Chlorination furnace and chlorination method

Abstract

The invention discloses a chlorination furnace and a chlorination method, the chlorination furnace comprises: an upper flow-state chlorination zone, the upper flow-state chlorination zone is used for carrying out a first chlorination reaction on a raw material added into the upper flow-state chlorination zone and a chlorinating agent; the lower fused salt chlorination area is used for enabling part of the materials in the upper flow state chlorination area to settle into the lower fused salt chlorination area to form fused salt, and the fused salt and a chlorinating agent are subjected to a second chlorination reaction; and the chloride flue gas discharge area is communicated with the upper space of the lower fused salt chlorination area and the upper flow state chlorination area, and is used for discharging chloride flue gas generated by the chlorination furnace out of the chlorination furnace. Raw materials in the upper flow-state chlorination zone can be rapidly chlorinated in the upper flow-state chlorination zone, high-boiling-point chlorides and unreacted raw materials in generated chlorides can be settled into the lower fused salt chlorination zone to form fused salt and realize full chlorination, and low-boiling-point chlorides can be discharged through the chloride flue gas discharge zone.

Description

Technical Field

[0001] The invention relates to a chlorination furnace and a chlorination method. Background Art

[0002] Currently, the main method for extracting lithium from lithium ore or waste batteries is hydrometallurgy. This method has a long process flow and has problems such as high cost and high pollution.

[0003] A preparation method and device of lithium chloride are disclosed in the Chinese patent literature of publication number CN112351953A, and it is proposed to utilize chlorination reaction to extract lithium chloride after mixing coke and chlorine in spodumene ore. The method and device proposed in this patent literature are to generate lithium chloride gas by chlorination reaction in chlorination furnace and then make this lithium chloride gas condense to obtain lithium chloride. However, the boiling point of lithium chloride is very high, so the output flue gas temperature of its chlorination furnace is also very high, increasing energy consumption. In addition, because spodumene ore often also contains elements such as iron, aluminum, silicon, calcium, magnesium (existing in the form of corresponding oxides) except lithium element (existing in the form of lithium oxide), they also exist to extract and recover value, but the method and device proposed in the above-mentioned patent literature tend to extract lithium by chlorination reaction alone, limiting the possibility of extracting other elements by chlorination reaction.

[0004] In fact, the iron, aluminum, silicon, calcium, magnesium and other elements in spodumene ore can be converted into corresponding chlorides through chlorination reaction. Among them, the boiling points of the chlorides converted from the oxides of iron, aluminum and silicon through chlorination reaction are much lower than lithium chloride, and can be classified as low-boiling point chlorides; while the boiling points of the chlorides converted from the oxides of calcium and magnesium through chlorination reaction are slightly higher than lithium chloride, and can be classified as high-boiling point chlorides. However, if these low-boiling point chlorides and high-boiling point chlorides are to be discharged from the chlorination furnace together with the lithium chloride gas, the output flue gas temperature of the chlorination furnace will be high, the chlorination reaction time will be long, and it will also increase the difficulty of separating the unused chlorides in the subsequent process. Summary of the invention

[0005] Based on the above background, the inventor of the present invention chooses to improve the chlorination furnace from the perspective of making the chlorination furnace get rid of the single chlorination method (fluidized chlorination or molten salt chlorination), which helps to shorten the chlorination time and improve the chlorination degree. Therefore, a chlorination furnace and a chlorination method are provided.

[0006] In the first aspect, a chlorination furnace is provided, comprising: an upper fluidized chlorination zone, the upper fluidized chlorination zone being used to cause a raw material added to the upper fluidized chlorination zone to undergo a first chlorination reaction with a chlorinating agent; a lower molten salt chlorination zone, the lower molten salt chlorination zone being used to cause part of the material in the upper fluidized chlorination zone to settle into the lower molten salt chlorination zone to form molten salt and undergo a second chlorination reaction with the chlorinating agent; a chloride flue gas discharge zone, the chloride flue gas discharge zone being connected to the upper space of the lower molten salt chlorination zone and the upper fluidized chlorination zone, and being used to discharge the chloride flue gas generated by the chlorination furnace out of the chlorination furnace.

[0007] According to an embodiment of the present invention, the upper fluidized chlorination zone is composed of a reaction tower, and the reaction tower has a vertical reaction tower body; the lower molten salt chlorination zone is composed of a molten salt pool arranged at the bottom of the reaction tower, and the molten salt pool has a horizontal molten salt pool body and the outer shell is an integral structure with the outer shell of the reaction tower; the chloride flue gas emission zone is composed of a vertical flue arranged at the top of the molten salt pool and deviated from the reaction tower; wherein, the interior of the molten salt pool is located above the molten salt and has a transverse flue with its two ends respectively connected to the bottom of the reaction tower and the bottom of the longitudinal flue.

[0008] According to an embodiment of the present invention, the inner width or inner diameter of the vertical reaction tower body is 0.5-15 meters, and the height of the vertical reaction tower body is 2.5-40 meters.

[0009] According to an embodiment of the present invention, the outer shell of the vertical reaction tower body and / or the horizontal molten salt pool body is made of refractory bricks or amorphous refractory materials.

[0010] According to an embodiment of the present invention, a water cooling structure is provided on the outer shell of the vertical reaction tower body and / or the horizontal molten salt pool body.

[0011] According to an embodiment of the present invention, the inner width or inner diameter of the horizontal molten salt pool body is greater than the inner width or inner diameter of the vertical reaction tower body by more than 0.4 meters.

[0012] According to an embodiment of the present invention, the inner surface of the vertical reaction tower body and / or the horizontal molten salt pool body is made of a high temperature resistant material that is resistant to chlorine corrosion.

[0013] According to an embodiment of the present invention, the raw material contains at least two metal elements, the at least two metal elements may contain metalloid elements, and the at least two metal elements can be chlorinated separately in the chlorination furnace to generate at least two metal chlorides with different boiling points; when the chlorination furnace is in operation, some of the at least two metal chlorides with lower boiling points are discharged from the chlorination furnace through the chloride flue gas emission zone without entering the molten salt, and some of the at least two metal chlorides with higher boiling points enter the molten salt and then are discharged from the chlorination furnace through the chloride flue gas emission zone and / or through the salt discharge port of the lower molten salt chlorination zone.

[0014] According to an embodiment of the present invention, the at least two metal elements include lithium, and the lithium exists in the raw material in the form of a lithium compound, making the raw material a lithium resource. The lithium compound can be chlorinated in the chlorination furnace to generate lithium chloride, and the lithium chloride is mainly discharged from the chlorination furnace through the salt discharge port.

[0015] According to an embodiment of the present invention, the lithium resource is lithium ore or a chloride metallurgical semi-finished product processed from lithium ore or a non-ferrous smelting product or a chloride metallurgical semi-finished product processed from a non-ferrous smelting product; the part of the metal chlorides with a lower boiling point includes at least one of aluminum trichloride, silicon tetrachloride, and ferric chloride, and the part of the metal chlorides with a higher boiling point includes lithium chloride or includes lithium chloride and at least one of zirconium chloride, zinc chloride, calcium chloride, magnesium chloride, cesium chloride, rubidium chloride, potassium chloride, sodium chloride, and manganese chloride in addition to lithium chloride.

[0016] According to an embodiment of the present invention, the lithium ore is spodumene or lepidolite. The chlorination metallurgy semi-finished product is made by finely grinding the lithium ore or the non-ferrous smelting product.

[0017] According to an embodiment of the present invention, a feeding structure is provided at the top of the upper fluidized chlorination zone, and the feeding structure is used to add at least the raw materials and the chlorinating agent among the raw materials, chlorinating agent, chlorination reaction reducing agent and combustion-supporting substances independently or mixedly into the upper fluidized chlorination zone.

[0018] According to an embodiment of the present invention, the lower molten salt chlorination zone is provided with a chlorine gas nozzle extending into the molten salt.

[0019] According to an embodiment of the present invention, a heating electrode is further provided in the lower molten salt chlorination zone. The heating electrode is preferably a graphite electrode. The number of the heating electrodes may be three or more.

[0020] According to an embodiment of the present invention, the raw material is a particulate matter with a particle size of ≤100 microns, ≤50 microns, ≤25 microns, or ≤10 microns. The chlorinating agent is chlorine. The chlorination reaction reducing agent is a carbon-based reducing agent, such as coke or petroleum coke powder. The combustion-supporting substance is fuel and / or oxygen.

[0021] In a second aspect, a chlorination method is provided, which uses the chlorination furnace of the first aspect to chlorinate the raw material.

[0022] According to a third aspect, a chlorination furnace is provided, comprising: an upper fluidized chlorination zone, wherein the upper fluidized chlorination zone is used to cause a raw material added to the upper fluidized chlorination zone to undergo a first chlorination reaction with a chlorinating agent; a lower molten salt chlorination zone, wherein the lower molten salt chlorination zone is used to cause part of the material in the upper fluidized chlorination zone to settle into the lower molten salt chlorination zone to form molten salt and undergo a second chlorination reaction with the chlorinating agent; an upper chloride discharge zone, wherein the upper chloride discharge zone is connected to the upper fluidized chlorination zone and is used to discharge the chloride flue gas generated in the upper fluidized chlorination zone out of the chlorination furnace; and a lower chloride discharge zone, wherein the lower chloride discharge zone is connected to the lower molten salt chlorination zone and is used to discharge the chloride generated in the lower molten salt chlorination zone out of the chlorination furnace.

[0023] According to an embodiment of the present invention, the upper fluid chlorination zone is composed of a reaction tower, and the reaction tower has a vertical reaction tower body; the lower molten salt chlorination zone is composed of a molten salt pool arranged at the bottom of the reaction tower, and the molten salt pool has a horizontal molten salt pool body and the outer shell is an integral structure with the outer shell of the reaction tower; the upper chloride discharge zone is composed of a first flue arranged at the top of the reaction tower; the lower chloride discharge zone includes a second flue arranged at the top of the molten salt pool and deviating from the reaction tower and / or a salt discharge port arranged on the side of the molten salt pool.

[0024] According to an embodiment of the present invention, if the lower chloride discharge zone includes the second flue, the second flue includes at least two exhaust structures spaced apart from each other around the circumference of the reaction tower.

[0025] According to an embodiment of the present invention, the inner width or inner diameter of the vertical reaction tower body is 0.5-15 meters, and the height of the vertical reaction tower body is 2.5-40 meters.

[0026] According to an embodiment of the present invention, the outer shell of the vertical reaction tower body and / or the horizontal molten salt pool body is made of refractory bricks or amorphous refractory materials.

[0027] According to an embodiment of the present invention, a water cooling structure is provided on the outer shell of the vertical reaction tower body and / or the horizontal molten salt pool body.

[0028] According to an embodiment of the present invention, the inner width or inner diameter of the horizontal molten salt pool body is greater than the inner width or inner diameter of the vertical reaction tower body by more than 0.4 meters.

[0029] According to an embodiment of the present invention, the inner surface of the vertical reaction tower body and / or the horizontal molten salt pool body is made of a high temperature resistant material that is resistant to chlorine corrosion.

[0030] According to an embodiment of the present invention, the raw material contains at least two metal elements, the at least two metal elements may contain metalloid elements, and the at least two metal elements can be chlorinated separately in the chlorination furnace to generate at least two metal chlorides with different boiling points; when the chlorination furnace is in operation, some of the metal chlorides with lower boiling points among the at least two metal chlorides are discharged from the chlorination furnace through the upper chloride discharge area, and some of the metal chlorides with higher boiling points among the at least two metal chlorides are discharged from the chlorination furnace through the lower chloride discharge area.

[0031] According to an embodiment of the present invention, the at least two metal elements include lithium, and the lithium exists in the raw material in the form of a lithium compound, making the raw material a lithium resource. The lithium compound can be chlorinated in the chlorination furnace to generate lithium chloride, and the lithium chloride is mainly discharged from the chlorination furnace through the salt discharge port arranged on the side of the lower molten salt chlorination zone.

[0032] According to an embodiment of the present invention, the lithium resource is lithium ore or a chloride metallurgical semi-finished product processed from lithium ore or a non-ferrous smelting product or a chloride metallurgical semi-finished product processed from a non-ferrous smelting product; the part of the metal chlorides with a lower boiling point includes at least one of aluminum trichloride, silicon tetrachloride, and ferric chloride, and the part of the metal chlorides with a higher boiling point includes lithium chloride or includes lithium chloride and at least one of zirconium chloride, zinc chloride, calcium chloride, magnesium chloride, cesium chloride, rubidium chloride, potassium chloride, sodium chloride, and manganese chloride in addition to lithium chloride.

[0033] According to an embodiment of the present invention, the lithium ore is spodumene or lepidolite. According to an embodiment of the present invention, the chlorination metallurgy semi-finished product is made by finely grinding the lithium ore or the non-ferrous smelting product.

[0034] According to an embodiment of the present invention, a feeding structure is provided at the upper part of the upper fluidized chlorination zone, and the feeding structure is used to add at least the raw material among the raw material, the chlorination reaction reducing agent and the combustion-supporting material into the upper fluidized chlorination zone independently or in a mixed manner.

[0035] According to an embodiment of the present invention, a chlorine gas inlet and / or a hot gas inlet is provided at the lower portion of the upper fluidized chlorination zone.

[0036] According to an embodiment of the present invention, the lower molten salt chlorination zone is provided with a chlorine gas nozzle extending into the molten salt.

[0037] According to an embodiment of the present invention, a heating electrode is further provided in the lower molten salt chlorination zone. The heating electrode is preferably a graphite electrode. The number of the heating electrodes may be three or more. The three or more heating electrodes may be evenly distributed along the circumference of the lower molten salt chlorination zone.

[0038] According to an embodiment of the present invention, the lower molten salt chlorination zone is an annular structure. The annular structure may be formed by a protrusion arranged at the bottom of the lower molten salt chlorination zone.

[0039] According to an embodiment of the present invention, the raw material is a particulate matter with a particle size of ≤100 microns, or a particle size of ≤50 microns, or a particle size of ≤25 microns, or a particle size of ≤10 microns.

[0040] According to an embodiment of the present invention, the chlorinating agent is chlorine. The chlorination reaction reducing agent may be a carbon-based reducing agent, such as coke or petroleum coke powder. The combustion-supporting substance may be fuel and / or oxygen.

[0041] In a fourth aspect, a chlorination method is provided, which uses the chlorination furnace of the third aspect to chlorinate the raw material.

[0042] Fluidized chlorination and molten salt chlorination are two known chlorination methods. During fluidized chlorination (i.e., the first chlorination reaction), the granular reaction raw materials are in a fluidized state; during molten salt chlorination (i.e., the second chlorination reaction), the reaction raw materials are in a slurry state. During fluidized chlorination, rapid chlorination is easily achieved by controlling the form of the raw materials, the method of adding the raw materials, the chlorination temperature and other conditions. Since the above-mentioned chlorination furnace includes an upper fluidized chlorination zone, a lower molten salt chlorination zone and a chloride flue gas emission zone, the raw materials in the upper fluidized chlorination zone can be chlorinated more quickly in the upper fluidized chlorination zone, and the unreacted raw materials can settle in the lower molten salt chlorination zone to form molten salt and achieve sufficient chlorination. Thereby, it helps to reduce the chlorination time and improve the degree of chlorination.

[0043] The present application is further described below in conjunction with the accompanying drawings and specific embodiments. Additional aspects and advantages of the present application will be partially given in the following description, partially become apparent from the following description, or be understood through practice. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] The drawings constituting a part of this specification are used to assist in understanding the present application. The contents provided in the drawings and their related descriptions in this specification may be used to explain the present invention, but do not constitute improper limitations on the present application.

[0045] Figure 1 The present invention is a schematic structural diagram of a chlorination furnace according to the first embodiment of the present invention.

[0046] Figure 2The figure is a schematic structural diagram of a chlorination furnace according to the second embodiment of the present invention.

[0047] Figure 3 It is a top view of 2. DETAILED DESCRIPTION

[0048] The present invention is described clearly and completely below in conjunction with the accompanying drawings. A person skilled in the art will be able to implement the present invention based on these descriptions.

[0049] Before describing the present invention in conjunction with the accompanying drawings, it should be particularly pointed out that the technical solutions and technical features provided in each part including the following description can be combined with each other without conflict. In addition, where possible, these technical solutions, technical features and related combinations can be assigned specific technical themes and protected by relevant patents.

[0050] The present invention involved in the following description is usually only a part of the embodiments rather than all the embodiments. Based on these embodiments, all other embodiments obtained by ordinary technicians in this field without making creative work should fall within the scope of patent protection.

[0051] About the terms and units in this specification: The terms "include", "comprises", "have" and any variations thereof in this specification and the corresponding claims and related parts are intended to cover non-exclusive inclusions. Other related terms and units can be reasonably interpreted based on the relevant content of this specification.

[0052] Figure 1 A schematic diagram of the structure of a chlorination furnace in the first embodiment of the present invention. The chlorination furnace is used to chlorinate the chlorination metallurgical semi-finished product (particle size of 1-10 microns) obtained by fine grinding of lithium ore. In this embodiment, spodumene is specifically selected as the lithium ore. Figure 1 As shown, the chlorination furnace includes: an upper fluidized chlorination zone, the upper fluidized chlorination zone is used to make the raw materials added to the upper fluidized chlorination zone undergo a first chlorination reaction with the chlorinating agent; a lower molten salt chlorination zone, the lower molten salt chlorination zone is used to make part of the materials in the upper fluidized chlorination zone settle into the lower molten salt chlorination zone to form molten salt and undergo a second chlorination reaction with the chlorinating agent; a chloride fume discharge zone, the chloride fume discharge zone is connected to the upper space of the lower molten salt chlorination zone and the upper fluidized chlorination zone, and is used to discharge the chloride fume generated by the chlorination furnace out of the chlorination furnace. The lithium ore is finely ground into a chlorination metallurgical semi-finished product with a particle size of 1-10 microns, which can further shorten the chlorination reaction time and make the chlorination occur in the upper fluidized chlorination zone as much as possible.

[0053] More specifically, the upper fluidized chlorination zone is composed of a reaction tower 1, which has a vertical reaction tower body; the lower molten salt chlorination zone is composed of a molten salt pool 3 arranged at the bottom of the reaction tower 1, and the molten salt pool 3 has a horizontal molten salt pool body and the outer shell is an integral structure with the outer shell of the reaction tower 1; the chloride flue gas emission zone is composed of a vertical flue 4 arranged at the top of the molten salt pool 3 and deviated from the reaction tower 1; wherein, the interior of the molten salt pool is located above the molten salt and has a transverse flue with two ends respectively connected to the bottom of the reaction tower 1 and the bottom of the longitudinal flue 4.

[0054] Generally speaking, a feeding structure 2 is provided at the top of the upper fluidized chlorination zone, and the feeding structure 2 is used to add at least the raw material and the chlorinating agent among the raw material, the chlorinating agent, the chlorination reaction reducing agent, and the combustion-supporting substance into the upper fluidized chlorination zone independently or in a mixed manner. Among them, the chlorinating agent can be chlorine. The chlorination reaction reducing agent (which can make the chlorination reaction more effective) usually adopts a carbon-based reducing agent, such as coke, petroleum coke powder, etc. The combustion-supporting substance is usually fuel and oxygen.

[0055] Specifically, the feeding structure 2 adopts a mixing nozzle, which can mix the raw materials, chlorinating agent, chlorination reaction reducing agent, and combustion-supporting material and spray them evenly into the upper fluid chlorination zone, which helps to increase the chlorination rate.

[0056] Generally speaking, the lower molten salt chlorination zone is provided with a chlorine gas nozzle 5 extending into the molten salt, so that the molten salt is stirred by chlorine gas to improve the heat transfer and mass transfer conditions of the molten salt. A salt discharge port 6 can be provided on the side or other suitable position of the lower molten salt chlorination zone.

[0057] In addition, a heating electrode 7 may be provided in the lower molten salt chlorination zone, and the heating electrode 7 is preferably a graphite electrode, and the number of the graphite electrodes may be three or more. Thus, the heating electrode 7 maintains an appropriate temperature of the molten pool, ensures sufficient chlorination, and avoids agglomeration due to a decrease in the molten pool temperature.

[0058] The operation process of the above-mentioned chlorination furnace is as follows: the raw material, i.e. the above-mentioned chlorination metallurgical semi-finished product, is added to the upper fluidized chlorination zone to undergo a first chlorination reaction with a chlorinating agent. The raw material contains elements such as iron, aluminum, silicon, calcium, magnesium, and aluminum (in the form of corresponding oxides). During the first chlorination reaction, they react rapidly in a high-temperature floating state to generate high-boiling lithium chloride, calcium chloride, and magnesium chloride as well as low-boiling aluminum chloride, silicon tetrachloride, and ferric chloride. Low-boiling chlorides such as silicon tetrachloride and aluminum chloride form flue gas, and high-boiling chlorides such as lithium chloride, calcium chloride, and magnesium chloride and a small portion of unreacted materials are precipitated into the molten salt pool 3 to form molten salt. Supplementary chlorine is introduced from the chlorine gas nozzle 5 to carry out a second chlorination reaction with the unreacted materials in the molten salt system to achieve complete chlorination of the lithium ore. The high-boiling chloride molten salt obtained by the first chlorination reaction and the second chlorination reaction can be discharged from the salt discharge port 6, and the low-boiling chloride flue gas is discharged from the longitudinal flue 4.

[0059] The above-mentioned chlorination furnace can convert all valuable metals in lithium ore into chloride salts, and realize the preliminary separation between chlorides with higher boiling points and chlorides with lower boiling points. In addition, it helps the chlorination furnace to more fully chlorinate the raw materials in the chlorination furnace in a shorter time.

[0060] Optionally, the inner width or inner diameter of the vertical reaction tower body is 0.5-15 meters, and the height of the vertical reaction tower body is 2.5-40 meters.

[0061] Optionally, the outer shell of the vertical reaction tower body and / or the horizontal molten salt pool body is made of refractory bricks or amorphous refractory materials.

[0062] Optionally, a water cooling structure, such as a copper water jacket, a water-cooled wall or an open water type water cooling protection device, is provided on the outer shell of the vertical reaction tower body and / or the horizontal molten salt pool body.

[0063] Optionally, the internal width or inner diameter of the horizontal molten salt pool body is greater than the internal width or inner diameter of the vertical reaction tower body by more than 0.4 meters;

[0064] Optionally, the inner surface of the vertical reaction tower body and / or the horizontal molten salt pool body is made of a high temperature resistant material that is resistant to chlorine corrosion.

[0065] In addition, an independent chlorine gas inlet 9 may be provided at the upper portion of the reaction tower 1 for introducing chlorine gas into the upper fluidized chlorination zone.

[0066] Figure 2 The figure is a schematic structural diagram of a chlorination furnace according to the second embodiment of the present invention. Figure 3 2 is a top view. The chlorination furnace is used to chlorinate the chlorination metallurgical semi-finished product (particle size of 1-10 microns) obtained by fine grinding of lithium ore. In this embodiment, lithium ore is specifically selected from lithium mica. Figure 2-Figure 3 As shown, the chlorination furnace includes: an upper fluidized chlorination zone, wherein the upper fluidized chlorination zone is used to cause the raw materials added to the upper fluidized chlorination zone to undergo a first chlorination reaction with a chlorinating agent; a lower molten salt chlorination zone, wherein the lower molten salt chlorination zone is used to cause part of the materials in the upper fluidized chlorination zone to settle into the lower molten salt chlorination zone to form molten salt and undergo a second chlorination reaction with the chlorinating agent; an upper chloride discharge zone, wherein the upper chloride discharge zone is connected to the upper fluidized chlorination zone and is used to discharge the chloride flue gas generated in the upper fluidized chlorination zone out of the chlorination furnace; and a lower chloride discharge zone, wherein the lower chloride discharge zone is connected to the lower molten salt chlorination zone and is used to discharge the chloride generated in the lower molten salt chlorination zone out of the chlorination furnace.

[0067] Fine grinding of lithium ore into chlorination metallurgical semi-finished products with a particle size of 1-10 microns can further shorten the chlorination reaction time and make chlorination occur in the upper fluid chlorination zone as much as possible.

[0068] More specifically, the upper fluid chlorination zone is composed of a reaction tower 1, which has a vertical reaction tower body; the lower molten salt chlorination zone is composed of a molten salt pool 3 arranged at the bottom of the reaction tower 1, and the molten salt pool 3 has a horizontal molten salt pool body and the outer shell is an integral structure with the outer shell of the reaction tower 1; the upper chloride discharge zone is composed of a first flue 10 arranged at the top of the reaction tower 1; the lower chloride discharge zone includes a second flue 11 arranged at the top of the molten salt pool 3 and deviated from the reaction tower 1, and a salt discharge port 6 arranged on the side of the molten salt pool 3.

[0069] In an optional embodiment, the second flue 11 may include at least two exhaust structures spaced apart from each other around the reaction tower 1. The exhaust structure may include gas collecting hoods located on each exhaust port. These gas collecting hoods may be connected to an exhaust main pipe 15.

[0070] Optionally, the inner width or inner diameter of the vertical reaction tower body is 0.5-15 meters, and the height of the vertical reaction tower body is 2.5-40 meters.

[0071] Optionally, the outer shell of the vertical reaction tower body and / or the horizontal molten salt pool body is made of refractory bricks or amorphous refractory materials.

[0072] Optionally, a water cooling structure, such as a copper water jacket, a water-cooled wall or an open water type water cooling protection device, is provided on the outer shell of the vertical reaction tower body and / or the horizontal molten salt pool body.

[0073] Optionally, the internal width or inner diameter of the horizontal molten salt pool body is greater than the internal width or inner diameter of the vertical reaction tower body by more than 0.4 meters;

[0074] Optionally, the inner surface of the vertical reaction tower body and / or the horizontal molten salt pool body is made of a high temperature resistant material that is resistant to chlorine corrosion.

[0075] Generally speaking, a feeding structure 12 is provided at the upper part of the upper fluidized chlorination zone, and the feeding structure 12 is used to add at least the raw material, the chlorination reaction reducing agent, and the combustion-supporting substance to the upper fluidized chlorination zone independently or in a mixed manner. Among them, the chlorination reaction reducing agent (which can make the chlorination reaction more efficient) is usually a carbon-based reducing agent, such as coke, petroleum coke powder, etc. The combustion-supporting substance is usually fuel and oxygen.

[0076] Generally speaking, the lower part of the upper fluidized chlorination zone is provided with a chlorine gas inlet 13 and a hot gas inlet 14. Hot gas is input into the upper fluidized chlorination zone through the hot gas inlet 14, which can be used for gas velocity regulation and temperature control in the upper fluidized chlorination zone.

[0077] Generally speaking, the lower molten salt chlorination zone is provided with a chlorine gas nozzle 5 extending into the molten salt, so that the molten salt is stirred by chlorine gas to improve the heat transfer and mass transfer conditions of the molten salt. A salt discharge port 6 can be provided on the side or other suitable position of the lower molten salt chlorination zone.

[0078] In addition, a heating electrode 7 may be provided in the lower molten salt chlorination zone, and the heating electrode 7 is preferably a graphite electrode, and the number of the graphite electrodes may be three or more, and the three or more heating electrodes 7 may be evenly distributed along the circumference of the lower molten salt chlorination zone. Thus, the heating electrode 7 maintains an appropriate temperature of the molten pool, ensures sufficient chlorination, and avoids agglomeration due to a decrease in the molten pool temperature.

[0079] In addition, the lower molten salt chlorination zone may be an annular structure, and the annular structure may be formed by a protrusion arranged at the bottom of the lower molten salt chlorination zone.

[0080] The operation process of the above-mentioned chlorination furnace is as follows: the raw material, i.e., the above-mentioned chlorination metallurgical semi-finished product, is added to the upper fluidized chlorination zone to undergo a first chlorination reaction with a chlorinating agent. The raw material contains elements such as potassium, sodium, silicon, rubidium, cesium, and aluminum (in the form of corresponding oxides). During the first chlorination reaction, they react rapidly under a high-temperature floating state to generate high-boiling lithium chloride, potassium chloride, sodium chloride, rubidium chloride, cesium chloride, and low-boiling aluminum chloride, silicon tetrachloride, etc. Low-boiling chlorides such as silicon tetrachloride and aluminum chloride form flue gas and are quickly discharged from the upper chloride discharge zone. High-boiling chlorides such as lithium chloride and a small portion of unreacted materials are precipitated into the molten salt pool 3 to form molten salt. Supplementary chlorine is introduced from the chlorine gas nozzle 5 to carry out a second chlorination reaction with the unreacted materials under the molten salt system to achieve complete chlorination of the lithium ore. The high-boiling chloride molten salt obtained by the first chlorination reaction and the second chlorination reaction can be discharged from the salt discharge port 6, and the chloride flue gas overflowing from the molten salt pool can be discharged from the second flue.

[0081] The above-mentioned chlorination furnace can convert all valuable metals in lithium ore into chloride salts, and realize the preliminary separation between chlorides with higher boiling points and chlorides with lower boiling points. In addition, it helps the chlorination furnace to more fully chlorinate the raw materials in the chlorination furnace in a shorter time.

[0082] The above is a description of the relevant contents of the present application. A person skilled in the art will be able to implement the present application based on these descriptions. Based on the above contents of this specification, all other embodiments obtained by a person skilled in the art without making any creative work shall fall within the scope of patent protection.

Claims

1. A chlorination furnace, characterized in that: include: An upper fluidized chlorination zone, wherein the upper fluidized chlorination zone is used to cause a first chlorination reaction between the raw material added to the upper fluidized chlorination zone and the chlorinating agent; A lower molten salt chlorination zone, wherein the lower molten salt chlorination zone is used to allow part of the material in the upper fluidized chlorination zone to settle into the lower molten salt chlorination zone to form molten salt and undergo a second chlorination reaction with a chlorinating agent; The chloride fume emission zone is connected with the upper space of the lower molten salt chlorination zone and the upper fluidized chlorination zone, and is used for discharging the chloride fume generated by the chlorination furnace out of the chlorination furnace.

2. The chlorination furnace according to claim 1, wherein: The upper fluidized chlorination zone is composed of a reaction tower, and the reaction tower has a vertical reaction tower body; The lower molten salt chlorination zone is composed of a molten salt pool arranged at the bottom of the reaction tower, and the molten salt pool has a horizontal molten salt pool body and an outer shell is an integral structure with the outer shell of the reaction tower; The chloride fume emission zone is composed of a vertical flue arranged on the top of the molten salt pool and deviating from the reaction tower; Wherein, the interior of the molten salt pool is located above the molten salt and has a transverse flue with two ends respectively connected to the bottom of the reaction tower and the bottom of the longitudinal flue.

3. The chlorination furnace according to claim 2, wherein: The internal width or inner diameter of the vertical reaction tower body is 0.5-15 meters, and the height of the vertical reaction tower body is 2.5-40 meters; And / or, the outer shell of the vertical reaction tower body and / or the horizontal molten salt pool body is made of refractory bricks or amorphous refractory materials; And / or, a water cooling structure is provided on the outer shell of the vertical reaction tower body and / or the horizontal molten salt pool body; And / or, the internal width or inner diameter of the horizontal molten salt pool body is greater than the internal width or inner diameter of the vertical reaction tower body by more than 0.4 meters; And / or, the inner surface of the vertical reaction tower body and / or the horizontal molten salt pool body is made of a high temperature resistant material that is resistant to chlorine corrosion.

4. The chlorination furnace according to claim 1, wherein: The raw material comprises at least two metal elements, the at least two metal elements may comprise metalloid elements, and the at least two metal elements can be chlorinated in the chlorination furnace to generate at least two metal chlorides with different boiling points; When the chlorination furnace is in operation, some of the metal chlorides with lower boiling points among the at least two metal chlorides are discharged from the chlorination furnace through the chloride fume discharge area without entering the molten salt, and some of the metal chlorides with higher boiling points among the at least two metal chlorides enter the molten salt and then are discharged from the chlorination furnace through the chloride fume discharge area and / or through the salt discharge port of the lower molten salt chlorination area.

5. The chlorination furnace according to claim 4, characterized in that: The at least two metal elements include lithium, and the lithium exists in the raw material in the form of lithium compound, making the raw material a lithium resource. The lithium compound can be chlorinated in the chlorination furnace to generate lithium chloride, and the lithium chloride is mainly discharged from the chlorination furnace through the salt discharge port.

6. The chlorination furnace according to claim 5, characterized in that: The lithium resource is lithium ore, non-ferrous smelting products, chloride metallurgical semi-finished products processed from lithium ore, or chloride metallurgical semi-finished products processed from non-ferrous smelting products; the part of the metal chlorides with lower boiling points includes at least one of aluminum trichloride, silicon tetrachloride, and ferric chloride, and the part of the metal chlorides with higher boiling points includes lithium chloride or includes lithium chloride and at least one of zirconium chloride, zinc chloride, calcium chloride, magnesium chloride, cesium chloride, rubidium chloride, potassium chloride, sodium chloride, and manganese chloride in addition to lithium chloride.

7. The chlorination furnace according to claim 6, wherein: The lithium ore is spodumene or lepidolite; and / or, the chlorination metallurgy semi-finished product is made by finely grinding the lithium ore or the non-ferrous smelting product.

8. A chlorination furnace as claimed in any one of claims 1 to 7, characterized in that: A feeding structure is provided at the top of the upper fluidized chlorination zone, and the feeding structure is used to add raw materials, chlorinating agent, chlorination reaction reducing agent, and combustion-supporting material, at least raw materials and chlorinating agent, independently or mixedly into the upper fluidized chlorination zone; and / or, the lower molten salt chlorination zone is provided with a chlorine gas nozzle extending into the molten salt; and / or, a heating electrode is also provided in the lower molten salt chlorination zone, and the heating electrode is preferably a graphite electrode, and the number of the heating electrodes can be three or more.

9. The chlorination furnace according to claim 7, wherein: The raw material is a particulate matter with a particle size of ≤100 microns, or ≤50 microns, or ≤25 microns, or ≤10 microns; and / or the chlorinating agent is chlorine; and / or the chlorination reaction reducing agent is a carbon-based reducing agent, such as coke, petroleum coke powder; and / or the combustion-supporting substance is fuel and / or oxygen.

10. A chlorination method, characterized in that: The chlorination furnace according to any one of claims 1 to 9 is used to chlorinate the raw material.

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