Method for recovering valuable metals from iron-aluminum slag resources containing nickel and cobalt

Abstract

The invention discloses a method for recycling valuable metals from nickel-cobalt-containing iron-aluminum slag resources, and relates to the technical field of waste slag recycling. Comprising the following steps: roasting: mixing and roasting the nickel-cobalt-containing iron-aluminum slag and a chlorinating agent, and controlling the roasting temperature to obtain roasted slag and roasted flue gas; step-by-step condensation is carried out, and ferric chloride, aluminum chloride and zinc chloride in the roasting flue gas are recycled; or step-by-step condensation is carried out, and ferric chloride and aluminum chloride in the roasting flue gas are recycled; and nickel and cobalt in the roasting slag are leached and recycled. According to the method, iron, aluminum and zinc are preferentially volatilized and separated through roasting, iron, aluminum and zinc are prevented from entering the nickel-cobalt leaching solution in the leaching process, and nickel, cobalt, iron, aluminum and zinc in the iron-aluminum slag containing nickel and cobalt are effectively separated and recycled.

Description

Technical Field

[0001] The invention relates to the technical field of waste slag recycling, and in particular to a method for recovering valuable metals from iron-aluminum slag resources containing nickel and cobalt. Background Art

[0002] Ferroaluminum slag is produced during the wet preparation of ternary precursors or the wet recovery of valuable metals from retired lithium-ion batteries. In the acid leaching process, valuable metals such as nickel, cobalt, and manganese and iron and aluminum are dissolved into the solution through acid. In the impurity removal process, sodium hydroxide or sodium carbonate is added to adjust the pH value of the leaching solution to 3-5 to remove iron and aluminum impurities. Iron is precipitated as natrolite or iron hydroxide, and aluminum is precipitated as aluminum hydroxide. The resulting precipitate is filtered and washed to form ferroaluminum slag.

[0003] Since the ferroaluminum slag has a high content of valuable metals and has considerable comprehensive utilization value, if it is handled arbitrarily, it will not only bring potential environmental pollution and harm, but also lose valuable metals such as nickel and cobalt, affecting the nickel and cobalt yield and causing waste of resources. In order to recover the valuable metals in the ferroaluminum slag, some companies use the secondary "acid dissolution + precipitation" method to recover the valuable metals such as nickel, cobalt, and copper. Although this method can recover some valuable metals such as nickel, cobalt, and copper, the recovery rate is not high, the acid and alkali consumption is large, and the secondary ferroaluminum slag produced still contains high levels of heavy metals such as nickel, cobalt, and copper, and there will still be potential environmental pollution and harm; some companies use pyrometallurgical processes to treat ferroaluminum slag. Although the nickel and cobalt in the slag can also be recovered, the energy consumption is large, the cost is high, and the output is a nickel-sulfur intermediate, which cannot be directly used as a product. Summary of the invention

[0004] The present invention aims to solve at least one of the technical problems existing in the prior art or related art.

[0005] To this end, the present invention provides a method for recovering valuable metals from nickel-cobalt-containing iron-aluminum slag resources, comprising:

[0006] Roasting, mixing the nickel-cobalt-containing iron-aluminum slag with a chlorinating agent and roasting, controlling the roasting temperature to obtain roasting slag and roasting fume;

[0007] Step-by-step condensation to recover ferric chloride, aluminum chloride and zinc chloride in the roasting flue gas; or, step-by-step condensation to recover ferric chloride and aluminum chloride in the roasting flue gas;

[0008] Leaching to recover nickel and cobalt in the roasted slag.

[0009] Furthermore, the controlling of the roasting temperature comprises:

[0010] When the mass fraction of zinc in the nickel-cobalt-containing iron-aluminum slag is ≤0.3%, the roasting temperature is controlled to be 400° C. to 600° C.;

[0011] When the mass fraction of zinc in the nickel-cobalt-containing iron-aluminum slag is greater than 0.3%, the roasting temperature is controlled to be 750°C to 900°C.

[0012] Furthermore, the stepwise condensation comprises:

[0013] When the roasting temperature is 400°C to 600°C, the condensation temperature is controlled to be 180°C to 280°C to recover ferric chloride, and the condensation temperature is controlled to be 50°C to 150°C to recover aluminum chloride;

[0014] When the roasting temperature is 750°C to 900°C, the condensation temperature is controlled to be 300°C to 600°C to recover zinc chloride, the condensation temperature is controlled to be 180°C to 280°C to recover ferric chloride, and the condensation temperature is controlled to be 50°C to 150°C to recover aluminum chloride.

[0015] Furthermore, the chlorinating agent is selected from one or more of hydrogen chloride, ammonium chloride, carbon tetrachloride, sodium chloride, calcium chloride and potassium chloride.

[0016] Furthermore, the chlorinating agent is hydrogen chloride and / or ammonium chloride, and the added amount of the chlorinating agent is 1.2 to 1.4 times the theoretical molar amount.

[0017] Furthermore, the calcination atmosphere is an inert gas or an oxidizing gas.

[0018] Furthermore, when the nickel-cobalt-containing iron-aluminum slag contains divalent iron, the roasting atmosphere is an oxidizing gas to convert the divalent iron into trivalent iron.

[0019] Further, the leaching comprises:

[0020] The calcined slag is leached with a leaching agent to obtain a nickel-cobalt leaching solution and leached slag, and the nickel-cobalt leaching solution is used to prepare a ternary precursor.

[0021] Furthermore, the liquid-solid mass ratio of the leaching agent to the roasted slag is controlled to be 2-5:1, the pH value at the leaching endpoint is 1-1.5, and the leaching temperature is 50°C-80°C.

[0022] Furthermore, when the copper content in the nickel-cobalt leaching solution is ≥0.1 g / L, the nickel-cobalt leaching solution also includes copper removal before being used to prepare the ternary precursor; wherein the copper removal method is: adding manganese powder or iron powder to the nickel-cobalt leaching solution, and the amount of manganese powder or iron powder added is 1.2 to 1.6 times the theoretical molar amount.

[0023] Compared with the prior art, the present invention has at least the following beneficial effects:

[0024] The method for recovering valuable metals from ferroaluminum slag containing nickel and cobalt provided by the present invention preferentially volatilizes and separates iron, aluminum and zinc through roasting, thereby avoiding the iron, aluminum and zinc from entering the nickel-cobalt leaching solution during the leaching process, and realizing effective separation and recovery of nickel, cobalt, iron, aluminum and zinc in the ferroaluminum slag containing nickel and cobalt. DETAILED DESCRIPTION

[0025] In order to better understand the above technical solution, the technical solution of the present application is described in detail below through specific embodiments.

[0026] The embodiment of the present invention provides a method for recovering valuable metals from iron-aluminum slag resources containing nickel and cobalt, comprising:

[0027] Roasting, mixing the nickel-cobalt-containing iron-aluminum slag with a chlorinating agent and roasting, controlling the roasting temperature to obtain roasting slag and roasting fume;

[0028] Step-by-step condensation to recover ferric chloride, aluminum chloride and zinc chloride in the roasting flue gas; or, step-by-step condensation to recover ferric chloride and aluminum chloride in the roasting flue gas;

[0029] Leaching to recover nickel and cobalt in the roasted slag.

[0030] The method for recovering valuable metals from the iron-aluminum slag containing nickel and cobalt provided in the embodiment of the present invention can effectively separate and recover nickel, cobalt, iron, aluminum and zinc from the iron-aluminum slag containing nickel and cobalt, and the process is simple, novel, low-cost, easy to operate, and has a high recovery rate of valuable metals. It is environmentally friendly and suitable for industrial production. During the roasting process, iron, aluminum and zinc volatilize in the form of roasting flue gas, which achieves preferential volatilization and separation of iron, aluminum and zinc, and avoids iron, aluminum and zinc from entering the nickel-cobalt leachate during the leaching process, resulting in a high content of iron, aluminum and zinc impurities in the nickel-cobalt leachate. The preferential volatilization and separation of iron, aluminum and zinc reduces the difficulty of subsequent separation and purification of the nickel-cobalt leachate. The method for recovering valuable metals from the iron-aluminum slag containing nickel and cobalt provided in the embodiment of the present invention obtains a nickel-cobalt leachate, an aluminum chloride product, an iron chloride product and a zinc chloride product, wherein the nickel-cobalt leachate can be directly used to produce a ternary precursor, and the aluminum chloride product, the iron chloride product and the zinc chloride product can be sold to obtain revenue, which can maximize the utilization of the iron-aluminum slag containing nickel and cobalt.

[0031] In a feasible implementation manner, controlling the roasting temperature comprises:

[0032] When the mass fraction of zinc in the nickel-cobalt-containing iron-aluminum slag is ≤0.3%, the roasting temperature is controlled to be 400° C. to 600° C., the roasting time is 1 to 5 hours, the leaching recovery rate of nickel is greater than 96%, the leaching recovery rate of cobalt is greater than 98%, the volatilization rate of iron is greater than 96%, and the volatilization rate of aluminum is greater than 97%; at this time, the ferric chloride and aluminum chloride in the roasting flue gas are recovered by stepwise condensation;

[0033] When the mass fraction of zinc in the nickel-cobalt-containing iron-aluminum slag is greater than 0.3%, the roasting temperature is controlled to be 750° C. to 900° C., the roasting time is 1 to 5 hours, the leaching recovery rate of nickel is greater than 94%, the leaching recovery rate of cobalt is greater than 97%, the volatilization rate of zinc is greater than 92%, the volatilization rate of iron is greater than 98%, and the volatilization rate of aluminum is greater than 98%; at this time, the ferric chloride, aluminum chloride and zinc chloride in the roasting flue gas are recovered by step-by-step condensation.

[0034] Specifically, the roasting device can be a resistance furnace, a smelting furnace or an arc furnace. If the mass fraction of zinc in the iron-aluminum slag containing nickel and cobalt is ≤0.3%, the roasting temperature is controlled to be 400°C to 600°C. At this roasting temperature, both iron and aluminum can form chloride gas, and the roasting temperature is preferably controlled to be 450°C to 500°C; during the step-by-step condensation, the first step condensation temperature is controlled at 180 to 280°C to recover ferric chloride, preferably the first step condensation temperature is controlled at 200 to 250°C to recover ferric chloride, and by controlling the first step condensation temperature, the condensation product ferric chloride impurity content is low; the second step condensation temperature is controlled at 50 to 150°C to recover aluminum chloride, preferably the second step condensation temperature is controlled at 80 to 120°C to recover aluminum chloride, and by controlling the second step condensation temperature, the condensation product aluminum chloride impurity content is low. It can be understood that the condensation temperature affects the iron, aluminum and zinc content of the condensation product, and the impurity content of the condensation product is low by controlling the condensation temperature.

[0035] Furthermore, if the mass fraction of zinc in the iron-aluminum slag containing nickel and cobalt is greater than 0.3%, the roasting temperature is controlled to be 750°C to 900°C. At this roasting temperature, iron, aluminum and zinc can all form chloride gas, and the roasting temperature is preferably controlled to be 800°C to 880°C; during the step-by-step condensation, the first step condensation temperature is controlled to be 300°C to 600°C to recover zinc chloride, and preferably the first step condensation temperature is controlled to be 400°C to 500°C to recover zinc chloride. By controlling the first step condensation temperature, the impurity content of the condensed product zinc chloride is low; the second step condensation temperature is controlled to be 180°C to 280°C to recover ferric chloride, and preferably the second step condensation temperature is controlled to be 200°C to recover ferric chloride. By controlling the second step condensation temperature, the impurity content of the condensed product ferric chloride is low; the third step condensation temperature is controlled to be 50°C to 150°C to recover aluminum chloride, and preferably the third step condensation temperature is controlled to be 80°C to recover aluminum chloride. By controlling the third step condensation temperature, the impurity content of the condensed product aluminum chloride is low.

[0036] It is understandable that the roasting temperature affects the volatilization rate of iron, aluminum and zinc and the leaching recovery rate of nickel and cobalt. Referring to the boiling point of metal chlorides in Table 1, the roasting temperature should be higher than the boiling point of iron, aluminum and zinc chlorides to ensure that iron, aluminum and zinc form chloride gas after roasting, but the roasting temperature should not be higher than the boiling point of nickel and cobalt chlorides. If the roasting temperature is higher than the boiling point of nickel and cobalt chlorides, nickel and cobalt will also form chloride gas after roasting, resulting in nickel and cobalt losses, and the nickel and cobalt leaching recovery rate will be reduced in the subsequent leaching stage.

[0037] In a feasible implementation, the roasting atmosphere is an inert gas or an oxidizing gas. The inert gas includes at least one of nitrogen, helium or argon. When the nickel-cobalt-containing iron-aluminum slag contains divalent iron, the roasting atmosphere is an oxidizing gas. This is because the boiling point of ferric chloride is much lower than that of ferrous chloride. See Table 1. The oxidizing roasting atmosphere is used to convert divalent iron into ferric iron so that the ferric chloride can be recovered in the step-by-step condensation stage.

[0038] Table 1 Boiling points of metal chlorides (℃)

[0039] chloride Ferric chloride Ferrous chloride Zinc chloride Cupric chloride Calcium chloride Nickel chloride Cobalt chloride Aluminum Chloride Manganese chloride Boiling point(℃) 315 1023 732 993 1600 973 1049 178 1190

[0040] In a feasible embodiment, the chlorinating agent is selected from one or more of hydrogen chloride, ammonium chloride, carbon tetrachloride, sodium chloride, calcium chloride, and potassium chloride.

[0041] It is understandable that the chlorinating agent is preferably hydrogen chloride and / or ammonium chloride, and no other impurities are introduced; it is found in experiments that when the amount of the chlorinating agent added is 1.2 to 1.4 times the theoretical molar amount, the roasting effect is better, that is, the effect of the iron, aluminum and zinc in the iron-aluminum slag generating chloride salts is better.

[0042] Specifically, in the roasting process, a chlorinating agent (for example, hydrogen chloride) is used for high-temperature roasting, which belongs to chlorination roasting, and the chemical equation of the reaction is as follows:

[0043] Fe2O3+6HCl(g)=2FeCl3(g)+3H2O(g);

[0044] 2Al+6HCl(g)=2AlCl3(g)+3H2(g).

[0045] During chlorination roasting, nickel, cobalt and other substances contained in the iron-aluminum slag do not participate in the chlorination reaction and continue to remain in the roasting slag.

[0046] In a feasible implementation manner, the leaching comprises: leaching the roasted slag with a leaching agent to obtain a nickel-cobalt leaching solution and leaching slag, and the nickel-cobalt leaching solution is used to prepare a ternary precursor.

[0047] Specifically, in the leaching process, the roasted slag reacts with sulfuric acid, and the chemical equation is:

[0048] M 2+ (Ni, Co) + H2SO4 = M 2+ SO4+2H + ;

[0049] The liquid-solid mass ratio of the leaching agent to the roasted slag is controlled to be 2-5:1, the pH value of the leaching end point is 1-1.5, and the leaching temperature is 50° C.-80° C. Under these conditions, the nickel-cobalt leaching effect is good and the leaching recovery rate is high, thereby realizing the effective recovery of nickel and cobalt in the iron-aluminum slag.

[0050] In a feasible embodiment, when the copper content in the nickel-cobalt leaching solution is ≥0.1 g / L, the nickel-cobalt leaching solution is further subjected to copper removal before being used to prepare the ternary precursor; wherein the copper removal method is: adding manganese powder or iron powder to the nickel-cobalt leaching solution, wherein the amount of manganese powder or iron powder added is 1.2 to 1.6 times the theoretical molar amount.

[0051] Specifically, if the copper content in the nickel-cobalt leaching solution is high, the process of removing copper by adding manganese powder or iron powder to the nickel-cobalt leaching solution is also included. The amount of manganese powder or iron powder added is 1.2 to 1.6 times the theoretical molar amount. The nickel-cobalt purified liquid and sponge copper are obtained by filtration. The nickel-cobalt purified liquid is sent to the company's production system for the preparation of a ternary precursor, and the sponge copper is sold as a product.

[0052] Example 1

[0053] The composition of the nickel-cobalt-containing ferroaluminum slag in Example 1 is shown in Table 2. The mass fraction of zinc in Example 1 is less than 0.3%. A method for recovering valuable metals from ferroaluminum slag containing nickel and cobalt comprises the following steps:

[0054] (1) Grinding 100 g of nickel-cobalt-containing iron-aluminum slag with a certain amount of ammonium chloride solid, the amount added being based on a molar ratio of chlorine in the ammonium chloride to iron and aluminum in the iron-aluminum slag of 1.3:1; placing the mixed materials into a porcelain boat, and then pushing it into the constant temperature area of ​​a tube furnace;

[0055] (2) Argon gas is introduced into the tubular furnace to completely exhaust the air in the tubular furnace, and the heating device of the tubular furnace is turned on to raise the temperature to 450°C. The temperature is kept for roasting for 1 hour. The flue gas generated during the roasting process is condensed in stages through a pipeline, wherein the first stage condensation temperature is controlled at 220-240°C to obtain ferric chloride; the second stage condensation temperature is controlled at 100-130°C to obtain aluminum chloride. After the roasting is completed, the roasting slag is taken out of the tubular furnace and sent to the subsequent leaching process.

[0056] (3) 30 g of calcined slag was acid-leached at a leaching temperature of 60° C. and a liquid-to-solid mass ratio of 3:1 for 2 hours. The end point pH of the solution was controlled to be 1.0 during the leaching process. After the leaching was completed, the nickel-cobalt leaching solution and leaching slag were filtered to obtain.

[0057] (4) adding manganese powder to the nickel-cobalt leaching solution to remove copper, wherein the added amount is based on a molar ratio of manganese in the manganese powder to copper in the nickel-cobalt leaching solution of 1.5:1; after the reaction is completed, filtering is performed to obtain a nickel-cobalt purified solution and sponge copper.

[0058] Unless otherwise specified, the volatility of iron, aluminum and zinc in this application is calculated using the following method. By analyzing the initial amount and residual amount of metal elements in the sample, the volatility of each metal element is calculated according to the following formula: α = 1-CM / C0M0. In the formula, α is the volatility of the metal element; C0 is the concentration of the metal element in the iron-aluminum slag sample before roasting, mg·g -1 ; M0 is the amount of iron-aluminum slag sample added before roasting, g; C is the concentration of metal elements in the residue after roasting, mg·g -1 ; M is the total mass of the residue after roasting, g.

[0059] Sampling was performed to detect the iron and aluminum content in the slag before and after roasting, and the volatilization rates of iron and aluminum during roasting were calculated. The results showed that the volatilization rates of iron were 96.51% and the volatilization rates of aluminum were 97.43%; sampling was performed to detect the content of each element in the first and second condensation products after roasting, as shown in Table 3 below. As can be seen from Table 3, the recovered first-stage condensation product mainly contains iron with low impurity content; the second-stage condensation product mainly contains aluminum with low impurity content; the condensation product can be directly sold as a product. The nickel-cobalt leaching solution was analyzed for composition and the nickel and cobalt leaching recovery rates were calculated, indicating that the leaching recovery rates of nickel and cobalt were 96.12% and 98.46%, respectively.

[0060] Example 2

[0061] The composition of the nickel-cobalt-containing ferroaluminum slag in Example 2 is shown in Table 2. The mass fraction of zinc in Example 2 is greater than 0.3%. A method for recovering valuable metals from nickel-cobalt-containing ferroaluminum slag resources comprises the following steps:

[0062] (1) 100 g of nickel-cobalt-containing iron-aluminum slag was placed in a porcelain boat and then pushed into the constant temperature area of ​​a tube furnace;

[0063] (2) Argon gas is introduced into the tubular furnace to completely exhaust the air in the tubular furnace, and then hydrogen chloride gas is introduced into the tubular furnace at a rate of 120 mL / min. The heating device of the tubular furnace is turned on to raise the temperature to 800°C, and the temperature is kept for roasting for 3 hours. The flue gas generated during the roasting process is condensed in stages through a pipeline, wherein the first stage condensation temperature is controlled at 330-360°C to obtain zinc chloride; the second stage condensation temperature is controlled at 180-210°C to obtain ferric chloride; the third stage condensation temperature is controlled at 60-90°C to obtain aluminum chloride. After the roasting is completed, the roasting slag is taken out of the tubular furnace and sent to the subsequent leaching process.

[0064] (3) 30 g of calcined slag was acid-leached at a leaching temperature of 60° C. and a liquid-to-solid mass ratio of 3:1 for 2 hours. The end point pH of the solution was controlled to be 1.5 during the leaching process. After the leaching was completed, the nickel-cobalt leaching solution and leaching slag were filtered to obtain.

[0065] Sampling was performed to detect the content of zinc, iron and aluminum in the slag before and after roasting, and the volatilization rates of zinc, iron and aluminum during roasting were calculated. The results showed that the volatilization rates of zinc, iron and aluminum were 92.10%, 98.94% and 98.24% respectively. The content of each element in the first, second and third condensation products after roasting was tested by sampling, as shown in Table 3 below. As can be seen from Table 3, the recovered first condensation product mainly contains zinc with low impurity content; the recovered second condensation product mainly contains iron with low impurity content; the third condensation product mainly contains aluminum with low impurity content; the condensation product can be directly sold as a product. The nickel-cobalt leaching solution was analyzed for composition and the nickel and cobalt leaching recovery rates were calculated, indicating that the leaching recovery rates of nickel and cobalt were 94.51% and 97.04% respectively.

[0066] Comparative Example 1

[0067] The difference between Comparative Example 1 and Example 1 is that: (2) Argon gas is introduced into the tubular furnace to completely exhaust the air in the tubular furnace, the heating device of the tubular furnace is turned on to raise the temperature to 300°C, and the temperature is kept for roasting for 1 hour. The iron and aluminum contents in the slag before and after roasting are sampled and tested, and the volatilization rates of iron and aluminum during roasting are calculated. The results show that the volatilization rate of iron is 52.38%, and the volatilization rate of aluminum is 94.13%; the leaching recovery rates of nickel and cobalt are 97.33% and 97.17%, respectively.

[0068] Comparative Example 2

[0069] The difference between Comparative Example 2 and Example 1 is that in step (2), the second stage condensation temperature is controlled at 180-210° C. to obtain aluminum chloride. The content of each element in the first and second stage condensation products after calcination was detected by sampling, as shown in Table 3 below. It can be seen from the table that the aluminum content in the second stage condensation product is significantly reduced, affecting the aluminum yield.

[0070] Comparative Example 3

[0071] The difference between Comparative Example 3 and Example 1 is that in step (2), the first stage condensation temperature is controlled at 350-400° C. to obtain ferric chloride. The content of each element in the first stage and second stage condensation products after roasting was detected by sampling, as shown in Table 3 below. As can be seen from Table 3, the iron content in the first stage condensation product is significantly reduced, and the iron content in the second stage condensation product is significantly increased, which affects the quality of the second stage condensation product.

[0072] Comparative Example 4

[0073] The difference between Comparative Example 4 and Example 2 is that: in step (2), the tubular furnace heating device is turned on to raise the temperature to 650°C, and the mixture is kept warm for 3 hours. Samples are taken to detect the contents of zinc, iron and aluminum in the slag before and after roasting, and the volatilization rates of zinc, iron and aluminum during the roasting process are calculated. The results show that the volatilization rate of zinc is 68.96%, the volatilization rate of iron is 98.36%, and the volatilization rate of aluminum is 98.19%; the leaching recoveries of nickel and cobalt are 95.88% and 97.91%, respectively.

[0074] Comparative Example 5

[0075] The difference between Comparative Example 5 and Example 2 is that in step (2), the first stage condensation temperature is controlled at 650-700°C to obtain zinc chloride. Samples were taken to detect the content of each element in the first, second and third stage condensation products after roasting, as shown in Table 3 below. As can be seen from Table 3, the zinc content in the first stage condensation product is significantly reduced, and the zinc content in the second stage condensation product is significantly increased, which affects the quality of the second stage condensation product.

[0076] Table 2 Iron-aluminum slag containing nickel and cobalt

[0077] Element(%) Ni Co Fe Al Ca Cu Zn <![CDATA[H2O]]> Example 1 6.07 0.41 6.93 1.75 0.02 3.39 0.15 60.41 Example 2 7.13 0.57 5.67 2.14 0.01 0.05 1.46 63.17

[0078] Table 3 Condensation products of the embodiments and comparative examples

[0079]

[0080] It is easy for those skilled in the art to understand that, under the premise of no conflict, the above-mentioned advantageous methods can be freely combined and superimposed. The above are only preferred embodiments of the present application and are not intended to limit the present application. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present application should be included in the protection scope of the present application. The above are only preferred implementation methods of the present application. It should be pointed out that for ordinary technicians in this technical field, several improvements and variations can be made without departing from the technical principles of the present application, and these improvements and variations should also be regarded as the protection scope of the present application.

Claims

1. A method for recovering valuable metals from iron-aluminum slag containing nickel and cobalt, characterized in that: include: Roasting, mixing the nickel-cobalt-containing iron-aluminum slag with a chlorinating agent and roasting, controlling the roasting temperature to obtain roasting slag and roasting fume; Step-by-step condensation to recover ferric chloride, aluminum chloride and zinc chloride in the roasting flue gas; or, step-by-step condensation to recover ferric chloride and aluminum chloride in the roasting flue gas; Leaching to recover nickel and cobalt in the roasted slag.

2. The method for recovering valuable metals from nickel-cobalt-containing iron-aluminum slag resources according to claim 1, characterized in that: The controlling of the roasting temperature comprises: When the mass fraction of zinc in the nickel-cobalt-containing iron-aluminum slag is ≤0.3%, the roasting temperature is controlled to be 400° C. to 600° C.; When the mass fraction of zinc in the nickel-cobalt-containing iron-aluminum slag is greater than 0.3%, the roasting temperature is controlled to be 750°C to 900°C.

3. The method for recovering valuable metals from nickel-cobalt-containing iron-aluminum slag resources according to claim 2, characterized in that: The stepwise condensation comprises: When the roasting temperature is 400°C to 600°C, the condensation temperature is controlled to be 180°C to 280°C to recover ferric chloride, and the condensation temperature is controlled to be 50°C to 150°C to recover aluminum chloride; When the roasting temperature is 750°C to 900°C, the condensation temperature is controlled to be 300°C to 600°C to recover zinc chloride, the condensation temperature is controlled to be 180°C to 280°C to recover ferric chloride, and the condensation temperature is controlled to be 50°C to 150°C to recover aluminum chloride.

4. The method for recovering valuable metals from nickel-cobalt-containing iron-aluminum slag resources according to any one of claims 1 to 3, characterized in that: The chlorinating agent is selected from one or more of hydrogen chloride, ammonium chloride, carbon tetrachloride, sodium chloride, calcium chloride and potassium chloride.

5. The method for recovering valuable metals from nickel-cobalt-containing iron-aluminum slag resources according to claim 4, characterized in that: The chlorinating agent is hydrogen chloride and / or ammonium chloride, and the added amount of the chlorinating agent is 1.2 to 1.4 times of the theoretical molar amount.

6. The method for recovering valuable metals from nickel-cobalt-containing iron-aluminum slag resources according to any one of claims 1 to 3, characterized in that: The calcination atmosphere is an inert gas or an oxidizing gas.

7. The method for recovering valuable metals from nickel-cobalt-containing iron-aluminum slag resources according to claim 6, characterized in that: When the nickel-cobalt-containing ferroaluminum slag contains divalent iron, the roasting atmosphere is an oxidizing gas to convert the divalent iron into trivalent iron.

8. The method for recovering valuable metals from nickel-cobalt-containing iron-aluminum slag resources according to any one of claims 1 to 3, characterized in that: The leaching comprises: The calcined slag is leached with a leaching agent to obtain a nickel-cobalt leaching solution and leached slag, and the nickel-cobalt leaching solution is used to prepare a ternary precursor.

9. The method for recovering valuable metals from nickel-cobalt-containing iron-aluminum slag resources according to claim 8, characterized in that: The liquid-solid mass ratio of the leaching agent to the roasted slag is controlled to be 2-5:1, the pH value of the leaching end point is 1-1.5, and the leaching temperature is 50°C-80°C.

10. The method for recovering valuable metals from nickel-cobalt-containing iron-aluminum slag resources according to claim 8, characterized in that: When the copper content in the nickel-cobalt leaching solution is ≥0.1 g / L, the nickel-cobalt leaching solution further includes copper removal before being used to prepare the ternary precursor; wherein the copper removal method is: adding manganese powder or iron powder to the nickel-cobalt leaching solution, and the amount of manganese powder or iron powder added is 1.2 to 1.6 times the theoretical molar amount.

Images