CN117737405A - Resource extraction method for micro-vulcanization of ferronickel - Google Patents

Abstract

A method for resource extraction of micro-sulfided nickel iron, including the following steps: (1) Mixing and batching of nickel iron, sulfiding agent and slagging agent, and micro-sulfide smelting to obtain sulfur-containing nickel iron, slag and flue gas; (2) ) Crushing the sulfur-containing nickel iron, oxidizing acid leaching, and solid-liquid separation to obtain leachate and leaching slag; (3) Collect nickel elements from the leaching liquid; roasting the leaching slag to obtain iron phosphate. The present invention obtains sulfur-containing ferronickel through micro-sulfide smelting, which is relatively easy to crush, reducing the difficulty of processing ferronickel, and has a high utilization rate of ferronickel; it innovatively uses the oxidative acid leaching method to process sulfur-containing ferronickel to achieve high values of ferronickel. Compared with the existing technology, the present invention requires less smelting time, significantly reduces energy consumption, and the production is more environmentally friendly. The obtained products can be used to prepare batteries and provide support for the development of the new energy industry.

Description

A resource extraction method for micro-sulfidation of nickel iron

Technical field

The invention relates to a resource extraction method for nickel iron, and in particular to a resource extraction method for nickel iron sulfide.

Background technique

Nickel is a strategic metal resource that plays a vital role in national economic development and national defense construction. It is often used in the manufacture of nickel-based high-temperature alloys, high-performance stainless steel, ternary power batteries, etc. In 2022, the global mine-produced nickel metal volume will be 3.3 million tons, a year-on-year increase of 21%, and consumption will be 2.89 million tons. In the future, with the rapid development of the new energy automobile industry and the development trend of high-nickel ternary materials, the new energy industry will become a new driving force for the growth of nickel consumption.

Direct wet leaching of laterite nickel ore produces nickel sulfate and cobalt sulfate. Although the products meet the nickel and cobalt sulfate requirements for the new energy industry, approximately 100,000 tons of hazardous waste residue containing cadmium is produced for every 10,000 tons of metallic nickel extracted, which seriously harms the environment. At the same time, the content of alkaline gangue such as MgO in laterite nickel ore is high and the acid consumption is large. Laterite nickel ore produces ferronickel through high-temperature methods such as reduction smelting ferronickel, reduction-magnetic separation ferronickel, and blast furnace smelting ferronickel. The slag has stable properties and can be used in the production of building materials, realizing the resource utilization of tailings slag. In order to achieve high-value utilization of nickel-iron products, the existing nickel-iron is added with a vulcanizing agent to produce low-nickel matte. The low-nickel matte is then blown through a blowing process to produce high-nickel matte. The high-nickel matte is produced through a wet process to produce nickel sulfate. This process exists. It has shortcomings such as low iron utilization rate, high energy consumption, low sulfur utilization rate, and harsh production environment. Therefore, it is urgent to develop new processes to process nickel iron to ensure the sustainable development of the new energy industry.

Contents of the invention

The technical problem to be solved by the present invention is to overcome the above-mentioned defects existing in the prior art and provide a resource extraction method for micro-sulfidation of nickel iron with low energy consumption.

The technical solution adopted by the present invention to solve the technical problem is as follows: a resource extraction method of micro-sulfidation of nickel iron, including the following steps:

(1) Mix ferronickel, vulcanizing agent and slagging agent, and perform slight sulfide smelting to obtain sulfur-containing ferronickel, slag and flue gas;

(2) Crushing the sulfur-containing nickel iron, oxidizing and acid leaching, and solid-liquid separation to obtain leachate and leaching residue;

(3) Collect nickel element from the leaching solution; roast the leaching residue to obtain iron phosphate.

By adopting the above technical solution, the present invention extracts nickel and iron separately, realizes high-value utilization of nickel-iron, reduces the difficulty of processing nickel-iron, reduces smelting time, significantly reduces energy consumption, and makes production more environmentally friendly.

Preferably, the ferronickel contains 10-35wt% nickel element and 60-88wt% iron element.

By adopting the above technical solution, a better micro-sulfide smelting effect is achieved.

Preferably, in step (1), the vulcanizing agent is one or more of sulfur, pyrite, and gypsum slag.

By adopting the above technical solution, the difficulty of processing nickel iron is reduced. The main purpose of micro-sulfidation of nickel iron is to facilitate crushing. Nickel-iron alloy has a high hardness and is difficult to break directly.

Preferably, in step (1), the slagging agent is one or more of quartz, limestone, and dolomite.

Adding a slagging agent allows some impurities in the nickel iron to be removed during the sulfur supplementation process. By adopting the above technical solution, the impurity removal pressure of the subsequent wet method can be reduced.

Preferably, in step (1), the added amount of the vulcanizing agent is 2-10% of the mass of ferronickel.

By adopting the above technical solution, the sulfur-containing nickel iron obtained by micro-sulfide smelting has a suitable sulfur content (for example, 2-5% is feasible), which facilitates subsequent crushing and extraction.

Preferably, in step (1), the added amount of the slagging agent is 2-8% of the mass of ferronickel.

By adopting the above technical solution, the impurity removal effect is good.

Preferably, in step (1), the micro-vulcanization smelting temperature is 1400-1500°C and the time is 1-4 hours.

By adopting the above technical solution, a better micro-sulfide smelting effect is achieved.

Preferably, in step (2), the sulfur-containing ferronickel is crushed to a particle size less than 0.074 mm.

By adopting the above technical solution, the subsequent oxidative acid leaching operation is facilitated.

Preferably, in step (2), during the oxidative acid leaching process, the crushed sulfur-containing nickel iron is leached in phosphoric acid under the condition of introducing oxygen;

Based on the difference in phosphate solubility, by adopting the above technical solution, during the leaching process, Fe ³⁺ reacts with PO ₄ ^3- to generate iron phosphate, while Ni ²⁺ and Co ²⁺ are in the solution, thus achieving the priority of Ni/Co over Selective leaching of Fe.

More preferably, in step (2), the oxygen introduction rate is: 400-1000L/min per ton of sulfur-containing nickel iron.

By adopting the above technical solution, a better oxidative acid leaching effect is achieved.

More preferably, in step (2), the concentration of the phosphoric acid is 8-20 mol/L, and the liquid-solid ratio of the phosphoric acid used to the sulfur-containing nickel iron is 0.5-6 mL/g.

By adopting the above technical solution, a better oxidative acid leaching effect is achieved.

Preferably, the leachate is removed with sulfuric acid, and nickel sulfate is obtained after extraction.

The extraction can adopt common extraction methods in the prior art, and the purpose is to extract Ni ³⁺ in the leachate. By adopting the above technical solution, nickel sulfate products can be obtained. The iron content in the obtained nickel sulfate is less than 0.001g/L.

More preferably, the concentration of sulfuric acid is 0.5-12 mol/L.

By adopting the above technical solution, a better impurity removal effect is achieved.

More preferably, the weight ratio of sulfuric acid to leachate is 1:4-20.

By adopting the above technical solution, a better impurity removal effect is achieved.

Preferably, in step (3), the roasting is performed under an inert atmosphere.

In an inert atmosphere, product oxidation can be avoided. By adopting the above technical solution, the decrease in product purity during roasting can be avoided.

Preferably, in step (3), the calcination temperature is 100-120° C. and the calcination time is 1-5 h.

The purpose of roasting is to remove moisture. After roasting, the crystal water in FePO ₄ ·2H ₂ O is removed to obtain FePO ₄ . By adopting the above technical solution, the roasting effect is good.

The iron phosphate product obtained by the invention contains 36.1%-36.9% iron and 20.52%-20.98% phosphorus.

The main chemical reactions involved in nickel-iron in step (1) of the present invention are as follows:

Ni+S ₂ (g)→Ni ₃ S ₂ (1.1)

Fe+S ₂ (g)→FeS (1.2)

Ni+FeS ₂ →Ni ₃ S ₂ +FeS (1.3)

The main components of the slag produced in step (1) are iron-silicon slag, namely FeO and SiO ₂ ; the flue gas is mainly SO ₂ , N ₂ , O ₂ , etc.

The main chemical reactions that occur in step (2) oxidative acid leaching are as follows:

Ni ₃ S ₂ +O ₂ (g)→NiO+SO ₂ (g) (1.4)

NiO+H ⁺ →Ni ³⁺ +H ₂ O (1.5)

Fe ₂ O ₃ +H ⁺ →Fe ³⁺ +H ₂ O (1.6)

Fe ³⁺ +PO ₄ ^3- +2H ₂ O→FePO ₄ ·2H ₂ O (1.7)

After solid-liquid separation, Ni ³⁺ enters the obtained leaching solution; the leaching residue mainly contains FePO ₄ ·2H ₂ O. FePO ₄ can be obtained after roasting.

Compared with the prior art, the advantages of the present invention are:

1. The present invention obtains sulfur-containing ferronickel that is relatively easy to crush through micro-sulfide smelting, thereby reducing the difficulty of processing ferronickel and achieving a high utilization rate of ferronickel;

2. The present invention innovatively uses oxidative acid leaching to treat sulfur-containing nickel iron to achieve high-value utilization of nickel iron;

3. Compared with the existing technology, the present invention requires less smelting time, significantly reduces energy consumption, and makes production more environmentally friendly;

4. The present invention extracts nickel and iron separately, and the obtained products can be used to prepare batteries, opening up a new technological path from nickel-iron to the new energy industry, and providing support for the development of the new energy industry.

Description of drawings

Figure 1 is a process flow chart of the resource extraction method of nickel iron microsulfidation in Examples 1 to 3 of the present invention.

Detailed ways

In order to facilitate understanding of the present invention, the present invention will be described more comprehensively and in detail below with reference to the accompanying drawings and preferred embodiments. However, the protection scope of the present invention is not limited to the following specific embodiments.

Unless otherwise defined, all technical terms used below have the same meanings as commonly understood by those skilled in the art. The technical terms used herein are only for the purpose of describing specific embodiments and are not intended to limit the scope of the present invention.

Unless otherwise specified, various raw materials, reagents, instruments and equipment used in the present invention can be purchased in the market or prepared by existing methods.

Example 1

The ferronickel used in this embodiment contains: 25.1wt% nickel element and 73.5wt% iron element.

The resource extraction method of micro-sulfidation of nickel iron in this embodiment, the process is shown in Figure 1, including the following steps:

(1) Mix 1kg of ferronickel, 5% vulcanizing agent (referring to 5% of the mass of ferronickel, the same below) and 4% slagging agent, and smelt slightly at 1500°C for 2.5h to obtain sulfur-containing nickel containing 2.5% sulfur. Iron, slag and flue gas; the vulcanizing agent is sulfur; the slagging agent is quartz;

(2) Crush the sulfur-containing nickel iron to a particle size less than 0.074mm, and leach it in phosphoric acid under the condition of introducing oxygen. The oxygen introduction rate is: 450L/min per ton of sulfur-containing nickel iron; the phosphoric acid The concentration is 13 mol/L, and the liquid-to-solid ratio of the phosphoric acid used and sulfur-containing nickel iron is 1.9 mL/g; filter to obtain the leachate and leach residue;

(3) Use sulfuric acid to remove impurities from the leachate, and obtain nickel sulfate after extraction with P507; the concentration of sulfuric acid is 10 mol/L, and the weight ratio of sulfuric acid to leachate is 1:20; the leaching residue is roasted under a nitrogen atmosphere to obtain phosphoric acid Iron, the roasting temperature is 120℃, and the roasting time is 3h.

After testing, the obtained nickel sulfate product contained iron 0.00098g/L, and the obtained iron phosphate product contained 36.5% iron and 20.67% phosphorus.

Example 2

The ferronickel used in this embodiment contains: 25.1wt% nickel element and 73.5wt% iron element.

The resource extraction method of micro-sulfidation of nickel iron in this embodiment, the process is shown in Figure 1, including the following steps:

(1) Mix 1kg of ferronickel, 5% vulcanizing agent (referring to 5% of the mass of ferronickel, the same below) and 4.5% slagging agent, and smelt at 1500°C for 2.5 hours to obtain sulfur-containing nickel containing 2.47% sulfur. Iron, slag and flue gas; the vulcanizing agent is sulfur; the slagging agent is quartz;

(2) Crush the sulfur-containing nickel iron to a particle size less than 0.074mm, and leach it in phosphoric acid under the condition of introducing oxygen. The oxygen introduction rate is: 450L/min per ton of sulfur-containing nickel iron; the phosphoric acid The concentration is 13 mol/L, and the liquid-to-solid ratio of the phosphoric acid used and sulfur-containing nickel iron is 1.9 mL/g; filter to obtain the leachate and leach residue;

(3) Use sulfuric acid to remove impurities from the leachate, and obtain nickel sulfate after extraction with P507; the concentration of sulfuric acid is 1 mol/L, and the weight ratio of sulfuric acid to leachate is 1:10; the leaching residue is roasted under a nitrogen atmosphere to obtain phosphoric acid Iron, the roasting temperature is 120℃, and the roasting time is 3h.

After testing, the obtained nickel sulfate product contained iron 0.00096g/L, and the obtained iron phosphate product contained 36.48% iron and 20.63% phosphorus.

Example 3

The ferronickel used in this embodiment contains: 25.1wt% nickel element and 73.5wt% iron element.

The resource extraction method of micro-sulfidation of nickel iron in this embodiment, the process is shown in Figure 1, including the following steps:

(1) Mix 1kg of ferronickel, 5% vulcanizing agent (referring to 5% of the mass of ferronickel, the same below) and 4% slagging agent, and smelt slightly at 1500°C for 2.5h to obtain sulfur-containing nickel containing 2.5% sulfur. Iron, slag and flue gas; the vulcanizing agent is sulfur; the slagging agent is quartz;

(2) Crushing the sulfur-containing nickel iron to a particle size less than 0.074mm, and leaching it in phosphoric acid under the condition of introducing oxygen. The oxygen introduction rate is: 550L/min per ton of sulfur-containing nickel iron; the phosphoric acid The concentration is 12.5 mol/L, and the liquid-to-solid ratio of the phosphoric acid used and sulfur-containing nickel iron is 2.0 mL/g; filter to obtain the leachate and leach residue;

(3) Use sulfuric acid to remove impurities from the leachate, and obtain nickel sulfate after extraction with P507; the concentration of sulfuric acid is 5mol/L, and the weight ratio of sulfuric acid to leachate is 1:5; the leaching residue is roasted in a nitrogen atmosphere to obtain phosphoric acid Iron, the roasting temperature is 120℃, and the roasting time is 3h.

After testing, the obtained nickel sulfate product contained iron 0.00089g/L, and the obtained iron phosphate product contained 36.59% iron and 20.59% phosphorus.

Claims (10)

1. A resource extraction method for micro-sulfidation of nickel iron, which is characterized in that it includes the following steps: (1) Mixing nickel iron, a sulfiding agent and a slag-forming agent, and smelting them under slight sulfidation to obtain sulfur-containing nickel iron, slag and flue gas; (2) Crushing the sulfur-containing nickel iron, oxidizing and acid leaching, and solid-liquid separation to obtain leachate and leaching residue; (3) Collect nickel element from the leaching solution; roast the leaching residue to obtain iron phosphate. 2. The resource extraction method of micro-sulfide ferronickel according to claim 1, characterized in that the ferronickel contains 10-35wt% nickel element and 60-88wt% iron element. 3. The resource extraction method of micro-sulfidation of nickel iron according to claim 1 or 2, characterized in that in step (1), the vulcanizing agent is one or two of sulfur, pyrite, and gypsum slag. Above; the slagging agent is one or more of quartz, limestone and dolomite. 4. The resource extraction method of micro-sulfidation of ferronickel according to any one of claims 1 to 3, characterized in that in step (1), the addition amount of the vulcanizing agent is 2-10 of the mass of ferronickel. %; the addition amount of the slagging agent is 2-8% of the mass of nickel iron. 5. The resource extraction method of micro-sulfide nickel iron according to any one of claims 1 to 4, characterized in that in step (1), the temperature of the micro-sulfide smelting is 1400-1500°C, and the time is 1-4h. 6. The resource extraction method of micro-sulfide ferronickel according to any one of claims 1 to 5, characterized in that in step (2), the sulfur-containing ferronickel is crushed to a particle size of less than 0.074mm; During the oxidative acid leaching process, the crushed sulfur-containing nickel iron is leached in phosphoric acid under the condition of introducing oxygen. 7. The resource extraction method of micro-sulfide nickel iron according to claim 6, characterized in that in step (2), the oxygen introduction rate is: 400-1000L/min per ton of sulfur-containing nickel iron; The concentration of the phosphoric acid is 8-20 mol/L, and the liquid-to-solid ratio of the phosphoric acid used to the sulfur-containing nickel iron is 0.5-6 mL/g. 8. The resource extraction method of micro-sulfidation of nickel iron according to any one of claims 1 to 7, characterized in that the leachate is impurity removed with sulfuric acid, and nickel sulfate is obtained after extraction. 9. The resource extraction method of micro-sulfidation of nickel iron according to claim 8, characterized in that the concentration of the sulfuric acid is 0.5-12 mol/L; the weight ratio of the sulfuric acid and the leachate is 1:4~20. 10. The resource extraction method of micro-sulfide nickel iron according to any one of claims 1 to 9, characterized in that in step (3), the roasting is carried out under an inert atmosphere; the roasting temperature is 100- 120℃, roasting time is 1-5h.