Carbonylation of mhp

Abstract

The present disclosure relates to the production of nickel tetracarbonyl and cobalt tetracarbonyl hydride from mixed metal hydroxide precipitate (MHP) comprising nickel, cobalt, and manganese.

Description

[0001] BASF SE B25.144P-WO

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

[0003] Carbonylation of MHP

[0004] Field of the invention

[0005] This invention relates to the production of nickel tetracarbonyl and cobalt tetracarbonyl hydride from mixed metal hydroxide precipitate (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 iron-aluminium 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] Summary of the invention

[0009] The present disclosure provides a process for the production of nickel tetracarbonyl and cobalt tetracarbonyl hydride from mixed metal hydroxide precipitates (MHP) comprising nickel, cobalt, and manganese.

[0010] 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 a mixture of carbon monoxide and hydrogen to obtain nickel tetracarbonyl, cobalt tetracarbonyl hydride, and a residue depleted of nickel and cobalt.

[0011] Detailed description

[0012] The present disclosure provides a process for the production of nickel tetracarbonyl and cobalt tetracarbonyl hydride 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 a mixture of carbon monoxide and hydrogen to obtain nickel tetracarbonyl, cobalt tetracarbonyl hydride, and a residue depleted of nickel and cobalt.

[0013] 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.

[0014] 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 a mixture of carbon monoxide and hydrogen to obtain nickel tetracarbonyl, cobalt tetracarbonyl hydride, and a residue depleted of nickel and cobalt.

[0015] 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 a mixture of carbon monoxide and hydrogen to obtain nickel tetracarbonyl, cobalt tetracarbonyl hydride, and a residue depleted of nickel and cobalt. To recover nickel carbonyl and cobalt tetracarbonyl hydride from the reduced MHP, pressures in the range of from 1 bar to 250 bar, e.g. from 50 bar to 200 bar, may be used. At low pressures, formation of nickel tetracarbonyl and cobalt tetracarbonyl hydride 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 may be used to form nickel tetracarbonyl and cobalt tetracarbonyl hydride. It has been found that the formation of nickel tetracarbonyl and cobalt tetracarbonyl hydride proceeds very slowly at temperatures below 80°C, so that it is preferred to use higher temperatures.

[0018] 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.

[0019] The mixture of carbon monoxide and hydrogen comprises from 65 to 99.9 vol% carbon monoxide and from 0.1 to 35 vol% hydrogen. In some embodiments of the process, mixture of carbon monoxide and hydrogen comprises from 90 to 99.8 vol% carbon monoxide and from 0.2 to 10 vol% hydrogen. In some embodiments of the process, mixture of carbon monoxide and hydrogen comprises from 95 to 99.7 vol% carbon monoxide and from 0.3 to 5 vol% hydrogen.

[0020] In a particular embodiment of the process, the reduced MHP is reacted with a gas mixture containing 99.6 vol% to 99.7 vol% carbon dioxide and 0.3 vol% to 0.4 vol% hydrogen at a pressure of from 10 bar to 200 bar, e.g., from 80 bar to 200 bar, for instance, from 120 bar to 200 bar, or from 80 bar to 120 bar, and at a temperature in the range of from 80°C to 200°C, e.g., from 80°C to 160°C, or from 160°C to 200°C, for a time period of from 2 hrs to 48 hrs, e.g., from 6 hrs to 24 hrs, or from 8 hrs to 12 hrs.

[0021] The nickel tetracarbonyl and cobalt tetracarbonyl hydride formed are swept from the reactor by the gas flow and can be recovered from the gas stream, e.g., by condensation.

[0022] According to litterature, the production of Co2(CO)s or HCo(CO)4 requires gas pressures of about 300 bar. We have found that significant cobalt carbonylation rates can be achieved under much milder conditions when MHPwash.red is used as starting material. The process of the present disclosure allows for recovering both nickel and cobalt from MHP comprising nickel, cobalt, and manganese. In some embodiments, the reduced MHP is comminuted before reacting it with the mixture of carbon monoxide and hydrogen. 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 gas stream does not encounter too great a resistance during the carbonyl formation By these measures, dust losses are also reduced by a minimum.

[0023] Examples

[0024] 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.

[0025] Feedstocks

[0026] Experiments were conducted with different feedstocks. The first 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 second feed MHPwash, red was MHP that had been washed with water to remove water-soluble sulfates prior to the reduction step under H2. The composition of the feedstocks is shown in Table 1 .

[0027] Sample Preparation

[0028] 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. Table 1 : Elemental composition, average particle size (d50) and identified phases according to XRD of MHP.

[0029] Yield Determination

[0030] 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 which proved to be a valuable complementation. XRF measurements 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.

[0031] In the experiments, the fundamental reaction parameters (flow rate, pressure, and temperature) were systematically varied to investigate their influence on the yield of Ni(CO)4 and HCo(CO)4. The results are shown in Table 2.

[0032] The Ni yields obtained from MHPred (Example 10) 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 reduction and 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 2). 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 MH Pwash, red (both carbonylation experiments carried out with at: p = 200 bar, T = 200 °C, flow rate = 8 NL / h, t = 8 h).

[0033] Table 2: Reaction parameters and yields of selected carbonylation experiments with washed and reduced MHP comparative example

Claims

BASF SE B25.144P-WO67056 Ludwigshafen am Rhein 12.08.2025 / lg / np / jlClaims1 . A process for the production of nickel tetracarbonyl and cobalt tetracarbonyl hydride 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 a gas mixture comprising from 65 vol% to 99.9 vol% carbon monoxide and from 0.1 vol% to 35 vol% hydrogen to obtain nickel tetracarbonyl, cobalt tetracarbonyl hydride, and a residue depleted of nickel and cobalt.

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 a mixture of carbon monoxide and hydrogen 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 a mixture of carbon monoxide and hydrogen at pressures of from 10 bar to 200 bar.

10. The process of claim 9, wherein in step c) the reduced MHP is reacted with a mixture of carbon monoxide and hydrogen at pressures of from 50 bar to 120 bar.

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

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

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

14. The process of any one of claims 1 to 13, wherein in step c) the gas mixture contains from 99.6 vol% to 99.7 vol% carbon monoxide and from 0.3 vol% to 0.4 vol% hydrogen.

15. The process of claim 14, wherein in step c) the reduced MHP is reacted with the gas mixture at a total pressure in the range of from 80 bar to 200 bar, and at a temperature in the range of from 120°C to 200°C.

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