PROCESS FOR PRECIPITATING A MIXED CARBONATE OR MIXED (OXY)HYDROXIDE

Abstract

Process for precipitating a mixed carbonate or mixed (oxy)hydroxide comprising nickel from an aqueous solution comprising a nickel salt, wherein such process is carried out in a vessel comprising (A) a vessel body, (B) one or more elements selected from draft tubes and guide vanes, (C) at least one stirrer whose pressure zone is in or between element(s) (B), and wherein the process comprises the step of simultaneously adding said solution comprising a nickel salt in or between element(s) (B) and a solution of alkali metal carbonate or hydroxide in or between or outside element(s) (B).

Claims

1-10. (canceled)

11. A process for precipitating a mixed carbonate or mixed (oxy)hydroxide comprising nickel from an aqueous solution comprising a nickel salt and at least one more transition metal chosen from manganese and cobalt salts, wherein the process is carried out in a vessel comprising: (A) a vessel body, (B) one or more elements chosen from draft tubes and guide vanes, and (C) at least one stirrer having a pressure zone in or between the one or more elements (B), wherein the process comprises simultaneously adding the solution comprising a nickel salt in or between the one or more elements (B) and a solution of alkali metal carbonate or hydroxide in or between or outside the one or more elements (B).

12. The process according to claim 11, wherein the vessel comprises two stirrers (C) and each have a pressure zone located in or between the one or more elements (B).

13. The process according to claim 11, wherein the at least one stirrer has stirrer elements chosen from pitch blade turbines, propellers, and hydrofoils.

14. The process according to claim 11, wherein the one or more elements (B) are mounted to an internal surface of the vessel.

15. The process according to claim 11, wherein the one or more elements (B) are mounted between the vessel lid and the vessel side walls.

16. The process according to claim 11, wherein the vessel is a tank reactor.

17. The process according to claim 1, wherein the vessel further comprises: (D) a solid-liquid separation device in which mother liquor is withdrawn from the slurry formed in the process.

18. The process according to claim 11, wherein the process is a process for precipitating a mixed hydroxide or oxyhydroxide comprising at least two different transition metals chosen from nickel, cobalt and manganese with an average particle diameter (D50) ranging from 3 μm to 16 μm.

19. The process according to claim 11, wherein the process is a process for precipitating a mixed carbonate comprising at least two different transition metals chosen from nickel, cobalt and manganese with an average particle diameter (D50) ranging from 3 μm to 16 μm.

20. The process according to claim 11, wherein the process is a continuous process.

Description

BRIEF DESCRIPTION OF THE DRAWING:

[0092] A: vessel body

[0093] B.1: a draft tube

[0094] B.2: baffles

[0095] C: stirrer element

[0096] D: Inlet pipes for dosing outside the draft tube

[0097] E: inlet pipes for dosing into the pressure zone

[0098] F: engine for stirrer

[0099] The drawing is a conceptual one. In the drawing, further details have been omitted for simplification matters.

Working Example 1

[0100] A 50 L stirred vessel in accordance with FIG. 1 is charged with an aqueous solution of (NH.sub.4).sub.2SO.sub.4, 25 g of per kg of solution. The vessel body (A) of the vessel is equipped with baffles (B.2), a draft tube (B.1) and two propeller elements (C) with a diameter of 0.165 m and placed below the draft tube (diameter 0.23 m).

[0101] The temperature of the vessel volume is set to 45° C. The stirrer element is activated and constantly operated at 500 rounds per minute (“rpm”, ˜2.7 Watt/I). An aqueous solution containing NiSO.sub.4, CoSO.sub.4 and MnSO.sub.4 (molar ratio 6:2:2, total metal concentration: 1.65 mol/kg), an aqueous solution containing sodium hydroxide (25 wt % NaOH) and aqueous ammonia solution (25 wt % ammonia) are simultaneously introduced through different feeds into the vessel. The aqueous solution containing nickel, cobalt and manganese is fed through inlet pipes E. The molar ratio ammonia to transition metals is 0.2. The sum of volume flows is set to adjust the mean residence time to 8 hours. The flow rate of the NaOH is adjusted by a pH regulation circuit to keep the pH value at a constant value of 12.05. The apparatus is operated continuously keeping the liquid level in the reaction vessel constant. A mixed hydroxide of Ni, Co and Mn is collected via free overflow from the vessel. The resulting product slurry contains about 120 g/l hydroxide precursor with an average particle diameter (D50) of 6 μm. The hydroxide precursor is excellently suited as precursor for a lithium ion battery cathode active material, and the through-put is high.

Working Example 2

[0102] The protocol of Working Example 1 is repeated with the following modification: the rotation speed of the Rushton turbine stirrer is set to 300 rpm (˜0.6 Watt/I). The resulting slurry contains about 120 g/l hydroxide precursor with an average particle diameter (D50) of 7 μm. The hydroxide precursor is excellently suited as precursor for a lithium ion battery cathode active material.