Cobalt nickel hydroxide or cobalt hydroxide drying system based on waste heat steam utilization

Abstract

The utility model relates to the technical field of drying and energy saving, and particularly discloses a cobalt nickel hydroxide or cobalt hydroxide drying system based on waste heat steam utilization, which comprises a mixing device, a steam rotary drying device, a dust removal device and a spray washing device which are connected in sequence, steam in the upstream flash evaporation process is subjected to deacidification treatment and then is introduced into a heat exchange tube bundle of the steam rotary drying device to serve as a heat source; the discharging end of the steam rotary drying device is respectively connected with a discharging branch and a material returning loop through a discharging screw; the material returning loop is connected to one feeding hole of the material mixing device, and the other feeding hole of the material mixing device is connected with a nickel cobalt hydroxide or cobalt hydroxide wet material conveying device. An indirect heat exchange mode is adopted, only a small amount of hot air is needed to serve as moisture-carrying gas, the tail gas amount is greatly reduced, meanwhile, damage to materials caused by direct contact with high-temperature hot air in a traditional drying mode is avoided, the physical property of the materials can be kept, and the particle size and quality of products are improved.

Description

Technical Field

[0001] This utility model relates to the field of drying and energy-saving technology, and in particular to a nickel-cobalt hydroxide or cobalt hydroxide drying system based on the utilization of waste heat steam. Background Technology

[0002] The statements in this section are merely background information related to this utility model and do not necessarily constitute prior art.

[0003] In the pressure acid leaching process of laterite nickel ore, the leachate is precipitated to produce nickel cobalt hydroxide or a mixture of nickel cobalt hydroxide (MHP) as an intermediate product. This nickel cobalt hydroxide or cobalt hydroxide filter cake typically has a moisture content as high as 40-60%, and needs to be dried to ≤10% to meet the requirements for transportation, storage, or further processing (such as electrolytic purification).

[0004] Currently, the commonly used drying and dehydration method is to use a flash dryer. The principle is that the wet material is crushed and dried under the action of stirring and vortex airflow. After being screened by the classifier at the top of the drying chamber, the material with qualified humidity and particle size is carried by gas from the dryer outlet to the cyclone separator for separation and collection.

[0005] This drying method typically uses electric hot air or gas as a heat source, but it is energy-intensive. Furthermore, because the material is broken into fine particles by the rotating blade, these fine particles are easily carried by the high-speed airflow, resulting in high exhaust gas dust removal pressure. In addition, since the product is mainly in the form of fine powder, it generates a lot of dust during subsequent packaging and transportation, which may pose a certain health hazard to the operators. Utility Model Content

[0006] To address the aforementioned issues, this invention proposes a nickel-cobalt hydroxide or cobalt hydroxide drying system based on waste heat steam utilization. It employs a steam rotary drying method and utilizes waste steam from high-pressure acid leaching as a heat source for material drying, which can significantly reduce energy consumption and improve product particle size and quality.

[0007] In some implementations, the following technical solutions are adopted:

[0008] A nickel-cobalt hydroxide or cobalt hydroxide drying system based on waste heat steam utilization includes: a mixing device, a steam rotary dryer, a dust removal device, and a spray washing device connected in sequence; the steam from the upstream flash evaporation process is deacidified and then introduced into the heat exchange tube bundle of the steam rotary dryer as a heat source; the discharge end of the steam rotary dryer is connected to a discharge branch and a return circuit respectively through a discharge screw; the return circuit is connected to one of the feed ports of the mixing device, and the other feed port of the mixing device is connected to a nickel-cobalt hydroxide or cobalt hydroxide wet material conveying device.

[0009] As a further embodiment, the discharge port of the mixing device is connected to the feed end of the steam rotary dryer via a feed screw.

[0010] As a further embodiment, the mixing device includes: a vertical rotary mixing drum and multiple layers of rotating blades eccentrically disposed within the vertical rotary mixing drum; the top of the vertical rotary mixing drum is provided with at least two feed inlets, and the bottom is provided with a tiltable unloading tray system; the vertical rotary mixing drum and the multiple layers of rotating blades are driven to rotate by independent drive systems, the rotation speed of the vertical rotary mixing drum is less than the rotation speed of the multiple layers of rotating blades, and the two rotate in opposite directions.

[0011] As a further embodiment, the steam rotary drying device includes a rotary cylinder and a heat exchange tube bundle disposed within the rotary cylinder; nickel-cobalt hydroxide or cobalt hydroxide wet material flows outside the heat exchange tube bundle and indirectly contacts and exchanges heat with the steam inside the heat exchange tube bundle.

[0012] As a further embodiment, multiple sets of baffle rings are spaced apart along the axial direction inside the rotary drum. Each set of baffle rings includes two baffles arranged radially opposite each other, with a gap between the two baffles for material to pass through.

[0013] As a further embodiment, the feed end of the rotary drum is higher than the discharge end, and an air inlet is provided on the side of the rotary drum near the feed end; an exhaust gas outlet, a steam inlet, and a condensate outlet are respectively provided on the side of the rotary drum near the discharge end.

[0014] As a further embodiment, the discharge branch includes a cooling spiral connected to the discharge spiral, through which part of the dried material enters the cooling spiral and is cooled and transported to the downstream process.

[0015] As a further embodiment, the return material circuit includes: a return material rotary unloading valve and a scraper conveyor connected in sequence with the discharge screw; part of the dried material is conveyed to the mixing device via the scraper conveyor; an exhaust port is opened above the scraper conveyor, and the exhaust port is connected to the air inlet of the dust removal device.

[0016] As a further solution, part of the steam from the upstream flash evaporation process is transported to a steam heat exchanger, and external air is also transported to the steam heat exchanger. The two exchange heat indirectly. After the air is heated to the set temperature, it is transported to the steam rotary drying unit under the action of the induced draft fan. The steam from the upstream flash evaporation process after heat exchange is sent to the condensate return pipeline.

[0017] As a further embodiment, the dust removal device is a bag filter, with the exhaust gas from the steam rotary dryer and the scraper conveyor respectively entering the bag filter, which is connected to a spray washing device via an induced draft fan.

[0018] Compared with the prior art, the beneficial effects of this utility model are:

[0019] (1) This utility model uses a steam rotary drying device to replace the traditional flash drying method. This drying method does not require a high degree of material crushing. It does not require the wet nickel hydroxide or cobalt hydroxide material to be crushed into fine particles. Therefore, it can avoid dust flying, reduce the pressure of tail gas dust removal, and reduce the difficulty of subsequent packaging and transportation. In addition, the indirect heat exchange method only requires a small amount of hot air as the moisture-carrying gas, which greatly reduces the amount of tail gas. At the same time, it avoids the damage to the material caused by direct contact with high temperature hot air in the traditional drying method. It helps to maintain the physical properties of the material, improve the particle size and quality of the product, effectively reduce energy consumption and operating costs, and provide a new technical path for the efficient and green treatment of laterite nickel ore.

[0020] (2) This utility model uses the waste steam from the upstream process as a drying heat source, which can meet the drying requirements of nickel-cobalt hydroxide or wet cobalt hydroxide materials, and can significantly reduce the dependence on electricity or gas, thereby reducing energy consumption and operating costs. With a production line design of 75t / h processing capacity, the drying process of this utility model can reduce the production cost per ton of product by about 79% compared with the traditional flash drying process.

[0021] (3) This utility model uses a return material loop to return some of the dried material to the wet material and mix them evenly in the mixing device to achieve "return material + new material" dual feeding. The amount of return material is adjustable. When the moisture content of nickel hydroxide or cobalt hydroxide material fluctuates, the return material unloading valve (star valve) is rotated to achieve the unloading function. A variable frequency motor is used to adjust the valve speed. The faster the speed, the larger the amount of return material, and the slower the speed, the smaller the amount of return material. The proportion of return material can be controlled by adjusting the speed to achieve the stability of the moisture content of the final product.

[0022] (4) In this invention, multiple sets of delayed baffle rings are added at intervals along the axial direction in the heat exchange section of the rotary kiln. Each baffle ring forms a multi-segment baffle structure, which can repeatedly lift and scatter materials during the rotation of the kiln body, forming a multi-layer material curtain and forcibly changing the axial flow velocity of the materials, thereby effectively extending the average residence time and significantly enhancing the heat transfer efficiency.

[0023] Other features and advantages of this invention will be set forth in part in the description which follows, and in part will be obvious from the description or may be learned by practice of this aspect. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of the structure of the nickel-cobalt hydroxide or cobalt hydroxide drying system based on waste heat steam utilization in this embodiment of the present invention;

[0025] Figure 2 This is a schematic diagram of the mixing machine structure in an embodiment of the present invention;

[0026] Figure 3 This is a structural diagram of the internal structure of the steam rotary dryer in the embodiments of this utility model;

[0027] Figure 4 This is a diagram showing the arrangement of the steam return heat pipe and baffle ring in an embodiment of this utility model;

[0028] Among them, 1. Mixer, 2. Feeding screw, 3. Steam rotary dryer, 4. Discharge screw, 5. Cooling screw, 6. Return rotary discharge valve, 7. Scraper conveyor, 8. Bag dust collector, 9. Exhaust fan, 10. Spray washing tower, 11. Steam heat exchanger; 12. Support frame, 13. Vertical rotary mixing tank, 14. Multi-layer rotary blades, 15. Return feed inlet, 16. Material feed inlet, 17. Discharge system, 18. Baffle ring, 19. Heat exchange tube. Detailed Implementation

[0029] It should be noted that the following detailed description is illustrative and intended to provide further explanation of the present invention. Unless otherwise specified, all technical and scientific terms used in this invention have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.

[0030] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the exemplary embodiments according to the present invention. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0031] Example 1

[0032] In one or more embodiments, a nickel-cobalt hydroxide or cobalt hydroxide drying system based on waste heat steam utilization is disclosed, combined with Figure 1 Specifically, it includes: a mixing device, a steam rotary dryer, a dust removal device, and a spray washing device connected in sequence; the steam from the upstream flash evaporation process is deacidified and then introduced into the heat exchange tube bundle of the steam rotary dryer as a heat source; the discharge end of the steam rotary dryer is connected to the discharge branch and the return circuit respectively through the discharge screw 4; the return circuit is connected to one of the feed ports of the mixing device, and the other feed port of the mixing device is connected to the nickel-cobalt hydroxide or cobalt hydroxide wet material conveying device.

[0033] In this embodiment, the mixing device is a mixer 1, used to receive nickel-cobalt hydroxide or cobalt hydroxide wet filter cake material from the upstream process; combined with Figure 2The structure of the mixer 1 specifically includes: a support 12, on which a low-speed rotating vertical rotary mixing barrel 13 and a high-speed rotating multi-layered rotating blade 14 eccentrically arranged inside the vertical rotary mixing barrel 13 are provided; the top of the vertical rotary mixing barrel 13 is provided with at least two feed inlets, namely a return feed inlet 15 for entering the dried return material and a material feed inlet 16 for entering the upstream process nickel-cobalt hydroxide or cobalt hydroxide wet filter cake material; the bottom is provided with a tiltable material tray unloading system 17 for unloading after mixing is completed.

[0034] In this embodiment, the vertical rotary mixing drum 13 and the multi-layer rotating blades 14 are driven by independent drive systems. The rotational speed of the vertical rotary mixing drum 13 is lower than that of the multi-layer rotating blades 14, and their rotation directions are opposite. Under the rotation of the inclined vertical rotary mixing drum 13, the material is carried to the high-positioned multi-layer rotating blades 14 area. During the mixing process, since the rotor speed can reach up to 2000-3000 r / min, it has a good crushing effect on lumpy materials. Under the mechanical disturbance of the multi-layer rotating blades 14, the material undergoes three mixing processes: convection, shearing, and diffusion, achieving a highly efficient crushing and mixing process for nickel-cobalt hydroxide or cobalt hydroxide.

[0035] In this embodiment, the discharge port of the mixer 1 is connected to the feed end of the steam rotary dryer through the feed screw 2; after the nickel-cobalt hydroxide or cobalt hydroxide wet filter cake material is mixed and crushed by the mixer 1, it is conveyed to the steam rotary dryer through the feed screw 2.

[0036] In this embodiment, the steam rotary drying device is a steam rotary dryer 3. The steam rotary dryer 3 includes a rotary cylinder, inside which a steam heat exchange tube bundle is arranged along the axial direction. The feed end of the rotary cylinder is higher than the discharge end. The rotary cylinder is also equipped with a lifting plate to continuously lift and scatter the material, increase the contact area with the heat exchange tube bundle, and improve the drying efficiency.

[0037] As an optional example, combined Figure 3 and Figure 4 Multiple sets (e.g., 3 sets) of delayed baffle rings 18 are spaced apart along the axial direction inside the steam rotary dryer. Each set of baffle rings 18 includes two baffles arranged radially opposite each other, with a gap between the two baffles for material to pass through. The baffles have a radially convex baffle structure, which can repeatedly lift and scatter materials during the rotation of the kiln. The materials can flow through the gap between the two opposite baffles. Multiple sets of baffle rings form a multi-layer material curtain and forcibly change the axial flow velocity of the materials. The materials can form an "overflow" discharge when they flow through the baffle rings, effectively ensuring the residence time of nickel-cobalt hydroxide or cobalt hydroxide materials in the cylinder and improving the heat exchange efficiency of the steam rotary dryer 3.

[0038] The baffle plate is provided with multiple through holes for the heat exchange tubes to pass through, and the heat exchange tubes 19 are used to exchange heat between the material and the steam, thereby achieving the drying of the material.

[0039] Nickel-cobalt hydroxide or cobalt hydroxide wet filter cake material moves from the higher feed end to the lower discharge end under the tilt and rotation of the rotating cylinder, and undergoes continuous tumbling motion. The nickel-cobalt hydroxide or cobalt hydroxide wet material flows outside the heat exchange tube bundle, and indirectly contacts the steam inside the heat exchange tube bundle for heat exchange.

[0040] In this embodiment, the saturated steam heat source of the heat exchange tube bundle comes from the waste steam of the upstream high-pressure acid leaching-flash evaporation process. After the waste steam is deacidified, it is introduced into the heat exchange tube bundle inside the dryer cylinder.

[0041] Compared to traditional methods that use electric hot air or gas as a heat source, this embodiment makes full use of the waste steam from the upstream flash evaporation process as a heat source, realizing the reuse of waste heat and significantly reducing the operating cost of the drying process.

[0042] In this embodiment, the discharge end of the steam rotary dryer 3 is connected to the discharge screw 4. After being discharged by the discharge screw 4, the dried material is divided into two paths. One path is the discharge branch path, which specifically includes the cooling screw 5 connected to the discharge screw 4. Part of the dried material enters the cooling screw 5 through the discharge screw 4 and is cooled and transported to the downstream process. The other path is the return path, which specifically includes the return rotary discharge valve 6 and the scraper conveyor 7 connected in sequence to the discharge screw 4. Part of the dried material is transported to the mixing device through the scraper conveyor 7. An exhaust port is opened above the scraper conveyor 7, which is connected to the air inlet of the dust removal device. Under the action of the induced draft fan, a slight negative pressure is maintained inside the scraper conveyor 7 to avoid the "powder escaping" phenomenon.

[0043] In this embodiment, the mixing device is fed with wet filter cake material of nickel cobalt hydroxide or cobalt hydroxide from the upstream process and dried nickel cobalt hydroxide or cobalt hydroxide material respectively. The dried return material is premixed with the wet material to be dried in advance, and then enters the steam rotary dryer 3 for drying. This can reduce the humidity and viscosity of the material, avoid the problem of the material clumping in the steam rotary dryer 3 due to excessive viscosity and uneven drying, and improve drying efficiency and safety.

[0044] As a specific example, the rotary discharge valve 6 is a star-shaped valve. A variable frequency motor can directly drive the main shaft of the star-shaped valve rotor, thereby controlling the valve's rotational speed. A higher speed results in a larger return volume, while a lower speed results in a smaller return volume. By adjusting the rotational speed, the return ratio can be controlled, thus ensuring the stability of the moisture content of the steam rotary dryer's output. In a more specific application scenario, the variable frequency motor speed can be adjusted manually. After the equipment has been running for a period of time, the moisture content of the steam rotary dryer's output can be manually measured. If it does not meet the preset moisture content range, the variable frequency motor speed can be adjusted, thereby adjusting the return ratio and affecting the moisture content of the upstream mixture, ensuring the stability of the steam rotary dryer's output moisture content.

[0045] The dried material is recycled back through the return circuit and mixed evenly with the wet material in the mixing device, realizing dual feeding of "recycled material and new material". The amount of recycled material is adjustable. When the moisture content of nickel-cobalt hydroxide or cobalt hydroxide material fluctuates, the unloading function is realized by rotating the return unloading valve (star valve). A variable frequency motor is used to adjust the valve speed. The faster the speed, the larger the amount of recycled material, and the slower the speed, the smaller the amount of recycled material. By adjusting the speed, the proportion of recycled material can be controlled to achieve the stability of the moisture content of the final product.

[0046] In a specific implementation, an air inlet is provided on the side of the rotary drum near the feed end; a tail gas outlet, a steam inlet, and a condensate outlet are respectively provided on the side of the rotary drum near the discharge end.

[0047] A portion of the steam from the upstream flash evaporation process is supplied to steam heat exchanger 11, along with external air. Indirect heat exchange occurs between the two. After being heated to a certain temperature, the air is transported to the rotary steam dryer by the induced draft fan 9. The steam from the upstream flash evaporation process, after heat exchange, is sent to the condensate return pipeline. The external air, after heat exchange, enters the rotary steam dryer through the air inlet, acting as a moisture carrier to carry away the water vapor evaporated from the material, forming exhaust gas, which is discharged from the exhaust gas outlet. The exhaust gas outlet is connected to the inlet of a bag filter dust collector to transport the exhaust gas from the drying process to the bag filter dust collector for dust removal.

[0048] Another portion of the steam from the upstream flash evaporation process enters the steam rotary dryer through the steam inlet, and after heat exchange, it becomes condensate and is discharged from the condensate outlet.

[0049] In this embodiment, the dust removal device is a bag filter 8, the spray washing device is a spray washing tower 10, the exhaust gas of the steam rotary dryer enters the bag filter 8, and the bag filter 8 is connected to the spray washing device through the induced draft fan 9.

[0050] The specific working principle of the nickel-cobalt hydroxide or cobalt hydroxide drying system in this embodiment is as follows:

[0051] Nickel-cobalt hydroxide or cobalt hydroxide wet filter cake from the upstream process is fed into mixer 1 via conveying equipment (such as belt conveyor). Inside mixer 1, the wet filter cake is vigorously mixed and crushed with the dried return material from scraper conveyor 7 to form a premixed wet material with uniform particle size. The mixed premixed wet material is quantitatively fed into the feed end of steam rotary dryer 3 via feed screw 2. Inside steam rotary dryer 3, the material moves from the higher feed end to the lower discharge end under the action of the cylinder tilt angle and rotation, and makes continuous tumbling motion. Saturated steam comes from the upstream flash evaporation process and is introduced into the heat exchange tube bundle inside the dryer cylinder after certain deacidification treatment. The material flows outside the heat exchange tube bundle and indirectly contacts the steam inside the tube bundle for heat exchange. The material absorbs heat and rises in temperature. The water vapor generated during the evaporation and drying process of the liquid (mainly water) is carried away by independently introduced air as a moisture carrier to form tail gas.

[0052] The dried material is discharged from the dryer's outlet and enters the discharge screw 4; the dried material is divided as follows: part of it is used as finished dried material, which is cooled by the cooling screw 5 and then transported to the downstream process. The other part of the dried material is returned as waste material, which is discharged quantitatively through the return rotary discharge valve 6 and enters the scraper conveyor 7.

[0053] Dust-laden exhaust gas from the steam rotary dryer enters the bag filter 8. Fine powder entrained in the exhaust gas is captured by the filter bags and falls to the bottom of the dust collector. The captured material is discharged through the unloading device (bag screw and airlock) at the bottom of the dust collector and enters the scraper conveyor 7. The scraper conveyor 7 transports the dried material (return material) from the return rotary discharge valve 6 and the bag filter 8 back to the mixer 1, where it is mixed with fresh wet filter cake to achieve the return material premixing process. The exhaust gas, which has been preliminarily purified by the bag filter 8, is drawn by the induced draft fan 9 and sent to the spray scrubbing tower 10 for deep washing and dust removal. Finally, the purified exhaust gas is discharged from the top of the spray scrubbing tower 10 in compliance with standards.

[0054] In one specific implementation, the upstream process's nickel-cobalt hydroxide or cobalt hydroxide wet filter cake, containing 55% water, enters the mixer 1 via a belt conveyor and is pre-mixed and crushed with the return material at a mass ratio of 1:1. The mixture is then fed into a rotary steam dryer 3 via a feed screw 2. The rotary drum has an inclination angle of 2° and a rotation speed of 2 rpm, with 0.4 MPa saturated steam flowing through the heat exchange tubes. After drying, the material is cooled to 50°C via a discharge screw 4 and a cooling screw 5. 50% of the material is used as finished product and enters the packaging process, while the remaining 50% is returned to the mixer 1 via a return material rotary discharge valve 6 and a scraper conveyor. The exhaust gas is sequentially discharged through a bag filter dust collector 8, an induced draft fan 9, and a spray scrubbing tower 10. The product moisture content is 8.7%, and the steam consumption per unit product is 0.81 kg / kg.

[0055] In this embodiment, the steam rotary drying method uses indirect heat exchange, requiring only a small amount of hot air as the moisture-carrying gas, which greatly reduces the amount of exhaust gas. Furthermore, because indirect heat exchange is used, it avoids the damage to the material caused by direct contact with high-temperature hot air, helping to maintain the material's physical properties, reducing dust emissions, and improving product particle size and quality.

[0056] Although the specific embodiments of the present utility model have been described above in conjunction with the accompanying drawings, this is not intended to limit the scope of protection of the present utility model. Those skilled in the art should understand that various modifications or variations that can be made by those skilled in the art without creative effort based on the technical solution of the present utility model are still within the scope of protection of the present utility model.

Claims

1. A nickel-cobalt hydroxide or cobalt hydroxide drying system based on waste heat steam utilization, characterized in that, include: The mixing device, the steam rotary dryer, the dust removal device, and the spray washing device are connected in sequence. The steam from the upstream flash evaporation process is deacidified and then introduced into the heat exchange tube bundle of the steam rotary dryer as a heat source. The discharge end of the steam rotary dryer is connected to the discharge branch and the return circuit through the discharge screw. The return circuit is connected to one of the feed ports of the mixing device, and the other feed port of the mixing device is connected to the nickel-cobalt hydroxide or cobalt hydroxide wet material conveying device.

2. The nickel-cobalt hydroxide or cobalt hydroxide drying system based on waste heat steam utilization as described in claim 1, characterized in that, The discharge port of the mixing device is connected to the inlet of the steam rotary dryer via a feeding screw.

3. A nickel-cobalt hydroxide or cobalt hydroxide drying system based on waste heat steam utilization as described in claim 1, characterized in that, The mixing device includes: a vertical rotary mixing drum and multiple layers of rotating blades eccentrically arranged inside the vertical rotary mixing drum; the top of the vertical rotary mixing drum is provided with at least two feed inlets, and the bottom is provided with a tiltable material tray unloading system; the vertical rotary mixing drum and the multiple layers of rotating blades are driven to rotate by independent drive systems, the rotation speed of the vertical rotary mixing drum is less than the rotation speed of the multiple layers of rotating blades, and the two rotate in opposite directions.

4. A nickel-cobalt hydroxide or cobalt hydroxide drying system based on waste heat steam utilization as described in claim 1, characterized in that, The steam rotary drying device includes a rotary cylinder and a heat exchange tube bundle disposed inside the rotary cylinder; nickel-cobalt hydroxide or cobalt hydroxide wet material flows outside the heat exchange tube bundle and indirectly contacts the steam inside the heat exchange tube bundle for heat exchange.

5. A nickel-cobalt hydroxide or cobalt hydroxide drying system based on waste heat steam utilization as described in claim 4, characterized in that, Multiple sets of baffle rings are spaced apart along the axial direction inside the rotary cylinder. Each set of baffle rings includes two baffles arranged radially opposite each other, with a gap between the two baffles for material to pass through.

6. A nickel-cobalt hydroxide or cobalt hydroxide drying system based on waste heat steam utilization as described in claim 4, characterized in that, The feed end of the rotary drum is higher than the discharge end, and an air inlet is provided on the side of the rotary drum near the feed end; an exhaust gas outlet, a steam inlet, and a condensate outlet are respectively provided on the side of the rotary drum near the discharge end.

7. A nickel-cobalt hydroxide or cobalt hydroxide drying system based on waste heat steam utilization as described in claim 1, characterized in that, The discharge branch includes a cooling spiral connected to the discharge spiral. Part of the dried material enters the cooling spiral through the discharge spiral and is cooled and transported to the downstream process.

8. A nickel-cobalt hydroxide or cobalt hydroxide drying system based on waste heat steam utilization as described in claim 1, characterized in that, The return material circuit includes a return material rotary unloading valve and a scraper conveyor connected in sequence with the discharge screw. Part of the dried material is conveyed to the mixing device via the scraper conveyor. An exhaust port is opened above the scraper conveyor and is connected to the air inlet of the dust removal device.

9. A nickel-cobalt hydroxide or cobalt hydroxide drying system based on waste heat steam utilization as described in claim 1, characterized in that, Part of the steam from the upstream flash evaporation process is delivered to the steam heat exchanger, and external air is also delivered to the steam heat exchanger. The two exchange heat indirectly. After the air is heated to the set temperature, it is delivered to the steam rotary dryer by the action of the induced draft fan. The steam from the upstream flash evaporation process after heat exchange is sent to the condensate return pipeline.

10. A nickel-cobalt hydroxide or cobalt hydroxide drying system based on waste heat steam utilization as described in claim 1, characterized in that, The dust removal device is a bag filter. The exhaust gas from the steam rotary dryer and the scraper conveyor enters the bag filter, which is connected to a spray washing device via an induced draft fan.

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