System for preparing electrodeposited nickel by using coarse nickel cobalt hydroxide

Abstract

The utility model relates to a system for preparing electrodeposited nickel by using coarse nickel cobalt hydroxide, which comprises an ore grinding unit, a first tank, a leaching unit, a solid-liquid separation unit, a purification unit, a first filter press, an extraction unit, a heat exchanger, a nickel electrodeposition tank, a lower tank and an evaporation and concentration unit which are communicated in sequence, and a concentrated solution outlet of the evaporation and concentration unit is communicated with the first tank and the leaching unit. According to the system disclosed by the utility model, the anolyte can be effectively utilized under the condition of not carrying out acid-base neutralization on the anolyte, the solution balance of the system is ensured, continuous and stable industrial production can be realized, the process is simplified, the acid consumption is reduced, and the production efficiency and quality are improved.

Description

TECHNICAL FIELD

[0001] The utility model relates to a system for preparing electrodeposited nickel by using crude nickel-cobalt hydroxide, and belongs to the field of hydrometallurgy equipment. BACKGROUND

[0002] Nickel is a very important silver-white metal material, which has good mechanical strength and ductility, melting resistance and high-temperature resistance, very high chemical stability, and excellent features such as not being oxidized in the air, and is often used as a raw material for making stainless steel and alloy structural steel, and is widely used in airplanes and radars. In recent years, the amount of nickel used in color televisions and new communication equipment has rapidly increased. Due to its excellent performance, nickel has become an indispensable metal in the development of modern industrial systems.

[0003] The main forms of global nickel ore are sulfide ore and laterite nickel ore. At present, about 60% of nickel production comes from sulfide nickel ore. However, with the gradual expansion of downstream demand for stainless steel, existing sulfide ore resources are insufficient to meet the growing demand for nickel resources. Therefore, laterite nickel ore, which has abundant reserves and is easy to mine, is gradually becoming the focus of the industry. However, in the process of recovering nickel from laterite nickel ore and preparing nickel from crude nickel-cobalt hydroxide produced by laterite nickel ore, there are currently still problems such as high acid and alkali consumption, the need to use liquid alkali to neutralize sulfuric acid in the anode liquid, and the need to precipitate nickel in the anode liquid. After pressure filtration, the nickel hydroxide precipitate is used to neutralize the sulfuric acid in the anode liquid. This process has high production costs and low production efficiency, which limits the further large-scale production of electrodeposited nickel (such as nickel plates). In addition, the existing system for preparing nickel from crude nickel-cobalt hydroxide often needs to return leaching slag washing water, purified slag washing water, etc. to the leaching process to reduce the loss of valuable metals. At the same time, steam is often introduced into the reaction system to control the leaching temperature, which can gradually increase the liquid volume of the reaction system and increase the difficulty of recycling the anode liquid. SUMMARY

[0004] The utility model aims at the shortage of prior art, provides a kind of system for preparing electrodeposited nickel by using crude nickel-cobalt hydroxide, to better realize stable production.

[0005] The technical scheme adopted by the utility model is as follows:

[0006] A system for preparing electrodeposited nickel by using crude nickel-cobalt hydroxide, comprising a grinding unit, a first tank, a leaching unit, a solid-liquid separation unit, a purification unit, a first filter press, an extraction unit, a heat exchanger, a nickel electrodeposition tank, a low tank and an evaporation and concentration unit, which are connected in sequence. The concentrated liquid outlet of the evaporation and concentration unit is communicated with the first tank and the leaching unit.

[0007] Thus, the crude nickel-cobalt hydroxide ore slurry can be grinded and then input into the leaching unit for heating (steam can be input for heating) and leaching, and then solid-liquid separation is performed, and then the obtained filtrate is treated for iron and aluminum removal (the crude nickel-cobalt hydroxide can be added) in the purification unit, and then pressure filtration is performed, and then Cu, Zn, Al, Mn, Co, Mg and other metals are removed by extraction, and then the nickel-containing raffinate is obtained. Subsequently, the nickel-containing raffinate is heated and then input into the nickel electrodeposition tank for electrodeposition, and then cathode nickel (i.e. electrodeposited nickel) is obtained at the cathode, and then anode liquid is obtained at the low-position tank. The anode liquid can be further concentrated by evaporation in the evaporation concentration unit, the volume of the anode liquid is reduced without loss of acid and valuable metals, and then the concentrated anode liquid is returned to the first tank and the leaching unit to participate in subsequent slurry and leaching processes, which is helpful to realize the solution balance of the whole system, ensure the stability of the composition of the slurry entering the leaching unit and subsequent functional units, and is helpful to realize industrial production.

[0008] Further, the leaching unit comprises at least two leaching tanks connected in series.

[0009] Further, the leaching tank is a continuous leaching tank. Thus, it is helpful to reduce the equipment footprint and realize continuous production.

[0010] Further, a second tank is arranged between the leaching unit and the solid-liquid separation unit, a third tank is arranged between the purification unit and the first filter press, a fourth tank and a first filter are arranged in sequence between the first filter press and the extraction unit, a second filter and a fifth tank are arranged in sequence between the extraction unit and the heat exchanger, and a high-position tank is arranged between the heat exchanger and the nickel electrodeposition tank. Thus, the related tanks can play a role in buffering, which is convenient for the system to run more stably, the fifth tank can be used to configure the cathode liquid according to the electrodeposition needs (for example, adjust the composition of the cathode liquid by adding boric acid, pure water, etc.) to better perform electrodeposition, and the first filter and the second filter can further improve the solution quality and better ensure the stable operation of the heat exchanger, the nickel electrodeposition tank and the like.

[0011] Further, the first filter is a precision filter, and the second filter is a bag filter. Thus, it is helpful to obtain better filtering effect and ensure good service life of the filter.

[0012] Further, the bottom flow outlet of the solid-liquid separation unit is communicated with a second filter press, and the liquid outlet of the second filter press is communicated with the inlet of the purification unit. Thus, it is helpful to further improve the yield of valuable metals.

[0013] Further, the purification unit comprises at least two purification tanks connected in series, which is helpful to ensure better purification and impurity removal effect.

[0014] Further, the purification tank is a continuous purification tank.

[0015] Further, the ore grinding unit is a wet overflow type ball mill.

[0016] Further, the solid-liquid separation unit is a thickener. Optionally, the heat exchanger is a plate heat exchanger.

[0017] Optionally, a pump can be arranged between adjacent functional units as needed to facilitate the transfer of materials.

[0018] Compared with the prior art, the system can effectively utilize the anolyte without neutralizing the anolyte, and ensure the system solution balance, so that continuous and stable industrial production can be realized, which is helpful for simplifying the process, saving acid consumption and alkali consumption, and improving production efficiency and quality. BRIEF DESCRIPTION OF DRAWINGS

[0019] Figure 1 is a structural diagram of the system for preparing electrodeposited nickel by using coarse nickel cobalt hydroxide according to the present application. DETAILED DESCRIPTION

[0020] The present application will be described in detail below with reference to the drawings and in combination with embodiments. It should be noted that the embodiments in the present application and the features in the embodiments can be combined with each other without conflict. For the convenience of description, if the terms "upper", "lower", "left", "right" appear in the following text, they only mean consistent with the upper, lower, left and right directions of the drawings themselves, and do not limit the structure.

[0021] Embodiment 1

[0022] Referring to Figure 1 A system for preparing electrodeposited nickel by using coarse nickel cobalt hydroxide, comprising, in sequence, an ore grinding unit 1, a first tank 2, a first pump 3, a leaching unit, a second tank 5, a second pump 6, a solid-liquid separation unit 7, a purification unit, a third tank 11, a fourth pump 12, a first filter press 13, a fourth tank 14, a fifth pump 15, a first filter 16, an extraction unit 17, a sixth pump 18, a second filter 19, a fifth tank 20, a seventh pump 21, a heat exchanger 22, an elevated tank 23, a nickel electrodeposition tank 24, a low tank 25, an eighth pump 26, and an evaporation and concentration unit 27 (MVR evaporator), wherein the concentrated liquid outlet of the evaporation and concentration unit 27 is in communication with the first tank 2 and the leaching unit, a first valve is arranged between the concentrated liquid outlet of the evaporation and concentration unit 27 and the first tank 2, and a second valve is arranged between the concentrated liquid outlet of the evaporation and concentration unit 27 and the leaching unit.

[0023] The leaching unit comprises two leaching tanks 4 connected in series, and adjacent leaching tanks are connected through a first chute. The leaching tank 4 is a continuous leaching tank. The first filter 16 is a precision filter, and the second filter 19 is a bag filter. The underflow outlet of the solid-liquid separation unit 7 is connected with a second filter press 9, and the liquid outlet of the second filter press 9 is connected with the inlet of the purification unit. The purification unit comprises two purification tanks 10 connected in series, and adjacent purification tanks are connected through a second chute. The purification tank 10 is a continuous purification tank. The ore grinding unit 1 is a wet overflow type ball mill. The solid-liquid separation unit 7 is a thickener. The heat exchanger is a plate heat exchanger.

[0024] The above system is used to prepare electrodeposited nickel by using the crude nickel-cobalt hydroxide with the components shown in Table 1 as raw material.

[0025] Table 1

[0026]

[0027] The specific steps for preparing electrodeposited nickel are as follows:

[0028] 1) Raw material pretreatment: 100 kg of crude nickel-cobalt hydroxide material is quantitatively sent to the ore grinding unit 1 for ball milling and classification, the ball milling slurry water is industrial water, the liquid-solid mass ratio in the ore grinding unit 1 is controlled to be 1.5:1, the crude nickel-cobalt hydroxide slurry with a particle size of less than 200 μm is continuously slurried, and then the slurry is pumped to the first tank 2 for temporary storage, and then pumped to the leaching unit by the first pump. The particles with a particle size of more than 200 μm are returned to the ball mill. Evaporated and concentrated anode liquid is added during the slurry process, the slurry liquid-solid mass ratio is 5-6:1, and the temporary storage time is 4 h.

[0029] 2) Continuous leaching: the slurried crude nickel-cobalt hydroxide slurry is sent to the leaching unit to complete the leaching reaction, during which, concentrated sulfuric acid, evaporated and concentrated anode liquid, steam, mixed washing water (MHP secondary leaching residue first washing water, MHP primary purification residue first washing water), MHP secondary leaching liquid, part of MHP primary purification residue slurry, etc. are mainly added, the initial mass ratio of the leaching liquid to the solid is controlled to be 13:1, the temperature is 80°C, the final pH is 1.5, and the continuous leaching reaction is carried out. After the reaction is completed, the slurry flows into the second tank 5 for 2 h of buffering to obtain the continuous leaching slurry.

[0030] 3) Thickening and secondary leaching: after the continuous leaching slurry is thickened, the thickening underflow enters the second filter press 9 for primary pressure filtration to obtain primary pressure filtration residue and primary pressure filtration liquid.

[0031] Subsequently, the primary pressure filtration residue can be mixed with concentrated sulfuric acid and part of the evaporated and concentrated anode solution, steam is introduced for intermittent leaching, the solid-liquid initial mass ratio of the leaching solution is controlled to be 4:1, the temperature is 85-95°C, and the terminal point acidity (H2SO4) is 100-120 g / L. Then, secondary pressure filtration is performed, the secondary pressure filtration residue is washed with water and then sent to the residue treatment process, and the secondary pressure filtration liquid is returned to the leaching unit.

[0032] 4) Purification: after the thickened supernatant and the primary pressure filtration liquid are mixed, crude nickel-cobalt hydroxide is added for iron and aluminum removal purification treatment, and then the first filter press 13 is used for pressure filtration to obtain pressure filtration purified liquid and purification residue. The pressure filtration purified liquid is subjected to precision filtration to obtain precision filtration purified liquid, and the purification residue is partially returned to the leaching unit and partially treated in an open circuit.

[0033] 5) Impurity removal by extraction: the precision filtration purified liquid is subjected to P204 extraction to remove Cu, Zn, Al, Mn and other impurity metals, and then subjected to P507 extraction to remove Co and Mg, to obtain a nickel-containing raffinate.

[0034] 6) Cathode solution preparation: the nickel-containing raffinate is subjected to bag-type filtration, and then subjected to cathode solution preparation in the fifth tank 20. According to process requirements, boric acid, sodium sulfate, pure water and the like are added during the preparation process to adjust the composition of the cathode solution, to obtain the cathode solution.

[0035] 7) Electrowinning: the cathode solution is sent to a plate heat exchanger for heat exchange, and then the heat-exchanged cathode solution is pumped into a high tank, the cathode solution in the high tank flows into a nickel electrowinning tank, the anode solution in the nickel electrowinning tank overflows into a low tank, and then is input into an evaporation and concentration unit 27 through an eighth pump 26 for evaporation and concentration treatment. The cathode plate produces cathode nickel, and the cathode nickel is stripped and packaged to obtain a nickel plate product. The input liquid (cathode solution) of the electrowinning liquid contains Ni 2+ 85 g / L, and the output liquid (anode solution) of the electrowinning liquid contains Ni 2+ 60 g / L, the sulfuric acid content is 41.74 g / L, and the solution temperature is 60-65°C. The anode solution is sent to the first tank after MVR evaporation and concentration (the evaporated water content is 18wt% of the solution amount), the anode solution after evaporation and concentration contains Ni 73.17 g / L, the sulfuric acid content is 50.90 g / L, and is returned to slurry, or can be partially returned to the continuous leaching, intermittent leaching and cathode solution preparation processes as needed. The condensate water generated by the evaporation and concentration unit can be sent to the leaching unit, the purification unit and other functional units for reuse.

[0036] Through the above system, the crude nickel-cobalt hydroxide can be continuously and stably used to prepare electrowinning nickel, and the obtained nickel plate product contains Ni≥99.96wt%, which meets the product quality requirements of GB / T 6516-2010 "Electrolytic Nickel".

[0037] The above-mentioned embodiments should be understood as being only for more clearly describing the present application, and should not be used to limit the scope of the present application, and after reading the present application, various equivalent modifications of the present application by those skilled in the art all fall within the scope defined by the claims attached herein.

Claims

1. A system for preparing electrowinning nickel using crude nickel cobalt hydroxide, characterized by, The process comprises a grinding unit (1), a first tank (2), a leaching unit, a solid-liquid separation unit (7), a purification unit, a first filter press (13), an extraction unit (17), a heat exchanger (22), a nickel electrowinning tank (24), a low tank (25) and an evaporation and concentration unit (27) in sequence.

2. The system of claim 1, wherein, The leaching unit comprises at least two leaching tanks (4) in sequence.

3. The system of claim 2, wherein, The leaching tank (4) is a continuous leaching tank.

4. The system of claim 1, wherein, A second tank (5) is arranged between the leaching unit and the solid-liquid separation unit (7); a third tank (11) is arranged between the purification unit and the first filter press (13); a fourth tank (14) and a first filter (16) in sequence are arranged between the first filter press (13) and the extraction unit (17); a second filter (19) and a fifth tank (20) in sequence are arranged between the extraction unit (17) and the heat exchanger (22); a high tank (23) is arranged between the heat exchanger (22) and the nickel electrowinning tank (24).

5. The system of claim 4, wherein, The first filter (16) is a precision filter; the second filter (19) is a bag filter.

6. The system of claim 1, wherein, A second filter press (9) is communicated with the underflow outlet of the solid-liquid separation unit (7), and the liquid outlet of the second filter press (9) is communicated with the inlet of the purification unit.

7. The system of claim 1, wherein, The purification unit comprises at least two purification tanks (10) in sequence.

8. The system of claim 7, wherein, The purification tank (10) is a continuous purification tank.

9. The system according to any of claims 1-8, characterized in that, The grinding unit (1) is a wet overflow type ball mill.

10. The system of any of claims 1-8, wherein, The solid-liquid separation unit (7) is a thickener; and the heat exchanger (22) is a plate heat exchanger.

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