BRPI0605892B1 - Nickel and cobalt recovery process from an ion exchange resin eluate - Google Patents

Description

The process of obtaining nickel, cobalt, copper and other metals from lateritic ores containing them, for example, ores, is a process of recovering nickel and cobalt from an ion exchange resin elute. saprolitic or limonitic, as well as products obtained by processing this type of ore. The choice of the technological route and the final product to be produced by a nickel industrial unit depends directly on the characteristics of the ore to be fed into the plant. There is no conventional process. Over the past decade, high nickel and cobalt prices have led the nickel industry to look for less costly process alternatives that could reduce operating costs to maintain business profitability at lower nickel and nickel price levels. cobalt. The development of lower investment cost technologies such as atmospheric tank or battery leaching and pulp resin (RIP) technology, coupled with declining sulfur prices, has provided some companies with the opportunity to reconsider development. of lateritic ores with low contents and reserves, which were not used for production through traditional processes.

Historically, innovations in the nickel production process are mainly the result of harnessing the technology initially employed in the processing of uranium, which was later also applied to the gold industry. A good example of this is the pulp resin (RIP) process. Flexibility, low capital cost, high metal recovery and low operating cost regime, as well as energy savings translate into logistics that may indicate that the technological process of acid leaching followed by pulp resin and nickel recovery and cobalt may be chosen in the development of lateritic deposits in the medium and long term. Many analysts believe that, based on pulp resin technology, operating costs could be reduced by 15/25% from the current market costs of major producer groups. Smaller investments (cost of capital / year) are expected, given the simplicity of the flowchart (represented by figures 2 and 3) that is being proposed here. Several hydrometallurgical routes have been applied for the extraction of nickel and cobalt contained in lateritic ores. In these routes, the objective is to solubilize the metallic species using inorganic acids, followed by solid-liquid separation and neutralization, before the final recovery of the metal. Selective recovery of the metal present in the leaching pulp is an important step in the design of the economic assessment. The presence of many impurities, such as copper, iron, manganese and magnesium, among others, can be considered as the main technological difficulty to be overcome in nickel processing. This creates complex flowcharts with a large number of unit operations, high investment and operating costs, and technological risks such as early shutdown, long ramp-up time, and difficulty producing at the projected scale.

Based on the above, it can be concluded that several factors have been encouraging the development of new flowcharts for nickel laterite processing, such as: high nickel and cobalt prices, underexploited lateritic deposits, low nickel metal demand growth price of sulfur and H2S04. With the creation of these new flowcharts, a number of advantages are expected to be achieved: cost savings, operational simplicity, higher recoveries, cobalt recovery as a by-product. The conventional flow of a basic aqueous extraction process flowchart presents the steps of preparation - leaching - solid / liquid separation - solution treatment - metal recovery for metal or metal compound production.

In terms of leaching, the most commonly found process options are acid pressure leaching or reduction followed by ammoniacal atmospheric leaching (Caron process). Even with conventional and industrially proven technologies such as economically intensive pressure sulfur leaching and the Caron process, there is a relentless pursuit of less expensive technologies such as acid atmospheric leaching.

In terms of solution treatment, conventional solvent extraction and precipitation technologies can be cited. • Solvent extraction directly applied to the leaching effluent, such as the Bulong plant, offers the advantage of high nickel and cobalt recoveries, however the presence of high concentrations of impurities and the need to control them still requires intense optimization of this technology. One of the main impurities is chromium, Cr3 + and Cr6 +, whose behavior is little known in the presence of Cyanex 272, solvent used for the separation of nickel and cobalt in sulfuric medium.

Some parameters still remain conflicting as metal oxidation state, pH, presence of anions such as nitrate, chloride, sulfate and acetate. Other challenges can be cited as Mn separation from Co and Ca separation from Ni and effects of degradation products using extractants such as Cyanex 272, versatic acid, hydroxy oximes, D2EHPA. Due to these still poorly understood restrictions, especially the high concentration of impurities contained in this effluent, Bulong's industrial operation was interrupted by operational problems. • Precipitation techniques such as the production of mixed nickel and cobalt hydroxide and sulfide precipitate are very dependent on the quality of the feed solution. In this case, it is of fundamental importance the correct and efficient operation of the previous purification units, in order to prevent the contamination of the product “nickel and cobalt hydroxide” - precipitated with the addition of magnesia - with elements such as iron, aluminum and silica, as is the case with the Cawse plant. In the case of chromium it must be reduced to be precipitated efficiently in previous operations. The presence of silica causes poor nickel recovery in subsequent ammonia leaching operations. Manganese precipitation is influenced by residence time. The same strict control of impurities occurs in the case of the production option of mixed nickel and cobalt sulfide precipitate. Addition of H2S occurs to obtain selective precipitation of nickel and cobalt. This precipitate is then relixivated under oxidizing conditions and impurities such as iron, copper and zinc are removed, such as the Moa Bay and Murrin Murrin plants. MHP (mixed hydroxide precipitate) and MSP (mixed sulfide precipitate) technologies are industrially proven and perform similarly. The choice between one and the other will depend on environmental factors, safety, infrastructure, economic balance sheets, strategies for producing a sulfide product or hydroxide for commercialization.

In terms of metal recovery, conventional technologies in hydrometallurgical flowcharts present the recovery of nickel and cobalt in metallic form through operations such as electrolysis and hydrogen reduction. There is also the option of producing intermediate products such as nickel and cobalt carbonates, hydroxides and oxides.

Conventional hydrometallurgical flowcharts differ greatly from each other, precisely because of the lack of a standard and optimized flowchart that meets the chemical and mineralogical needs of lateritic nickel ores. The various flowchart options have technical and economic constraints and limitations that must be minimized or even eliminated by optimizing the unit operations involved. Figure 2 illustrates a basic flowchart of the aqueous extraction process.

An example is the solid / liquid separation step which poses major problems for conventional circuits. Due to the poor sedimentation characteristics of Counter-Current Decantation (CCD), about 10% of soluble nickel and cobalt is lost in the tailings. To minimize this significant loss, series of at least six large thickeners, over 50 meters in diameter for each stage, are used in solid / liquid separations to achieve correct solid sedimentation and produce clear overflow. Thus, the capital cost of a simple CCD step with conventional thickeners can be as high as 30% of that of a titanium autoclave used in High Pressure Acid Leaching (HPAL). If chlorides are present, as in some lateritic deposits of arid regions, even more expensive thickeners are required. In addition to capital costs, operating costs are also high as they include not only the energy consumption for each rake, but also flocculants required for settling the fine material. Flocculant consumption ranges from 200 to 800 grams per ton of solids, which increases the total plant operating cost by up to 10%.

Another difficulty to be overcome is the recovery of nickel and cobalt from the resulting solution, or PLS, due to the present impurities and low concentration of the metals of interest. Ion exchange is an efficient method of crossing these barriers, it is effective at low concentrations, and selectivity can be greatly enhanced by the correct choice of an ion exchange resin.

A number of factors encourage not only the optimization of pre-existing flowcharts but also the proposal of new high innovative process flowcharts. For most companies, and most of the time, the fundamental focus is on improving and improving existing operations as a way to address obstacles. Considerable gains are often achieved by installing new technologies in parts of the plant, rather than completely modifying the entire operation. Thus, an adequate understanding of the process fundamentals is possible, especially with improvements in equipment, designs, operating procedures, reagents and mathematical modeling.

One of the most significant factors for the proposal of new flowcharts is the high price of nickel driven by the slow growth of primary nickel production and the massive growth of Chinese consumption, which suggest an intense race to develop new proposals for hydrometallurgical processes. In many cases, many projects so far could not be economically viable based on long-term projected nickel prices. Existing acid leaching operations for treatment of lateritic ores have failed to produce projected levels, even closing mills, as occurred with Bulong in 2003. This has had a massive impact on nickel supply as well as on investments elsewhere. of the nickel industry.

Because of the increasing complexity of chemical, mineralogical and size deposits, finding a resource-rich, high-grade deposit that is easily plowed and processed is an ideal situation that many companies aspire to. Conventional technologies can be used with less technical risk, much based on the experience of recent hydrometallurgical operations. There is a perception that the deployment of new technologies is challenging, often resulting in the choice of what is conventional. However, the overconfidence of the latter option often leads to a number of problems on an even larger scale, such as inadequate or nonexistent pilot operation, start-up delays due to operational problems, lack of skilled personnel, project engineering and cost projection, operational problems and complexity, low operational efficiency, cost-effective and time-saving operational simplifications, inadequate doubtful resources, market under-judgment are common. On the other hand, new technologies pay dividends perfectly, but often in the long run of research and development until they reach a state of excellence.

In view of the objectives mentioned above, a process was developed to obtain nickel, cobalt, copper and other metals from ores containing them, comprising the following steps: (a) ore preparation or pretreatment for enrichment through the rejection of silica; (b) acid leaching of the pretreated ore; (c) treatment of effluent pulp obtained in the leaching stage using ion exchange resin; (d) elution or desorption of the ion exchange resin employing regenerated hydrochloric acid from the pyrohydrolysis step; (e) removing copper and other impurities by precipitation employing sulfide or hydrogen sulfide; (f) the solution still containing nickel and cobalt is subjected to solvent extraction process; (g) stripping or reextraction and precipitation of cobalt using regenerated hydrochloric acid from the pyrohydrolysis step; (h) pyrohydrolysis of the nickel-containing solution, thereby obtaining nickel as oxide and hydrochloric acid.

Given the limitations of conventional flowcharts and the expectation of the great potential for use of emerging technologies that are currently under development, the proposed solution is the innovation of flowcharts under the hydrometallurgical approach, aiming at greater operational simplicity, higher process efficiencies and lower operating costs. investment and operational.

In terms of leaching, the proposal is the use of acid atmospheric leaching, whether sulfuric or hydrochloric, limonitic and saprolytic ores, pressure leaching and the combination of atmospheric and pressure leaching.

In terms of treatment of the effluent solution, the proposal here is the use of ion exchange resin, preferably the use of pulp resin, with the particularity that the elution or desorption of the resin must be carried out with hydrochloric acid. The product of this step, known as eluate, which in addition to containing nickel and cobalt also has impurities such as copper, must be purified. The proposal is the addition of H2S or NaHS at low concentrations for the precipitation of metal sulfides, mainly copper sulfide and small proportions of other metal sulfides. A second option for copper removal may be the use of fixed bed resins for selective copper adsorption and other impurities. The solution that still contains nickel and cobalt is taken to a solvent extraction step with Alamine 308 to separate these metals. The efficiency should be significantly increased given the high purity of the feed solution, which was purified in a previous pulp resin step. It is known that the use of solvent extraction directly applied to the leaching effluent involves a number of risks, mainly due to the non-availability of an extractant that is sufficiently selective for nickel against other impurities. Producing a higher purity intermediate (eluate) is a reasonable option to address the deficiency of current commercial extractants. Once separated in the previous step, nickel and cobalt follow separate and independent flows to be recovered.

In terms of metal recovery, cobalt should be recovered as hydroxide or carbonate and nickel should be recovered as oxide through the HCI regenerated pyrohydrolysis process. The flowchart of the invention, illustrated in FIGURE 3, offers a number of advantages that can be cited: • Ore leaching should preferably be acidic, with the options of using sulfuric acid and hydrochloric acid. Pressure sulfur leaching has the advantage of being a conventional technology, widely consolidated by various industrial applications. Highlight should be presented by the leaching technologies under atmospheric pressure and temperature below the pulp boiling point, around 105 ° C. This option has the disadvantage of lower nickel recovery efficiency but higher operating cost, given the higher acid consumption. However, the lower investment cost makes this option a highly attractive technical alternative. Another option with great potential for success is the combination of atmospheric and pressurized leaching types, which can provide great savings in process acid consumption. • The pulp resin process has the various advantages already mentioned, however, emphasis should be given to the benefit of eliminating the costly solid-liquid separation step, simplifying the flowchart, eliminating a number of unit operations, reducing potential. investment and operating costs, achieving high recovery efficiencies and selectivity for nickel and cobalt metals of interest. At this stage the elution of the resin, that is, the desorption of the resin metals must necessarily occur with hydrochloric acid, since all other operations in the flowchart backend are dependent on this condition. The hydrochloric acid used in this step is the result of the regenerated hydrochloric acid in the final step of the flow chart, known as pyrohydrolysis. • The solvent extraction step at this point in the flowchart has enormous potential for success and minimal technical risk. To reduce the overload of this step and the contamination of the end products with undesirable elements, a prior step of copper removal via sulfide precipitation is suggested. In contrast to other direct solvent extraction applications in leach effluents in various nickel ore processing flowcharts, here the solution that feeds this step is considered to be of high purity as it comes from a previous step of high efficiency ion exchange. . The low level of impurities and high concentration of metals of interest, nickel and cobalt, favor the high performance of the technique. The extractant used is Alamine 308 which is a specific reagent for separation of nickel and cobalt in hydrochloric medium, as is the case. The stripping step, ie the cobalt reextraction of the organic extractant, should also be done with hydrochloric acid from the pyrohydrolysis step responsible for acid regeneration. The use of regenerated hydrochloric acid in the resin elution and stripping steps of the organic extractant gives the flowchart that is being proposed, a saving of acid consumption and consequently a reduction of the operational cost. • Pyrohydrolysis can be considered a decisive step for the proposed flowchart. It is precisely at this stage that the final nickel oxide product is obtained and the hydrochloric acid regeneration of the process will be used in the ion exchange and solvent extraction steps. The option of this flowchart is the generation of intermediate products of both nickel and cobalt, avoiding the increase of capital costs with the insertion of steps such as electrolysis and reduction with the use of hydrogen.

In a nutshell we can say that the invention achieved the following objectives: (1) lower environmental impact - lower water consumption and opportunity for water recycling; (2) lower operating and capital cost; (3) higher quality of metal products - high selectivity for metals of interest and high separation capacity and high metal recovery efficiency; (4) operational simplicity with elimination of unitary operations; (5) lower technical risk by optimizing unit operations with respect to operating conditions, reagents, feed solution purity.

In detail the invention contemplates: Pretreatment: This step aims to enrich the ore by rejecting silica. Operations include crushing (primary and secondary), scrubbing for fine particle release, classification for rejection of low grade silicate coarse, attrition to maximize recovery of nickel contained in fine particles. Figure 1 illustrates the enrichment potential of nickel content with the cut size in the classification step.

Leaching: Exploration of lateritic nickel reserves has grown over the years as exploitable reserves of sulphide ores deplete. Due to this fact, new processes are being developed for the extraction of nickel and cobalt from these weathered ores. Each process involves dissolving the target metals with the aid of an acid, followed by a solid / liquid separation step and a purification step until it reaches the recovery step. From these processes, Pressure Acid Leaching (PAL) has become the most used option for laterite treatment. Pressure leaching occurs in pressurized vessels or autoclaves made of carbon steel coated with an 8mm grade 17 titanium layer, the solids percentage is about 30 to 34%, residence time 60 to 120 minutes, 250 to 270 ° C. Acid consumption is dependent on the presence of consuming elements, but can be minimized by acid regeneration by hydrolysis that occurs under these conditions. Another form of emergent leaching is that which occurs under conditions of atmospheric pressure and pulp temperature below the boiling temperature. Under these conditions there is the possibility of acid leaching with reagents such as hydrochloric acid and sulfuric acid in rubber coated carbon steel tanks. Under these conditions the residence time is significantly longer and can reach up to 24 hours and solids percentage around 33%. Under these conditions it is possible to treat limonitic or saprolitic ores, with the most varied chemical and mineralogical compositions. Acid consumption tends to be higher under these conditions, but offset by the lower investment cost. The combined leaching between these two types of leaching is equally attractive by reducing acid consumption.

Pulp resin: The ion exchange resin technique is considered an emerging option, without large-scale application, among the treatment options for solutions in nickel processing flowcharts.

Studies have been intensifying with several promising approaches and results. Initially created for gold, it evolved from the carbon-in-pulp (CIP) process by switching from activated carbon to ion-exchange resin. The first commercial plant to use RIP for gold recovery was the Golden Jubilee Mine in South Africa (Fleming, C.A., 1988). Industrial operation at this mine served as the basis for analyzing the advantages of RIP over CIP (Fleming, C.A., 1991). What can be observed recently is a great incentive for the development of the nickel-oriented technique, as it can compete with conventional technologies such as solvent extraction and precipitation-relixiviation, given its operational simplicity, fewer equipment and lower costs involved. The main advantages are the efficient recovery and removal of small concentrations of some metal ions selectively over an excess of other metals, high metal loading, high mechanical strength reducing friction losses, fast elution characteristics and low contamination losses. organic matter. Industrially employing acid leaching for lateritic ores include a multi-stage counter-current settling circuit for solid-liquid separation, which involves significant capital and operating costs, occupies large areas and requires a significant amount of wash water. . Taking advantage of the great advantages of ion exchange technology, an alternative for nickel and cobalt recovery from leaching pulp without the use of thickeners is the application of a resin-in-pulp system. Usually between the leaching step and the pulp resin step, there is a neutralizing step that aims to neutralize the excess acid from the leaching effluent, as well as precipitate iron and some impurities. At this stage the temperature can be in the range of 70 to 95 ° C, there is the addition of limestone and air injection to oxidize the iron. The pH at this stage ranges from 4 to 5. The pulp resin operation has three distinct steps. 1) Adsorption: Nickel and cobalt are selectively recovered in the adsorption step. This step can be performed in air agitated pachucas or in mechanically agitated tanks. The suggested resins for this type of application are those with iminodiacetic acid or picolylamine functional group. The contact between resin and pulp is made in countercurrent flow with intermediate sieves between tanks for phase separation. The charged resin from the first tank is removed from the circuit, washed to remove aggregate solids and transferred to the elution circuit. 2) Elution: Elution should be carried out with hydrochloric acid, in the concentration of about 50 to about 150g / L, obtained in the regeneration process that took place in the pyrohydrolysis step. 3) Regeneration: The eluted resin is then contacted with some reagent such as soda or limestone to regenerate it and reverse it to calcium or sodium form.

Solvent Extraction: Several extractants can be used for the recovery of nickel in sulfate medium, such as carboxylic acids (versatile 10) and forphoric acid derivatives (D2EHPA). There are also those selective extractants for phosphinic acid-based cobalt (Cyanex 301 and cyanex 272). These extractants do not offer high selectivity for nickel compared to other elements such as manganese, iron, cobalt, magnesium and calcium. For better nickel selectivity, these reagents require rigorous pH control and multiple washing stages. The development of selective nickel extractants is always a challenge since nickel electrolysis is very pH sensitive where there is an optimal pH window in the range of 3.5 to 4.0. This pH is significantly higher than the typical pH of leaching effluent solutions, ie an extractant used for recovery of nickel from effluent solutions with pH in the range 1-2 should be regenerated at pH = 4. For better efficiency of the solvent extraction, a step is being proposed for copper removal which may be by precipitation of the metal in the form of sulfide or recovery of it in fixed bed ion exchange resin.

In the case of the flowchart that is being proposed, the solvent medium is hydrochloric acid and the metallic species are in the form of chlorides. The only organic extractant option in this case is Alamine 308 (tri-isooctylamine). This reagent preferably extracts cobalt over other metals. Three basic steps are part of the process: extraction, washing and reextraction. Cobalt stripping of the organic extractant should be done with hydrochloric acid, resulting from regeneration in the pyrohydrolysis step. The final cobalt product must be obtained as a precipitate with the addition of soda and consequent formation of cobalt carbonate. □ Alamine 308 (tri-isooctylamine) This tertiary amine is used as an ion exchange extractant to extract CoCl42- from hydrochloric acid leached solutions. Nickel does not form chlorine complexes and is not extracted, but copper and zinc are healthy, the latter being extracted at lower chlorine concentrations than cobalt.

Because it contains a basic nitrogen atom, it easily reacts with a variety of organic and inorganic acids, forming amine salts, which are capable of undergoing ion exchange reactions, as the equations below show.

Protonation [R3N] org + [HA] aq <- »[R3NH + A-] org Ion Exchange [R3NH + A-] org + [B-] ~ [R3NH + B-] org + [A-] aq The ion exchange rate between the anions of A and B is a function of their relative affinity with organic cation and their respective solvation energies. The regeneration step of the target species can be done by a wide range of inorganic salt solutions such as NaCl, Na2 CO3 and (NH4) 2 SO4. The stripping step reagent depends on the full process recovery, but generally basic agents that reverse the protonation reaction give better results in a smaller number of stages. The equation below brings the recovery by Na2C03. 2 [R3'NH + B-] org + [2Na + + C032-] aq <-► 2 [R3N] org + H20 + C02 In some cases the formation of anionic complexes and their subsequent extraction depend on the concentration of this anion, as for example the extraction of cobalt as chloro-complex.

Pyrohydrolysis: The conventional application of fluidized bed pyrohydrolysis offers the regeneration of hydrochloric acid. Using this process offers two major advantages. First, the recycling of hydrochloric acid which is an environmental necessity. In many hydrometallurgical processes, recovering the leachate (HCI, CI2, FeCl3) is absolutely essential since the disposal of the leachate and the metals contained therein are economically and ecologically unacceptable. Second, the savings caused by acid regeneration while minimizing operating costs with reagents. Recovery above 99% is commonly achieved with high purity, which is important if HCI is intended for sale. During pyrohydrolysis, hydrochloric acid is regenerated, which is used in the elution of the resin and in the extraction of the organic solvent.

In some hydrometallurgical processes, metal oxide is the desired product and regenerated HCl is the by-product. In some cases, a concentrated NiCl2 solution may also be produced. This solution can be processed by pyrohydrolysis, generating NiO and HCI or processed by electrolysis generating nickel metal and chlorine gas. To obtain the metal from NiO, the oxide must be reduced to 750 ° C with H2.

Electrolysis offers the advantage that nickel metal is produced in a single stage. However, there are some disadvantages, such as the chlorine required to produce HCI for leaching is generated in small quantities in thousands of anodes, which must be carefully collected and treated, as well as the high cost involved in generating electricity whose efficiency is only 35%. %. Pyrohydrolysis also produces nickel oxide in a single step, but also produces HCI simultaneously in the form of off-gas which is absorbed in water. Primary fuels such as gas or oil may be used. Metal reduction can occur in a separate furnace with stoichiometric addition of H2. In this case, nickel oxide in the granular form is desired, as the thin form may agglomerate in the reduction furnace. At relatively high temperatures above 1000K (727 ° C), nickel pyrohydrolysis occurs. Thermodynamic data show that if the off-gas system temperature drops to 700 ° C, the opposite reaction of NiO originating NCI 2 occurs. The exact temperature will depend on the HCI / H20 off-gas ratio. At high partial pressure of HCl, the opposite reaction to formation of NCI 2 occurs at temperatures above 700 ° C. The only experience of nickel chloride pyrohydrolysis operation occurred at Falconbridge Matte Leach Plant from 1968 to 1984.

In this process, high temperatures are required for the reaction to occur and to prevent the reverse reaction of NiCl2 formation. On the other hand, NiCl2 sublimates at a temperature of 950 ° C when its vapor pressure reaches 1 atm. The following examples serve to further illustrate the scope of the invention, but should not be taken for purposes of limitation thereof: Examples: SAMPLE 1 (SJP-FM08 46.95 to 49.25m) The particle size fraction between 32 # and 200 # Sample 1 of lateritic nickel is composed of 0.5% Ni, 0.02% Co, 44.23% Fe and 0.28% Mg. Such a fraction, together with a 96% sulfuric acid solution, fed Atmospheric Leaching (AL) at 950 ° C, stirring 385 rpm and 33% solids for 6 hours. Extraction of 73.3% Ni and 59.0% Fe occurred in LA, resulting in an effluent with a concentration of 2.9 g / L Ni, 229.1 g / L Fe and 138.1 g / l residual free acidity and a residue with 0,23% Ni and 31,20% Fe. Part of this liquor formed, together with a 96% sulfuric acid solution, and another fraction (below 200 #) from sample 1 (composed of 0.62% Ni, 0.03% Co, 43.10% Fe and 0.31% Mg), fed an autoclave to perform Pressure Leaching (HPAL): at 2500 ° C, 500 rpm agitation, 650 psi pressure, 30% solids for 75 minutes. When the HPAL was fed, the liquor was diluted and acquired concentrations of 0.02 g / l Ni and 1.37 g / l Fe. After HPAL, the autoclave effluent presented 4.7 g / l Ni and 56.6 g / l Fe, so that 41.0% Fe from LA liquor was precipitated. And, the residue showed 0.02% Ni and 44.1% Fe. The hydrolysis reaction of ferric sulfate caused the precipitation of Fe in the form of hematite, regenerating about 128.5 kg / t of acid which represents 30%. % of gross consumption. 93.9 kg / t of acid (22% of global consumption) was taken from the residual free acidity present in the LA effluent, requiring only 48% (206.6 kg / t) of acid to be added. The extraction of Ni (AL followed by HPAL) was 96.7%. It can be emphasized that in Pressure Leaching the extraction was 94.3% of Ni for a gross acid consumption of 429.0 kg / t. SAMPLE 2 (SJP-FM09 27.00 to 28.00m) To perform AL, a fraction from 32 # to 200 # was fed with: 1.11% Ni, 0.21% Co, 37.76% Fe and 0.79% Mg; and a 96% sulfuric acid solution. The operating variables used were: 950C temperature, 385 rpm agitation, 33% solids for 6 hours. At Atmospheric Leaching, a concentration liquor of 7.0 g / l Ni, 107.6 g / l Fe and a residual free acidity of 39.5 g / l was produced. The residue showed 0.34% Ni and 32.90% Fe, and the extraction of Ni was 76.5% and Fe was 33.3%. The next step (HPAL) was fed with part of this liquor, a 96% sulfuric solution and an ore mass corresponding to the fraction below 200 # (1.49% Ni, 0.13% Co, 26.30% Fe (1.07% Mg). Due to the addition of the solution to the liquor, dilution occurred and the feed was 0.04 g / l Ni and 0.58 g / l Fe. Pressure Leaching was performed at 2500 ° C, stirring at 500 rpm. , 650 psi pressure, with 30% solids for 75 minutes. The produced liquor obtained 8.8 g / l Ni and 12.5 g / l Fe and the residue showed 0.15% Ni and 30.60% Fe. It can be seen that there was a reduction in the amount of Fe in HPAL liquor when compared to LA effluent; such reduction corresponds to 61.1% of Fe which was precipitated. Within the autoclave there was a regeneration of 108.3 kg / t sulfuric acid, equivalent to 30% of gross consumption. For this reason, the mass of acid to be added to the autoclave was 63%, that is, 226.0 kg / t were fed and 26.6 kg / t (7% of gross consumption) were used from LA. Ni extraction for a single HPAL step was 94.1% and in LA followed by HPAL was 91.0%. TABLE 5 Table 6: Comparison of results between HPAL and AL followed by HPAL. TABLE 6 SAMPLE 3 (SJP-FM09 51.45 to 53.00m) The composition of the fraction (-32 # + 200 #) that feeds AL is 0.71% Ni, 0.06% Co, 13, 89% Fe and 1.67% Mg. This fraction was added to a 96% sulfuric acid solution and leached at 950 ° C, 385 rpm stirring and 33% solids for 6 hours. The LA effluent presented 75.6% Ni extraction and 53.0% Fe extraction, with concentrations equal to 3.3 g / L Ni, 45.0 g / L Fe and 110.9 g / L free acidity. The residue was characterized by 0.20% Ni and 7.54% Fe. A fraction of this liquor together with a 96% sulfuric solution and the fine fraction (-200 #) of this sample fed the autoclave for the realization. from HPAL. The fine fraction composition is 4.53% Ni, 0.11% Co, 27.80% Fe and 3.31% Mg. The concentration of the liquor that fed the HPAL was 0.02 g / l Ni and 0.30 g / l Fe due to the dilution promoted by the sulfuric solution. The operating parameters used in the HPAL were: 2500C temperature; 500 rpm agitation; 650 psi pressure; and 30% solids for 75 minutes. This leaching obtained a liquor with 24.1 g / l Ni and 5.6 g / l Fe and a residue with 0.20% Ni and 34.60% Fe. During HPAL there was regeneration of 40% of Fe. acid (174.4 kg / t), taking advantage of 76.1 kg / t (17%) from free acidity and requiring only 42% of virgin acid which corresponds to 185.4 kg / t. The liquor generated by this Leaching under Pressure presented an extraction of 96.2% Ni, obtaining 2 percentage points more than HPAL not preceded by LA. It was also observed that 61.1% Fe was precipitated.

Table 7: Sample Composition and Product Data from LA .________________ _________________________________________________ TABLE 7 Table 8: Sample Composition and Product Data from HPAL. _________________ Pressure Leaching - HPAL___________________________ TABLE 8 Table 9: Comparison of results between HPAL and AL followed by HPAL. TABLE 9

Claims (21)

1. “NICKEL AND COBALT RECOVERY PROCESS FROM ION EXCHANGE RESIN ELUTE”, characterized by the following steps: (a) Preparation or pretreatment of ore for enrichment through the rejection of silica; (b) acid leaching of the pretreated ore; (c) Treatment of the effluent solution obtained in the leaching step using ion exchange resin applied to pulp; (d) Elution or desorption of the ion exchange resin employing regenerated hydrochloric acid from the pyrohydrolysis step; (e) Removal of copper and other impurities by precipitation employing sulfide or hydrogen sulfide; (f) the solution still containing nickel and cobalt foot subjected to solvent extraction; (g) striping or reextraction using regenerated hydrochloric acid from the pyrohydrolysis step; (h) Cobalt precipitation in the form of carbonate or any other product, such as sulphate, oxide, hydroxide. (i) Pyrohydrolysis of the nickel-containing solution, thereby obtaining nickel as oxide and hydrochloric acid. 2. "NICKEL AND COBALT RECOVERY PROCESS FROM AN ION EXCHANGE RESIN ELUTE" according to claim 1, characterized in that ore pretreatment includes: crushing (primary and secondary), scrubbing for fine particle release , rejection rating of low-grade silica coarse material and attrition to maximize nickel recovery. 3. "NICKEL AND COBALT RECOVERY PROCESS FROM ION EXCHANGE RESIN ELUTE" according to claim 1, characterized in that the leaching occurs in the presence of sulfuric acid or hydrochloric acid. 4. "NICKEL AND COBALT RECOVERY PROCESS FROM AN ION EXCHANGE RESIN ELUTE" according to claim 1, characterized in that the leaching of the ore can be by pressure and / or atmospheric leaching or combinations thereof. 5. "NICKEL AND COBALT RECOVERY PROCESS FROM ION EXCHANGE RESIN ELUTE" according to claim 1, characterized in that optionally the leaching effluent may be neutralized prior to treatment with ion exchange resin. 6. "NICKEL AND COBALT RECOVERY PROCESS FROM AN ION EXCHANGE RESIN ELUTE" according to claim 1, characterized in that the ion exchange resin in pulp is employed. 7. "NICKEL AND COBALT RECOVERY PROCESS FROM AN ION EXCHANGE RESIN ELUTE" according to claim 1 or 6, characterized in that in the step employing ion exchange resin, the elution or desorption occurs in the presence of hydrochloric acid. regenerated from the pyrohydrolysis step. 8. "NICKEL AND COBALT RECOVERY PROCESS FROM AN ION EXCHANGE RESIN ELUTE" according to claim 1, characterized in that resins having the iminodiacetic acid or picolylamine functional group can be employed. 9. "NICKEL AND COBALT RECOVERY PROCESS FROM AN ION EXCHANGE RESIN ELUTE" according to claim 1, characterized in that the concentration of hydrochloric acid in the elution step may range from about 50 to about 150 g / l. 10. "NICKEL AND COBALT RECOVERY PROCESS FROM ION EXCHANGE RESIN ELUTE" according to claim 1, characterized in that fixed bed resins are used for the selective absorption of copper and impurities. 11. "NICKEL AND COBALT RECOVERY PROCESS FROM AN ION EXCHANGE RESIN ELUTE" according to claim 1, characterized in that sodium acid sulfide or sulfuric acid is used to remove copper and impurities. 12. "NICKEL AND COBALT RECOVERY PROCESS FROM ION EXCHANGE RESIN ELUTE" according to claim 1, characterized in that the selective extractant in the solvent extraction step for cobalt removal may be a tertiary amine employed in hydrochloric medium. 13. "Nickel and cobalt recovery process from an ion exchange resin elute" according to claim 1, characterized in that cobalt removal can take place in three stages: extraction, washing and re-extraction. 14. The process of recovering nickel and cobalt from an ion exchange resin elute, according to claim 1, wherein the cobalt is recovered as cobalt hydroxide, oxide, sulphate or carbonate. 15. "NICKEL AND COBALT RECOVERY PROCESS FROM AN ION EXCHANGE RESIN ELUTE" according to claim 1, characterized in that the cobalt selective re-extractant may be regenerated hydrochloric acid from the pyrohydrolysis step. 16. "Nickel and cobalt recovery process from an ion exchange resin elute" according to claim 1, characterized in that the selective cobalt extractants may be based on phosphinic acid. 17. "NICKEL AND COBALT RECOVERY PROCESS FROM AN ION EXCHANGE RESIN ELUTE" according to claim 1, characterized in that the selective nickel sulfate extractants may be carboxylic acids and / or phosphoric acid derivatives. 18. "Nickel and cobalt recovery process from an ion exchange resin elute" according to claim 1, characterized in that cobalt is recovered as a precipitate with the addition of soda and consequent formation of cobalt carbonate. 19. The process of recovering nickel and cobalt from an ion exchange resin elute according to claim 1, characterized in that pyrohydrolysis may occur in a fluidized bed. 20. "NICKEL AND COBALT RECOVERY PROCESS FROM AN ION EXCHANGE RESIN ELUTE" according to claim 1, characterized in that pyrohydrolysis regenerates hydrochloric acid which is used in the elution of the resin and in the extraction of the organic solvent. 21. "Nickel and cobalt recovery process from an ion exchange resin elute", according to claim 1, characterized in that the nickel oxide obtained is in granular form.