Production of nickel tetracarbonyl from mhp

Abstract

This invention relates to the production of nickel tetracarbonyl from mixed metal hydroxide precipitates (MHP) comprising nickel, cobalt, and manganese.

Description

[0001] BASF SE B25.165P-WO

[0002] 67056 Ludwigshafen am Rhein 12.08.2025 / lg / np / jl

[0003] Production of nickel tetracarbonyl from MHP

[0004] Field of the invention

[0005] This invention relates to the production of nickel tetracarbonyl from mixed metal hydroxide precipitates (MHP) comprising nickel, cobalt, and manganese.

[0006] Background

[0007] AU 2022271428 A1 discloses a nickel-cobalt precipitation method for a nickel laterite ore acid leaching solution after iron and aluminium removal. The precipitation method includes adding a reducing agent to the post ironaluminium removal solution;, continuously feeding the mixed solution into a reactor to perform an alkali conversion precipitation reaction; continuously performing a dense separation treatment on the precipitation slurry; adding a precipitation inducer to a part of an overflow so as to perform the alkali conversion reaction, then mixing and homogenizing the alkali conversion overflow and the first part of an underflow; or, adding the precipitation inducer to the first part of the underflow so as to perform the alkali conversion reaction, continuously feeding the alkali conversion crystal slurry into the reactor; and filtering and washing the second part of the underflow and obtain a mixed hydroxide precipitate (MHP) product.

[0008] CN 103 130 284 A relates to a method for producing nickel powder from nickel hydroxide comprising the following steps: adding nickel hydroxide into a rotary roasting furnace, removing water at high temperature, and roasting to obtain nickel oxide; adding the oxide into a hydrogen reducing furnace to perform reduction, thereby generating active nickel; adding the active nickel into a nickel carbonyl synthesis reactor to make counterflow contact with CO, and reacting to generate nickel carbonyl gas; delivering the nickel carbonyl gas to a nickel carbonyl decomposer, and decomposing the nickel carbonyl gas in the nickel carbonyl decomposer to produce the nickel powder. CN 104 480 326 A relates to a method for producing nickel by using nickel hydroxide being an intermediate product of nickel laterite ore. The method comprises the following steps: drying nickel hydroxide being an intermediate product of nickel laterite ore, heating to oxidize nickel hydroxide to oxide of nickel, reacting the oxide of nickel with hydrogen, reducing to produce coarse nickel powder; performing oxo synthesis on the crude nickel powder and CO to obtain raw nickel carbonyl; and performing evaporation and rectifying purification on the raw nickel carbonyl, and performing thermal decomposition to produce nickel.

[0009] US 2008 / 267810 A1 discloses an apparatus and a process for making high purity nickel. A mixed metal oxide composition comprising oxides of nickel, cobalt, copper and iron is reduced in a hydrogen atmosphere to produce a mixture of the respective metals. The atmosphere further comprises water vapour at a concentration, temperature and time to effect selective reduction of the oxides of nickel cobalt and copper relative to the iron oxide to produce the metallic mixture having a reduced ratio of metallic iron relative to metallic nickel, cobalt and copper.

[0010] Summary of the invention

[0011] The present disclosure provides a process for the production of nickel tetracarbonyl from mixed metal hydroxide precipitates (MHP) comprising nickel, cobalt, and manganese.

[0012] MHP is first washed with water to remove water-soluble sulfates. The washed MHP is subjected to a reductive heat treatment under H2 to reduce Ni2+and Co2+present in the MHP to Ni and Co, respectively. The reduced MHP then is reacted with carbon monoxide to obtain nickel tetracarbonyl and a residue depleted of nickel. Detailed description

[0013] The present disclosure provides a process for the production of nickel tetracarbonyl from mixed metal hydroxide precipitate (MHP) comprising nickel, cobalt, and manganese, comprising the steps of a) washing the MHP with water to remove water-soluble sulfates and obtain washed MHP, b) reducing the washed MHP with hydrogen to obtain reduced MHP, and c) reacting the reduced MHP with carbon monoxide to obtain nickel tetracarbonyl and a residue depleted of nickel.

[0014] In the present disclosure, the term mixed metal hydroxide precipitate (MHP) means a mixture of metal hydroxides, hydroxycarbonates, and / or carbonates comprising nickel hydroxide, cobalt hydroxide and other metals, e.g., manganese. In some embodiments, the MHP is obtained by precipitating metal hydroxides from a metal salt solution. MHP typically comprises from 0 to 2 wt% Li, from 10 to 50 wt% Ni, from 0.1 to 20 wt% Co, from 0.01 to 15 wt% Mn. Moisture content generally is in the range of from 20 to 60 wt%, relative to the total weight of MHP. A typical range for particle size dso is from 1 to 150 pm. In some embodiments, the MHP is an intermediate nickel product produced from laterite nickel ore, which contains both nickel and a small percentage of cobalt. MHP is typically produced using a high-pressure acid leaching (HPAL) process. The beneficiation process of lateritic (oxidic) Ni ores includes leaching with H2SO4 and subsequent precipitation of MHP with NaOH. The MHP mostly consists of nickel hydroxide, but also contains valuable cobalt hydroxides and various other impurities, the main one being manganese. Ni content typically is 34-55 wt%, relative to the total weight of the MHP, Co content typically 1-6 wt%, relative to the total weight of the MHP.

[0015] The process of the present disclosure comprises the steps of a) washing the MHP with water to remove water-soluble sulfates, b) reducing the washed MHP with hydrogen, and c) reacting the reduced MHP with carbon monoxide to obtain nickel tetracarbonyl and a residue depleted of nickel. In step a), MHP is washed with water to remove water-soluble sulfates prior to the reduction step under H2. In some embodiments of the process, mass ratio of water to MHP is in the range of from 1 :2 to 2:1. In some embodiments of the process, washing is performed by dispersing MHP in water using a stirrer or mixer, and subsequently recovering the washed MHP by filtration. In some embodiments of the process, washing is repeated several times. In some embodiments of the process, MHP is washed until the sulfur content of the washed MHP is 5 wt% or less, relative to the dry mass of the washed MHP.

[0016] In step b), the washed MHP is subjected to a reductive heat treatment under H2 to reduce Ni2+and Co2+to Ni and Co, respectively. A temperature is chosen which is sufficient for the quantitative reduction of Ni. In some embodiments of the process, a temperature in the range of from 350°C to 500°C is chosen, e.g., 450°C. In some embodiments of the process, reaction time is in the range of from 0.5 hours to 2 hours, e.g., 1 hour. In some embodiments of the process, hydrogen flow rate is in the range of from 10 to 50 Nl / hr, e.g., 20 Nl / hr. In some embodiments of the process, sulfur content of the reduced material is 6 wt% or less, e.g., in the range of from 5.0 to 5.5 wt%, or from 4.0 to 5.0 wt%, relative to the total weight of the reduced material.

[0017] In step c), the reduced MHP is reacted with carbon monoxide to obtain nickel tetracarbonyl and a residue depleted of nickel. To recover nickel carbonyl from the reduced MHP, pressures in the range of from 1 bar to 250 bar, e.g., from 50 bar to 200 bar, or from 80 to 120bar, may be used. At low pressures, formation of nickel tetracarbonyl proceeds slower. Temperatures in the range of from 20°C to 250°C, e.g., from 40°C to 230°C, or from 90°C to 200°C, or from 120°C to 160°C, may be used to form nickel tetracarbonyl. It has been found that the formation of nickel tetracarbonyl proceeds very slowly at temperatures below 80°C, so that it is preferred to use higher temperatures. In some embodiments, the reaction time is in the range of from 1 hour to 24 hours, e.g., from 4 hours to 12 hours. In some embodiments, the flow rate of carbon monoxide is set to a value in the range of from 5 to 20 NL / h. The nickel tetracarbonyl formed is sweeped from the reactor by the flow of carbon monoxide and can be recovered from the gas stream, e.g., by condensation, or decomposed to obtain nickel metal.

[0018] In some embodiments, the nickel tetracarbonyl is oxidized in a subsequent step d) to yield nanoparticulate NiO. The nanoparticulate NiO can be used as a precursor for the production of Cathode Active Materials (CAM) for lithium-ion batteries. It is particularly interesting for the subsequent production of singlecrystal CAMs (sc-CAMs), which offer higher cycle stability than their polycrystalline counterparts.

[0019] In some embodiments, the reduced MHP is comminuted before reacting it with carbon monoxide. Since the comminution of the reduced MHP yields a more or less fine powder, it is preferable to subsequently convert the powder into a pieced form, for example by pressing, by making into a paste with a binding agent and drying, or by sintering together, so that the stream of carbon monoxide does not encounter too great a resistance during the carbonyl formation. Through these measures, dust losses are also reduced by a minimum.

[0020] Examples

[0021] The carbonylation experiments were carried out in an autoclave. 7 g of the solid feedstock were filled into two small containers (3.5 g each) consisting of sintered steel with 60 pm pore size, which were mounted to the lid of the autoclave. The set-up allowed for the following parameter ranges: T = room temperature - 200 °C, p = 1 - 200 bar, and a flow rate between 5 and 20 NL / h. The default carbonylation duration was 8 h. In a typical experiment, the gas streams would be pre-heated before entering the autoclave via an inlet and leaving it via an outlet. Feedstocks

[0022] Experiments were started with different primary feedstocks. The suitability of the set-up was tested and proven with elemental Ni in powder form. The compositions of the other feedstocks are shown in Table 1. The second feed MHP was a so-called mixed hydroxide precipitate, which is the typical intermediate after beneficiation (including leaching with H2SO4 and subsequent precipitation with NaOH) of oxidic (lateritic) Ni ores and, thus, consists predominantly of Ni(OH)2. The third feed MHPred was MHP that had been subjected to a reductive heat treatment under H2 to reduce Ni2+and Co2+to Ni and Co, respectively. A temperature of 450°C was chosen as this had proven to be sufficient for the quantitative reduction of Ni. Reaction time was 1 hour. The fourth feed MHPwash, red was MHP that had been washed with water to remove water-soluble sulfates prior to the reduction step under H2.

[0023] Sample Preparation

[0024] The MHP, which contained roughly 50% water, was first dried at T = 105 °C and p = 5 mbar for 2 h and then comminuted by grinding with mortar and pestle.

[0025] Table 1 : Elemental composition, average particle size (d50) and identified phases according to XRD of MHP.

[0026] Yield Determination

[0027] The carbonylation yields of the respective metals of interest (Ni / Co) were calculated based on the amount of metal removed from the starting material during the experiment. To this end, ICP measurements were performed on the remnant solid. XRF measurements were conducted in parallel and proved to be a valuable complementation. As XRF measurements could be carried out directly, they enabled a quick evaluation of the reaction outcome. Although of course less precise than ICP - if accuracies of ca. + / - 5% sufficed - ICP measurements could be saved.

[0028] Carbonylation of Primary Feedstocks

[0029] The elemental Ni powder (BHP Group, dso = 162 pm) could be carbonylated quantitatively in several initial experiments targeted at the verification of the suitability of the set-up. Next, the qualitative carbonylation of pre-reduced MHP (MHPred) could be shown (reaction parameters in all cases relatively mild: p = 50 bar, T = 120 °C, flow rate = 5 NL / h, t = 8 h) with Ni(CO)4 yields of around 40%.

[0030] Table 2: Ni yields (Y(Ni)) during initial experiments with the primary feedstocks at p = 50 bar, T = 120 °C, flow rate = 5 NL / h, t = 8 h.

[0031] In subsequent experiments, the fundamental reaction parameters (flow rate, pressure, and temperature) were systematically varied to investigate their influence on the Ni(CO)4 yield (Table 3).

[0032] Table 3: Reaction parameters and Ni yield of selected carbonylation experiment with reduced MHP As the initial Ni yields obtained from reduced MHP were unexpectedly low with a maximum of only 75%. The S content of reduced MHP is about 7%, but no Cu or Fe are present to bind any S. It was thus tried to reduce its S content, which can be done quite easily as the S is bound as sulfates. A certain fraction (e. g., Na2SO4 and MgSCU) is well soluble in water, so the MHP was washed prior to the necessary reduction step under H2. The S content could be reduced to roughly 65% of its initial value. As a result of washing the MHP prior to carbonylation, the Ni yield during carbonylation is reliably increased from at most 75% to up to 97%. Carbonylation experiments with washed and reduced MHP (MHPwash, red) delivered nickel yields of 94-97% (see Table 4).

[0033] Sonication-assisted washing of MHP allows for a further reduction of the S content: 45% reduction compared to 33% reduction without sonication. However, the lower S content had no influence on the Ni yield: 97% with MHPTur-wash, red vs. 97% maximum yield obtained with the conventionally washed MHPwash, red (both carbonylation experiments carried out with at: p = 200 bar, T = 200 °C, flow rate = 8 NL / h, t = 8 h).

[0034] Table 4: Reaction parameters and Ni yield of selected carbonylation experiments with washed and reduced MHP

Claims

BASF SE B25.165P-WO67056 Ludwigshafen am Rhein 12.08.2024 / lg / np / jlClaims1. A process for the production of nickel tetracarbonyl from mixed metal hydroxide precipitate (MHP) comprising nickel, cobalt, and manganese, comprising the steps of a) washing the MHP with water to remove water-soluble sulfates and obtain washed MHP, b) reducing the washed MHP with hydrogen to obtain reduced MHP, and c) reacting the reduced MHP with carbon monoxide to obtain nickel tetracarbonyl and a residue depleted of nickel.

2. The process of claim 1 , wherein the MHP is obtained by beneficiation of oxidic (lateritic) Ni ores, including leaching of the ore with H2SO4 and subsequent precipitation of MHP with NaOH.

3. The process of claim 1 or 2, wherein the MHP comprises from 34 to 55 wt% Ni, relative to the total weight of the MHP, and from 1 to 6 wt% Co, relative to the total weight of the MHP.

4. The process of any one of claims 1 to 3, wherein in step a) MHP is washed until the sulfur content of the washed MHP is 5 wt% or less, relative to the dry mass of the washed MHP.

5. The process of any one of claims 1 to 4, wherein in step b) washed MHP is subjected to a reductive heat treatment under H2 at conditions sufficient to quantitatively reduce Ni2+present in the MHP to Ni°.

6. The process of any one of claims 1 to 5, wherein step b) is conducted at a temperature in the range of from 350°C to 500°C.

7. The process of claims 1 to 6, wherein reaction time in step b) is in the range of from 0.5 hours to 2 hours.

8. The process of any one of claims 1 to 7, wherein in step c) the reduced MHP is reacted with carbon monoxide at pressures of from 1 bar to 250 bar.

9. The process of claim 8, wherein in step c) the reduced MHP is reacted with carbon monoxide at pressures of from 50 bar to 200 bar.

10. The process of any one of claims 1 to 9, wherein in step c) the reduced MHP is reacted with carbon monoxide at temperatures of from 40°C to 230°C.

11. The process of claim 10, wherein in step c) the reduced MHP is reacted with carbon monoxide at temperatures of from 120°C to 200°C.

12. The process of any one of claims 1 to 11 , wherein in step c) the reduced MHP is reacted with carbon monoxide for a time interval in the range of from 1 hour to 24 hours.

13. The process of any one of claims 1 to 12, additionally comprising a step d) of oxidizing the nickel tetracarbonyl obtained in step c) to yield nanoparticulate NiO.

14. The process of any one of claim 13, additionally comprising a step e) of using the nanoparticulate NiO obtained in step d) as a precursor for the production of Cathode Active Materials (CAM) for lithium-ion batteries.

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