Method and device for online continuous production of high-purity oxide powder

Abstract

A method and device for online continuous production of a high-purity oxide powder. The method comprises: spraying a waste acid solution into a production furnace (1), and roasting same to generate an oxide powder; transferring flue gas generated in the production furnace (1) to a flue gas treatment unit, and conveying a primary oxide powder generated by the production furnace (1) to a secondary reactor to be heated and purified again, so as to obtain hot gas and a secondary oxide powder; and performing gas-solid separation on the hot gas generated in the secondary reactor, and recovering a gas phase obtained by the gas-solid separation into the production furnace (1) to recover acid radical ions. The primary oxide powder generated by the roasting in the production furnace (1) is heated and purified again by means of the secondary reactor, and therefore residual acid radical ions and moisture in the powder are further released, and the quality and performance of the oxide powder is improved, thereby obtaining an oxide powder that is free from moisture and acid radical ions; moreover, a stable and airtight internal production environment required for the production furnace (1) can be well maintained.

Description

A method and device for online continuous production of high-purity oxide powder Technical Field

[0001] The present invention relates to the technical field of waste acid or waste acid liquid regeneration, and in particular to a method and device for online continuous production of high-purity oxide powder. Background Art

[0002] The metallurgical, chlor-alkali, and alkaline material manufacturing industries, including those producing new energy materials like cobalt, nickel, iron, and molybdenum, use hydrochloric acid and other acids to soak or pickle minerals and steel, generating large amounts of acid or waste acid containing ferrous ions. This acid or waste acid, when subjected to high-temperature hydrolysis, can be used to produce oxide powder, which is widely used in the new energy and magnetic material manufacturing industries. The impurity content in the oxide powder directly affects the quality and grade of the resulting magnetic material. To obtain high-performance oxide powder, it is necessary to reduce the content of various impurities and improve its purity.

[0003] In existing production systems, it is difficult to improve the performance and quality of oxide powders. Furthermore, when the energy supply and stability of the production furnace are poor, the reaction flow field within the furnace can fluctuate frequently, degrading the production environment and making it difficult to produce oxide powders with stable performance and high quality. Therefore, a method and apparatus for the online continuous production of high-purity oxide powders free of moisture and acid ions is urgently needed to address these issues.

[0004] Summary of the Invention

[0005] In order to solve the above problems, the present invention provides a method for online continuous production of high-purity oxide powder, comprising:

[0006] The waste acid liquid is sprayed into a production furnace for roasting to generate oxide powder, wherein the production furnace is provided with at least one first heating mechanism for roasting the waste acid liquid;

[0007] The flue gas generated in the production furnace is sent to the flue gas treatment unit, and the primary oxide powder generated in the production furnace is sent to the secondary reactor for further heating and purification to obtain hot gas and secondary oxide powder;

[0008] The hot gas generated in the secondary reactor is subjected to gas-solid separation, and the gas phase obtained by the gas-solid separation is recycled into the production furnace or returned to the flue gas treatment unit to recover acid ions.

[0009] Furthermore, the secondary reactor includes a screw conveying unit, and the primary oxide powder is transported from the feed port to the discharge port of the screw conveying unit. During the transportation process, it moves toward and contacts the high-temperature heating gas fed into the screw conveying unit to remove moisture and acid ions in the primary oxide.

[0010] Furthermore, the temperature of the high-temperature heating gas is not less than 450°C.

[0011] Furthermore, it also includes a waste heat recovery mechanism, and the waste heat heated air is heated by the waste heat recovery mechanism and then sent to the secondary reactor. The waste heat recovery mechanism is arranged on the production furnace.

[0012] Furthermore, the number of the first heating mechanisms is multiple groups, and the multiple groups of the first heating mechanisms are layered from top to bottom on the production furnace, and the first heating mechanisms are arranged along the tangent direction of the furnace body of the production furnace.

[0013] Furthermore, the heat provided to the production furnace by the first heating mechanism makes the heat obtained in the middle of the production furnace higher than the heat obtained in the bottom and top of the production furnace.

[0014] Furthermore, the first heating mechanism includes a first heating unit, and the first heating unit is connected to a gas pipeline for supplying gas and a combustion-supporting air pipeline for supplying combustion-supporting air.

[0015] Furthermore, the discharge end of the production furnace is connected to a crusher and a first discharge valve, and the oxide powder in the production furnace is crushed by the crusher and then enters the secondary reactor through the first discharge valve.

[0016] Furthermore, the solid oxide powder obtained after gas-solid separation of the hot gas generated in the secondary reactor is transported to the storage mechanism through the conveying mechanism.

[0017] On the other hand, the present invention also provides an apparatus for the above-mentioned method for online continuous production of high-purity oxide powder, comprising:

[0018] A production furnace, used for roasting waste acid liquid, wherein the production furnace is provided with at least one set of first heating mechanisms;

[0019] A secondary reactor, used for heating and purifying the primary oxide powder obtained from the production furnace, the secondary reactor being connected to the discharge end of the production furnace;

[0020] The return silo is used to separate the hot gas in the secondary reactor into gas and solid. The feed end of the return silo is connected to the secondary reactor, and the gas outlet end of the return silo is connected to the production furnace.

[0021] Due to the adoption of the above technical solution, the present invention has the following beneficial effects compared with the prior art:

[0022] 1) The method provided by the present invention for online continuous production of high-purity oxide powders is to reheat and purify the primary oxide material generated by roasting in the production furnace in a secondary reactor, thereby improving the heat utilization rate of the production furnace and increasing the residence time of the oxide powder. Under the heating action of the secondary reactor, the residual acid ions and moisture in the powder are further released, thereby achieving the purpose of improving the quality and performance of the oxide powder, and thus obtaining oxide powder free of moisture and acid ions. At the same time, the device can also effectively maintain the stable and closed production environment required in the production furnace.

[0023] 2) The method provided by the present invention for online continuous production of high-purity oxide powder comprises multiple sets of first heating mechanisms arranged on the production furnace, providing a centrifugal flow field for the reaction and purification of the oxide powder in the furnace, screening the oxide powder, and promoting the oxide powder to react in different areas according to particle size and weight, thereby ensuring the residence time required for the oxide powder reaction, allowing the residual acid ions and moisture in the powder to be fully released, and further removing the acid ions and moisture under heating and purification in the secondary reactor, thereby improving the quality and performance of the oxide powder. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0025] FIG1 is a schematic diagram of the structure of an apparatus for online continuous production of high-purity oxide powder provided in Example 2 of the present invention.

[0026] 1-production furnace; 2-screw conveying unit; 21-feed port; 22-discharge port; 23-exhaust port; 24-air inlet; 3-combustion heater; 4-powder conveying main pipe; 5-return silo; 6-oxide powder unloading pipe; 7-flue gas duct; 8-crusher; 9-first discharge valve; 10-first discharge pipe; 11-second discharge valve; 12-second discharge pipe; 13-third discharge valve; 14-third discharge pipe; 15-fourth discharge valve; 16-exhaust valve; 17-first heating mechanism; 18-waste heat recovery mechanism; 19-waste heat conveying pipeline. DETAILED DESCRIPTION

[0027] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. All other embodiments obtained by persons of ordinary skill in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention. In the accompanying drawings, the sizes and relative sizes of certain parts may be exaggerated for clarity.

[0028] In the description of the present invention, unless otherwise clearly specified and limited, the terms "connection" and "connected" should be interpreted broadly. For example, it can be a fixed connection, a detachable connection, or an integrated connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0029] In the description of the present invention, terms such as "up", "down", "left", "right", "front", and "back" and other orientations or positional relationships are based on the orientations or positional relationships shown in the accompanying drawings and are only for the convenience of description and simplification of operation, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation. Therefore, they should not be understood as limiting the present invention.

[0030] Furthermore, in the description of the present invention, the terms "first" and "second" are used solely to distinguish between features in the description and should not be understood to indicate or imply relative importance or implicitly specify the number of the technical features being described. Furthermore, features designated as "first" or "second" may explicitly or implicitly include one or more of the features.

[0031] Example 1

[0032] The present invention provides a method for online continuous production of high-purity oxide powder, comprising:

[0033] The waste acid liquid is sprayed into the production furnace 1 for roasting to generate oxide powder. The production furnace 1 is provided with at least one first heating mechanism 17 for roasting the waste acid liquid;

[0034] The flue gas generated in the production furnace 1 is sent to the flue gas treatment unit, and the primary oxide powder generated in the production furnace 1 is sent to the secondary reactor for further heating and purification to obtain hot gas and secondary oxide powder;

[0035] The hot gas generated in the secondary reactor is subjected to gas-solid separation, and the gas phase obtained by the gas-solid separation is recycled into the production furnace 1 or returned to the flue gas treatment unit to recover acid ions.

[0036] Preferably, the obtained high-purity oxide powder is delivered to the storage mechanism through the conveying mechanism 4, which includes a powder conveying main pipe and branch pipes. The pipeline is under negative pressure and can be used for powder conveying. The end of the powder conveying main pipe is connected to the storage mechanism.

[0037] Preferably, the waste acid liquid comes from the acid liquid containing ferrous or ferric ions in the pickling system, and the waste acid liquid is subjected to high-temperature thermal hydrolysis in the production furnace 1 to generate primary oxide powder and hydrochloric acid, and the obtained primary oxide powder is transported to the secondary reactor for heating. The temperature of the primary oxide powder coming out of the production furnace 1 is relatively high, and the heat of the production furnace 1 can be fully utilized to extend the residence time of the primary oxide powder, so that the primary oxide material is further thermally hydrolyzed in the secondary reactor to fully remove the acid radical ions and moisture therein to obtain secondary oxide powder, thereby improving the quality of the oxide powder. The hot gas in the secondary reactor enters the production furnace 1 for recovery in the gas phase after gas-solid separation, thereby avoiding overflow of acidic flue gas and affecting the environment.

[0038] Specifically, soaking or pickling minerals and steel with hydrochloric acid produces a large amount of hydrochloric acid waste liquid. This waste liquid is primarily composed of metal chloride solutions, containing a large amount of corrosive chloride ions and valuable metal ions. This waste liquid can be subjected to high-temperature roasting treatment using spray roasting or fluidized bed methods to recover the hydrochloric acid and metal oxides. The waste acid liquid is subjected to high-temperature roasting in production furnace 1, undergoing a chemical-thermohydrolysis reaction to produce metal oxides and hydrochloric acid.

[0039] Among them, the chemical pyrolysis reaction is:

[0040] MeCl x +H2O+O2=Me y O z +HCl

[0041] Me-Metal refers to metal elements such as Mg, Al, Fe, Ti, Ni, Co, Mn, etc.

[0042] The conditions for chemical hydrolysis of different metal chlorides are slightly different, and the operating parameters can be adjusted according to the specific situation. For example, the temperature required for MgCl2 solution is about 800℃; the temperature required for FeCl2 solution is about 600℃; the temperature required for FeCl3 solution is about 250℃; AlC l3 The required temperature of the solution is 180-300° C. The metal oxide powder obtained in the production furnace 1 is further treated in a secondary reactor to remove residual acid ions and moisture, thereby improving the quality of the oxide powder.

[0043] The hot gas containing acid ions in the secondary reactor is recovered into the production furnace 1 or returned to the flue gas treatment unit. It can be recycled together with the flue gas in the production furnace 1. On the one hand, it can prevent the overflow of the gas containing acid ions and its impact on the environment. On the other hand, it can improve the recovery efficiency of the acid ions. The acid ions are mostly chloride ions. The chloride ions in the hot gas and the flue gas generated in the production furnace 1 can be recycled into hydrochloric acid to obtain acid solution. The flue gas treatment unit can include a flue gas pipeline for guiding the flue gas in the production furnace to the next treatment process for flue gas treatment. The flue gas can be dissolved in water to recover the acid ions therein.

[0044] In an optimized implementation mode, the secondary reactor includes a screw conveying unit 2, and the primary oxide powder enters the screw conveying unit 2, and is conveyed from the feed port to the discharge port under the action of the screw conveying unit 2. During the transmission process, the primary oxide powder moves toward and contacts the high-temperature heated gas fed into the screw conveying unit to remove moisture and acid radical ions in the oxide powder in turn; the primary oxide powder heated again by the secondary reactor is further removed of moisture and acid radical ions to obtain high-purity secondary oxide powder, and the secondary oxide powder obtained in the screw conveying unit 2 is discharged from the discharge port and conveyed to the storage mechanism via the conveying mechanism 4 for storage. The storage mechanism is preferably a storage bin, and the temperature of the oxide powder storage area is not lower than 360°C.

[0045] Specifically, the secondary reactor further includes a second heating mechanism 3 , which supplies high-temperature heating gas required by the screw conveying unit 2 .

[0046] In an optimized implementation method, the temperature of the high-temperature heating gas discharged by the second heating mechanism 3 is not lower than 450°C. The primary oxide powder is heated by the high-temperature heating gas, so that the residual acid ions and moisture in the primary oxide powder can be separated again, thereby achieving the purpose of improving the quality and performance of the oxide powder. The acid ions and moisture separated from the primary oxide powder are discharged from the spiral conveying unit 2 along with the hot gas. After gas-solid separation, the gas phase is recovered to the production furnace 1, and the solid-phase oxide powder can be recovered to the storage mechanism through the conveying mechanism 4.

[0047] The optimized implementation mode also includes a waste heat recovery mechanism 18, and the waste heat heated air is heated by the waste heat recovery mechanism 18 and then sent to the secondary reactor. The waste heat recovery mechanism 18 is arranged on the production furnace 1; in this embodiment, the waste heat recovery mechanism 18 is preferably a waste heat recovery ring sleeve, which is arranged on the upper part of the production furnace 1 and is located on the upper part of the topmost first heating mechanism 17. The waste heat in the production furnace 1 can be used to heat the waste heat heated air, and the heated waste heat heated air is sent to the second heating mechanism 3 through the waste heat conveying pipe 19. The second heating mechanism 3 assists in heating the waste heat heated air to obtain high-temperature heated gas. The temperature of the high-temperature heated gas is not lower than 450°C. The high-temperature heated gas is sent to the spiral conveying unit 2 for sufficient heat exchange with the primary oxide powder, and the residual acid ions and moisture in the primary oxide powder are fully separated from the powder. Heating the waste heat heated air by the waste heat recovery mechanism 18 can fully utilize the waste heat of the production furnace 1, and the heated waste heat heated air is assisted by the second heating mechanism 3 and then used for re-heating and purification of the primary oxide powder.

[0048] In an optimized implementation manner, there are multiple groups of the first heating mechanisms 17, and the multiple groups of the first heating mechanisms 17 are layered from top to bottom on the production furnace 1. The first heating mechanisms 17 are arranged along the tangential direction of the furnace body of the production furnace 1 to provide a centrifugal flow field for the reaction and purification of the oxide powder in the production furnace 1.

[0049] Specifically, the first heating mechanisms 17 are arranged in layers on the production furnace 1. Each layer of heating mechanisms can be controlled according to the size and weight of the oxide powder particles in the production furnace 1 to provide the heat required by the oxide powder in different states, thereby meeting the roasting requirements in the production furnace 1 and avoiding energy waste. In this embodiment, a group of first heating mechanisms 17 is provided at the top of the production furnace 1, and a group of first heating mechanisms 17 is provided at the bottom. Of course, the number and location of the first heating mechanisms 17 can be adjusted according to actual needs.

[0050] Preferably, the heat provided to the production furnace 1 by the first heating mechanism 17 makes the heat obtained in the middle of the production furnace 1 higher than the heat obtained at the bottom and top. Specifically, the heat provided by the multi-layer heating mechanism is the most in the middle of the production furnace 1, the second most at the bottom, and the least at the top, so that the waste acid liquid in the production furnace 1 is roasted more fully; the acid radical ions and water vapor separated in the secondary reactor enter the production furnace 1 under negative pressure after gas-solid separation with the hot gas, and will be centrifuged, screened and purified in the heating area at the bottom of the production furnace 1, so that the separated acid radical ions can be further recovered to avoid overflow and impact on the environment.

[0051] In an optimized implementation manner, the first heating mechanism 17 includes a first heating unit, which is connected to a gas pipeline for supplying gas and a combustion-supporting air pipeline for supplying combustion-supporting air. The first heating unit uses gas as fuel and burns under the action of combustion-supporting air to roast the waste acid liquid in the production furnace 1 to obtain oxide powder.

[0052] In an optimized implementation method, the discharge end of the production furnace 1 is connected to a crusher 8 and a first discharge valve 9. The primary oxide powder in the production furnace 1 is crushed by the crusher 8 and then enters the secondary reactor through the first discharge valve 9. The crusher 8 is set at the discharge end of the production furnace 1 to crush the agglomerated primary oxide powder into powder, so that it can fully react in the secondary reactor to remove moisture and acid ions.

[0053] As one of the specific implementation methods, in the production furnace 1, when the spiral conveying unit 2 and the second heating mechanism 3 are started, the production furnace 1 controls the combustion system of the production furnace 1 to enter the temperature adjustment mode after receiving the above-mentioned start-up signal, automatically adjusts the combustion system gas and combustion-supporting air system, controls the combustion effect according to the index requirements of the oxide powder, and adjusts the flow field temperature in the production furnace 1. When a higher moisture and acid ion content is required, the flow field temperature in the production furnace 1 is lowered, but not lower than 600°C; when a lower moisture and acid ion content is required, the flow field temperature in the production furnace 1 is increased, but not higher than 750°C.

[0054] As one of the specific implementation methods, when the spiral conveying unit 2 and the second heating mechanism 3 are started, after the production furnace 1 receives the above-mentioned start-up signal, when it is necessary to reduce the moisture content and acid radical ion content of the oxide powder, the spray pressure of the acid liquid in the production furnace 1 is changed from medium-low pressure to high-pressure spraying state, and the spray state of the acid liquid is further fine-grained, so that the reaction in the production furnace 1 is more sufficient, and the high-pressure spray pressure is not less than 0.45Mpa; when it is necessary to increase the moisture content and acid radical ion content of the oxide powder, the spray pressure of the acid liquid in the production furnace 1 is changed from high pressure to medium-low pressure spraying state, and the spray state of the acid liquid is further coarse-grained, and the spray pressure is not less than 0.4Mpa.

[0055] According to the optimized implementation method, after the primary oxide powder has undergone preliminary water removal and acid radical removal, it needs to be further processed in depth. That is, after the powder is output from the secondary reactor and auxiliary equipment, it is transported through a gas pipeline and subjected to multiple blending and mixing, water injection and slurry mixing, molding, kiln dehydration and calcination, double-sided grinding, and high-quality finished products.

[0056] Example 2

[0057] As shown in Figure 1 of the specification, the present invention also provides an apparatus for the online continuous production of high-purity oxide powder based on the method described in Example 1, comprising:

[0058] A production furnace 1, used for roasting waste acid liquid, wherein the production furnace 1 is provided with at least one set of first heating mechanisms 17;

[0059] A secondary reactor, used for heating and purifying the primary oxide obtained from the production furnace 1, the secondary reactor being connected to the discharge end of the production furnace 1;

[0060] The return silo 5 is used for separating the hot gas in the secondary reactor into gas and solid. The feed end of the return silo 5 is connected to the secondary reactor, and the gas outlet end of the return silo 5 is connected to the production furnace 1.

[0061] Preferably, it further comprises a conveying mechanism 4 connected to the secondary reactor, and the end of the conveying mechanism 4 is connected to a storage mechanism.

[0062] In an optimized implementation manner, the secondary reactor includes a screw conveying unit 2 and a second heating mechanism 3, and a feed port 21 and a discharge port 22 are respectively provided at both ends of the screw conveying unit 2. The screw conveying unit 2 includes an air inlet 24 and an exhaust port 23 for high-temperature heating gas to flow through, and the air inlet 24 is connected to the gas outlet of the second heating mechanism 3; specifically, after the primary oxide powder enters the screw conveying unit 2, it is flipped and transported under the drive of the screw conveying unit 2. On the one hand, the primary oxide powder coming out of the production furnace 1 has a certain temperature, which can increase the residence time of the primary oxide powder in the screw conveying unit 2. On the other hand, the second heating mechanism 3 can heat the primary oxide powder to further remove the residual acid ions and moisture in the primary oxide powder to obtain secondary oxide powder, thereby improving the quality of the oxide powder. The heated secondary oxide powder enters the powder conveying main pipe and then enters the silo for storage. Preferably, the powder conveying main pipe is under negative pressure.

[0063] Preferably, in order to avoid frequent fluctuations in reaction flow in the production furnace 1, the connection between the secondary reactor and the production furnace 1 is sealed. Preferably, the screw conveying unit 2 adopts a sealed screw conveyor.

[0064] Preferably, the screw conveying unit 2 adopts a single-axis or double-axis screw conveyor, is electrically driven, and is connected to a drive motor. The screw conveying unit 2 can rotate forward or reverse to change the transmission direction.

[0065] In an optimized implementation manner, the spiral conveying unit 2 is tilted and the tilt angle is not greater than 30°, the feed port 21 is located at the lower end of the spiral conveying unit 2, and the discharge port 22 is located at the higher end of the spiral conveying unit 2; the primary oxide powder in the production furnace 1 enters the spiral conveying unit 2 from the feed port 21, and the primary oxide powder moves toward the discharge port 22 under the drive of the spiral conveying unit 2. A second heating mechanism 3 is provided on the spiral conveying unit 2, and the hot air generated by the second heating mechanism 3 can heat the primary oxide powder, so that the residual acid ions and moisture in the primary oxide powder are removed. Preferably, the air inlet 24 is located between the feed port 21 and the discharge port 22.

[0066] In an optimized implementation mode, the air inlet 24 of the spiral conveying unit 2 is arranged close to the discharge port 22, and the exhaust port 23 is arranged on the side of the feed port 21 of the spiral conveying unit 2 away from the air inlet 24. Specifically, the primary oxide powder entering the spiral conveying unit 2 is conveyed from bottom to top, and the hot air generated by the second heating mechanism 3 contacts the primary oxide powder in the opposite direction from top to bottom along the spiral conveying unit 2. Under the action of the negative pressure in the production furnace 1, the hot air enters the return silo 5 along the exhaust port. In the return silo 5, the oxide powder carried in the flue gas is deposited at the bottom of the return silo 5, enters the powder conveying main pipe 4, and is transported to the silo for storage. The flue gas in the return silo 5 returns to the production furnace 1 through the flue gas pipe 7.

[0067] Preferably, in order to improve the waste heat recovery efficiency of the production furnace 1, the high-temperature heating gas supplied to the spiral conveying unit 2 comes from the combustion air heated by the waste heat recovery mechanism 18, and is sent to the spiral conveying unit 2 after auxiliary heating by the second heating mechanism 3.

[0068] Preferably, in order to return the flue gas generated by the spiral conveying unit 2 to the production furnace 1 and maintain the negative pressure in the flue gas duct 7, a fan can be connected to the flue gas duct 7 so that the flue gas can flow through the return silo 5 and then return to the production furnace 1.

[0069] Preferably, an air cooling device is provided on the periphery of the shell of the second heating mechanism 3 and enters along the tangent line.

[0070] Preferably, multiple groups of first heating mechanisms 17 are layered on the production furnace 1. The first heating mechanism 17 includes a first heating unit and a gas pipeline and a combustion-supporting air pipeline connected to the first heating unit. The combustion-supporting air used to supply the first heating unit can also be preheated by the waste heat recovery mechanism 18 and then passed into the first heating unit, which can improve the combustion efficiency of the first heating mechanism 17.

[0071] The device provided in this application can be added to the existing production line. Installing the secondary reactor on the production furnace 1 can effectively improve the quality of the oxide powder and can continuously produce oxide powder without moisture and acid ions online.

[0072] In an optimized implementation mode, a crusher 8 is connected to the discharge end of the production furnace 1 to crush the agglomerated oxide powder and improve the purification efficiency of the oxide powder.

[0073] In an optimized implementation manner, a first discharge valve 9 is provided on the oxide powder unloading pipe 6, and the first discharge valve 9 is located below the crusher 8. The discharge volume of the crusher 8 and the first discharge valve 9 is greater than the production volume; a first discharge pipe 10 is connected between the spiral conveying unit 2 and the powder conveying main pipe 4, and a second discharge valve 11 is provided on the first discharge pipe 10, and a second discharge pipe 12 is provided between the return silo 5 and the powder conveying main pipe 4, and a third discharge valve 13 is provided on the second discharge pipe 12. Preferably, the first discharge valve 9, the second discharge valve 11 and the third discharge valve 13 are preferably sealed discharge valves.

[0074] Preferably, the discharge volume of the second discharge valve 11 is not less than the discharge volume of the agglomerate crusher 8 and the first discharge valve 9, and is greater than the production volume of the oxide powder.

[0075] Preferably, a third discharge pipe 14 is connected between the oxide powder unloading pipe 6 and the powder conveying main pipe 4, and a fourth discharge valve 15 is provided on the third discharge pipe 14. Preferably, the fourth discharge valve 15 is preferably a sealed discharge valve. When the device of the present application is working normally, the fourth discharge valve 15 is closed, and the primary oxide powder in the production furnace 1 is heated in the secondary reactor and then sent to the silo for storage through the powder conveying main pipe 4. When the device needs to be stopped for inspection, the primary oxide powder in the production furnace 1 can directly enter the powder conveying main pipe 4 through the fourth discharge pipe 14.

[0076] In an optimized implementation mode, a gas-solid separation mechanism is provided in the return silo 5 , which can perform gas-solid separation on the flue gas entering the return silo 5 so as to better collect the oxide powder; preferably, an exhaust valve 16 is provided on the flue gas pipe 7 .

[0077] In an optimized implementation manner, the connection point between the flue gas duct 7 and the production furnace 1 is higher than the highest powder accumulation height in the production furnace 1 .

[0078] The workflow of the device of this application is:

[0079] When the system starts, the second discharge valve 11 of the secondary reactor and the third discharge valve 13 of the return silo 5 are started first, and then the screw conveying unit 2 is started; the first discharge valve 9 is started first, and then the crusher 8 is started. After the exhaust valve 16 on the flue gas duct 7 is started, the second heating mechanism 3 is started again;

[0080] When the system stops, the pulverizer 8 is closed first and then the first discharge valve 9 is stopped; after the second heating mechanism 3 is closed, the spiral conveying unit 2 is stopped.

[0081] The method of the present application utilizes the centrifugal flow field of the multi-layer heating mechanism of the production furnace 1 to screen the oxide powder, promote the oxide powder to react in different areas according to particle size and weight, thereby ensuring the residence time required for the oxide powder reaction, so that the residual acid ions and moisture in the powder are fully released. At the same time, the residual heat at the top of the production furnace 1 is fully utilized. Under the action of the second heating mechanism 3 of the secondary reactor, the residual acid ions and moisture in the powder are separated again through the pulverization of the agglomerate crusher 8 and the stirring of the secondary reactor, thereby achieving the purpose of improving the quality and performance of the oxide powder. At the same time, this method can also well maintain the stable and closed production environment required in the production furnace 1.

[0082] Those skilled in the art will appreciate that the present invention can be implemented in many other specific forms without departing from the spirit and scope of the present invention. Although embodiments of the present invention have been described, it should be understood that the present invention should not be limited to these embodiments, and those skilled in the art can make changes and modifications within the spirit and scope of the present invention as defined by the appended claims.

Claims

1. A method for continuously producing high-purity oxide powder online, characterized in that, Comprising: Injecting waste acid liquid into a production furnace for roasting to generate oxide powder, and at least one set of first heating mechanisms for roasting waste acid liquid are arranged on the production furnace; Sending the flue gas generated in the production furnace to a flue gas treatment unit, and sending the primary oxide powder generated by the production furnace into a secondary reactor for reheating and purification to obtain hot gas and secondary oxide powder; Performing gas-solid separation on the hot gas generated in the secondary reactor, and recycling the gas phase obtained by the gas-solid separation into the production furnace or returning it to the flue gas treatment unit to recover acid radical ions.

2. The method for continuously and online producing high-purity oxide powder according to claim 1, wherein The secondary reactor includes a screw conveying unit, and the primary oxide powder is transported from the feed port of the screw conveying unit to the discharge port, and moves in opposite directions and contacts with the high-temperature heating gas fed into the screw conveying unit during the transportation process to remove moisture and acid radical ions in the primary oxide.

3. The method for continuously and online producing high-purity oxide powder according to claim 2, characterized in that, The temperature of the high-temperature heating gas is not lower than 450 °C.

4. The method for continuously and online producing high-purity oxide powder according to claim 1, characterized in that, It further includes a waste heat recovery mechanism, and the waste heat heating air is sent into the secondary reactor after being heated by the waste heat recovery mechanism, and the waste heat recovery mechanism is arranged on the production furnace.

5. The method for continuously producing high-purity oxide powder online according to claim 1, characterized in that, The number of the first heating mechanisms is multiple groups, and the multiple groups of the first heating mechanisms are arranged in layers from top to bottom on the production furnace, and the first heating mechanisms are arranged along the tangent direction of the furnace body of the production furnace.

6. The method for continuously producing high-purity oxide powder online according to claim 5, characterized in that, The heat provided by the first heating mechanism to the production furnace makes the heat obtained in the middle of the production furnace higher than the heat obtained at its bottom and top.

7. The method for continuously and online producing high-purity oxide powder according to claim 1, characterized in that, The first heating mechanism includes a first heating unit, and the first heating unit is connected with a gas pipeline for supplying fuel gas and a combustion-supporting air pipeline for supplying combustion-supporting air.

8. The method for continuously producing high-purity oxide powder online according to claim 1, characterized in that, The discharge end of the production furnace is connected with a pulverizer and a first discharge valve, and the oxide powder in the production furnace enters the secondary reactor through the pulverizer and the first discharge valve after being pulverized.

9. The method for continuously producing high-purity oxide powder online according to claim 1, characterized in that, Sending the solid-phase oxide powder obtained by gas-solid separation of the hot gas generated in the secondary reactor to a storage mechanism through a conveying mechanism.

10. An apparatus for the method of continuously producing high-purity oxide powder online according to any one of claims 1-9, characterized in that, Comprising: A production furnace for roasting waste acid liquid, and at least one set of first heating mechanisms are arranged on the production furnace; A secondary reactor for heating and purifying the primary oxide powder obtained by the production furnace, and the secondary reactor is connected with the discharge end of the production furnace; A return silo for gas-solid separation of the hot gas in the secondary reactor, the feed end of the return silo is connected with the secondary reactor, and the gas outlet end of the return silo is connected with the production furnace.

Images