Aluminum oxide raw material ore bin cleaning method and cleaning device

Abstract

According to the aluminum oxide raw material ore bin cleaning method and device, steam is introduced into an ore bin, so that stubborn wall hanging materials on the bin wall of the ore bin are gradually loosened and fall off under the action of a uniform infiltration softening mechanism in combination with auxiliary vibration. Through steam and auxiliary vibration, stubborn wall-hanging materials on the bin wall of the ore bin can automatically fall off, the cleaning effect is good, time and labor are saved, the whole cleaning process does not need to manually enter the bin for cleaning, safety and efficiency are achieved, due to the mobility of the steam, the straight-through section, the bent section and the like of the bin body can be effectively cleaned, limitation of the bin body structure is avoided, and adaptability is good; and in addition, steam introduced into the ore bin is dead steam of a self-evaporator of condensed water of the dissolved-out new steam for aluminum oxide production, so that the dead steam can be recycled, the environment-friendly standard is met, and green production is promoted.

Description

Technical Field

[0001] This invention relates to a method and apparatus for cleaning alumina raw material ore bins, belonging to the technical field of alumina production equipment. Background Technology

[0002] Alumina raw materials (bauxite, etc.) have high adhesion (adhesion force reaches 0.3-0.6 MPa at a moisture content of 8%-15%) and high abrasiveness (Mohs hardness 4-6). They are also prone to forming a crusty layer (5-10 cm thick) due to silicon and iron impurities. The problem of material buildup on the walls of raw material silos, where alumina raw materials are stored, has long remained unresolved, especially during the rainy season when the material is wet or muddy. This causes the silos to bulge, leading to idle mill operation, equipment damage, and reduced mill operating rates. Furthermore, statistics show that many large alumina plants experience a 15%-30% loss of effective volume in their raw material silos due to adhesion to the silo walls, requiring cleaning more than 12 times per year. Traditional cleaning techniques include manual cleaning, mechanical cleaning, high-pressure water jet cleaning, and robotic cleaning. However, these methods have the following shortcomings: Manual warehouse clearing: inefficient, limited workspace, high operational risk, and prone to suffocation accidents; Mechanical equipment cleaning: mainly using mechanical force, chain scraper system + bin wall vibrator, which has high energy consumption, large equipment wear and tear, high maintenance cost, and is prone to damaging the bin body. It is also usually only suitable for straight sections and has poor adaptability. Robotic cleaning machines: They have high operating efficiency, but their operating costs are relatively high. Summary of the Invention

[0003] Therefore, the purpose of this invention is to provide a method and apparatus for cleaning alumina raw material ore bins, so as to at least solve the technical problems mentioned in the background art.

[0004] The objective of this invention is achieved through the following technical solution: A method for cleaning an alumina raw material ore silo includes the following steps: S1. Determine whether the ore bin has reached the cleaning conditions. If so, introduce steam into the ore bin. Under the action of the uniform wetting and softening mechanism, the stubborn materials attached to the ore bin wall will gradually loosen and fall off. S2. After the steam has been in action for a period of time, the cleaning process is assisted by vibration using a vibration device.

[0005] Furthermore, pressurized steam is introduced locally into the ore bin to remove stubborn materials adhering to the bin walls. Specifically, steam is introduced locally into the upper part of the cone bottom of the ore bin or any place in the ore bin where materials easily adhere to the walls. Under the action of the uniform wetting and softening mechanism, the stubborn materials adhering to the bin walls gradually loosen and fall off.

[0006] Furthermore, determining whether an ore bin has met the cleanup criteria includes: the ore bin's operating cycle has exceeded one month; Alternatively, the thickness of the material adhering to the walls of the ore bin can be calculated. When the material adhering to the walls reaches a certain thickness, a cleaning operation can be carried out. The calculation method for the thickness of the material adhering to the walls includes direct measurement or volume inverse calculation.

[0007] Furthermore, the steam pressurization methods include using a reduced-diameter steam inlet pipe to connect the ore bin to the steam supply equipment, that is, gradually reducing the inner diameter of the pipe along the steam inlet direction to increase the steam pressure; or installing a booster pump on the steam inlet pipe to increase the steam pressure.

[0008] Furthermore, the steam supply time into the ore bin shall not be less than 20 minutes, and during the steam supply time, a continuous steam supply method or an intermittent steam supply method shall be adopted.

[0009] A cleaning device for an alumina raw material ore silo based on the above-mentioned cleaning method includes a steam outlet pipe system installed on the ore silo wall. The steam outlet pipe system is connected to a steam supply device through a steam inlet pipe. The steam supply device is a self-evaporator for leaching fresh steam and condensate in alumina production. The steam inlet end of the steam inlet pipe is connected to the exhaust steam pipe of the self-evaporator for leaching fresh steam and condensate. A vibration device is provided on the outside of the ore silo.

[0010] Furthermore, the steam outlet pipe system consists of at least two layers located in the upper part of the cone bottom of the ore bin or anywhere within the ore bin where materials are prone to adhere to the walls.

[0011] Furthermore, the steam outlet piping system includes several steam outlet branch pipes evenly distributed circumferentially on the ore bin wall; the specific connection methods of the steam outlet branch pipes are as follows: Outside the ore bin, there are several steam inlet pipes that correspond one-to-one with each steam outlet branch pipe, so that each steam outlet branch pipe is connected to the exhaust steam pipe of the evaporator of the dissolved new steam condensate through the corresponding steam inlet pipe. Alternatively, an annular pipe is fixed to the wall of the ore bin, and several steam outlet branches arranged in a circumferential direction with the opposite annular pipe are connected to the annular pipe. The steam inlet of the annular pipe is connected to the exhaust steam pipe of the evaporator through the steam inlet pipe.

[0012] Furthermore, the diameter of the steam inlet pipe is larger than that of the annular pipe, and the diameter of the annular pipe is larger than that of the steam outlet branch pipe, so that the inner diameter of the corresponding connecting pipe gradually decreases along the steam inlet direction, thereby increasing the steam pressure.

[0013] Furthermore, a downward-bending elbow is provided at the steam outlet of the steam branch pipe, wherein the elbow is a stainless steel elbow or a high-temperature resistant soft rubber elbow.

[0014] Compared with the prior art, the beneficial effects of the present invention are: (1) Good cleaning effect Conventional water softening methods suffer from uneven wetting of stubborn wall-mounted materials, which can easily dilute production indicators. This invention introduces steam into the ore bin. Under the mechanism of thermal expansion and contraction, the stubborn wall-mounted materials on the ore bin wall are caused to crack and detach from the bin wall after contraction. At the same time, the steam comes into contact with the stubborn wall-mounted materials to form condensate, which allows the stubborn wall-mounted materials to be more evenly penetrated and softened by the condensate. Combined with auxiliary vibration, the stubborn wall-mounted materials are automatically detached, resulting in good cleaning effect, high efficiency, and time-saving and labor-saving operation. (2) Good adaptability The cleaning process uses steam combined with auxiliary vibration, eliminating the need for manual entry into the silo. It is safe and efficient, and due to the fluidity of steam, it can effectively clean straight sections and curved sections of the silo. It is not limited by the silo structure and has good adaptability. It effectively solves the problems of low efficiency and high operational risks of manual cleaning of existing ore silos, as well as the problems of high wear and tear, high cost, easy damage to the silo, and poor adaptability of machine cleaning equipment. (3) Cost savings This invention has a simple structure. It introduces the steam from the ore bin as the exhaust steam from the condensate evaporator used for alumina production, which can realize the recycling of exhaust steam, meet environmental protection standards, promote green production, and allow for flexible adjustment of steam flow according to the type and thickness of stubborn wall-mounted materials during the cleaning process. This ensures good cleaning results while saving steam consumption and optimizing cleaning cost. (4) Optimize production efficiency and stability It can achieve timely cleaning of ore bins, avoid loss of effective volume due to adhesion to the bin walls, ensure that raw materials can be delivered to the production line in a timely manner, and thus ensure the continuous stability of the production process.

[0015] Other advantages, objectives, and features of the invention will be set forth in part in the description which follows, and in part will be apparent to those skilled in the art from the following examination, or may be learned from practice of the invention. The objectives and other advantages of the invention can be realized and obtained through the following description. Attached Figure Description

[0016] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will now be described in further detail with reference to the accompanying drawings, wherein: Figure 1 This is a schematic diagram of the alumina raw material ore bin cleaning device provided in Embodiment 1 of the present invention; Figure 2 for Figure 1 Schematic diagram of the central steam outlet branch pipe; Figure 3 This is a schematic diagram of the steam outlet branch pipe provided in Embodiment 2 of the present invention.

[0017] In the diagram: 1. Ore bin; 2. Steam outlet branch pipe; 3. Steam inlet pipe; 4. Self-evaporator for dissolving fresh steam and condensate; 5. Circular pipe; 6. Arch breaker. Detailed Implementation

[0018] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0019] Example 1 like Figures 1-2 As shown, the first embodiment of the present invention provides a method for cleaning an alumina raw material ore bin. This method uses steam to clean the bin walls. After the steam enters the bin, the stubborn material adhering to the bin walls softens and cracks under the action of a uniform wetting and softening mechanism. Combined with auxiliary vibration, this causes the material to automatically detach. The specific cleaning steps include: S1. Determine whether the ore bin 1 has reached the cleaning conditions. If so, introduce steam into the ore bin 1. Under the action of the uniform wetting and softening mechanism, the stubborn wall material on the ore bin 1 will gradually loosen and fall off. S2. After the steam has been working for a period of time, use a vibration device to assist in cleaning, making the cleaning more thorough.

[0020] In step S1, pressurized steam is introduced locally into the ore bin 1 to remove stubborn material adhering to the bin walls. Pressurizing the steam improves the efficiency of wetting the adhering material, making it easier for stubborn material to detach, resulting in better cleaning. Local steam introduction prevents large areas or large pieces of material from clogging the discharge port. Specifically, local steam is introduced into the upper part of the cone bottom of the ore bin 1 or any area within the ore bin where adhering material easily sticks to the walls. This allows the stubborn material adhering to the bin walls to gradually loosen and detach under the action of a uniform wetting and softening mechanism.

[0021] Determining whether ore bin 1 has reached the cleaning conditions includes: the operation cycle of ore bin 1 has reached more than one month.

[0022] Alternatively, the thickness of the material adhering to the walls of ore bin 1 can be calculated, and a cleaning operation can be performed when the material reaches a certain thickness. Preferably, the cleaning operation is performed when the thickness of the material adhering to the walls is greater than 5 cm.

[0023] The methods for calculating the thickness of wall-mounted materials include direct measurement or volumetric inverse calculation.

[0024] The calculation formula for the direct measurement method is: , In the formula, d 平均 This is the average value of n measurements taken at the bottom of the warehouse. d i The measured value at point i at the bottom of the warehouse was obtained manually using a ruler or laser rangefinder after the warehouse was cleared. n and i represent the number of measurements, which are integers greater than 1.

[0025] The formula for calculating the volume inverse algorithm is: , In the formula, d is the average thickness of the wall material in ore bin 1; V C The volume of material remaining in the silo after unloading is defined as follows: the total volume V0 of the ore silo 1 initially loaded using a belt scale or truck; and the volume V of the material unloaded using a level gauge or 3D scanning. d V can be obtained c Value, V c =V0-V d ; A represents the bottom area of ​​ore bin 1.

[0026] Steam pressurization methods include connecting the ore bin 1 to the steam supply equipment using a reduced-diameter steam inlet pipe, that is, gradually reducing the inner diameter of the pipe along the steam inlet direction to increase the steam pressure. Alternatively, a booster pump can be installed on the steam inlet pipe to increase the steam pressure.

[0027] The steam introduction time into the ore bin 1 shall not be less than 20 minutes. Preferably, the steam introduction time can be 20-30 minutes, 30-60 minutes, 1-2 hours, 2-4 hours, etc., and the specific steam introduction time can be set according to the type of wall-mounted material and the thickness of the wall-mounted material in the ore bin 1. For example, if the wall-mounted material is not very viscous and the wall-mounted material thickness is about 5-6 cm, the steam introduction time can be 20-30 minutes; if the wall-mounted material is not very viscous and the wall-mounted material thickness is 6-10 cm, the steam introduction time can be 30-60 minutes; if the wall-mounted material is not very viscous and the wall-mounted material thickness is greater than 10 cm, the steam introduction time can be 1-2 hours; if the wall-mounted material is very viscous and the wall-mounted material thickness is 5-10 cm, the steam introduction time can be 1-2 hours; if the wall-mounted material is very viscous and the wall-mounted material thickness is greater than 10 cm, the steam introduction time can be 2-4 hours.

[0028] During the steam supply period, either continuous or intermittent steam supply can be used. Specifically, the steam supply method can be set according to the steam supply time, the type of material adhering to the wall, and the thickness of the material adhering to the wall of ore bin 1. For example, if the adhering material has low viscosity and the steam supply time is short (within 1 hour), continuous steam supply can be used; if the adhering material has low viscosity and the steam supply time is no more than 1 hour, continuous steam supply can be used; if the adhering material has low viscosity and the steam supply time is longer than 1 hour, intermittent steam supply can be used; if the adhering material has high viscosity and the steam supply time is longer than 1 hour, continuous or intermittent steam supply can be used; if the adhering material thickness is 5-10 cm, continuous steam supply can be used; if the adhering material thickness is greater than 10 cm, intermittent steam supply can be used. Furthermore, for the intermittent steam supply method, the duration of two consecutive steam supply cycles can be the same or different. When the material adhering to the wall is thick, intermittent steam supply can reduce the amount of steam used while allowing the stubborn material to be subjected to cold and heat intermittently. This is more conducive to the cracking and falling off of the material, and also extends the soaking and softening time of the material, thus saving on cleaning costs.

[0029] The alumina raw material ore bin cleaning device based on the above cleaning method includes a steam outlet pipe system installed on the bin wall of the ore bin 1. The steam outlet pipe system is connected to a steam supply device through a steam inlet pipe 3. The steam supply device is a self-evaporator 4 for leaching fresh steam and condensate for alumina production. The steam inlet end of the steam inlet pipe 3 is connected to the exhaust steam pipe of the self-evaporator 4 for leaching fresh steam and condensate. A vibration device is provided on the outside of the ore bin 1.

[0030] The steam outlet pipe system is installed in multiple layers at any location within the ore bin where materials easily adhere to the walls. Specifically, the steam outlet pipe system is installed in at least two layers at the upper part of the cone bottom of the ore bin 1. Since the cone bottom of the ore bin 1 is prone to material adhesion and wall bulging, cleaning the material adhering to the cone can ensure the stable operation of the subsequent production line.

[0031] The steam outlet piping system includes several steam outlet branch pipes 2 that are evenly distributed circumferentially on the wall of the ore bin 1. Preferably, there are at least three steam outlet branch pipes 2 that are evenly distributed circumferentially on the wall of the ore bin 1.

[0032] The specific connection method of the steam outlet branch pipe 2 is as follows: Several steam inlet pipes 3 corresponding to each steam outlet branch pipe 2 are provided outside the ore bin 1, so that each steam outlet branch pipe 2 is connected to the exhaust steam pipe of the evaporator 4 through the corresponding steam inlet pipe 3.

[0033] Alternatively, an annular pipe 5 is fixedly connected to the outside of the ore bin 1, and several steam outlet branch pipes 2 arranged in a circumferential manner with the annular pipe 5 are interconnected with the annular pipe 5. The steam inlet of the annular pipe 5 is connected to the exhaust steam pipe of the evaporator 4 through the steam inlet pipe 3.

[0034] The diameter of the steam inlet pipe 3 is larger than that of the annular pipe 5, and the diameter of the annular pipe 5 is larger than that of the steam outlet branch pipe 2. This causes the inner diameter of the corresponding connecting pipes to gradually decrease along the steam inlet direction, thereby increasing the steam pressure. Specifically, the steam inlet pipe 3 can be a DN80 pipe, the steam outlet branch pipe 2 can be a DN20 pipe, and the annular pipe 5 can be a DN50 pipe. This causes the inner diameter of the corresponding connecting pipes to gradually decrease along the steam inlet direction, thereby increasing the steam pressure and improving the cleaning effect of the material adhering to the wall.

[0035] The vibration device can be an arch breaker 6, which is fixed to the lower part of the outer side of the ore bin 1 and is used for auxiliary vibration cleaning of materials adhering to the wall. The arch breaker 6 includes a pneumatic arch breaker (air cannon) and an electric vibrator.

[0036] The condensate from the leaching steam is provided with a waste steam outlet at the top of the evaporator 4. The waste steam outlet is connected to the steam outlet branch pipe 2 in the ore bin 1 through the steam inlet pipe 3, so that the waste steam of the leaching flash evaporator is introduced into the ore bin 1 through the steam inlet pipe 3 to clean the wall material attached to the inner wall of the ore bin 1.

[0037] Example 2 like Figure 3 As shown, based on Example 1, in order to prevent the steam outlet of the steam branch pipe 2 from being blocked by material, a downwardly bent elbow 7 is provided at the steam outlet of the steam branch pipe 2, so that the outlet is equivalent to the material facing downward, which is not easy to block.

[0038] The elbow 7 can be a stainless steel elbow or a high-temperature resistant soft rubber elbow, preferably a high-temperature resistant soft rubber elbow. When the pressurized steam enters the steam outlet branch pipe 2, the elbow 7 vibrates under the pressure, which not only provides flexible buffering for the elbow 7, improving its service life, but also effectively cleans the material adhering to the walls of the steam outlet branch pipe 2 and the elbow 7, thus better preventing blockage at the pipe outlet. Specifically, the downward tilt angle of the elbow 7 can be 30-90 degrees.

[0039] The above description is merely a preferred embodiment of the present invention and is not intended to limit the scope of the present invention in any way. Any simple modifications, equivalent changes, and alterations made to the above embodiments without departing from the technical solution of the present invention and based on the technical essence of the present invention shall still fall within the scope of the technical solution of the present invention.

Claims

1. A method for cleaning an alumina raw material ore bin, characterized in that, Includes the following steps: S1. Determine whether the ore bin (1) has reached the cleaning conditions. If so, introduce steam into the ore bin (1). Under the action of the uniform wetting and softening mechanism, the stubborn wall material on the ore bin (1) will gradually loosen and fall off. S2. After the steam has been in action for a period of time, the cleaning process is assisted by vibration using a vibration device.

2. The cleaning method according to claim 1, characterized in that, The stubborn wall-attached material is removed by partially introducing pressurized steam into the ore bin (1). Specifically, steam is introduced locally into the upper part of the cone bottom of the ore bin (1) or any place in the ore bin where the wall-attached material is easy to adhere. Under the action of the uniform wetting and softening mechanism, the stubborn wall-attached material gradually loosens and falls off.

3. The cleaning method according to claim 2, characterized in that, Determining whether the ore bin (1) has reached the cleaning conditions includes: the operation cycle of the ore bin (1) has reached more than one month; Alternatively, the thickness of the wall material in the ore bin (1) can be calculated. When the wall material reaches a certain thickness, a cleaning operation can be carried out. The calculation method for the thickness of the wall material includes direct measurement or volume inverse calculation.

4. The cleaning method according to claim 2, characterized in that, Steam pressurization methods include using a reduced-diameter steam inlet pipe to connect the ore bin (1) to the steam supply equipment, that is, along the steam inlet direction, the inner diameter of the pipe is gradually reduced, thereby increasing the steam pressure; or a booster pump is installed on the steam inlet pipe to increase the steam pressure.

5. The cleaning method according to claim 2, characterized in that, Steam shall be introduced into the ore bin (1) for no less than 20 minutes, and during the steam introduction period, either continuous steam supply or intermittent steam supply shall be used.

6. A cleaning device for alumina raw material ore bins based on the cleaning method of claim 1, characterized in that, It includes a steam outlet pipe system installed on the wall of the ore bin (1), the steam outlet pipe system is connected to the steam supply equipment through the steam inlet pipe (3), the steam supply equipment is a self-evaporator (4) for leaching new steam condensate for alumina production, the steam inlet end of the steam inlet pipe (3) is connected to the exhaust steam pipe of the self-evaporator (4), and a vibration device is provided on the outside of the ore bin (1).

7. The cleaning device according to claim 6, characterized in that, The steam outlet pipe system consists of at least two layers located in the upper part of the cone bottom of the ore bin (1) or in any place within the ore bin where materials are prone to adhere to the wall.

8. The cleaning device according to claim 7, characterized in that, The steam outlet piping system includes several steam outlet branch pipes (2) evenly distributed circumferentially on the wall of the ore bin (1); the specific connection methods of the steam outlet branch pipes (2) are as follows: Outside the ore bin (1), there are several steam inlet pipes (3) that correspond one-to-one with each steam outlet branch pipe (2), so that each steam outlet branch pipe (2) is connected to the exhaust steam pipe of the evaporator (4) through the corresponding steam inlet pipe (3); Alternatively, an annular pipe (5) is fixed to the wall of the ore bin (1), and several steam outlet branches (2) arranged in a circumferential manner with the annular pipe (5) are connected to each other. The steam inlet of the annular pipe (5) is connected to the exhaust steam pipe of the evaporator (4) through the steam inlet pipe (3).

9. The cleaning device according to claim 8, characterized in that, The diameter of the steam inlet pipe (3) is greater than that of the annular pipe (5), and the diameter of the annular pipe (5) is greater than that of the steam outlet branch pipe (2), so that the inner diameter of the corresponding connecting pipe gradually decreases along the steam inlet direction, thereby increasing the steam pressure.

10. The cleaning device according to claim 8 or 9, characterized in that, A downward-bending elbow (7) is provided at the steam outlet of the steam outlet branch pipe (2), and the elbow (7) is a stainless steel elbow or a high-temperature resistant soft rubber elbow.

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