METHOD FOR PREPARING NICKEL SULFATE FROM FERRONICKEL

Abstract

The present disclosure discloses a method for preparing nickel sulfate from ferronickel, including: S1: in a high-pressure oxygen environment, mixing crushed ferronickel with sulfuric acid, introducing a carbon monoxide gas to allow a reaction, and conducting solid-liquid separation (SLS) to obtain a filtrate and a filter residue; S2: adding an oxidizing agent and a precipitating agent successively to the filtrate, controlling a pH of the filtrate, and conducting SLS to obtain a nickel-containing filtrate and an iron hydroxide precipitate; and S3: subjecting the nickel-containing filtrate to extraction and back-extraction to obtain a nickel sulfate solution. In the present disclosure, the carbon monoxide gas is introduced under high-pressure acidic conditions to first react with nickel and iron to form nickel tetracarbonyl and iron pentacarbonyl, and the nickel tetracarbonyl and iron pentacarbonyl are oxidized by oxygen and then smoothly react with sulfuric acid to form nickel sulfate and iron sulfate.

Claims

1. A method for preparing nickel sulfate from ferronickel, comprising the following steps: S1: in a high-pressure oxygen environment, mixing crushed ferronickel with sulfuric acid, introducing a carbon monoxide gas to allow a reaction, and conducting solid-liquid separation to obtain a filtrate and a filter residue, the reaction is conducted in a closed space, the carbon monoxide gas is introduced through a bottom of the crushed ferronickel, and a volume concentration of the carbon monoxide gas in the closed space is controlled at 2.5%; the reaction is conducted at 40 C. to 200 C.; the sulfuric acid has a concentration of 3 mol/L to 8 mol/L; S2:adding an oxidizing agent to the filtrate, and then adding a precipitating agent, controlling a pH of the filtrate, and conducting solid-liquid separation to obtain a nickel-containing filtrate and an iron hydroxide precipitate; and S3: subjecting the nickel-containing filtrate to extraction and back-extraction to obtain a nickel sulfate solution; a process of the extraction and back-extraction comprises: adding an extracting agent to the nickel-containing filtrate for nickel extraction to obtain a nickel-containing organic phase, and adding a sulfuric acid solution to the nickel-containing organic phase for nickel back-extraction to obtain the nickel sulfate solution; the extracting agent is one or more selected from the group consisting of P204, P507, DEHPA, and Cyanex272.

2. The method according to claim 1, wherein in S1, the reaction is conducted at a pressure of 3.0 MPa to 6.5 MPa.

3. The method according to claim 1, wherein in S2, the oxidizing agent is one or more selected from the group consisting of hydrogen peroxide, compressed air, chlorine, and sodium chlorate.

4. The method according to claim 1, wherein in S2, the precipitating agent is one or more selected from the group consisting of ammonia water, sodium hydroxide, sodium carbonate, and sodium bicarbonate.

5. The method according to claim 1, wherein in S2, the pH is 3 to 3.5.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0030] The present disclosure is further described below with reference to accompanying drawings and examples.

[0031] The sole FIGURE is a schematic diagram illustrating a process flow of Example 1 of the present disclosure.

DETAILED DESCRIPTION OF ILLUSTRATED EXAMPLES

[0032] The concepts and technical effects of the present disclosure are clearly and completely described below in conjunction with examples, so as to allow the objectives, features and effects of the present disclosure to be fully understood. Apparently, the described examples are merely some rather than all of the examples of the present disclosure. All other examples obtained by those skilled in the art based on the examples of the present disclosure without creative efforts should fall within the protection scope of the present disclosure.

EXAMPLE 1

[0033] In this example, nickel sulfate was prepared from ferronickel. The ferronickel had the following composition: nickel: 16.79%, iron: 75.10%, silicon: 1.96%, carbon: 1.46%, sulfur: and chromium: 0.24%. As shown in the sole figure, a specific preparation process was as follows: [0034] (1) Raw material pretreatment: 100 g of ferronickel was crushed into a powdery or granular material. [0035] (2) Catalytic oxidation: In a closed high-pressure oxygen environment, the crushed material obtained in step (1) was subjected to acid-leaching with sulfuric acid, and a carbon monoxide gas was introduced from a bottom of the crushed material to catalyze a reaction, where a volume concentration of the carbon monoxide gas in the closed space was controlled at 2.5%, the reaction was conducted at 40 C. to 50 C. and 6.5 Mpa for 3.5 h, and the sulfuric acid had a concentration of 3 mol/L. [0036] (3) Filtration: After the reaction in step (2) was completed, SLS was conducted to obtain a filtrate and a filter residue. [0037] (4) Precipitation: Hydrogen peroxide was added to the filtrate obtained in step (3) to oxidize ferrous iron in the filtrate, then ammonia water was added, and a pH of the filtrate was controlled at 3 to 3.5; and a resulting mixture was filtered to obtain a nickel-containing filtrate and an iron hydroxide precipitate, and the iron hydroxide precipitate was washed and heated to obtain iron red. [0038] (5) Extraction: An extracting agent P204 was added to the nickel-containing filtrate collected in step (4) for nickel extraction, a resulting mixture was settled into layers, and the layers were separated to obtain a nickel-containing organic phase and an impurity-containing raffinate. [0039] (6) Back-extraction: A 3 mol/L H.sub.2SO.sub.4 solution was added to the nickel-containing organic phase obtained in step (5) for nickel back-extraction to obtain a battery-grade nickel sulfate solution.

[0040] As determined, 71.32 g of iron red (calculated based on iron) and 16.73 g of nickel sulfate (calculated based on nickel) were obtained, indicating an iron leaching rate of 94.97% and a nickel leaching rate of 99.64%.

EXAMPLE 2

[0041] In this example, nickel sulfate was prepared from ferronickel. The ferronickel had the following composition: nickel: 18.22%, iron: 72.03%, silicon: 1.85%, carbon: 1.41%, sulfur: 0.362%, and chromium: 0.12%. A specific preparation process was as follows: [0042] (1) Raw material pretreatment: 100 g of ferronickel was crushed into a powdery or granular material. [0043] (2) Catalytic oxidation: In a closed high-pressure oxygen environment, the crushed material obtained in step (1) was subjected to acid-leaching with sulfuric acid, and a carbon monoxide gas was introduced from a bottom of the crushed material to catalyze a reaction, where a volume concentration of the carbon monoxide gas in the closed space was controlled at 2.5%, the reaction was conducted at 100 C. to 120 C. and 4.5 Mpa for 2.5 h, and the sulfuric acid had a concentration of 8 mol/L. [0044] (3) Filtration: After the reaction in step (2) was completed, SLS was conducted to obtain a filtrate and a filter residue. [0045] (4) Precipitation: Chlorine was introduced into the filtrate obtained in step (3) to oxidize ferrous iron in the filtrate, then sodium hydroxide was added, and a pH of the filtrate was controlled at 3 to 3.5; and a resulting mixture was filtered to obtain a nickel-containing filtrate and an iron hydroxide precipitate, and the iron hydroxide precipitate was washed and heated to obtain iron red. [0046] (5) Extraction: An extracting agent P507 was added to the nickel-containing filtrate collected in step (4) for nickel extraction, a resulting mixture was settled into layers, and the layers were separated to obtain a nickel-containing organic phase and an impurity-containing raffinate. [0047] (6) Back-extraction: A 4 mol/L H.sub.2SO.sub.4 solution was added to the nickel-containing organic phase obtained in step (5) for nickel back-extraction to obtain a battery-grade nickel sulfate solution.

[0048] As determined, 65.47 g of iron red (calculated based on iron) and 18.10 g of nickel sulfate (calculated based on nickel) were obtained, indicating an iron leaching rate of 90.89% and a nickel leaching rate of 99.34%.

EXAMPLE 3

[0049] In this example, nickel sulfate was prepared from ferronickel. The ferronickel had the following composition: nickel: 18.77%, iron: 71.65%, silicon: 0.94%, carbon: 2.21%, sulfur: 0.136%, and chromium: 0.61%. A specific preparation process was as follows:

[0050] (1) Raw material pretreatment: 100 g of ferronickel was crushed into a powdery or granular material.

[0051] (2) Catalytic oxidation: In a closed high-pressure oxygen environment, the crushed material obtained in step (1) was subjected to acid-leaching with sulfuric acid, and a carbon monoxide gas was introduced from a bottom of the crushed material to catalyze a reaction, where a volume concentration of the carbon monoxide gas in the closed space was controlled at <2.5%, the reaction was conducted at 150 C. to 200 C. and 3 Mpa for 1 h, and the sulfuric acid had a concentration of 5 mol/L.

[0052] (3) Filtration: After the reaction in step (2) was completed, SLS was conducted to obtain a filtrate and a filter residue.

[0053] (4) Precipitation: Sodium chlorate was added to the filtrate obtained in step (3) to oxidize ferrous iron in the filtrate, then sodium carbonate was added, and a pH of the filtrate was controlled at 3 to 3.5; and a resulting mixture was filtered to obtain a nickel-containing filtrate and an iron hydroxide precipitate, and the iron hydroxide precipitate was washed and heated to obtain iron red.

[0054] (5) Extraction: An extracting agent DEHPA was added to the nickel-containing filtrate collected in step (4) for nickel extraction, a resulting mixture was settled into layers, and the layers were separated to obtain a nickel-containing organic phase and an impurity-containing raffinate.

[0055] (6) Back-extraction: A 5 mol/L H2504 solution was added to the nickel-containing organic phase obtained in step (5) for nickel back-extraction to obtain a battery-grade nickel sulfate solution.

[0056] As determined, 66.72 g of iron red (calculated based on iron) and 18.65 g of nickel sulfate (calculated based on nickel) were obtained, indicating an iron leaching rate of 93.12% and a nickel leaching rate of 99.36%.

[0057] The present disclosure is described in detail with reference to the accompanying drawings and examples, but the present disclosure is not limited to the above examples. Within the scope of knowledge possessed by those of ordinary skill in the technical field, various changes can also be made without departing from the purpose of the present disclosure. In addition, the examples in the present disclosure or features in the examples may be combined with each other in a non-conflicting situation.