A process for the recovery of nickel from laterite nickel ores

Abstract

The application discloses a method for recovering nickel from laterite nickel ore, which comprises the following steps: 1) after drying, the laterite nickel ore is mixed with reducing coal and sulfuration agent, and the mixture is sent to an oxygen-rich side-blown furnace for reduction smelting, the temperature and reducing atmosphere in the furnace are controlled by controlling the oxygen-material ratio and oxygen-coal ratio, and low nickel matte, slag and dust are obtained; 2) the low nickel matte is blown, high nickel matte and blown slag are obtained by controlling the fuel rate and slagging rate; 3) the high nickel matte is ground and roasted after water quenching, and the roasted sand is subjected to reduction smelting to obtain refined nickel alloy; and 4) the refined nickel alloy is cast into anode plates, and electrolytic refining is carried out to obtain electrolytic nickel. The electrolytic nickel contains 99.92-99.97% of nickel. The application realizes comprehensive utilization of the laterite nickel ore, and low nickel matte, high nickel matte, nickel alloy and electrolytic nickel products are obtained.

Description

TECHNICAL FIELD

[0001] The present application relates to the recovery of nickel metal resources from laterite nickel ore or oxidized nickel, in particular to a method for recovering nickel from laterite nickel ore. BACKGROUND

[0002] Nickel is a very important silver-white metal material because it has good mechanical strength and ductility, resistance to melting and high temperature characteristics, and high chemical stability, and is not oxidized in the air, and is often used to make stainless steel and alloy structural steel, and is widely used in aircraft, radar. In recent years, the amount of nickel used in color televisions and new communication equipment has increased rapidly because of its excellent performance, and has become an indispensable metal in the development of modern aviation industry and modern system of national defense industry.

[0003] The main distribution of global nickel ore is laterite nickel ore (accounting for 55%), sulfide ore (accounting for 28%), and manganese nodule in the seabed (accounting for 17%). At present, about 60% of the nickel output comes from sulfide nickel ore. With the gradual expansion of downstream stainless steel demand, existing sulfide ore resources are insufficient to meet the growth of human demand for nickel resources. Therefore, technologies such as RKEF method for smelting nickel-iron from laterite ore, HPAL wet smelting of laterite ore to prepare nickel-cobalt hydroxide, and pyrometallurgical smelting of laterite ore to prepare high-ice nickel are gradually developed and applied to industrial application. Producing nickel-iron is an important way for laterite nickel ore, because of the huge amount of stainless steel used, there is a huge demand for nickel and iron. Laterite nickel ore can be smelted into nickel-iron for direct use, without the need to further separate nickel and iron, or to sulfide nickel-iron. The current newly-built nickel-iron industry chain enterprises almost all adopt the RKEF method. RKEF is to use a rotary kiln reduction roasting process to preheat and pre-reduce the laterite ore, and the obtained high-temperature pre-reduced roasting sand is directly hot charged into an electric arc furnace for smelting. RKEF produces about 12% of nickel-iron, and the grade of nickel cannot be further improved. SUMMARY

[0004] The purpose of the present application is to provide a method for recovering nickel from laterite nickel ore, so as to realize the comprehensive utilization of laterite nickel ore and obtain low-ice nickel, high-ice nickel, nickel alloy and electrolytic nickel products.

[0005] In order to achieve the above purpose, the technical scheme adopted by the present application is as follows:

[0006] The method for recovering nickel from laterite nickel ore provided by the present application comprises the following steps:

[0007] 1) First, dry the laterite nickel ore, then mix the dried laterite nickel ore with reducing coal and sulfidizing agent uniformly to obtain a mixture, and then send the mixture to an oxygen-rich side-blown furnace for reduction smelting, and after smelting, obtain low-ice nickel, side-blown furnace slag and side-blown furnace dust;

[0008] 2) adding flux to the low nickel matte obtained in step 1), and converting to obtain high nickel matte and converting slag;

[0009] 3) grinding and roasting the high nickel matte obtained in step 2) after water quenching to obtain calcine, and then reducing smelting the calcine to obtain refined nickel alloy;

[0010] 4) pouring the refined nickel alloy obtained in step 3) into anode plates, and electrolytic refining to obtain electrolytic nickel.

[0011] The mass percentage contents of NiO, SiO2, MgO, Fe2O3, CaO, Al2O3, Mn, S, and Cr in the laterite nickel ore are 1% to 9%, 9% to 42%, 0.2% to 22%, 14% to 60%, 0.1% to 2.75%, 1% to 25%, 0.1% to 25%, 0.05% to 0.2%, and 0.1% to 2%, respectively.

[0012] As a further improvement, in step 1), the oxygen concentration during the reduction smelting in the oxygen-enriched side-blown furnace is 60% to 85%, and the oxygen / charge ratio is 200 to 400 Nm 3 / t, and the oxygen / coal ratio is controlled to be 0.5 to 0.9.

[0013] It should be noted that during the reduction smelting in the oxygen-enriched side-blown furnace, the temperature and the reducing atmosphere in the furnace are controlled by controlling the oxygen / charge ratio and the oxygen / coal ratio, and the temperature and the reducing atmosphere make the concentration of carbon monoxide in the mixture of carbon monoxide and carbon dioxide gas in the temperature range for generating ferrosilicates, and the volume fraction of CO / (CO+CO2) is not less than 50%. However, further reduction, i.e., the reduction of ferrous iron into metal, and the generation of nickel-iron alloy should be prevented.

[0014] As a further improvement, in step 1), the reduction temperature of the oxygen-enriched side-blown furnace is controlled to be 1150 to 1550℃, and the reduction time is 1 to 5h.

[0015] As a further improvement, in step 1), the sulfurizing agent is at least one of calcium sulfate, ferrous sulfide, and sulfur; in the slag in the oxygen-enriched side-blown furnace, the slag contains 0.1% to 0.25% of Ni, 35% to 45% of SiO2, not more than 50% of the sum of SiO2 and Al2O3, 14% to 18% of FeO, 34% to 36% of the sum of CaO and MgO, and 0.45% to 1% of S; and in the low nickel matte, the sum of Ni, Fe, and S is more than 90%, and the S is less than 25%.

[0016] Further improvement, in the step 2), the flux is quartz stone; the temperature of the blowing is 1200-1250 DEG C, the blowing time is 1-3h; the oxygen concentration during blowing is 21%-24%; in the slag of blowing, the slag contains SiO2 26%-28%, the slag contains Al2O3 5%-8%, the slag contains CaO 5%-8%, the slag contains Ni 1%-2%; in the high nickel, the content of Ni is 68%-78%, the content of S is 21%-24%, the content of Fe is 0.25%-0.5%.

[0017] Further improvement, in the step 3), the high nickel is ground to 40-60 mesh.

[0018] Further improvement, in the step 3), the roasting is carried out in two stages, first, the temperature is controlled at 450-500 DEG C, then gradually heated to 780-800 DEG C, the roasting time is 1-3h, which is the first stage; then the roasting slag is crushed to 200 mesh or less after passing through the cylinder cooler, the second stage roasting is carried out, the temperature is 700-800 DEG C, and the temperature is increased to 1200-1300 DEG C, the roasting time is 1-3h. The nickel content in the calcined sand is 77%-78%, the sulfur content is 0.01%-0.02%, and the iron content is 0.05%.

[0019] Further improvement, in the step 3), the reduction smelting of the calcined sand is divided into the following processes: furnace charge reduction and softening, furnace charge melting and nickel metal appearance, and nickel metal refining; the temperature of the reduction smelting of the calcined sand is 900-1000 DEG C, and the time is 6-8h; the nickel content in the refined nickel alloy is 95.6%, the iron content is 4%, and the waste slag contains 0.2-0.4% of Ni.

[0020] Further improvement, in the step 4), the refined nickel alloy is poured into anode plates, and electrolytic refining is carried out in a nickel chloride solution; the solution from the cathode chamber is returned to the cathode chamber after being purified to remove iron, so that nickel is deposited, and electrolytic nickel is obtained; the nickel content in the electrolytic nickel is 99.92-99.97%.

[0021] The principle of the application is:

[0022] The main reactions of the oxygen-enriched side-blown furnace reduction smelting are (1)-(6):

[0023] 2C+O2=2CO (1)

[0024] Fe3O4+CO=3FeO+CO2 (2)

[0025] CaSO4+4CO=CaS+4CO2 (3)

[0026] 2CaS+3NiO+C=Ni3S2+2CaO+CO (4)

[0027] 7CaS + 9NiO = 3Ni3S2 + 7CaO + SO2 (5)

[0028] CaO + SiO2 = CaO·SiO2 (6)

[0029] The blowing of the top-blown furnace or converter, the main reactions are (7)-(8):

[0030] 2Fe + O2 + SiO2 = 2FeO·SiO2 (7)

[0031] 2FeS + 3O2 + SiO2 = 2FeO·SiO2 + 2SO2 (8)

[0032] The main reactions in the high-ice nickel roasting furnace are (9)-(11):

[0033] Ni + 0.5O2 = NiO (9)

[0034] Ni3S2 + 3.5O2 = 3NiO + 2SO2 (10)

[0035] NiO + SO2 + 0.5O2 = NiSO4 (11)

[0036] The main reactions in the calcine electric furnace reduction are (12)-(13):

[0037] NiO + CO = Ni + CO2 (12)

[0038] In order to further purify, a small amount of limestone is added in the electric furnace charge, and the reaction is:

[0039] Ni3S2 + 2CaO + 2C = 3Ni + 2CaS + 2CO (13)

[0040] The advantage of the present application is to recover nickel by oxygen-rich side-blown furnace sulfidation reduction, and by adding calcium sulfate or ferrous sulfide, sulfur and other sulfidation agents in the process, the sulfidation reduction of nickel is realized, SO2 in the flue gas is desulfurized, and then calcium sulfate is generated for sulfidation, realizing efficient recycling of sulfur. BRIEF DESCRIPTION OF DRAWINGS

[0041] Figure 1 The process flow chart of the present application. DETAILED DESCRIPTION

[0042] The present application will be further described in detail below in combination with examples.

[0043] In an embodiment of the present application, a method for recovering nickel from laterite nickel ore, comprising the following steps:

[0044] 1) first dry the laterite nickel ore, then mix the dried laterite nickel ore with reducing coal and sulfuration agent to obtain a batch, then send the batch to a side-blown furnace for reduction smelting, after the smelting, low nickel matte, side-blown furnace slag and side-blown furnace dust are obtained;

[0045] 2) add flux to the low nickel matte obtained in step 1) and blow, to obtain high nickel matte and blowed slag;

[0046] 3) grind and roast the high nickel matte obtained in step 2) after water quenching, to obtain calcine, then perform reduction smelting on the calcine, to obtain refined nickel alloy;

[0047] 4) cast the refined nickel alloy obtained in step 3) into anode plates, electrolytic refine, to obtain electrolytic nickel.

[0048] In an embodiment of the present application, the mass percentage of NiO, SiO2, MgO, Fe2O3, CaO, Al2O3, Mn, S and Cr in the laterite nickel ore is 1% to 9%, 9% to 42%, 0.2% to 22%, 14% to 60%, 0.1% to 2.75%, 1% to 25%, 0.1% to 25%, 0.05% to 0.2% and 0.1% to 2% respectively.

[0049] In an embodiment of the present application, the heat source for drying the laterite nickel ore is hot air generated by burning coal or other fuel, and the drying intensity is controlled by controlling the amount of hot air, and the water content of the dried laterite nickel ore is 18% to 25%.

[0050] In an embodiment of the present application, in step 1), the oxygen concentration in the oxygen-rich side-blown furnace during reduction smelting is 60% to 85%, the oxygen / charge ratio is 200 to 400 Nm 3 / t, and the oxygen / coal ratio is controlled by the combustion coefficient and is controlled to be 0.5 to 0.9.

[0051] It should be noted that, during the reduction smelting in the oxygen-rich side-blown furnace, the temperature and reducing atmosphere in the furnace are controlled by controlling the oxygen / charge ratio and the oxygen / coal ratio, and the temperature and reducing atmosphere make the concentration of carbon monoxide in the mixture of carbon monoxide and carbon dioxide gas in the temperature range of ferrosilicate formation, the volume fraction of CO / (CO+CO2) is not less than 50%. However, further reduction, i.e. the phenomenon of oxidized ferrous iron being reduced to metal and nickel-iron alloy being produced, should be prevented.

[0052] In an embodiment of the present application, in step 1), the reduction temperature of the oxygen-rich side-blown furnace is controlled to be 1150 to 1550℃, and the reduction time is 1 to 5h.

[0053] In one embodiment of the present application, in the step 1), the sulfuration agent is at least one of calcium sulfate, ferrous sulfide and sulfur; in the slag in the oxygen-enriched side-blown furnace, the slag contains 0.1-0.25% of Ni, 35-45% of SiO2, not more than 50% of SiO2 and Al2O3 in total, 14-18% of FeO, 34-36% of CaO and MgO in total, and 0.45-1% of S; and the sum of Ni, Fe and S in the low-ice nickel is above 90%, in which S is below 25%.

[0054] In one embodiment of the present application, the slag obtained in the step 1) can be directly sold after water quenching; the flue dust is recovered by the waste heat boiler, then enters the dust removal system for dust removal, to obtain smelting flue dust and flue gas after dust removal, the smelting flue dust can be returned to the oxygen-enriched side-blown furnace, and the flue gas after dust removal is sent to a desulfurization and denitrification system.

[0055] In one embodiment of the present application, in the step 2), the low-ice nickel is sent into a top-blown converter or a converter by a chute or a nickel bag, and high-ice nickel and converter slag are obtained by blowing with the addition of quartz.

[0056] In one embodiment of the present application, in the step 2), the converter slag obtained by blowing can be returned to the oxygen-enriched side-blown furnace for smelting.

[0057] In one embodiment of the present application, in the step 2), flue gas is also generated during blowing, the flue gas is recovered by the waste heat boiler, then enters the dust removal system for dust removal, and the flue gas after dust removal is sent to an acid production system.

[0058] In one embodiment of the present application, in the step 2), the flux is quartz; the blowing temperature is 1200-1250°C, the blowing time is 1-3h, the oxygen-enriched concentration during blowing is 21-24%, the slag contains 26-28% of SiO2, 5-8% of Al2O3, 5-8% of CaO and 1-2% of Ni; the high-ice nickel contains 68-78% of Ni, 21-24% of S and 0.25-0.5% of Fe.

[0059] In one embodiment of the present application, in the step 3), the high-ice nickel is crushed to 40-60 mesh in a ball mill after water quenching, and then is roasted, so that the sulfur content is 0.01-0.02%.

[0060] In one embodiment of the present application, in step 3), the roasting is carried out in two stages, first the temperature is controlled at 450-500°C, then gradually increased to 780-800°C, the roasting time is 1-3h, which is the first stage; then the roasting slag is crushed to 200 mesh or less after passing through a cylinder cooler, and the second stage roasting is carried out, the temperature is increased to 1200-1300°C from 700-800°C, the roasting time is 1-3h. The calcined sand contains Ni 77-78%, S 0.01-0.02%, and Fe 0.05%.

[0061] In one embodiment of the present application, in step 3), the reduction smelting of the calcined sand is carried out in the following processes: reduction and softening of the furnace charge, melting of the furnace charge and appearance of nickel metal, and refining of the nickel metal; the temperature for the reduction smelting of the calcined sand is 950-1500°C, and the time is 6-8h; the refined nickel alloy contains Ni 95.6% and Fe 4%, and the waste slag contains Ni 0.2-0.4%.

[0062] In one embodiment of the present application, in step 3), a small amount of limestone can be added during the reduction smelting of the calcined sand for further purification.

[0063] In one embodiment of the present application, in step 4), the refined nickel alloy is cast into anode plates, and electrolytic refining is carried out in a nickel chloride solution; the solution from the cathode chamber is returned to the cathode chamber after being purified to remove iron, so that nickel is deposited, and electrolytic nickel is obtained; the electrolytic nickel contains Ni 99.92-99.97%.

[0064] The present application is further described below in conjunction with specific embodiments.

[0065] The composition of the laterite nickel ore used in the following embodiments is as follows:

[0066]

[0067] Embodiment 1

[0068] According to the process shown in the figure, nickel is recovered from laterite nickel ore, and the specific steps are as follows: Figure 1

[0069] 100kg of laterite nickel ore (containing 20% of water), 25kg of coal, and 5kg of gypsum are uniformly mixed and charged into an oxygen-enriched side-blown furnace for reduction smelting, and oxygen-enriched air with an oxygen concentration of 65% is blown in, the oxygen-charge ratio is controlled at 200Nm 3 / t, the oxygen-coal combustion coefficient is controlled at 0.75, the reduction smelting temperature is controlled at 1450°C, and the smelting time is 2h, and 9kg of low-ice nickel is produced, which contains Ni 15%.

[0070] ​Put 9 kg of low nickel into the blowing furnace, add flux quartzite 2.5 kg, blow in oxygen with oxygen concentration of 22%, blowing temperature is 1250℃, blowing for 2h, output high nickel 2.5 kg, high nickel contains Ni 69%.

[0071] Grind the high nickel in the ball mill to 40-60 mesh, then roast in the roasting furnace. The roasting process first starts at 450℃, then gradually increases to 800℃, after roasting for 2h, further gradually increases to 1250℃, and roasts for another 2h to get roasted sand. The roasted sand contains Ni 78%, S 0.015%.

[0072] After the flue gas passes through waste heat recovery, it enters the electric dust collector, with dust concentration of 4-5g / Nm 3 , the dust-removed flue gas enters the flue gas treatment system.

[0073] Roast the roasted sand in the electric furnace, with reduction temperature of 1500℃, reduction for 6h, to get refined nickel alloy, which contains Ni 95.6% and Fe 4%. Pour the refined nickel alloy into anode plates, and electrolyze in concentrated nickel chloride solution. The cathode is made of nickel wire, and the solution coming out of the cathode chamber is returned to the cathode chamber after being purified to remove iron to make nickel deposit. The electrolytic nickel is columnar, containing 99.95% Ni.

[0074] Example 2

[0075] According to the process flow shown in Figure 1 , recover nickel from laterite nickel ore, the specific steps are as follows:

[0076] Mix 100 kg of laterite nickel ore (water content is 20%), 25 kg of coal and 5 kg of gypsum evenly, then add them into the oxygen side-blown furnace for reduction smelting, blow in oxygen with oxygen concentration of 85%, oxygen material ratio is controlled at 400 Nm 3 / t, oxygen coal combustion coefficient is controlled at 0.9, control the reduction smelting temperature at 1550℃, smelting for 2h, output low nickel 9.5 kg, which contains Ni 18%.

[0077] Put 9.5 kg of low nickel into the blowing furnace, add flux quartzite 2.5 kg, blow in oxygen with oxygen concentration of 24%, blowing temperature is 1200℃, blowing for 3h, output high nickel 2.6 kg, high nickel contains Ni 70%.

[0078] Grind the high nickel in the ball mill to 40-60 mesh, then roast in the roasting furnace. The roasting process first starts at 500℃, then gradually increases to 780℃, after roasting for 3h, further gradually increases to 1300℃, and roasts for another 1.5h to get roasted sand. The roasted sand contains Ni 78%, S 0.01%.

[0079] After the flue gas passes through waste heat recovery, it enters the electric dust collector, with dust concentration of 4-5g / Nm3 After dust removal, the flue gas enters the flue gas treatment system.

[0080] The calcined ore was reduced in an electric furnace at 1300℃ for 7 hours to obtain a refined nickel alloy containing 96.2% nickel and 3.5% iron. The refined nickel alloy was cast into an anode plate and electrolyzed in a concentrated nickel chloride solution. Nickel wire was used as the cathode. The solution exiting the cathode chamber was purified to remove iron and then returned to the cathode chamber to deposit nickel. The electrolyzed nickel was columnar and contained 99.96% Ni.

[0081] Example 3

[0082] according to Figure 1 The process flow shown recovers nickel from laterite nickel ore, and the specific steps are as follows:

[0083] 100 kg of laterite nickel ore (20% moisture content), 25 kg of coal, and 5 kg of gypsum were uniformly mixed and added to an oxygen-enriched side-blown furnace for reduction smelting. An oxygen-enriched furnace with an oxygen concentration of 60% was blown in, and the oxygen-to-material ratio was controlled at 300 Nm³. 3 / t, with the oxygen-coal combustion coefficient controlled at 0.5, the reduction smelting temperature controlled at 1150℃, and smelting for 5 hours, yielding 8.9 kg of low-grade nickel matte, containing 12% Ni.

[0084] 8.9 kg of low-grade nickel matte was fed into a hot refining furnace, 2.5 kg of flux quartz was added, and oxygen-enriched gas with an oxygen concentration of 21% was blown in. The refining temperature was 1200℃ and the refining time was 3 hours, producing 2.42 kg of high-grade nickel matte with a Ni content of 68%.

[0085] High-grade nickel matte was ground to 40-60 mesh in a ball mill and then calcined in a calcining furnace. The calcination process began at 480℃, then gradually increased to 780℃ for 3 hours, followed by a further gradual increase to 1200℃ and calcination for another 3 hours to obtain calcined sand. The calcined sand contained 77% Ni and 0.01% S.

[0086] After waste heat recovery, the flue gas enters the electrostatic precipitator, with a dust concentration of 4-5 g / Nm³. 3 After dust removal, the flue gas enters the flue gas treatment system.

[0087] The calcined ore was reduced in an electric furnace at 1000℃ for 8 hours to obtain a refined nickel alloy containing 95.4% nickel and 4% iron. The refined nickel alloy was cast into an anode plate and electrolyzed in a concentrated nickel chloride solution. Nickel wire was used as the cathode. The solution exiting the cathode chamber was purified to remove iron and then returned to the cathode chamber to deposit nickel. The electrolyzed nickel was columnar and contained 99.92% Ni.

Claims

1. A method for recovering nickel from laterite nickel ore, comprising the following steps: 1) First, dry the laterite nickel ore, then mix the dried laterite nickel ore with reducing coal and sulfiding agent evenly to obtain the batching. Then, send the batching to the oxygen-enriched side-blown furnace for reduction smelting. After smelting, low-grade nickel matte, side-blown furnace slag, and side-blown furnace dust are obtained. 2) Add flux to the low-grade nickel matte obtained in step 1), and smelt to obtain high-grade nickel matte and smelting slag; 3) The high-grade nickel matte obtained in step 2) is quenched in water, ground, and roasted to obtain calcined sand. Then, the calcined sand is reduced and smelted to obtain a refined nickel alloy. 4) Cast the refined nickel alloy obtained in step 3) into an anode plate, and electrolyze it to obtain electrolytic nickel; In step 1), during reduction smelting in an oxygen-enriched side-blown furnace, the oxygen concentration is 60%~85%, and the oxygen-to-material ratio is 200~400 Nm. 3 / t, the oxygen-to-coal ratio is expressed by the combustion coefficient and controlled at 0.5~0.9; the reduction temperature of the oxygen-enriched side-blown furnace is controlled at 1150~1550℃, and the reduction time is 1~5h; In step 2), the slag from the blowing process contains 26%~28% SiO2, 5%~8% Al2O3, 5%~8% CaO, and 1%~2% Ni; the high-grade nickel matte contains 68%~78% Ni, 21%~24% S, and 0.25%~0.5% Fe. In step 3), the roasting is carried out in two stages. First, the temperature is controlled at 450℃~500℃, and then gradually increased to 780℃~800℃, with a roasting time of 1~3 hours, which is the first stage. Then, the roasted slag is passed through a cylindrical cooler and crushed to below 200 mesh for the second stage of roasting, with the temperature increased from 700℃~800℃ to 1200℃~1300℃, and the roasting time is 1~3 hours. The roasted sand contains 77%~78% Ni, 0.01%~0.02% S, and 0.05% Fe.

2. The method according to claim 1, characterized in that, The mass percentage contents of NiO, SiO2, MgO, Fe2O3, CaO, Al2O3, Mn, S, and Cr in the laterite nickel ore are 1%~9%, 9%~42%, 0.2%~22%, 14%~60%, 0.1%~2.75%, 1%~25%, 0.1%~25%, 0.05%~0.2%, and 0.1%~2%, respectively.

3. The method according to claim 1, characterized in that, In step 1), the sulfiding agent is at least one of calcium sulfate, ferrous sulfide, and sulfur; the slag in the oxygen-enriched side-blown furnace contains 0.1%~0.25% Ni, 35%~45% SiO2, the sum of SiO2 and Al2O3 is not higher than 50%, FeO is 14%~18%, CaO and MgO are 34%~36%, and S is 0.45%~1%; the sum of Ni, Fe, and S in low-grade nickel matte is above 90%, of which S is below 25%.

4. The method according to claim 1, characterized in that, In step 2), the flux is quartz; the blowing temperature is 1200℃~1250℃, the blowing time is 1~3h; and the oxygen concentration during blowing is 21%~24%.

5. The method according to claim 1, characterized in that, In step 3), the reduction smelting of calcined sand is divided into the following processes: furnace charge reduction and softening, furnace charge melting and appearance of nickel metal, and nickel refining; the temperature for reduction smelting of calcined sand is 950℃~1500℃, and the time is 6~8h; the refined nickel alloy contains 95.6% nickel, 4% iron, and the waste slag contains 0.2~0.4% Ni.

6. The method according to claim 1, characterized in that, In step 4), the refined nickel alloy is cast into an anode plate, electrolyzed and refined in a nickel chloride solution, and the solution coming out of the cathode chamber is purified to remove iron and then returned to the cathode chamber to deposit nickel, thus obtaining electrolytic nickel; the electrolytic nickel contains 99.92% to 99.97% nickel.

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