A method for producing high nickel matte from ferronickel

Abstract

The invention discloses a method for producing high-nickel matte from ferronickel, wherein ferronickel particles are mixed with quartz for oxidative roasting to obtain a mixed melt containing nickel iron oxide and nickel iron silicate, the mixed melt is granulated and crushed, magnetic separation is performed to obtain magnetic concentrate and magnetic tailings, the magnetic concentrate is reduced and roasted to obtain foamed nickel iron, and the foamed nickel iron is mixed with sulfur for sulfidation roasting to obtain high-nickel matte. The invention generates nickel iron oxide with high nickel content and nickel iron silicate with high iron content by oxidative roasting of ferronickel and quartz, separates nickel iron oxide and nickel iron silicate by magnetic separation, generates foamed nickel iron by reduction roasting of the magnetic concentrate, and performs sulfidation reaction with the foamed nickel iron to generate high-nickel matte, the foamed nickel iron is more easily sulfided, the required temperature is much lower than the temperature of sulphur supplementation after ferronickel melting, the sulphur utilization rate reaches more than 80%, and the process is easier to control, and the cost is greatly reduced.

Description

Technical Field

[0001] The invention belongs to the technical field of high-nickel matte production, and in particular relates to a method for producing high-nickel matte from ferronickel. Background Art

[0002] Nickel is an important strategic metal. With the expansion of the new energy vehicle market, the demand for nickel is increasing. High-grade nickel ore resources are no longer sufficient to supply the entire market, but high-density, high-range and high-nickel batteries are the development direction of mainstream car companies. In the context of the nickel resource gap, it is necessary to vigorously expand the utilization boundaries of nickel resources and develop corresponding smelting processes.

[0003] At present, nickel-iron sulfidation has not been put into production in China, but there are nickel-iron sulfidation represented by Eramet SLN abroad. The nickel-iron sulfidation process of SLN is to add a converter after the production of nickel-iron, and the converter sulfidates the nickel-iron to obtain low-grade nickel matte, and then obtains high-grade nickel matte after multiple sulfidation. This process belongs to the post-sulfurization process and is currently used by Tsingshan. At present, the main idea of ​​ferronickel sulfidation in China is as follows: Related technologies disclose a process for producing high nickel matte from ferronickel blocks, wherein ferronickel blocks are sent to an electric arc furnace for smelting, and the molten ferronickel water is sent to a converter for sulfidation and blowing. During the sulfidation and blowing process, liquid sulfur and quartz flux are added to the converter. After ferronickel sulfidation forms nickel sulfide and ferrous sulfide, the iron element is first oxidized and combined with quartz to form iron olivine. Finally, molten high nickel matte melt remains in the furnace, and the high nickel matte melt is granulated by water quenching to form high nickel matte particles. This patent has high operating requirements, and the transportation and use of liquid sulfur are relatively troublesome. The high-temperature smelting of electric furnaces and converters has high energy consumption, low sulfur utilization rate, and great environmental pressure. Related technologies also disclose a method for preparing nickel matte from ferronickel and gypsum, wherein gypsum, liquid ferronickel and flux are added to a sulfidation furnace for smelting and producing nickel matte, but this method is for producing low-grade nickel matte, and the sulfur utilization rate is low.

[0004] In summary, the current process generally has the problem of low utilization rate of vulcanizing agent, which is due to the inevitable loss of sulfur in the converter blowing process. Blowing and vulcanizing is actually a process of oxidation smelting and vulcanizing at the same time, and this process has huge contradictions. Desulfurization and sulfur supplementation at the same time lead to excessive waste of vulcanizing agent and low utilization rate. Summary of the invention

[0005] The present invention aims to solve at least one of the technical problems existing in the above-mentioned prior art. To this end, the present invention provides a method for producing high-nickel matte from ferronickel, which can greatly improve the utilization rate of the sulfiding agent.

[0006] According to one aspect of the present invention, a method for producing high-nickel matte from ferronickel is provided, comprising the following steps:

[0007] S1: mixing nickel-iron particles with quartz, and performing oxidation roasting to obtain a mixed melt containing nickel-iron oxide and nickel-iron silicate;

[0008] S2: granulating and crushing the mixed melt, and magnetically separating the obtained crushed material to obtain magnetic separation concentrate and magnetic separation tailings;

[0009] S3: reducing and roasting the magnetically separated concentrate to obtain nickel-iron foam;

[0010] S4: Mix the nickel iron foam with sulfur, and perform sulfurization roasting at 350-550° C. in an inert atmosphere to obtain the high-nickel matte.

[0011] In some embodiments of the present invention, in step S1, the mass ratio of the nickel-iron particles to the quartz is 1:(0.14-0.20).

[0012] In some embodiments of the present invention, in step S1, the oxidative roasting is carried out in an oxygen-containing atmosphere, and the oxygen concentration of the oxygen-containing atmosphere is controlled to be 21-25%. Specifically, oxygen-containing gas is introduced for the oxidative roasting, and the flow rate of the oxygen-containing gas is controlled to be above 1000 cubic meters per ton. Specifically, more than 1000 cubic meters of oxygen-containing gas is introduced per ton of ferronickel.

[0013] In some embodiments of the present invention, in step S1, the oxygen-containing gas is at least one of oxygen-enriched air or compressed air.

[0014] In some embodiments of the present invention, in step S1, the temperature of the oxidation roasting is 1200-1500° C. Further, the time of the oxidation roasting is 20-30 minutes.

[0015] In some embodiments of the present invention, in step S2, the granulation is one of water quenching, gas quenching or mixed quenching.

[0016] In some embodiments of the present invention, in step S2, the particle size of the crushed material is not greater than 0.075 mm, accounting for 75%.

[0017] In some embodiments of the present invention, in step S2, the magnetic field strength of the magnetic separation is 150-300 kA / m.

[0018] In some embodiments of the present invention, step S2 further includes: calcining the magnetic tailings to obtain nickel-containing iron concentrate and quartz through magnetic separation. Further, the calcination temperature is 1400-1700°C. The main chemical equations for calcining the magnetic tailings are: Fe2SiO4=2FeO+SiO2, 6FeO+O2=2Fe3O4.

[0019] In some embodiments of the present invention, in step S3, the reduction roasting is carried out under a reducing atmosphere, and the reducing atmosphere is at least one of carbon monoxide, water gas or hydrogen. Specifically, the reduction roasting is carried out by introducing a reducing gas, and the flow rate of the reducing gas is controlled at 1050-1180 cubic meters per ton.

[0020] In some embodiments of the present invention, in step S3, the reduction roasting temperature is 500-900° C. Further, the reduction roasting time is 30-120 min.

[0021] In some embodiments of the present invention, in step S4, the mass ratio of the nickel-iron foam to the solid sulfur is 1:(0.16-0.3). Sulfur is selected as the vulcanizing agent in order to avoid introducing other impurities, because the finished product can be directly obtained after the nickel-iron foam and the solid sulfur are vulcanized and roasted.

[0022] In some embodiments of the present invention, in step S4, the time of the sulfurization roasting is 40-120 minutes.

[0023] In some embodiments of the present invention, the equipment used for the oxidation roasting, reduction roasting and sulfidation roasting is a rotary kiln.

[0024] According to a preferred embodiment of the present invention, at least the following beneficial effects are achieved:

[0025] 1. The present invention generates nickel iron oxide with high nickel content and nickel iron silicate with high iron content by oxidative roasting of nickel iron and quartz, and the iron in the mixed melt mainly exists in the form of iron silicate; the nickel iron oxide and nickel iron silicate are separated by magnetic separation, the magnetic separation concentrate is nickel iron oxide, and the magnetic separation tailings are nickel iron silicate. The magnetic separation tailings can be further calcined to obtain nickel-iron concentrate and quartz, so as to realize the regeneration and reuse of quartz; the magnetic separation concentrate is reduced and roasted to produce nickel iron foam, because nickel iron oxide can form a porous substance by low-temperature reduction, and the nickel iron foam is used for sulfurization reaction to generate high nickel matte, wherein the nickel iron foam is easier to be sulfurized, and the required temperature is much lower than the temperature of sulfur supplementation after nickel iron is melted, the sulfur utilization rate reaches more than 80%, and the process is easier to control, and the cost is greatly reduced.

[0026] 2. This method realizes the feasibility of directly producing high-nickel matte from ferronickel. The quality of high-nickel matte produced by ferronickel is reliable, which provides a basis for subsequent high-nickel matte applications and reduces costs.

[0027] 3. The method of the present invention is simple and feasible, the equipment is simple and effective, and green metallurgy can be basically realized, which is conducive to large-scale promotion.

[0028] 4. The quartz of the present invention can be reused, the iron grade in the nickel-containing iron concentrate is above 60%, the nickel grade in the high-nickel matte and the nickel grade in the nickel-containing iron concentrate can be controlled according to production needs, and the nickel-containing iron concentrate can be further used for wet nickel and cobalt extraction or pyrometallurgical smelting of nickel iron. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] The present invention will be further described below with reference to the accompanying drawings and embodiments, wherein:

[0030] Figure 1 This is a process flow chart of Example 1 of the present invention. DETAILED DESCRIPTION

[0031] The following will be combined with the embodiments to clearly and completely describe the concept of the present invention and the technical effects produced, so as to fully understand the purpose, characteristics and effects of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, other embodiments obtained by those skilled in the art without creative work are all within the scope of protection of the present invention.

[0032] Example 1

[0033] A method for producing high nickel matte from ferronickel, referring to Figure 1 , the specific process is:

[0034] (1) A raw material of nickel-iron alloy (containing Ni: 16.69wt%, S: 0.31wt%, Fe: 75.23wt%, Co: 0.44wt%) is crushed and sieved into nickel-iron particles, and the nickel-iron particles are added to a rotary kiln 1 and mixed with quartz in a mass ratio of 1:0.15, and compressed air is introduced for oxidation roasting. The gas flow rate is controlled at 1100 cubic meters / ton, the oxidation roasting temperature is 1400°C, and the roasting time is 20 minutes to obtain a mixed melt containing nickel-iron oxide and nickel-iron silicate.

[0035] (2) the mixed melt of step (1) is subjected to water quenching, granulation, crushing and grinding, and then subjected to magnetic separation in a weak magnetic separator with a magnetic field strength of 200 kA / m to obtain magnetic separation concentrate nickel iron oxide and magnetic separation tailings nickel iron silicate, the magnetic separation tailings are calcined at 1500° C. to generate nickel-containing iron concentrate (containing Fe: 62.22 wt %, Ni: 4.67 wt %) and quartz, and the nickel-containing iron concentrate and quartz are obtained by magnetic separation, and the quartz can be reused;

[0036] (3) adding the magnetically separated concentrate into the rotary kiln 2, introducing water gas for reduction roasting, the water gas flow rate is 1100 cubic meters / ton, the reduction roasting temperature is 900° C., and the roasting time is 30 minutes to obtain nickel-iron foam;

[0037] (4) The foamed nickel iron and solid sulfur are fully mixed in a mass ratio of 1:0.2 and then sent to a rotary kiln 3, and nitrogen is introduced to perform sulfurization roasting at a temperature of 500° C. The roasting time is 45 minutes to obtain a high-nickel matte (containing Ni: 72.32wt%, S: 21.64wt%, Fe: 2.21wt%, Co: 0.38wt%). The nickel recovery rate is 96.5%, and the sulfur utilization rate is 81%.

[0038] Example 2

[0039] A method for producing high-nickel matte from ferronickel, the specific process is:

[0040] (1) crushing and screening a raw material of nickel-iron alloy (containing Ni: 16.69wt%, S: 0.31wt%, Fe: 75.23wt%, Co: 0.44wt%) into nickel-iron particles, adding the nickel-iron particles and quartz into a rotary kiln 1 in a mass ratio of 1:0.15, introducing compressed air for oxidative roasting, controlling the gas flow rate to 1100 cubic meters / ton, the oxidative roasting temperature to 1300° C., and the roasting time to 25 minutes to obtain a mixed melt containing nickel-iron oxide and nickel-iron silicate;

[0041] (2) the mixed melt of step (1) is subjected to water quenching, granulation, crushing and grinding, and then subjected to magnetic separation in a weak magnetic separator with a magnetic field strength of 200 kA / m to obtain magnetic separation concentrate nickel iron oxide and magnetic separation tailings nickel iron silicate, the magnetic separation tailings are calcined at 1600° C. to generate nickel-containing iron concentrate (containing Fe: 63.15wt%, Ni: 2.88wt%) and quartz, and the nickel-containing iron concentrate and quartz are obtained by magnetic separation, and the quartz can be reused;

[0042] (3) adding the magnetically separated concentrate to the rotary kiln 2, introducing water gas for reduction roasting, the water gas flow rate is 1100 cubic meters / ton, the reduction roasting temperature is 850° C., and the roasting time is 35 minutes to obtain nickel-iron foam;

[0043] (4) The foamed nickel iron and solid sulfur are fully mixed in a mass ratio of 1:0.2 and then sent to a rotary kiln 3, and nitrogen is introduced to perform sulfurization roasting at a temperature of 550° C. for 40 minutes to obtain a high-nickel matte (containing Ni: 71.41wt%, S: 24.64wt%, Fe: 2.82wt%, Co: 0.39wt%). The nickel recovery rate is 97.3% and the sulfur utilization rate is 83%.

[0044] Example 3

[0045] A method for producing high-nickel matte from ferronickel, the specific process is:

[0046] (1) crushing and screening a raw material of nickel-iron alloy (containing Ni: 16.69wt%, S: 0.31wt%, Fe: 75.23wt%, Co: 0.44wt%) into nickel-iron particles, adding the nickel-iron particles and quartz into a rotary kiln 1 in a mass ratio of 1:0.15, introducing compressed air for oxidative roasting, controlling the gas flow rate to 1100 cubic meters / ton, the oxidative roasting temperature to 1200° C., and the roasting time to 30 minutes to obtain a mixed melt containing nickel-iron oxide and nickel-iron silicate;

[0047] (2) the mixed melt of step (1) is subjected to water quenching, granulation, crushing and grinding, and then subjected to magnetic separation in a weak magnetic separator with a magnetic field strength of 200 kA / m to obtain magnetic separation concentrate nickel iron oxide and magnetic separation tailings nickel iron silicate, the magnetic separation tailings are calcined at 1500° C. to generate nickel-containing iron concentrate (containing Fe: 64.12 wt %, Ni: 3.04 wt %) and quartz, and the nickel-containing iron concentrate and quartz are obtained by magnetic separation, and the quartz can be reused;

[0048] (3) adding the magnetically separated concentrate to the rotary kiln 2, introducing water gas for reduction roasting, the water gas flow rate is 1100 cubic meters / ton, the reduction roasting temperature is 600° C., and the roasting time is 90 minutes to obtain foamed nickel iron;

[0049] (4) The foamed nickel iron and solid sulfur are fully mixed in a mass ratio of 1:0.2 and then sent to a rotary kiln 3, and nitrogen is introduced to perform sulfurization roasting at a temperature of 400° C. The roasting time is 80 minutes to obtain a high-nickel matte (containing Ni: 71.94wt%, S: 23.46wt%, Fe: 1.93wt%, Co: 0.41wt%). The nickel recovery rate is 96.9% and the sulfur utilization rate is 82%.

[0050] Comparative Example 1

[0051] A method for producing high nickel matte from ferronickel, which differs from Example 1 in that in step (3), the magnetic concentrate is not reduced and roasted into nickel-iron foam, and sulfur is directly added to the molten magnetic concentrate for sulfidation roasting. The specific process is as follows:

[0052] (1) crushing and screening a raw material of nickel-iron alloy (containing Ni: 16.69wt%, S: 0.31wt%, Fe: 75.23wt%, Co: 0.44wt%) into nickel-iron particles, adding the nickel-iron particles and quartz into a rotary kiln 1 in a mass ratio of 1:0.15, introducing compressed air for oxidative roasting, controlling the gas flow rate to 1100 cubic meters / ton, the oxidative roasting temperature to 1400° C., and the roasting time to 20 minutes to obtain a mixed melt containing nickel-iron oxide and nickel-iron silicate;

[0053] (2) the mixed melt of step (1) is subjected to water quenching, granulation, crushing and grinding, and then subjected to magnetic separation in a weak magnetic separator with a magnetic field strength of 200 kA / m to obtain magnetic separation concentrate nickel iron oxide and magnetic separation tailings nickel iron silicate, and the magnetic separation tailings are calcined to generate nickel iron concentrate (containing Fe: 62.22wt%, Ni: 4.67wt%) and quartz, and the quartz can be reused;

[0054] (3) The magnetically separated nickel iron oxide concentrate was added into a melting furnace and melted at 1300-1550°C, and then liquid sulfur was introduced at a mass ratio of 1:0.5 for sulfidation roasting. The roasting time was 60 minutes to obtain high nickel matte (containing Ni: 70.29wt%, S: 24.31wt%, Fe: 2.57wt%, Co: 0.37wt%). The nickel recovery rate was 96.3% and the sulfur utilization rate was 52%.

[0055] The embodiments of the present invention are described in detail above in conjunction with the accompanying drawings, but the present invention is not limited to the above embodiments. Various changes can be made within the knowledge of ordinary technicians in the relevant technical field without departing from the purpose of the present invention. In addition, the embodiments of the present invention and the features in the embodiments can be combined with each other without conflict.

Claims

1. A method for producing high-nickel matte from ferronickel, characterized in that: The following steps are involved: S1: mixing nickel-iron particles with quartz, and performing oxidation roasting to obtain a mixed melt containing nickel-iron oxide and nickel-iron silicate; S2: granulating and crushing the mixed melt, and magnetically separating the obtained crushed material to obtain magnetic separation concentrate and magnetic separation tailings; S3: reducing and roasting the magnetically separated concentrate to obtain nickel-iron foam; S4: Mix the nickel iron foam with sulfur, and perform sulfurization roasting at 350-550° C. in an inert atmosphere to obtain the high-nickel matte.

2. The method according to claim 1, characterized in that In step S1, the mass ratio of the nickel-iron particles to the quartz is 1:(0.14-0.20).

3. The method according to claim 1, characterized in that In step S1, the oxidative roasting is performed in an oxygen-containing atmosphere, and the oxygen concentration of the oxygen-containing atmosphere is controlled to be 21-25%.

4. The method according to claim 1, characterized in that: In step S1, the temperature of the oxidation roasting is 1200-1500°C.

5. The method according to claim 1, characterized in that In step S2, the granulation is one of water quenching, gas quenching or mixed quenching.

6. The method according to claim 1, characterized in that In step S2, the magnetic field strength of the magnetic separation is 150-300 kA / m.

7. The method according to claim 1, characterized in that Step S2 also includes: calcining the magnetic separation tailings, and obtaining nickel-containing iron concentrate and quartz through magnetic separation.

8. The method according to claim 1, characterized in that In step S3, the reduction roasting is carried out under a reducing atmosphere, and the reducing atmosphere is at least one of carbon monoxide, water gas or hydrogen.

9. The method according to claim 1, characterized in that: In step S3, the reduction roasting temperature is 500-900°C.

10. The method according to claim 1, characterized in that In step S4, the mass ratio of the nickel-iron foam to the solid sulfur is 1:(0.16-0.3).

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