Preparation device for oxide powder

Abstract

A preparation device for oxide powder, comprising a production furnace (1), and further comprising a return bin (5), a powder conveying main pipe (4), and a secondary reactor for powder heating. A feeding port (21) of the secondary reactor is connected to the production furnace (1) by means of an oxide powder discharging pipe (6); a discharge port (22) of the secondary reactor is connected to the powder conveying main pipe (4); an exhaust port (23) of the secondary reactor is connected to the return bin (5); the return bin (5) is connected to the production furnace (1) by means of a flue gas pipeline (7); and the bottom of the return bin (5) is connected to the powder conveying main pipe (4). The secondary reactor is connected to the production furnace (1), so that the heat utilization rate of the production furnace (1) can be increased, the retention time of the oxide powder is prolonged, acid radical ions and moisture remaining in the powder are further released under the heating effect of the secondary reactor, and the quality and performance of the oxide powder are improved. In addition, a stable and closed production environment required in the production furnace (1) can be well maintained.

Description

A device for preparing oxide powder Technical Field

[0001] The utility model relates to the technical field of acid solution or waste acid solution regeneration, in particular to a device for preparing 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 the existing production system, it is difficult to improve the performance and quality of oxide powder. Moreover, when the energy medium supply and stability of the production furnace are poor, it is very easy to cause frequent fluctuations in the reaction flow field in the production furnace, the production environment deteriorates, and it is difficult to produce oxide powder with stable performance and high quality.

[0004] Utility Model Content

[0005] In order to solve the above problems, the utility model provides a device for preparing oxide powder, including a production furnace for high-temperature thermal hydrolysis of acid liquid or waste acid liquid, and also including a return silo, a powder conveying main pipe and a secondary reactor for powder heating. The feed port of the secondary reactor is connected to the production furnace through an oxide powder unloading pipe, the discharge port of the secondary reactor is connected to the powder conveying main pipe, the exhaust port of the secondary reactor is connected to the return silo, the return silo is connected to the production furnace through a flue gas pipe, and the bottom of the return silo is connected to the powder conveying main pipe.

[0006] Furthermore, the secondary reactor includes a screw conveying unit and a combustion heater, the feed port and the discharge port are arranged on the screw conveying unit, the screw conveying unit includes an air inlet for high-temperature heating gas to flow through, and the air inlet is connected to the gas outlet of the combustion heater.

[0007] Furthermore, the air inlet is arranged close to the discharge port, and the exhaust port is arranged on a side of the feed port of the spiral conveying unit away from the air inlet.

[0008] Furthermore, the air inlet is located between the feed port and the discharge port.

[0009] Furthermore, the combustion heater is connected to a gas pipeline and a combustion-supporting air pipeline.

[0010] Furthermore, the spiral conveying unit is tilted and the tilt angle is no more than 30°, the feed port is located at the lower end of the spiral conveying unit, and the discharge port is located at the higher end of the spiral conveying unit.

[0011] Furthermore, a crusher is provided at the discharge end of the production furnace.

[0012] Furthermore, sealed discharge valves are provided on the pipelines between the secondary reactor and the return silo and the powder conveying main pipe, as well as on the oxide powder unloading pipe.

[0013] Furthermore, a gas-solid separation mechanism is provided in the return silo.

[0014] Furthermore, the connection point between the flue gas duct and the production furnace is higher than the highest powder accumulation height in the production furnace.

[0015] Due to the adoption of the above technical solution, the present invention has the following beneficial effects compared with the prior art:

[0016] 1) The oxide powder preparation device provided by the present invention has a secondary reactor connected to a production furnace, which can improve the heat utilization rate of the production furnace and increase 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. At the same time, the device can also effectively maintain the stable and closed production environment required in the production furnace;

[0017] 2) The oxide powder preparation device provided by the present invention has a crusher installed at the discharge end of the production furnace, which can crush the agglomerates into powder, and the powder is turned and stirred in the spiral conveying unit, which can accelerate the release of residual acid ions and moisture in the powder and improve the quality of the oxide powder. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] 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.

[0019] FIG1 is a schematic structural diagram of an apparatus for preparing oxide powder according to Example 1;

[0020] Figure 2 is a schematic diagram of the structure of the oxide powder preparation apparatus of Example 2. 1 - Production furnace; 2 - Screw conveying unit; 21 - Feed inlet; 22 - Discharge outlet; 23 - Exhaust outlet; 24 - Air inlet; 3 - Combustion heater; 4 - Powder conveying main pipe; 5 - Return silo; 6 - Oxide powder discharge pipe; 7 - Flue gas duct; 8 - Pulverizer; 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 - Heating unit; 18 - Waste heat recovery mechanism; 19 - Waste heat conveying pipe. DETAILED DESCRIPTION

[0021] The following will be combined with the accompanying drawings of the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative work are within the scope of protection of the present invention. In the drawings, the size and relative sizes of some parts may be exaggerated for clarity.

[0022] 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 integral 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, and it can be the internal communication between 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.

[0023] In the description of the present invention, the terms "up", "down", "left", "right", "front", "back", "center", "horizontal", "vertical", "top", "bottom", "inside", "outside" and other orientations or positional relationships are based on the orientations or positional relationships shown in the accompanying drawings. They 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 operated in a specific orientation. Therefore, they cannot be understood as limitations on the present invention.

[0024] Furthermore, in the description of this utility model, the terms "first" and "second" are used solely to distinguish between the features in the description and should not be understood to indicate or imply relative importance or implicitly specify the number of the technical features indicated. Furthermore, features designated as "first" or "second" may explicitly or implicitly include one or more of the features.

[0025] As shown in Figure 1 of the specification, the utility model provides a device for preparing oxide powder, including a production furnace 1 for high-temperature thermal hydrolysis of acid liquid or waste acid liquid, and also including a return silo 5, a powder conveying main pipe 4 and a secondary reactor for heating the powder. The feed port 21 of the secondary reactor is connected to the production furnace 1 through an oxide powder unloading pipe 6, the discharge port 22 of the secondary reactor is connected to the powder conveying main pipe 4, the exhaust port 23 of the secondary reactor is connected to the return silo 5, the return silo 5 is connected to the production furnace 1 through a flue gas pipe 7, and the bottom of the return silo 5 is connected to the powder conveying main pipe 6. In this embodiment, the acid liquid or waste acid liquid is subjected to high-temperature thermal hydrolysis in the production furnace 1 to generate oxide powder and hydrochloric acid, and the obtained oxide powder is transported to the secondary reactor for heating. The temperature of the 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 oxide powder, so that the oxide material is further thermally hydrolyzed in the secondary reactor to fully remove the acid radical ions and moisture therein, thereby improving the quality of the oxide powder. The flue gas in the secondary reactor is separated from the solid powder through the return silo 5 and then enters the production furnace 1 for recovery, thereby avoiding the overflow of acidic flue gas and the impact on the environment.

[0026] 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 using spray roasting or fluidized bed methods to recover the hydrochloric acid and metal oxides. The waste acid liquid is roasted at high temperature in production furnace 1, undergoing a chemical-thermohydrolysis reaction to produce metal oxides and hydrochloric acid.

[0027] Among them, the chemical pyrolysis reaction is: MeCl x +H2O+O2=Me y O z +HCl

[0028] Me-Metal refers to metal elements such as Mg, Al, Fe, Ti, Ni, Co, Mn, etc.

[0029] 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.

[0030] In an optimized implementation mode, the secondary reactor includes a screw conveying unit 2 and a combustion heater 3, the feed port 21 and the discharge port 22 are respectively arranged at both ends of the screw conveying unit 2, and the screw conveying unit 2 includes an air inlet 24 for high-temperature heating gas to flow through, and the air inlet 24 is connected to the gas outlet of the combustion heater 3; specifically, after the 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 oxide powder coming out of the production furnace 1 has a certain temperature, which can increase the residence time of the oxide powder in the screw conveying unit 2. On the other hand, the combustion heater 3 can heat the oxide powder, so that the residual acid ions and moisture in the oxide powder are further removed, thereby improving the quality of the oxide powder. The heated oxide powder enters the powder conveying main pipe 4 and then enters the silo for storage. Preferably, the powder conveying main pipe 4 is under negative pressure.

[0031] 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.

[0032] 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.

[0033] 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 oxide powder in the production furnace 1 enters the spiral conveying unit 2 from the feed port 21, and the oxide powder moves toward the discharge port 22 under the drive of the spiral conveying unit 2. A combustion heater 3 is provided on the spiral conveying unit 2, and the hot air generated by the combustion heater 3 can heat the oxide powder, so that the residual acid ions and moisture in the oxide powder are removed. Preferably, the air inlet 24 is located between the feed port 21 and the discharge port 22.

[0034] In an optimized embodiment, the air inlet 24 of the spiral conveying unit 2 is arranged near the discharge port 22, and the exhaust port 23 is arranged on a side of the feed port 21 of the spiral conveying unit 2 away from the air inlet 24. Specifically, the oxide powder entering the spiral conveying unit 2 is conveyed from bottom to top, and the hot gas generated by the combustion heater 3 contacts the 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 gas 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.

[0035] 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.

[0036] Preferably, the combustion heater 3 is connected to a gas pipeline and a combustion-supporting air pipeline for heating the gas, and an air cooling device is provided on the periphery of the combustion heater shell and enters along a tangent line.

[0037] The preparation device of the present application can be added to the original 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.

[0038] 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.

[0039] 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.

[0040] 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 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 oxide powder in the production furnace 1 can directly enter the powder conveying main pipe 4 through the fourth discharge pipe 14.

[0041] 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 .

[0042] 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 .

[0043] The working process of the preparation device of the present application is as follows: when the system starts, the second discharge valve 11 of the secondary reactor and the third discharge valve 13 of the return hopper 5 are started first, and then the spiral conveying unit 2 is started; the first discharge valve 9 is started first, and then the pulverizer 8 is started. After the exhaust valve 16 on the flue gas duct 7 is started, the combustion heater 3 is started again; when the system stops, the pulverizer 8 is closed first, and then the first discharge valve 9 is stopped; after the combustion heater 3 is closed, the spiral conveying unit is stopped.

[0044] Example 2

[0045] As shown in Figure 2 of the specification, the present invention also provides another device for preparing oxide powder, and the parts having the same structure as that in Example 1 are not described in detail here.

[0046] Preferably, the production furnace 1 is provided with a plurality of groups of heating units 17 for heating, and the plurality of groups of heating units 17 are arranged in layers from top to bottom on the production furnace 1. The heating units 17 in each layer can be regulated according to the size and weight of the oxide powder particles in the production furnace 1 to provide the heat required for oxide powder in different states, so as to meet the roasting requirements in the production furnace 1 and avoid energy waste.

[0047] The heating unit 17 is connected to a gas pipeline for supplying gas and a combustion-supporting air pipeline for supplying combustion-supporting air.

[0048] Preferably, a waste heat recovery mechanism 18 is provided at the upper end of the production furnace. The waste heat recovery mechanism 18 is preferably a waste heat recovery sleeve. The waste heat recovery sleeve is provided at the upper portion of the production furnace 1 and is located above the uppermost heating unit 17. The waste heat in the production furnace 1 can be used to heat the waste heat heated air. The heated waste heat heated air is then delivered to the combustion heater 3 via the waste heat delivery pipe 19. The combustion heater 3 assists in heating the waste heat heated air to obtain high-temperature heated gas. Heating the waste heat heated air by the waste heat recovery mechanism 18 can fully utilize the waste heat of the production furnace 1. The heated waste heat heated air is then auxiliary-heated by the combustion heater 3 and used for further heating and purification of the oxide powder.

[0049] Meanwhile, the contents not described in detail in this specification belong to the prior art known to those skilled in the art.

[0050] Those skilled in the art will appreciate that the present invention may 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 may make changes and modifications within the spirit and scope of the present invention as defined by the appended claims.

Claims

1. An apparatus for preparing oxide powder, comprising a production furnace for high-temperature hydrolysis of acid solution or waste acid solution, characterized in that, It further includes a return silo, a main powder conveying pipe, and a secondary reactor for heating the powder. The feed inlet of the secondary reactor is connected to the production furnace through an oxide powder discharge pipe. The discharge outlet of the secondary reactor is connected to the main powder conveying pipe. The exhaust outlet of the secondary reactor is connected to the return silo. The return silo is connected to the production furnace through a flue gas pipe. The bottom of the return silo is connected to the main powder conveying pipe.

2. The preparation apparatus for the oxide powder according to claim 1, wherein, The secondary reactor includes a screw conveying unit and a combustion heater. The feed inlet and the discharge outlet are arranged on the screw conveying unit. The screw conveying unit includes an air inlet through which high-temperature heating gas flows, and the air inlet is connected to the gas outlet of the combustion heater.

3. The preparation apparatus for the oxide powder according to claim 2, wherein The air inlet is arranged close to the discharge outlet, and the exhaust outlet is arranged on the side of the feed inlet of the screw conveying unit away from the air inlet.

4. The preparation apparatus for oxide powder according to claim 2, wherein, The air inlet is located between the feed inlet and the discharge outlet.

5. The preparation apparatus for the oxide powder according to claim 2, wherein The combustion heater is connected with a gas pipeline and a combustion-supporting air pipeline.

6. The preparation apparatus for the oxide powder according to claim 1, characterized in that, The screw conveying unit is arranged obliquely with an inclination angle not greater than 30°. The feed inlet is located at the lower end of the screw conveying unit, and the discharge outlet is located at the higher end of the screw conveying unit.

7. The preparation apparatus for the oxide powder according to claim 1, characterized in that, A pulverizer is arranged at the discharge end of the production furnace.

8. The preparation apparatus for oxide powder according to claim 1, characterized in that, Sealed discharge valves are provided on the pipelines between the secondary reactor and the return silo and the main powder conveying pipe, as well as on the oxide powder discharge pipe.

9. The preparation apparatus for oxide powder according to claim 1, characterized in that, An air-solid separation mechanism is provided in the return silo.

10. The preparation apparatus for the oxide powder according to claim 1, characterized in that, The connection point of the flue gas pipe and the production furnace is higher than the highest powder accumulation height in the production furnace.

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