a solid-liquid separation stage prior to solution processing, solvent extraction to remove impurities, and purified nickel metal production stages such as electrolytic deposition or hydrogen reduction.

  It is ferronickel in that the amount of mixed hydroxide product that is smelted is about one-fifth of the equivalent amount of corrosive rock that would be required primarily for power reduction. It has great advantages over the usual corrosive rock smelting process to produce.

  A further advantage of this process over the normal ferronickel smelting process is that the corrosive rocks smelting cobalt become part of ferronickel and its value is lost to the manufacturer, whereas the expensive metallic cobalt Is collected separately for sale.

  A further advantage of the described process is that the impurity level in ferronickel produced with this nickel hydroxide product as a result of the resin elution and solvent extraction process steps is currently achieved by the majority of commercial manufacturers. It will be much lower than what is done and will be lower than that of the “ultra-pure” ferronickel grade.

  This treatment is particularly attractive, with large amounts of low-grade coral rocks or limonite present in established coral rock mining and smelting operations that produce ferronickel from high-grade ores. This process allows the processing of lower ores that would normally be rejected to produce a mixed hydroxide feedstock in an existing blast furnace, reducing unit power consumption per ton of nickel produced Producing cobalt for sale and significantly improving the overall economics of concentrate or processing of the entire ore body.

  This process allows a lower iron nickel hydroxide product suitable for feeding to a ferronickel blast furnace to be produced by this process at a plant located in a laterite ore body, which is economical. The flexibility of being able to be transported cost-effectively due to the high nickel content relative to remote existing ferronickel blast furnaces.

(Experimental example)
(Experimental example 1)
Samples of the slurry obtained from high pressure acid leaching (HPAL) of lateritic nickel ore are neutralized and screened for processing by an in-pulp resin (RIP) processing process.

  15 L of HPAL pulp slurry was placed in a 20 liter drum and stirred using an overhead stirrer. The pulp slurry was adjusted to pH 4.5 by adding limestone slurry. After neutralization, the ORP of this pulp was adjusted from 300 to 400 mV by the addition of 20% sodium metabisulfite solution.

  The pulp was then screened to 212 microns and excess material was discharged. Pulp that passed through a 212 micron screen was collected and used in the RIP circuit. The screened and neutralized pulp was raised to a temperature of 50 ° C. and continuously added to a 10-stage lip pilot plant to contact Cleantech R604 resin (Clean TeQ R604). R604 is an ion exchange resin containing iminodiacetic acid groups. Nickel cobalt and other metals were adsorbed on the resin. The resin was then separated from the pulp and metal separated therefrom by treatment with a 15% sulfuric acid solution.

  Table 1 shows the average metal content in the solution and the solids content of the ore pulp slurry before and after the lip (RIP) treatment during the 50 hour trial run. The extraction rate was greater than 99.7 for both nickel and cobalt in the pulp liquid phase and there was also a large recovery of nickel and cobalt from the solid phase.

  The composition of the resin acid peeling eluate is shown in Table 2 below. This indicates that a nickel concentration of about 39 g / l can be achieved with low levels of impurities such as chromium and silica in the eluate.

(Experimental example 2)
A synthetic vessel was prepared for testing that simulates the leachate produced from atmospheric leaching of laterite ore. This solution was prepared by dissolving nickel, cobalt, copper, manganese, iron and magnesium sulfate along with calcium hydroxide and sodium chloride in water and keeping the solution in a nitrogen atmosphere to prevent oxidation . It is then neutralized by adjusting the pH to 4.5 by addition of calcium carbonate, allowing it to stabilize, so that a clear poured solution becomes the test feed solution. Made possible. Solution analysis before and after the neutralization stage is shown in Table 3.

  The solvent extraction test plant (pilot plant) consisting of 10 water-jacketed mixer settlers performs countercurrent semi-continuous extraction test, washing test (scrubbing) and stripping test with the feed solution after neutralization. Used to do. The organic solution used as the solvent contained 15% Cyanex 272 (v / v) and 5% TPB in Shellsol D70. The volumes of the mixer and the settler were 0.16L and 0.38L, respectively. The temperature of the solution was kept constant at 40 ° C. An impeller with 6 vanes (diameter 30 mm) was used for solution mixing and a diaphragm pump (diaphragm pump) was used for dissolution circulation.

  During the semi-continuous extraction operation, it was pumped in the countercurrent direction through three extraction stage mixer / settler. Sodium hydroxide solution or sulfuric acid was used to maintain the pH in the mixer at 5.8. When required, water recycling was placed in the mixer to obtain a 1: 1 A / O volume ratio. Nitrogen gas was bubbled in the first stage mixer to prevent oxidation of Fe (II) to Fe (III).

  Table 4 shows the amount of metal extracted in the organic solvent. This test shows that complete extraction of Co, Cu, Zn, Mn and Fe was achieved.

(Experimental example 3)
The purpose of the semi-continuous scrubbing test was to minimize the scrubbing of the packed organic solution to remove the co-extracted Ni, Mg and Ca.

  The packed organic solution obtained in a series of semi-continuous extraction tests similar to Example 1 was combined and used for a semi-continuous scrubbing test. The parameters changed were controlled pH (5.4 and 5.6 by addition of sulfuric acid), number of steps (1 and 2 steps) and cleaning solution (solutions 1 and 2) and temperature of 40 ° C. It was.

  A synthetic wash solution was prepared to simulate the diluted solution from the strip solution. Typical results from semi-continuous cleaning (scrubbing) are summarized in FIG. Nickel scrub efficiency ranged from 90 to 93% with 38 to 53 ppm Ni remaining in the organic solution.

  Higher concentrations of Co, Cu, Mn and Zn in the scrub solution do not affect the scrubbing efficiency, and one stage of scrubbing has a lower Ni scrub efficiency (77.8%) and a higher scrubbing organic solution. Gave a higher Ni concentration (118 ppm).

(Experimental example 4)
The organic solution obtained from the semi-continuous cleaning (scrubbing) test of Example 2 was combined and used in a semi-continuous three-step stripping test to recover the cobalt value.

  During the semi-continuous stripping operation, the pre-packed scrubbed organic solution was removed using a sulfuric acid solution having a final stage pH controlled to 2.0.

  The results of the stripping test are summarized in Table 6. In three stages, approximately 99% Co, Cu, Mn and Zn and 78% Fe were removed at pH 2.0.

(Experimental example 5)
The raffinate solution obtained from the semi-continuous extraction test of Experimental Example 1 was combined into a hydroxide precipitate. The purpose of the batch nickel hydroxide precipitation test was to determine the test conditions at nickel deposition efficiencies above 99%. A total of three tests were performed with MgO to Ni molar ratios of 1: 1, 1.2: 1 and 1.4: 1.

  The purity of MgO used in the precipitation test was 96%.

  Weighed MgO powder was added slowly and the slurry was mixed for 1 hour prior to vacuum filtration. The filtrate was collected in a vacuum flask, weighed, and its mass was measured. The cake is reslurried with 100 mL of tap water and the slurry vacuum is filtered. Three washings are performed on each filter cake and the three washing solutions are combined. The washed filter cake is dried at 105 ° C. and weighed at room temperature.

  Nickel deposition efficiency reached over 99.9% in the three tests performed, indicating very low Ni loss and high Ni recovery (Table 7 below). While the Ni recovery in these three tests is nearly identical, the Mg content in the Ni product cake increases from 3.36% at a molar ratio of 1: 1 to 7 at 1.2: 1 with increasing molar ratio. .14% and even increased to 9.55% at 1.4: 1. This means that a 1: 1 molar ratio showed the best results among the three tests performed.

  As can be seen in Table 8 below, elemental analysis of the produced nickel hydroxide precipitates shows very low levels of impurities, cobalt, copper, zinc, manganese, and iron.

(Experimental example 6)
The solvent extraction strip solution obtained from the semi-continuous organic strip test of Example 3 was combined and provided to the sulfide precipitate mixed to recover the cobalt content using a sodium hydrosulfide solution. This pH was adjusted to 3.5 by controlling the temperature to 80 ° C. using sodium hydroxide solution or sulfuric acid solution. After mixing for 60 minutes, the slurry was filtered and the cake was reslurried with tap water and refiltered 3 times before being dried at 105 ° C. The cobalt deposition efficiency under these conditions was very high at 99.82.

  Table 9 below shows the deposition efficiency of other metals in the solvent extraction strip solution.

  The above description is intended to illustrate preferred embodiments of the present invention. It should be understood by those skilled in the art that many variations and modifications can be made without departing from the spirit of the invention as illustrated herein.

FIG. 2 shows a preferred flow chart of a method for recovering nickel as nickel hydroxide and recovering cobalt as a mixture of cobalt sulfide according to the method of the present invention. FIG. 2 shows a preferred flow chart of a method for recovering nickel as nickel hydroxide and recovering cobalt as a mixture of cobalt sulfide according to the method of the present invention.

Explanation of symbols

1 Limonite fragments 2 Corrosion rock fragments 21 Nickel hydroxide product 24 Cobalt sulfide product

Claims (22)

A method of recovering nickel and cobalt from an acidic resin eluate containing at least nickel and cobalt,
(A) treating the eluate with an immiscible organic reagent to selectively absorb most of the cobalt present in the eluate and part of copper, zinc and magnesium; Leaving a raffinate containing said nickel and a few impurities;
(B) neutralizing the raffinate to precipitate the nickel as nickel hydroxide;
(C) removing the cobalt from the organic reagent;
(D) recovering the cobalt;
Including methods.   2. The method according to claim 1, wherein the acidic resin eluate is an eluate removed from an ion exchange resin packed with at least nickel and cobalt in a resin circuit in a pulp in a nickel and cobalt recovery process.   The method of claim 2, wherein the ion exchange resin has an iminodiacetic acid functional group or a bis-picolylamine functional group.   4. The method of claim 3, wherein the ion exchange resin has iminodiacetic acid functional groups.   The method according to any one of claims 2 to 4, wherein the nickel and cobalt are recovered by acid leaching treatment of atmospheric or high pressure laterite ore or oxidation leaching treatment of nickel sulfide ore or nickel sulfide concentrate.   The method according to any one of claims 2 to 4, wherein the nickel and cobalt are recovered from the resulting slurry obtained by the acid leaching of a combination of laterite ore and sulfide ore.   6. The method of claim 5, wherein the nickel and cobalt are recovered by atmospheric pressure acid leaching of laterite ore. The laterite ore is
(A) separating the laterite ore into low magnesium limonite fragments and high magnesium corrosive rock fragments;
(B) treating the limonite debris with acid in a first leaching stage to produce a first leaching slurry;
(C) adding the corrosive rock debris to the first leaching slurry in a second leaching stage to initiate iron precipitation as goethite resulting in a high acid level available in the second leaching stage; Producing a second leaching slurry containing cobalt ions;
A method processed by a stage comprising:
8. The method of claim 7, wherein the second leaching slurry is sent to an in-pulp resin circuit where at least the nickel and cobalt are packed into the resin.   The pH of the second leaching slurry is partially neutralized to a pH of about 2 to substantially complete the precipitation of iron as goethite, and then before being sent to the resin circuit in the pulp, 9. The method of claim 8, further increased to a pH of about 4 that precipitates ions and other impurities.   The method according to claim 9, wherein the in-pulp resin circuit stuffs at least a part of nickel, cobalt, and copper, zinc, aluminum, ferrous ions and chromium present in the second leaching slurry.   11. The method of claim 10, wherein the resin is eluted with weak sulfuric acid to remove substantially all of magnesium, calcium and manganese before removing the resin.   12. The method of claims 8-11, wherein the resin of the in-pulp resin circuit is treated with concentrated acid to remove stuffed metal to produce the acidic resin leachate containing at least nickel and cobalt.   13. A method according to claim 12, wherein the concentrated acid used to remove the resin is sulfuric acid or hydrochloric acid.   13. The method of claim 12, wherein the acidic resin leachate containing nickel and cobalt is partially neutralized with a neutralizing agent to a pH of about 4.5 to 5 prior to separation of the nickel and cobalt.   The method according to claim 14, wherein the neutralizing agent is sodium hydroxide, sodium carbonate, magnesium carbonate, or calcium carbonate.   16. A method according to claim 15, wherein the eluate contains 10 to 80 g / L of nickel.   The method of claim 1, wherein the immiscible organic reagent used to selectively absorb most of the cobalt and the copper, zinc and manganese present is Cyanex 272.   The method of claim 1, wherein the sulfuric acid is used to remove cobalt from the immiscible organic reagent to produce a cobalt-containing sulfuric acid solution.   The method of claim 18, wherein the sulfide is added to a sulfuric acid solution to precipitate the cobalt as impure cobalt sulfide.   20. The method of claim 19, wherein the sulfide is sodium hydrosulfide, hydrogen sulfide, or potassium hydrosulfide.   The method of claim 1, wherein the raffinate is neutralized with a magnesium oxide slurry to deposit the nickel as nickel hydroxide.   The method of claim 21, wherein the pH of the raffinate is increased to a pH greater than 7.5 to allow precipitation and recovery of the nickel as nickel hydroxide.

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