Apparatus and method for producing iron oxide powder by spray roasting

Abstract

An apparatus and method for producing iron oxide powder by spray roasting. The apparatus comprises a production furnace (1), a first storage bin (7), a crushing mechanism (15), a classification mechanism (16), and a second storage bin (18). The first storage bin (7) is configured to receive and temporarily store iron oxide powder produced by the production furnace (1); the crushing mechanism (15) is configured to receive the iron oxide powder from the first storage bin (7) and crush same; the classification mechanism (16) is configured to classify the crushed iron oxide powder according to the particle size; and the second storage bin (18) is configured to store the classified iron oxide powder. The apparatus utilizes a waste acid solution to produce iron oxide powder by means of high-temperature roasting, thereby maintaining low energy consumption, and achieving efficient recovery of valuable substances from the waste acid solution; and then, by means of processing of the crushing mechanism (15) and the classification mechanism (16), the specific surface area and activity of the product are increased, and the product quality is improved.

Description

Device and method for producing iron oxide powder by spray roasting TECHNICAL FIELD

[0001] The present application relates to the technical field of iron oxide powder production, and in particular to a device and method for producing iron oxide powder by spray roasting. BACKGROUND

[0002] In key industries such as metallurgy, chlor-alkali, and new energy material manufacturing, acid substances such as hydrochloric acid are widely used in the leaching treatment of minerals and the pickling process of steel. These processes not only improve the processing performance of materials, but also generate a large amount of acid solution containing ferrous ions or waste acid solution. If these iron-containing acid solutions are not properly treated, not only will it cause resource waste, but also will pose a serious threat to the environment. Through the spray roasting process, the acid solution containing ferrous ions or waste acid solution can be converted into oxide powder with high added value. This oxide powder has shown a wide application prospect in the new energy material, magnetic material, and alkaline material manufacturing industries due to its excellent physical and chemical properties.

[0003] In the prior art, the iron oxide powder produced by the spray roasting method has the problems of wide particle size distribution and insufficient specific surface area, which limits the product quality. The traditional method of reducing the production concentration to increase the specific surface area can improve the specific surface area of the product, but at the cost of sacrificing production efficiency and increasing energy consumption, which is not economical in industrial applications. Therefore, there is an urgent need for a method and device for improving the quality of iron oxide powder produced by the spray roasting method to solve the above problems.

[0004] SUMMARY

[0005] To this end, the present application provides a device and method for producing iron oxide powder by spray roasting to solve the above problems.

[0006] To achieve the above purpose, the technical solutions provided by the present application are as follows:

[0007] A device for producing iron oxide powder by spray roasting, comprising a production furnace, a first bin, a crushing mechanism, a classification mechanism, and a second bin; the production furnace is used to receive waste acid solution and perform spray roasting thereon to convert and generate iron oxide powder; the first bin is used to receive and cache the iron oxide powder produced by the production furnace; the crushing mechanism can generate high-speed airflow to crush the iron oxide powder from the first bin; the classification mechanism is used to classify and process the crushed iron oxide powder according to particle size, so that the iron oxide powder meeting the classification set standard enters the second bin, and the iron oxide powder not meeting the classification set standard returns to the crushing mechanism; the second bin is used to store the classified iron oxide powder.

[0008] Optionally, the crushing mechanism comprises a crushing bin and a high-pressure airflow device, the high-pressure airflow device comprising a compressor, an air tank, an oil remover, a freeze dryer, an oil remover, a filter and an airflow nozzle connected in sequence; the airflow nozzle is connected to the crushing bin.

[0009] Optionally, the production furnace is provided with a spraying mechanism and a burner mechanism, the spraying mechanism being capable of uniformly spraying waste acid liquid into the production furnace; the burner mechanism being used to provide heat energy into the production furnace.

[0010] Optionally, the first bin and / or the second bin is provided with an impact cannon at the bottom.

[0011] Optionally, the second bin is provided with a dust removal mechanism at the top.

[0012] Optionally, a packing machine for packing the iron oxide powder is arranged below the discharge port of the second bin.

[0013] A method for producing iron oxide powder by spray roasting, using the device described above, comprising the following steps:

[0014] S1, spraying waste acid liquid into the production furnace to generate iron oxide powder by roasting;

[0015] S2, the iron oxide powder is transported to the crushing mechanism after being buffered in the first bin and is crushed by high-speed airflow;

[0016] S3, the crushed iron oxide powder is subjected to classification treatment in the classification mechanism, and the iron oxide powder reaching the classification requirement set value enters the second bin; the iron oxide powder not reaching the classification requirement set value returns to the crushing mechanism for crushing;

[0017] S4, the iron oxide powder is packed and stored at the outlet of the second bin.

[0018] Optionally, in S2, the particle size (D50) of the iron powder entering the crushing mechanism ranges from 25 to 50 μm.

[0019] Optionally, in S3, the particle size (D50) of the iron oxide powder entering the second bin ranges from 1 to 10 μm.

[0020] Optionally, in S3, the specific surface area of the iron oxide powder entering the second bin is not less than 3.0 m2 / g.

[0021] The technical scheme provided by the present application has the following beneficial effects: the waste acid liquid is used for high-temperature roasting to produce iron oxide powder, low energy consumption is maintained, valuable substances are efficiently recovered from the waste acid liquid, and remarkable economic and environmental benefits are achieved; after processing and treatment of the crushing mechanism and the grading mechanism, the specific surface area and activity of the product are improved, and the product quality is improved; and the whole set of equipment device is reasonably designed, easy to operate, and easy to realize industrial production, and has good popularization and application prospect. BRIEF DESCRIPTION OF DRAWINGS

[0022] Fig. 1 is a schematic diagram of the overall structure of the present embodiment.

[0023] Explanation of reference signs: 1, production furnace; 2, burner mechanism; 3, spraying mechanism; 4, crusher; 5, rotary valve; 6, shut-off valve; 7, first bin; 8, impact gun; 9, compressor; 10, gas storage tank; 11, oil remover; 12, freeze dryer; 13, filter; 14, air jet nozzle; 15, crushing mechanism; 16, grading mechanism; 17, crushing bin; 18, second bin; 19, dust removal mechanism; 20, conveying fan; 21, packing machine. DETAILED DESCRIPTION

[0024] To further illustrate the embodiments, the present application provides accompanying drawings. These drawings are part of the disclosure of the present application, mainly used to illustrate the embodiments, and can be used to explain the operating principle of the embodiments in conjunction with the related description of the specification. With reference to these contents, those skilled in the art should be able to understand other possible implementations and advantages of the present application. The components in the drawings are not drawn to scale, and similar component symbols are generally used to represent similar components.

[0025] In the description of the present application, unless otherwise explicitly specified and limited, the terms "connection", "connection" should be interpreted broadly, for example, it can be fixed connection, or detachable connection, or integral; it can be mechanical connection, or electrical connection; it can be direct connection, or indirect connection through intermediate medium; it can be the internal communication of two elements or the interaction relationship between two elements, and those skilled in the art can understand the specific meaning of the above terms in the present application according to the specific circumstances.

[0026] In the description of the present application, the terms "up", "down", "left", "right", "front", "back" and other orientation or position relationship are based on the orientation or position relationship shown in the drawings, which is only for the convenience of description and simplification of operation, and does not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, therefore it cannot be understood as a limitation on the present application.

[0027] Further, in the description of the present application, the terms "first", "second" are only used to distinguish in description, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. In addition, the features defined as "first", "second" can be explicitly or implicitly included one or more of the features.

[0028] The present application will be further described in conjunction with the accompanying drawings and specific embodiments.

[0029] Referring to FIG. 1, the present embodiment provides a device for producing iron oxide powder by spray roasting, which comprises a production furnace 1, a first bin 7, a crushing mechanism 15, a grading mechanism 16 and a second bin 18. The production furnace 1 is used to receive waste acid liquid and perform spray roasting thereon to convert and generate iron oxide powder. The first bin 7 is used to receive and store the iron oxide powder produced by the production furnace 1. The crushing mechanism 15 can generate high-speed airflow to crush the iron oxide powder from the first bin 7. The grading mechanism 16 is connected to the end of the crushing mechanism 15 and is used to perform grading treatment on the crushed iron oxide powder according to particle size, so that the iron oxide powder meeting the grading set standard enters the second bin 18, and the iron oxide powder not meeting the grading set standard returns to the crushing mechanism 15. The second bin 18 is used to store the graded iron oxide powder.

[0030] Specifically, the production furnace 1 is provided with a spraying mechanism 3 and a burner mechanism 2. The spraying mechanism 3 can uniformly spray the waste acid liquid into the production furnace 1. The burner mechanism 2 is used to provide heat energy into the production furnace 1. The burner mechanism 2 is used to introduce fuel gas and combustion air into the production furnace 1, ignite to generate a large amount of heat energy to roast the waste acid liquid spray. A flow guide device can be arranged in the production furnace 1 to enable the iron oxide powder to be output from the outlet of the production furnace 1. The bottom of the production furnace 1 is further provided with a crusher 4 to preliminarily crush the large powder in the furnace to ensure that the powder is not blocked at the discharge port and is smoothly conveyed to the first bin 7. A rotary valve 5 and a shut-off valve 6 are sequentially installed between the discharge port of the production furnace 1 and the feeding port of the first bin 7 to facilitate the control of the conveying of the powder.

[0031] The first bin 7 receives and stores the iron oxide powder produced by the production furnace 1. The bottom of the first bin 7 is in an inverted conical structure, and impact cannons 8 are arranged at intervals at the bottom thereof to ensure that the iron oxide powder can be smoothly conveyed out of the discharge port at the bottom of the first bin 7. A rotary valve 5 and a shut-off valve 6 are sequentially installed between the discharge port of the first bin 7 and the feeding port of the crushing mechanism 15 to facilitate the control of the conveying of the powder and ensure that the material smoothly enters the next link.

[0032] The crushing mechanism 15 includes a crushing bin 17 and a high-pressure airflow device, which includes a compressor 9, an air tank 10, an oil remover 11, a freeze dryer 12, an oil remover 11, a filter 13, and an airflow nozzle 14 connected in sequence; the airflow nozzle 14 is connected to the crushing bin 17. The bottom of the crushing bin 17 is in an inverted conical structure, and the airflow nozzles 14 are arranged at intervals inside the crushing bin 17. The iron oxide powder is fully and efficiently crushed by high-pressure airflow to increase the specific surface area of the iron oxide powder. The pressure range of the high-pressure airflow is 0.6-1.0 MPa. The particle size (D50) of the iron oxide powder entering the crushing bin 17 from the feed inlet ranges from 25 to 50 μm.

[0033] The classification mechanism 16 is connected to the end of the crushing bin 17, classifies the crushed iron oxide powder according to the particle size, and ensures that the powder particles meet the requirements of the subsequent process. The iron oxide powder that meets the classification standard enters the second bin 18, and the iron oxide powder that does not meet the classification standard returns to the crushing mechanism 15 for further crushing. In this embodiment, the classification particle size of the classification mechanism 16 is 5-15 μm, which ensures the uniformity and accuracy of the particle size distribution. After being treated by the classification mechanism 16, the particle size (D50) of the iron oxide powder entering the second bin 18 ranges from 1 to 10 μm, and the specific surface area BET of the powder is greater than or equal to 3.0 m2 / g. That is, smaller particles enter the second bin 18, and larger particles remain in the crushing mechanism 15 for further crushing.

[0034] The bottom of the second bin 18 is in an inverted conical structure, and impact cannons 8 are arranged at intervals at the bottom to ensure that the iron oxide powder can be smoothly transported out of the discharge port at the bottom of the second bin 18. Furthermore, the discharge port of the second bin 18 is sequentially connected to a shut-off valve 6, a rotary valve 5, and a packing machine 21, and the iron oxide powder is packed and stored in time by the packing machine 21. In addition, a dust removal mechanism 19 is arranged at the top of the second bin 18. The dust removal mechanism 19 can be a pulse dust collector, an electrostatic dust collector, or a plastic burning plate dust collector, which is used to efficiently remove dust in the tail gas, reduce environmental pollution, and improve product purity. The dust removal mechanism 19 is also connected to a conveying fan 20 to ensure the dust removal effect. In this embodiment, the dust removal mechanism 19 is a pulse dust collector.

[0035] The production workflow of the device is as follows:

[0036] Start the production furnace 1, uniformly spray the waste acid liquid into the furnace through the spraying mechanism 3, and control the flow rate of the waste acid liquid to be 50 liters / hour. Start the burner mechanism 2 to provide the necessary heat energy, adjust the temperature in the furnace to 800℃, to adapt to the high-temperature hydrolysis reaction of the waste acid liquid, and maintain the stability of the temperature in the furnace to ensure that the waste acid liquid is fully calcined. The iron oxide powder generated during the calcination process is collected by the flow guide device in the furnace and is transported to the first bin 7.

[0037] In the first hopper 7, the flow of iron oxide powder is controlled by the impact gun 8 to assist the discharge, and the material is ensured to enter the crushing mechanism 15 smoothly. The high-pressure airflow device is started, and the output pressure of the compressor 9 is set to 0.8 Mpa to generate a high-speed jet. The iron oxide powder is impacted by the high-speed airflow in the crushing chamber 17 to achieve crushing, and the pressure in the crushing chamber 17 is maintained at 0.65 Mpa. The crushed iron oxide powder is delivered to the classification mechanism 16 by the fan, and the classification wheel of the classification mechanism 16 is set to rotate at 2000 rpm to ensure that the powder with a particle size (D50) ranging from 1 to 10 μm is classified.

[0038] The classified iron oxide powder is sent to the second hopper 18 through the conveying system, and the pulse dust collector above the hopper is started to perform dust removal treatment on the tail gas. The packer 21 below the hopper is started to automatically pack the iron oxide powder.

[0039] The crushed iron oxide powder is sampled, and the particle size distribution is detected by a laser particle size analyzer to ensure that the requirement of (D50) 1-10 μm is met. The specific surface area of the iron oxide powder is measured by a BET specific surface area analyzer to ensure that it is not less than 3.0 m2 / g.

[0040] The embodiment also provides a method for producing iron oxide powder by spray roasting, which uses the above device and includes the following steps:

[0041] S1, the waste acid solution is sprayed into the production furnace 1 to generate iron oxide powder by roasting;

[0042] S2, the iron oxide powder is delivered to the crushing mechanism 15 after being buffered in the first hopper 7 and is crushed by high-speed airflow;

[0043] S3, the crushed iron oxide powder is classified in the classification mechanism 16, and the iron oxide powder meeting the classification requirement set value enters the second hopper 18; the iron oxide powder not meeting the classification requirement set value returns to the crushing mechanism 15 for crushing;

[0044] S4, the iron oxide powder is packed and stored at the outlet of the second hopper 18.

[0045] Specifically, in S2, the particle size (D50) of the iron powder entering the crushing mechanism 15 ranges from 25 to 50 μm. It should be noted that the particle size (D50) refers to the particle size corresponding to the cumulative particle size distribution percentage of 50% of a sample. Its physical meaning is that the particles with a particle size greater than it account for 50%, and the particles with a particle size less than it also account for 50%, and D50 is also called median diameter or median particle size.

[0046] Further, in S3, after the grading treatment, the iron oxide powder entering the second bin 18 has a particle size (D50) ranging from 1 to 10 μm, i.e. the smaller particles enter the second bin 18 and the larger particles stay in the crushing mechanism 15 to continue the crushing. The specific surface area of the iron oxide powder entering the second bin 18 is not less than 3.0 m2 / g.

[0047] This method uses waste acid to produce iron oxide powder by high-temperature roasting, maintains low energy consumption, realizes efficient recovery of valuable substances from waste acid, and has significant economic and environmental benefits; and after processing by the crushing mechanism 15 and the grading mechanism 16, the specific surface area and activity of the product are improved, and the product quality is improved.

[0048] Although the present application is specifically shown and described in connection with preferred embodiments, those skilled in the art will appreciate that various modifications in form and detail can be made without departing from the spirit and scope of the application as defined in the appended claims.

Claims

1. An apparatus for spray roasting production of iron oxide fines, characterized by: The device comprises a production furnace, a first bin, a crushing mechanism, a grading mechanism and a second bin; the production furnace is used for receiving waste acid liquid and performing spray roasting thereon to generate iron oxide powder; the first bin is used for receiving and buffering the iron oxide powder generated by the production furnace; the crushing mechanism can generate high-speed airflow to crush the iron oxide powder from the first bin; the grading mechanism is used for grading the crushed iron oxide powder according to particle size, so that the iron oxide powder meeting the grading standard enters the second bin, and the iron oxide powder not meeting the grading standard returns to the crushing mechanism; and the second bin is used for storing the graded iron oxide powder.

2. A device for spray roasting production of iron oxide powder according to claim 1, characterized in that: The crushing mechanism comprises a crushing bin and a high-pressure airflow device, the high-pressure airflow device comprises a compressor, a gas storage tank, an oil remover, a freeze dryer, an oil remover, a filter and an airflow nozzle connected in sequence, and the airflow nozzle is connected to the crushing bin.

3. A device for spray roasting production of iron oxide powder according to claim 1, characterized in that: The production furnace is provided with a spraying mechanism and a burner mechanism, the spraying mechanism can uniformly spray the waste acid liquid into the production furnace, and the burner mechanism is used for providing heat energy into the production furnace.

4. A device for spray roasting production of iron oxide powder according to claim 1, characterized in that: The first bin and / or the second bin is provided with an impact cannon at the bottom.

5. A device for spray roasting production of iron oxide powder according to claim 1, characterized in that: The second bin is provided with a dust removal mechanism at the top.

6. A device for spray roasting production of iron oxide powder according to claim 1, characterized in that: A packing machine for packing the iron oxide powder is arranged below the discharge port of the second bin.

7. A method for spray roasting production of iron oxide fines, characterized by: The device for producing iron oxide powder by spray roasting according to any one of claims 1-6 comprises the following steps: S1, spraying the waste acid liquid into the production furnace to generate iron oxide powder by roasting; S2, after the iron oxide powder is buffered by the first bin, it is transported into the crushing mechanism and crushed by high-speed airflow; S3, the crushed iron oxide powder is graded in the grading mechanism, and the iron oxide powder meeting the grading requirement enters the second bin; the iron oxide powder not meeting the grading requirement returns to the crushing mechanism for crushing; S4, the iron oxide powder is packed and stored at the outlet of the second bin.

8. A method of producing iron oxide powder by spray roasting according to claim 7, characterized in that: In S2, the particle size (D50) of the iron powder entering the crushing mechanism ranges from 25 to 50 μm.

9. A method of producing iron oxide powder by spray roasting according to claim 7, characterized in that: In S3, the particle size (D50) of the iron oxide powder entering the second bin ranges from 1 to 10 μm.

10. A method of producing iron oxide powder by spray roasting according to claim 7, characterized in that: In S3, the specific surface area of the iron oxide powder entering the second bin is not less than 3.0 m 2 / g.

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