Method and apparatus for separating iron from nickel-iron alloy

Abstract

The present invention relates to the field of resource utilization, and provides a method and an apparatus for separating iron from a nickel-iron alloy. The method comprises the following steps: roasting a nickel-iron alloy in a chlorine atmosphere, to obtain a ferrous chloride melt and a solid slag, and separating the ferrous chloride melt therefrom, the mass of chlorine being 0.8-1.5 times the mass of the nickel-iron alloy, and the roasting temperature being 600-850 °C. Chlorine is introduced into the ferrous chloride melt to perform a chlorination reaction, converting the ferrous chloride melt into ferric chloride gas. The ferric chloride gas is then condensed to obtain a solid ferric chloride product. The described method for separating iron from the nickel-iron alloy implements preferential chlorination of the iron in the alloy by means of controlling chlorination conditions, converting same into molten ferrous chloride. The ferrous chloride is then converted into gaseous ferric chloride, which is cooled to obtain ferric chloride. The process is simple, the procedure is short, and high-quality ferric chloride is obtained.

Description

Method and apparatus for separating iron from nickel-iron alloy

[0001] Cross-reference to related applications

[0002] This application is based on and claims priority to Chinese Patent Application No. 202410981328.X, filed on July 22, 2024, entitled “Method and Apparatus for Separating Iron from Nickel-Iron Alloy”, the full text of which is incorporated herein by reference as a part of this application. [Technical Field]

[0003] This invention relates to the field of resource utilization, and in particular to a method and apparatus for separating iron from nickel-iron alloys. [Background Technology]

[0004] The efficient and precise separation of valuable elements from alloys, including scrap alloys such as copper-cobalt alloys and waste high-temperature alloys, has always been a research challenge. Currently, methods for the resource utilization of scrap alloys include mechanical crushing, zinc melting, oxidation-reduction, electrochemical methods, and bioleaching. However, due to the stubborn properties of alloys, such as high hardness, density, corrosion resistance, and wear resistance, and the fact that many elements exist in the form of intermetallic compounds, most processes employ high-efficiency, high-temperature, high-volume, and high-energy-consumption metallurgical methods, resulting in long process flows, heavy environmental impact, and high energy consumption. Therefore, there is an urgent need to develop short-process, high-efficiency, high-quality, and low-cost scrap alloy processing technologies.

[0005] The aforementioned method for high-value utilization of nickel-iron alloys primarily involves first using reagents to wet leach the alloy, thereby disrupting its dense structure and allowing nickel and iron to enter the solution. Subsequent purification and extraction of valuable metals follow. However, this method lacks selectivity, as both nickel and iron are introduced into the leaching solution during the leaching process, leading to lengthy subsequent purification and separation steps. [Summary of the Invention]

[0006] The main objective of this invention is to provide a method and apparatus for separating iron from nickel-iron alloys, so as to solve the technical problem of long and numerous steps in the leaching process for separating nickel and iron.

[0007] To achieve the above objectives, the present invention provides a method for separating iron from a nickel-iron alloy, comprising the following steps:

[0008] The nickel-iron alloy is calcined in a chlorine atmosphere to obtain ferrous chloride melt and solid slag, and the ferrous chloride melt is separated. The mass of the chlorine gas is 0.8 to 1.5 times the mass of the nickel-iron alloy, and the calcination temperature is 500 to 850°C.

[0009] Chlorine gas is introduced into the ferrous chloride melt to carry out a chlorination reaction, thereby converting the ferrous chloride melt into ferric chloride gas.

[0010] The ferric chloride gas was condensed to obtain solid ferric chloride product.

[0011] In some embodiments of the present invention, in the step of introducing chlorine gas into the ferrous chloride melt for reaction, the chlorination temperature is 400-700°C, and the amount of chlorine gas introduced is 0.25-0.35 times the mass of the ferrous chloride melt.

[0012] In some embodiments of the present invention, in the step of condensing the ferric chloride gas, the ferric chloride gas is condensed to 100-250°C.

[0013] In some embodiments of the present invention, chlorine gas is introduced into the bottom of the nickel-iron alloy for roasting.

[0014] This application also provides an apparatus for separating iron from a nickel-iron alloy, comprising:

[0015] A roasting furnace includes a furnace body and a first chlorine gas inlet. The furnace body has a cavity for accommodating the nickel-iron alloy. The first chlorine gas inlet is connected to the cavity, and the mass of the chlorine gas introduced is 0.8 to 1.5 times the mass of the nickel-iron alloy. The roasting temperature inside the furnace is 500 to 850°C.

[0016] The separation mechanism is connected to the receiving cavity and separates the ferrous chloride melt generated in the furnace.

[0017] The chlorination reaction chamber has a second chlorine gas inlet and is connected to a separation mechanism to receive the ferrous chloride melt.

[0018] The condensation mechanism is connected to the chlorination reaction chamber and condenses the ferric chloride gas generated in the chlorination reaction chamber to produce solid ferric chloride product.

[0019] A collection mechanism, located below the condensation mechanism, collects the solid ferric chloride product.

[0020] In some embodiments of the present invention, the furnace body is cylindrical, and the ratio of the height to the diameter of the furnace body is (8-20):1. The first chlorine gas inlet is located at the bottom of the furnace body. The temperature control component of the roasting furnace is located at 1 / 4 to 1 / 2 of the height of the furnace body from the bottom.

[0021] In some embodiments of the present invention, the separation mechanism includes a filter plate embedded in the bottom of the furnace body, the filter plate having a pore size of 0.1 to 0.2 mm.

[0022] The device for separating iron from nickel-iron alloy also includes a melt collection tank, which is connected to the furnace body and communicates with the receiving cavity through the filter plate.

[0023] In some embodiments of the present invention, the chlorination reaction chamber is located below the furnace body.

[0024] The device for separating iron from nickel-iron alloy also includes a communicating vessel. The diameter of the communicating vessel is 1 / 8 of the diameter of the furnace body. One end of the communicating vessel is connected to the melt collection tank, and the other end is connected to the chlorination reaction chamber.

[0025] In some embodiments of the present invention, the chlorination reaction chamber has a gaseous ferric chloride rising channel on the side away from the communicating vessel, and the gaseous ferric chloride rising channel is connected to the condensation mechanism.

[0026] In some embodiments of the present invention, the collecting mechanism is a conical structure, the diameter of which matches the bottom of the condensation mechanism. Beneficial effects:

[0027] In the above-described method for separating iron from nickel-iron alloys, the preferential chlorination of iron in the alloy is achieved by controlling the chlorination conditions, transforming it into molten ferrous chloride. The ferrous chloride is then converted into gaseous ferric chloride, volatilized, and cooled to obtain ferric chloride. The elemental behavior of iron in the alloy involves a continuous process, transforming from a solid alloy to liquid ferrous chloride and then to gaseous ferric chloride. Furthermore, the reaction can be well controlled during the vaporization of molten ferrous chloride with chlorine gas, thus yielding high-quality ferric chloride. This method for separating iron from nickel-iron alloys is simple to operate, has a short process flow, and produces high-quality ferric chloride. [Attached Image Description]

[0028] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0029] Figure 1 is a flowchart of a method for separating iron from a nickel-iron alloy according to an embodiment of this application;

[0030] Figure 2 is a schematic diagram of the structure of a nickel-iron alloy iron separation device according to an embodiment of this application.

[0031] Explanation of reference numerals in the attached drawings: 100, calcining furnace; 200, separation mechanism; 300, chlorination reaction chamber; 400, condensation mechanism; 500, collection mechanism; 600, melt collection tank; 700, communicating vessel; 110, furnace body; 120, feeding assembly; 130, temperature control assembly; 140, slag outlet; 150, first chlorine gas inlet; 310, chlorination oxidation reaction chamber; 320, gaseous ferric chloride rising channel; 330, second chlorine gas inlet; 410, condensation chamber; 420, temperature control assembly; 510, discharge switch.

Detailed Implementation Methods

[0032] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0033] It should be noted that all directional indicators (such as up, down, etc.) in the embodiments of the present invention are only used to explain the relative positional relationship and movement of each component in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indicator will also change accordingly.

[0034] Furthermore, in this invention, descriptions involving "first," "second," etc., are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of that feature.

[0035] Furthermore, the technical solutions of the various embodiments of the present invention can be combined with each other, but only if they are based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such combination of technical solutions does not exist and is not within the scope of protection claimed by the present invention.

[0036] This invention provides a method for separating iron from a nickel-iron alloy, as shown in Figure 1, comprising the following steps:

[0037] S100: The nickel-iron alloy is calcined in a chlorine atmosphere to obtain ferrous chloride melt and solid slag, and the ferrous chloride melt is separated. The mass of the chlorine gas is 0.8 to 1.5 times the mass of the nickel-iron alloy, and the calcination temperature is 500 to 850°C.

[0038] This invention provides a method for separating iron from nickel-iron alloys. The overall concept is as follows: by controlling the chlorination conditions, preferential chlorination of the iron in the alloy is achieved, converting it into molten ferrous chloride. The unreacted nickel-iron alloy and the resulting solid slag are both solids, while the molten ferrous chloride is liquid and easily separated from the solids, such as by filtration or centrifugation. Specifically, in some embodiments, filter holes are provided at the bottom of the nickel-iron alloy reaction vessel (such as a calcining furnace), so that the molten ferrous chloride is filtered out from the bottom of the vessel.

[0039] In a subsequent step, chlorine gas is introduced into the obtained molten ferrous chloride, causing the ferrous chloride to convert into gaseous ferric chloride and volatilize. The gaseous ferric chloride is then condensed to obtain solid ferric chloride, thus completing the separation of iron from the nickel-iron alloy.

[0040] The nickel-iron alloys in this application are alloys whose main components are nickel and iron, and are smelting intermediates. In some embodiments, the nickel-iron alloys in this application are nickel-iron alloys obtained by pyrometallurgical smelting of laterite nickel ore, such as those obtained by the RK-EF process (Rotary Klin Electric Furnace), rotary kiln direct reduction-magnetic separation process, and rotary hearth furnace-melting furnace process. In some specific embodiments, the composition of the nickel-iron alloy is shown in Table 1.

[0041] Table 1: Chemical composition (wt%) of nickel-iron alloys

[0042] In step S100, the mass ratio of chlorine gas to the nickel-iron alloy and the calcination temperature are controlled to achieve preferential chlorination of iron in the alloy. When the calcination temperature and chlorine content are too high, both nickel and iron will form chlorides; nickel will form gaseous nickel chloride, and iron will form gaseous ferrous chloride or gaseous ferric chloride, thus failing to achieve solid-liquid separation. Conversely, when the calcination temperature and chlorine content are too low, less or no ferric chloride will be formed from iron, again failing to achieve solid-liquid separation.

[0043] The specific roasting time is not required, as long as ferrous chloride melt is produced. In some embodiments, a continuous method for separating iron from the nickel-iron alloy is used. Since the total amount of nickel-iron alloy is relatively large, in step S100, during the continuous reaction, a large amount of nickel-iron alloy is added at once or continuously. During roasting, ferrous chloride melt and solid slag are continuously generated. As the reaction proceeds, the solid slag from the completed reaction can also be separated.

[0044] In some specific embodiments, the mass of the chlorine gas is 0.8 to 1.5 times the mass of the nickel-iron alloy, and the calcination temperature is 600 to 800°C.

[0045] In the S100 step, possible reaction equations include:

[0046] Ni-Fe+Cl2(g)→FeCl2(l)+NiCl2(s)+Ni(s), FeCl2(l)+Cl2(g)→FeCl3(g), FeCl3(g)+Fe(s)→FeCl2(l); FeCl3(g)→Cl2(g)+FeCl2(g).

[0047] First, this application controls the reaction conditions, and the amount of chlorine added is relatively small. Therefore, it is not easy for FeCl2(l) to continue reacting to produce FeCl3(g).

[0048] Secondly, due to the relatively small amount of chlorine added, the iron in the nickel-iron alloy is in excess. The excess iron continues to react with FeCl3(g) to form FeCl2(l). FeCl2(l) is continuously separated from the reaction system, promoting the reaction to continue towards the formation of FeCl2(l) and consuming FeCl3(g).

[0049] Furthermore, studies have shown that FeCl3 decomposes into FeCl2+Cl2 at high temperatures (698K, i.e., 424.85℃). Thus, at some reaction temperatures in this application, the formation of ferrous chloride is further promoted, and FeCl3(g) is consumed.

[0050] Therefore, under the influence of the above-mentioned factors, the main product in step S100 of this application is FeCl2(l), i.e., ferric chloride melt, rather than ferric chloride.

[0051] In some more specific embodiments, the mass of the chlorine gas is 0.9 to 1.2 times the mass of the nickel-iron alloy, and the calcination temperature is 650 to 750°C.

[0052] S200: Chlorine gas is introduced into the ferrous chloride melt to carry out a chlorination reaction, thereby converting the ferrous chloride melt into ferric chloride gas.

[0053] The reaction can be well controlled during the vaporization of molten ferrous chloride with chlorine gas, thus enabling the preparation of high-quality ferric chloride. For example, chlorine gas is introduced into the chlorination reaction chamber to allow the ferrous chloride melt to undergo a chlorination reaction.

[0054] If a one-step process is used to convert iron-containing alloys into ferric chloride, it is difficult to continue the process. For example, in the later stages of the reaction, when only a small amount of alloy remains, the introduced chlorine gas is difficult to contact with the alloy, resulting in low utilization of chlorine gas.

[0055] After adopting a step-by-step processing method, one furnace is dedicated to producing ferrous chloride. That is, the second batch of material is added before the first batch of alloy has fully reacted, and then the third batch. The addition of material not only ensures the formation of ferrous chloride, but also ensures the contact efficiency between chlorine gas and alloy due to the high material content.

[0056] Furthermore, by adopting a step-by-step approach, the heat released during the reaction of ferrous chloride with chlorine is far lower than that released during the reaction of chlorine with iron to produce ferrous chloride. It releases almost no heat, so the temperature of this step is easy to control, and an external heat source can be used to control the temperature.

[0057] In step S200, the main reaction is Cl2(g) + FeCl2(g) → FeCl3(g), which is the reverse of the aforementioned FeCl3(g) → Cl2(g) + FeCl2(g). Therefore, in step S200, chlorine gas is introduced, which increases the concentration of reactants and shifts the chemical equilibrium towards the forward reaction, i.e., towards the formation of FeCl3(g).

[0058] Furthermore, the chlorination process directly chlorinates iron to ferric chloride, which requires stronger chlorination conditions (see the analysis in section S100). This can easily lead to the chlorination of other elements in the alloy. In addition, the continuous volatilization of iron during the chlorination process causes the reaction conditions to change constantly, making it impossible to obtain relatively stable reaction conditions, which is not conducive to large-scale industrial production.

[0059] S300: The ferric chloride gas is condensed to obtain solid ferric chloride product.

[0060] FeCl3 has a boiling point of 316℃. When ferric chloride gas condenses below its boiling point, solid ferric chloride is formed, which is easy to collect and store. Throughout the separation process, the elemental behavior of iron in the alloy changes from solid alloy to liquid ferrous chloride, and then to gaseous ferric chloride, thus achieving a continuous process.

[0061] In the above-described method for separating iron from nickel-iron alloys, the preferential chlorination of iron in the alloy is achieved by controlling the chlorination conditions, transforming it into molten ferrous chloride. The ferrous chloride is then converted into gaseous ferric chloride, volatilized, and cooled to obtain ferric chloride. The elemental behavior of iron in the alloy involves a continuous process, transforming from a solid alloy to liquid ferrous chloride and then to gaseous ferric chloride. Furthermore, the reaction can be well controlled during the vaporization of molten ferrous chloride with chlorine gas, thus yielding high-quality ferric chloride. This method for separating iron from nickel-iron alloys is simple to operate, has a short process flow, and produces high-quality ferric chloride.

[0062] In some embodiments, in the step of introducing chlorine gas into the ferrous chloride melt for reaction, the chlorination temperature is 400–700°C, and the amount of chlorine gas introduced is 0.25–0.35 times the mass of the ferrous chloride melt.

[0063] Under these conditions, the requirements for producing ferric chloride gas from ferrous chloride can be met, and the degree of reaction is relatively high.

[0064] Ferrous chloride melt has a relatively high temperature; in some cases, it can maintain a chlorination temperature of 400–700°C, such as when the chlorination reaction vessel has good insulation. In this situation, no additional energy source, such as electric heating or gas combustion heating, is required.

[0065] In other cases, the ferrous chloride melt cannot maintain a chlorination temperature of 400–700°C. In such cases, additional energy sources, such as electric heating or gas combustion heating, are provided as auxiliary sources.

[0066] In some specific embodiments, the chlorination temperature is 400–700°C, and the chlorine gas flow rate is 0.25–0.35 times the mass of the ferrous chloride melt.

[0067] In some embodiments, in the step of condensing the ferric chloride gas, the ferric chloride gas is condensed to 100-250°C.

[0068] Under these conditions, ferric chloride gas can be condensed into solid ferric chloride relatively quickly.

[0069] In some embodiments, chlorine gas is introduced into the bottom of the nickel-iron alloy for roasting.

[0070] Because chlorine is denser than air, unreacted chlorine tends to remain at the bottom of the reaction vessel and does not easily overflow upwards, thus avoiding chlorine waste and environmental pollution.

[0071] Furthermore, since chlorine gas is introduced from the bottom of the nickel-iron alloy, and the calcination heating area is also at the bottom, ferrous chloride melt is generated at the bottom, making it easy to separate. In addition, in this case, if ferric chloride gas subsequently enters the apparatus where the nickel-iron alloy is calcined, it will also react with the unreacted nickel-iron alloy above, reducing it to ferrous chloride melt.

[0072] This application also provides an apparatus for separating iron from nickel-iron alloy, as shown in Figure 2, which includes a calcining furnace 100, a separation mechanism 200, a chlorination reaction chamber 300, a condensation mechanism 400, and a collection mechanism 500.

[0073] The roasting furnace 100 includes a furnace body 110 and a first chlorine gas inlet 150. The furnace body 110 has a cavity for accommodating the nickel-iron alloy, and the first chlorine gas inlet 150 is connected to the cavity. The mass of chlorine gas introduced is 0.8 to 1.5 times the mass of the nickel-iron alloy. The roasting temperature inside the furnace body 110 is 500 to 850°C.

[0074] The specific shape of the roasting furnace 100 is not limited, such as cylindrical, square, etc.

[0075] In some embodiments, referring to Figure 2, the furnace body 110 is cylindrical, and the ratio of the height to the diameter of the furnace body 110 is (8-20):1. In this case, the nickel-iron alloy raw material is piled up relatively high, which allows for more precise control of the height region for the chlorination reaction of the nickel-iron alloy. For example, the chlorination reaction is carried out by roasting and heating at the bottom of the roasting furnace 100. Referring to the description of the beneficial effects of chlorine gas being introduced from the bottom of the nickel-iron alloy, it also has the effects of ferrous chloride melt separation, chlorine gas not escaping easily, and subsequent reduction of ferric chloride gas into ferrous chloride melt. In addition, it is also beneficial for the iron in the alloy to continuously flow into the next reactor in the form of molten ferrous chloride.

[0076] In some embodiments, the top of the furnace body 110 has a feeding assembly 120, such as a funnel-shaped structure.

[0077] In some embodiments, referring to Figure 2, there are two first chlorine gas inlets 150, located on both sides of the roasting furnace 100. In this embodiment, the first chlorine gas inlets 150 are symmetrically distributed, which is beneficial for uniform distribution of chlorine gas.

[0078] In some embodiments, referring to FIG2, the roasting furnace 100 further includes a temperature control component 130. Exemplarily, the temperature control component 130 is wrapped around the outside of the furnace body 110, with a height of 1 / 4 to 1 / 2 of the height of the furnace body 110. The temperature control component 130 is an electric temperature control component 130, implemented through electric heating coupled with air condensation; that is, electric heating is activated when heating is increased, and air condensation is activated when cooling is decreased.

[0079] The temperature control component 130 is located at the bottom, which is conducive to the reaction of nickel-iron alloy starting from the bottom. Therefore, it has the effects of separating ferrous chloride melt, preventing chlorine gas from escaping, and reducing ferric chloride gas to ferrous chloride melt in the future.

[0080] In some embodiments, referring to FIG2, the calcining furnace 100 further includes a slag outlet 140. The slag outlet 140 is located at 1 / 10 to 1 / 8 of the height of the furnace body 110 from the bottom. The solid slag obtained from the reaction is discharged from the slag outlet 140.

[0081] The separation mechanism 200 is connected to the receiving cavity and separates the ferrous chloride melt generated by the furnace body 110.

[0082] The separation mechanism 200 can be integrated with the furnace body 110 or it can be a separate unit.

[0083] Taking an integrated configuration as an example, in some embodiments, the separation mechanism 200 includes a filter plate embedded in the bottom of the furnace body 110, the filter plate having a pore size of 0.1 to 0.2 mm.

[0084] The filter plate is embedded in the furnace body 110, and its size is completely fitted to the bottom of the furnace body 110. The filter plate becomes part of the bottom of the furnace body 110. The filter plate has filter holes. In this way, the ferrous chloride melt generated by the reaction flows directly through the filter holes to the next process. For example, the pore size of the filter plate is 0.1 to 0.2 mm.

[0085] In some embodiments, referring to FIG2, the apparatus for separating iron from nickel-iron alloy further includes a melt collection tank 600, which is connected to the furnace body 110 and communicates with the receiving cavity through the filter plate. The melt collection tank 600 is located at the lower end of the filter plate and communicates with the filter plate. Exemplarily, the melt collection tank 600 is conical. The upper opening of the melt collection tank 600 matches and is fixedly connected to the bottom of the furnace body 110.

[0086] The chlorination reaction chamber 300 has a second chlorine gas inlet 330. The chlorination reaction chamber 300 is connected to the separation mechanism 200 and receives the ferrous chloride melt.

[0087] The condensation mechanism 400 is connected to the chlorination reaction chamber 300 to condense the ferric chloride gas generated in the chlorination reaction chamber 300 to produce solid ferric chloride product.

[0088] The collection mechanism 500 is located below the condensation mechanism 400 and collects the solid ferric chloride product.

[0089] The apparatus for separating iron from nickel-iron alloys is used to implement the aforementioned method for separating iron from nickel-iron alloys, and therefore has corresponding beneficial effects, which will not be elaborated further. Its specific structure can be appropriately adjusted according to different methods of iron separation.

[0090] In some embodiments, referring to FIG2, the chlorination reaction chamber 300 includes a chlorination oxidation reaction chamber 310 and the aforementioned second chlorine gas inlet 330.

[0091] For example, the chlorination oxidation reaction chamber 310 is rectangular, such as with a length:width:height ratio of 10:3:4 to 10:3:6. For example, the second chlorine gas inlet 330 consists of three chlorine gas inlet pipes, evenly distributed along the center line of the side. The highest inlet pipe is located at half the height of the chlorination oxidation reaction chamber 310 from the bottom, and the lowest inlet pipe is flush with the bottom of the chlorination oxidation reaction chamber 310. The second chlorine gas inlet 330 and the gaseous ferric chloride rising channel 320 are respectively distributed on both sides of the chlorination oxidation reaction chamber 310. The second chlorine gas inlet 330 is located in the lower side region of the chlorination oxidation reaction chamber 310 and is connected to the side.

[0092] In some embodiments, referring to FIG2, the chlorination reaction chamber 300 is located below the furnace body 110. The device for separating iron from nickel-iron alloy also includes a communicating vessel 700. The diameter of the communicating vessel 700 is 1 / 8 of the diameter of the furnace body 110. One end (first end) of the communicating vessel 700 is connected to the melt collection tank 600, and the other end (second end) is connected to the chlorination reaction chamber 300.

[0093] The communicating vessel 700 is located below the furnace body 110. Under gravity, the molten ferrous chloride in the melt collection tank 600 flows from the first end of the communicating vessel 700 to the second end, and then into the chlorination oxidation reaction chamber 310. The second end is connected to the chlorination reaction chamber 300 via a pipe, such as an inverted L-shaped pipe. The presence of molten ferrous chloride at the bottom of the communicating vessel 700 acts as a check valve, allowing only molten ferrous chloride to enter the chlorination reaction chamber 300. Gaseous ferric chloride produced in the chlorination reaction chamber 300, or chlorine gas introduced therein, cannot enter the melt collection tank 600 and then the furnace body 110 due to the presence of molten ferrous chloride at the bottom of the communicating vessel 700. In some embodiments, the communicating vessel 700 is a U-shaped communicating vessel 700.

[0094] In some embodiments, referring to FIG2, the chlorination reaction chamber 300 has a gaseous ferric chloride rising channel 320 on the side away from the communicating vessel 700, and the gaseous ferric chloride rising channel 320 is connected to the condensation mechanism 400.

[0095] For example, one end of the gaseous ferric chloride rising channel 320 is located at the top of the chlorination oxidation reaction chamber 310 and is connected to the top, while the other end is connected to the condensation mechanism 400. The second chlorine gas inlet 330 and the gaseous ferric chloride rising channel 320 are respectively distributed on both sides of the chlorination oxidation reaction chamber 310.

[0096] For example, the gaseous ferric chloride rising channel 320 is cylindrical, with a height of 1 / 3 to 1 / 2 of the furnace body 110 and a diameter of 1.1 to 1.2 times that of the furnace body 110.

[0097] In some embodiments, referring to FIG2, the condensation mechanism 400 includes a condensation chamber 410 and a temperature control component 420. Exemplarily, the condensation mechanism 400 is cylindrical, with a height of 1 / 3 to 1 / 2 of the gaseous ferric chloride rising channel 320 and a diameter of 5 to 10 times that of the gaseous ferric chloride rising channel 320.

[0098] The temperature control component 420 is wrapped around the top and all sides of the condenser chamber 410, and its temperature is regulated by a water-cooled coupled heating rod.

[0099] The collecting mechanism 500 is located at the bottom of the condensing mechanism 400 and is fully connected to the bottom. It is conical in shape, with the diameter of the cone's base circle matching that of the condensing chamber 410, and the height of the cone being 1.1 to 1.2 times that of the condensing chamber 410. The discharge switch 510 is located at the bottom of the collecting mechanism 500 and is connected to the collecting mechanism 500.

[0100] The technical solution of this application will be described below with reference to specific embodiments.

[0101] Example 1:

[0102] The iron-containing alloy was processed using the nickel-iron alloy separation device shown in Figure 2, under the following conditions:

[0103] 10 kg of nickel-iron alloy was added to the calcining furnace 100 in 10 batches at a uniform rate. After the first batch was added, chlorine gas was introduced into the calcining furnace 100 through the first chlorine inlet 150. The amount of chlorine gas introduced was 1.2 times the mass of the nickel-iron alloy in the calcining furnace 100, and the calcination temperature was 650℃. After the molten ferrous chloride in the calcining furnace 100 flowed into the chlorination reaction chamber 300, chlorine gas was introduced into the equipment through the second chlorine inlet 330. The chlorination temperature was 600℃, and the amount of chlorine gas introduced was 0.3 times the mass of the ferrous chloride in the chlorination reaction chamber 300. The ferric chloride volatilized from the chlorination reaction chamber 300 flowed into the condensation mechanism 400 for condensation and collection. The condensation temperature of the condensation mechanism 400 was controlled at 200℃. After the reaction was completed, the chlorinated slag in the calcining furnace 100 was analyzed, showing that the volatilization rate of iron in the alloy was 92.74%. The ferric chloride product collected from collection facility 500 was tested and found to have a purity of 99.31% and a ferrous chloride content of 0.05%.

[0104] Example 2:

[0105] The reaction equipment is the same as in Example 1.

[0106] The iron-containing alloy was treated using the same apparatus as in Example 1, under the following conditions:

[0107] 10 kg of nickel-iron alloy was added to the calcining furnace 100 in 10 batches at a uniform rate. After the first batch was added, chlorine gas was introduced into the equipment through the first chlorine inlet 150, with the chlorine gas flow rate being 1.2 times the mass of the nickel-iron alloy in the calcining furnace 100, and the calcination temperature being 600℃. After the molten ferrous chloride in the calcining furnace 100 flowed into the chlorination reaction chamber 300, chlorine gas was introduced into the equipment through the second chlorine inlet 330, with the chlorination temperature being 600℃ and the chlorine gas flow rate being 0.3 times the mass of the ferrous chloride in the chlorination reaction chamber 300. The ferric chloride volatilized from the chlorination reaction chamber 300 flowed into the condensation mechanism 400 for condensation and collection, with the condensation temperature of the condensation mechanism 400 controlled at 100℃. After the reaction was completed, the chlorinated slag in the calcining furnace 100 was analyzed, showing that the iron volatilization rate in the alloy was 87.51%. The ferric chloride product collected from collection facility 500 was tested and found to have a purity of 99.84% and a ferrous chloride content of 0.03%.

[0108] Example 3:

[0109] The reaction equipment is the same as in Example 1.

[0110] The iron-containing alloy was treated using the same apparatus as in Example 1, under the following conditions:

[0111] 10 kg of nickel-iron alloy was added to the calcining furnace 100 in 10 batches at a uniform rate. After the first batch was added, chlorine gas was introduced into the equipment through the first chlorine inlet 150, with the chlorine gas flow rate being 1.4 times the mass of the nickel-iron alloy in the calcining furnace 100, and the calcination temperature being 850℃. After the molten ferrous chloride in the calcining furnace 100 flowed into the chlorination reaction chamber 300, chlorine gas was introduced into the equipment through the second chlorine inlet 330, with the chlorination temperature being 650℃, and the chlorine gas flow rate being 0.4 times the mass of the ferrous chloride in the chlorination reaction chamber 300. The ferric chloride volatilized from the chlorination reaction chamber 300 flowed into the condensation mechanism 400 for condensation and collection, with the condensation temperature of the condensation mechanism 400 controlled at 100℃. After the reaction was completed, the chlorinated slag in the calcining furnace 100 was analyzed, showing that the iron volatilization rate in the alloy was 97.49%. The ferric chloride product collected from collection facility 500 was tested and found to have a purity of 98.94% and a ferrous chloride content of 0.01%.

[0112] Comparative Example 1:

[0113] One kilogram of nickel-iron alloy was added to a horizontal tube furnace (with quartz tubes as the furnace tubes). The chlorine gas flow rate was 1.8 times the mass of the nickel-iron alloy in the furnace, and the calcination temperature was 650°C, allowing the iron in the alloy to volatilize directly (the process was stopped once no obvious volatiles were observed in the reaction zone). The volatilized gas phase was then condensed at 100°C. Analysis of the chlorinated slag in the chlorination furnace showed that the chlorination volatilization rate of the iron in the alloy was 47.9%. Testing of the collected ferric chloride product revealed a purity of 95.01%, with a ferrous chloride content of 4.72%.

[0114] Comparative Example 2:

[0115] One kilogram of nickel-iron alloy was added to a horizontal tube furnace (with quartz tubes as the furnace tubes). The chlorine gas flow rate was 3.5 times the mass of the nickel-iron alloy in the furnace, and the calcination temperature was 650°C, allowing the iron in the alloy to volatilize directly (the process was stopped once no obvious volatiles were observed in the reaction zone). The volatilized gas phase was then condensed at a controlled temperature of 100°C. Analysis of the chlorinated slag in the chlorination furnace showed that the chlorination volatilization rate of the iron in the alloy was 87.49%. Testing of the collected ferric chloride product revealed a purity of 97.90%, with a ferrous chloride content of 1.94%.

[0116] Comparative Example 3:

[0117] One kilogram of nickel-iron alloy was added to a horizontal tube furnace (with quartz tubes as the furnace tubes). The chlorine gas flow rate was 3.5 times the mass of the nickel-iron alloy in the furnace, and the calcination temperature was 450°C, allowing the iron in the alloy to volatilize directly (the process was stopped once no obvious volatiles were observed in the reaction zone). The volatilized gas phase was then condensed at a controlled temperature of 100°C. Analysis of the chlorinated slag in the chlorination furnace showed that the chlorination volatilization rate of the iron in the alloy was 45.79%. Testing of the collected ferric chloride product revealed a purity of 99.31%, with a ferrous chloride content of 0.74%.

[0118] Comparative Example 4:

[0119] The reaction equipment is the same as in Example 1.

[0120] The iron-containing alloy was treated using the same apparatus as in Example 1, under the following conditions:

[0121] Ten kilograms of nickel-iron alloy were added to the calcining furnace 100 in ten batches at a uniform rate. After the first batch was added, chlorine gas was introduced into the equipment through the first chlorine inlet 150, with the chlorine gas flow rate being 0.75 times the mass of the nickel-iron alloy in the calcining furnace 100, and the calcination temperature being 650°C. After the molten ferrous chloride in the calcining furnace 100 flowed into the chlorination reaction chamber 300, chlorine gas was introduced into the equipment through the second chlorine inlet 330, with the chlorination temperature at 650°C and the chlorine gas flow rate being 0.3 times the mass of the ferrous chloride in the chlorination reaction chamber 300. The ferric chloride volatilized from the chlorination reaction chamber 300 flowed into the condensation mechanism 400 for condensation and collection, with the condensation temperature of the condensation mechanism 400 controlled at 100°C. After the reaction was completed, the chlorinated slag in the calcining furnace 100 was analyzed, showing that the volatile iron content in the alloy was 69.07%. The ferric chloride product collected from collection facility 500 was tested and found to have a purity of 98.95% and a ferrous chloride content of 0.09%.

[0122] Comparing Comparative Examples 1-4 and the various embodiments, it is evident that Comparative Example 1, due to its horizontal tube furnace, does not easily allow for continuous feeding of nickel-iron alloy. Furthermore, the horizontal arrangement of the furnace tubes results in a shorter vertical space, leading to a shorter nickel-iron alloy material height and easier overflow of chlorine gas along the furnace tubes, thus resulting in lower chlorine utilization. Even with a higher chlorine gas flow rate compared to the embodiments, the chlorination volatilization rate of the iron in the alloy remains low. It was only with Comparative Example 2, which introduced several times the chlorine gas flow rate of the embodiments, that a chlorination volatilization rate comparable to that of the embodiments was achieved. Moreover, the ferrous chloride content in the ferric chloride product obtained in the comparative examples is significantly higher than that in the ferric chloride product obtained in the embodiments.

[0123] Due to the excessively low calcination temperature and the use of a horizontal tube furnace, the chlorination volatilization rate of the iron in Comparative Example 3 remained low even with the introduction of a large amount of chlorine gas. Furthermore, the ferrous chloride content in the ferric chloride product obtained in Comparative Example 3 was significantly higher than that in the ferric chloride product obtained in the examples.

[0124] In Comparative Example 4, the chlorination volatilization rate of the iron in the alloy remained low due to the excessively low chlorine gas introduction rate.

[0125] The above technical solutions of the present invention are merely preferred embodiments of the present invention and do not limit the patent scope of the present invention. All equivalent structural transformations made under the technical concept of the present invention using the contents of the present invention specification and drawings, or direct / indirect applications in other related technical fields, are included in the patent protection scope of the present invention.

Claims

1. A process for separating iron from a ferronickel alloy, characterized in that, The method comprises the following steps: roasting the ferronickel alloy in a chlorine atmosphere to obtain ferrous chloride melt and solid residue, and separating the ferrous chloride melt; wherein the mass of the chlorine is 0.8-1.5 times the mass of the ferronickel alloy, and the roasting temperature is 600-850℃; passing chlorine into the ferrous chloride melt to perform a chlorination reaction, so that the ferrous chloride melt is converted into ferric chloride gas; wherein the chlorination temperature is 400-700℃, and the amount of chlorine passed in is 0.25-0.35 times the mass of the ferrous chloride melt; condensing the ferric chloride gas to obtain solid ferric chloride product.

2. The process for separating iron from a ferronickel alloy according to claim 1, characterized in that, In the step of condensing the ferric chloride gas, the ferric chloride gas is condensed to 100-250℃.

3. The method of separating iron from a nickel-iron alloy according to claim 1 or 2, characterized in that, The chlorine is passed into the bottom of the ferronickel alloy to perform roasting.

4. The process for separating iron from a ferronickel alloy according to claim 1, characterized in that, The device for performing the method of separating iron from the ferronickel alloy comprises: a roasting furnace comprising a furnace body and a first chlorine inlet, the furnace body having a containing cavity for containing the ferronickel alloy, and the first chlorine inlet being in communication with the containing cavity, and the mass of the chlorine passed in being 0.8-1.5 times the mass of the ferronickel alloy; the roasting temperature in the furnace body being 600-850℃; a separation mechanism in communication with the containing cavity and separating the ferrous chloride melt generated by the furnace body; a chlorination reaction chamber having a second chlorine inlet, the chlorination reaction chamber being in communication with the separation mechanism and receiving the ferrous chloride melt; a condensation mechanism in communication with the chlorination reaction chamber and condensing the ferric chloride gas generated by the chlorination reaction chamber to produce solid ferric chloride product; a collection mechanism located below the condensation mechanism and collecting the solid ferric chloride product.

5. The process for separating iron from a ferronickel alloy according to claim 4, characterized in that, The furnace body is cylindrical, the ratio of the height to the diameter of the furnace body being (8-20):1; the first chlorine inlet is located at the bottom of the furnace body; and the temperature control assembly of the roasting furnace is located at a position 1 / 4-1 / 2 of the height of the furnace body from the bottom.

6. The process for separating iron from a ferronickel alloy according to claim 4, characterized in that, The separation mechanism comprises a filter plate embedded in the bottom of the furnace body, and the pore size of the filter plate is 0.1-0.2mm; The device for separating iron from the ferronickel alloy further comprises a melt collection tank, which is connected with the furnace body and in communication with the containing cavity through the filter plate.

7. The process for separating iron from a ferronickel alloy according to claim 6, characterized in that, The chlorination reaction chamber is located below the furnace body; The device for separating iron from the ferronickel alloy further comprises a communicating vessel; the diameter of the communicating vessel is 1 / 8 of the diameter of the furnace body; one end of the communicating vessel is in communication with the melt collection tank, and the other end is in communication with the chlorination reaction chamber.

8. The process for separating iron from a ferronickel alloy according to claim 7, characterized in that, The side of the chlorination reaction chamber away from the communicating vessel has a gaseous ferric chloride upward channel, which is in communication with the condensation mechanism.

9. The process for separating iron from a ferronickel alloy according to claim 7, characterized in that, The collection mechanism is a conical structure, and the diameter of the conical structure matches the bottom of the condensation mechanism.

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