A short-process laterite nickel ore drying and pre-reduction device and its application

Abstract

The present invention relates to a short-process laterite nickel ore drying and pre-reduction device and its application, belonging to the technical field of non-ferrous metal smelting. The device comprises a drying kiln and a connecting hood; the feed port and air inlet of the drying kiln are respectively located at the two ends of the drying kiln, so that when the drying kiln is in operation, the flow direction of the high-temperature flue gas is opposite to the movement direction of the laterite nickel ore; the discharge port and air inlet of the drying kiln are located at the same end of the drying kiln; and the discharge port of the drying kiln is connected to the connecting hood. Its application comprises the following steps: S1, counter-smoke drying, S2, ore blending and reduction. The present invention causes the laterite nickel ore and the high-temperature flue gas to move in the opposite direction to achieve efficient drying, thereby improving the utilization rate of flue gas waste heat and the output of dry ore; a chute and a bypass pipe are provided in the connecting hood, and the produced dry ore directly enters the rotary kiln through the chute for roasting and pre-reduction, which can fully utilize the sensible heat of the dry ore and reduce the energy consumption of the rotary kiln, reduce the frequency of dry ore falling to the ground, reduce dust pollution, greatly shorten the RKEF process flow and reduce operating costs.

Description

Technical Field

[0001] The invention relates to a short-process laterite nickel ore drying and pre-reduction device and application thereof, belonging to the technical field of non-ferrous metal smelting. Background Art

[0002] Today, the most common method for producing ferronickel from laterite nickel ore is the rotary kiln-electric furnace process, or RKEF for short. The process involves the following steps: wet ore storage at a site, drying in a kiln, storage and blending in a blending workshop, roasting and pre-reduction in a rotary kiln, and finally smelting and casting in an electric furnace.

[0003] The free water content of laterite nickel ore stored in wet mining sites is approximately 40% by weight. Drying is achieved by exchanging heat with the laterite nickel ore in a drying kiln via the high-temperature flue gas from a rotary kiln. The flue gas removes the evaporated water from the laterite nickel ore, thereby drying the ore. The laterite nickel ore dried in the kiln is considered dry ore. Currently, the industry generally adopts a method where the high-temperature flue gas flows in the same direction as the laterite nickel ore to facilitate contact and heat exchange. This common direction of movement shortens the contact time, reduces the heat exchange area, and reduces the utilization rate of the high-temperature flue gas's waste heat. Even if the ore is dried to a satisfactory degree, achieving higher production yields often requires the addition of a hot air furnace or gas furnace as a supplemental heat source, further increasing energy consumption.

[0004] Typically, after drying, laterite nickel ore is discharged from the drying kiln discharge hood and then transferred to the blending workshop for storage. The blending workshop blends the ore according to process requirements and then sends it to the rotary kiln for roasting and pre-reduction. Within the blending workshop, the dry ore is often stored in floor-mounted piles, and loaders are used to transfer the dry ore to the blending silo during blending. However, the entire process from the dry ore entering the blending workshop to the floor-mounted piles and then to the silo requires a large number of construction vehicles, resulting in very high operating costs. Furthermore, the frequent transfer of dry ore creates dust pollution, further increasing environmental pressures. Currently, some factories in the same industry use elevated steel silos for dry ore storage. However, these silos require large floor space, large equipment dimensions, and numerous belt conveyors, making the construction of steel silo-type blending workshops arduous and expensive.

[0005] In the drying kiln, the dry ore discharged after heat exchange with the high-temperature flue gas from the rotary kiln has a free water content of approximately 22wt% and a temperature of 70°C to 85°C. It is then transported to the ore blending workshop. Due to the long storage time of the dry ore in the ore blending workshop, the temperature has dropped to room temperature when it is used, wasting sensible heat. When it is put into the rotary kiln for roasting and pre-reduction, it needs to go through another heat absorption and temperature rise process, thereby increasing the energy consumption of the rotary kiln roasting and pre-reduction sections. In addition, during storage, the dry ore will absorb moisture from the air, which makes it impossible to accurately proportion the reducing agent when blending, resulting in large fluctuations in product composition.

[0006] In summary, it can be seen that in the existing drying and pre-reduction methods of laterite nickel ore, the utilization rate of the waste heat of the rotary kiln flue gas and the sensible heat of the dry ore itself is low, the process is long, and the energy consumption is high. Therefore, a short-process method of drying, roasting and pre-reduction of laterite nickel ore is particularly important to reduce the energy consumption of nickel iron production by RKEF process. Summary of the Invention

[0007] In order to solve the above technical problems, the present invention provides a short-process laterite nickel ore drying and pre-reduction device and application, the purpose of which is to maximize the utilization of the waste heat of the rotary kiln flue gas, maximize the output of the dry ore, and maximize the sensible heat utilization rate of the dry ore, thereby reducing the energy consumption of the laterite nickel ore drying, roasting, and pre-reduction sections in the RKEF process for producing nickel iron, while reducing the frequency of the dry ore falling to the ground and being transported, thereby also achieving the purpose of reducing dust pollution and reducing operating costs.

[0008] To achieve the above object, the present invention is achieved as follows:

[0009] A shortened process for drying and pre-reducing laterite nickel ore involves directing the flow of high-temperature flue gas in the drying kiln in the opposite direction of the movement of the laterite nickel ore. This increases the contact area and duration between the high-temperature flue gas and the laterite nickel ore, maximizing the utilization of the rotary kiln's flue gas waste heat and the yield of dried ore. Furthermore, the dried ore produced using this method is not stored on the ground but instead goes directly into the rotary kiln for roasting and pre-reduction. This fully utilizes the sensible heat of the dry ore, reducing energy consumption in the rotary kiln's roasting and pre-reduction stages, while also effectively shortening the process and lowering operating costs.

[0010] The present invention discloses a short-process laterite nickel ore drying and pre-reduction device, comprising a drying kiln and a connecting cover. The feed port and the air inlet of the drying kiln are respectively located at two ends of the drying kiln, so that when the drying kiln is in operation, the flow direction of the high-temperature flue gas and the movement direction of the laterite nickel ore are opposite. The discharge port and the air inlet of the drying kiln are located at the same end of the drying kiln. The discharge port of the drying kiln is connected to the connecting cover, thereby providing the necessary conditions for achieving the reverse movement of the high-temperature flue gas and the laterite nickel ore to be dried in the drying kiln.

[0011] Preferably, the present invention provides a short-process laterite nickel ore drying and pre-reduction device, wherein the top of the connecting cover is provided with an opening, which is connected to the drying kiln; at the same time, the top of the connecting cover is also reserved for a reducing agent drop pipe connected to the reducing agent bin and a dry ore drop pipe for directly adding additional dry ore; the bottom and / or side of the connecting cover are designed with at least two outlets, at least one of which is connected to the rotary kiln and at least one is connected to the bypass hopper. In this way, basic mixing can be achieved in the connecting cover and the necessary conditions for completing precise control are provided, especially considering the problem of how to deal with excess production capacity of the rotary kiln and how to deal with insufficient production capacity in actual production. This provides the necessary conditions for subsequent efficient and high-quality reduction. Moreover, when mixing in the connecting cover, the particles emerging from the drying kiln have a certain degree of rotation and flowability, and carry a certain temperature and moisture; this is conducive to their uniform mixing with the reducing agent and the additional dry ore.

[0012] Preferably, the present invention provides a short-process laterite nickel ore drying and pre-reduction device, wherein a chute and a bypass pipe are provided in a connecting cover; the chute is connected to the rotary kiln, and the bypass pipe is connected to the bypass silo. The bypass pipe is also provided with a valve for controlling the feed amount of the bypass silo.

[0013] Preferably, in the short-process laterite nickel ore drying and pre-reduction device of the present invention, a plurality of observation holes for observing the discharge amount of the drying kiln and the discharge condition of the chute are further provided in the middle of the connecting cover.

[0014] Preferably, in a short-process laterite nickel ore drying and pre-reduction device of the present invention, the drying kiln is inclined with an inclination angle of 5° to 6°; the inclination angle of the chute is greater than that of the drying kiln, which is conducive to uniform mixing.

[0015] Preferably, in a short-process laterite nickel ore drying and pre-reduction device of the present invention, the distance from the plane where the rotary kiln feed port is located to the horizontal plane is greater than the distance from the plane where the bypass silo feed port is located to the horizontal plane; the bypass silo feed port is connected to the outlet on the connecting cover.

[0016] The application of a short-process laterite nickel ore drying and pre-reduction device of the present invention comprises the following steps:

[0017] S1. Reverse drying:

[0018] The laterite nickel ore to be dried is fed into the drying kiln from the feed port of the drying kiln; at the same time, the high-temperature flue gas from the rotary kiln is fed into the drying kiln from the flue gas inlet of the drying kiln; the flow direction of the high-temperature flue gas is opposite to the movement direction of the laterite nickel ore, that is, the high-temperature flue gas and the laterite nickel ore to be dried are in counter-movement;

[0019] S2, ore blending and reduction:

[0020] The flow rate of laterite nickel ore in the drying kiln is monitored, and reducing agent or reducing agent and additional dry ore are added according to the output of dry ore; the reducing agent and dry ore are preliminarily mixed in the connecting hood and sent to the rotary kiln, and then reduced in the rotary kiln.

[0021] The present invention discloses an application of a short-process laterite nickel ore drying and pre-reduction device. In step S1, the laterite nickel ore stored in a wet ore yard is transported to a drying kiln feed port via a belt conveyor. After entering the drying kiln, the laterite nickel ore moves in the opposite direction to the high-temperature flue gas from the rotary kiln entering from the drying kiln discharge port, i.e., the smoke inlet. As the drying kiln rotates axially, the high-temperature flue gas passes through the gaps in the roiling laterite nickel ore, achieving efficient drying. The dried ore is discharged from the discharge port and directly falls into a connecting cover.

[0022] The present invention discloses an application of a short-process laterite nickel ore drying and pre-reduction device. When the dry ore output exceeds the demand or falls short of the demand, a corresponding adjustment device is used to respond in real time. The specific adjustment method is as follows: when the dry ore output exceeds the demand of the rotary kiln, the excess dry ore is discharged through a bypass pipe in a connecting cover; the bypass pipe quantitative feeder monitors the discharge volume of the dry ore in real time, and controls the discharge of the dry ore in real time through a valve on the bypass pipe. The discharged dry ore is transferred through a bypass silo and then stored in an ore blending workshop, which can greatly reduce the amount of dry ore stored and transported on the ground; when the dry ore output is less than the demand of the rotary kiln, the dry ore previously stored in the ore blending workshop is mixed with a reducing agent and then transported to the rotary kiln through a spare belt conveyor as a supplementary raw material.

[0023] The present invention discloses an application of a short-process laterite nickel ore drying and pre-reduction device. In order to achieve the purpose of more accurate ore blending, the device is equipped with a high-precision laterite nickel ore belt scale, a reducing agent quantitative feeder, and a bypass pipe quantitative feeder. A microwave dynamic moisture meter is installed on the reducing agent conveying belt conveyor, the laterite nickel ore conveying belt conveyor, the dry ore quantitative feeder, and the bypass pipe quantitative feeder to measure the free water content of the dry ore in real time. The automatic control system designs a logical algorithm for the high-precision laterite nickel ore weighing scale, the reducing agent quantitative feeder, the bypass pipe quantitative feeder, and the microwave dynamic moisture meter to ensure that the amount of reducing agent is adjusted in real time as the amount of dry ore entering the rotary kiln changes, thereby achieving the purpose of accurate ore blending. In addition, the use of the microwave dynamic moisture meter can also monitor the dryness of the dry ore in real time.

[0024] The invention discloses an application of a short-process laterite nickel ore drying and pre-reduction device. The high-temperature flue gas temperature at the drying kiln smoke inlet is 350° C. to 450° C., the flue gas temperature at the drying kiln smoke outlet is 110° C. to 130° C., the particle size of the laterite nickel ore entering the drying kiln is ≤100 mm, the filling rate is 13% to 17%, the rotation rate of the drying kiln is 0.32 rpm to 3.2 rpm, the free water content of the dry ore produced at the drying kiln discharge port is 18 wt% to 22 wt%, and the temperature is 90° C. to 95° C.

[0025] In industrial application, the laterite nickel ore is measured by weight using a high-precision belt scale installed on a belt conveyor and the free water content is measured using a microwave dynamic moisture meter in the wet ore yard. The ore is then transported to the feed port of the drying kiln. After entering the drying kiln, the laterite nickel ore moves in the opposite direction to the high-temperature flue gas from the rotary kiln entering the discharge port of the drying kiln. As the drying kiln rotates axially, the lifting plate in the drying kiln churns the laterite nickel ore, and the high-temperature flue gas from the rotary kiln passes through the gaps in the churning laterite nickel ore, thereby increasing the contact area and contact time between the two. Before the laterite nickel ore enters the drying kiln, the free water content is about 40wt% and the temperature is in the room temperature range (about 25°C). After being dried in the drying kiln, the free water content of the dry ore produced is 18wt%-22wt% and the temperature is between 90°C and 95°C. Then, the rotary kiln and the drying kiln are rotated. The connecting cover is connected as a whole, and a chute and a bypass pipe are provided inside the connecting cover. Under normal production conditions, the dry ore slides into the rotary kiln through the chute after being discharged from the drying kiln for roasting and pre-reduction in the subsequent processes; when the dry ore output exceeds demand or is in short supply, the corresponding adjustment device will respond in real time. The specific adjustment method is: when the dry ore output is higher than the demand of the rotary kiln, the excess dry ore will be discharged through the bypass pipe in the connecting cover, and the bypass pipe quantitative feeder will monitor the discharge volume of the dry ore in real time, and control the discharge of the dry ore in real time through the valve on the bypass pipe. The discharged dry ore is transferred through the bypass silo and stored in the ore blending workshop; when the dry ore output is less than the demand of the rotary kiln, the dry ore previously stored in the ore blending workshop will be mixed with the reducing agent and transported to the rotary kiln through the spare belt conveyor as supplementary raw materials.

[0026] In order to enable the method of the present invention to achieve the purpose of more accurate ore blending, the device is equipped with a high-precision belt scale for laterite nickel ore, a reducing agent quantitative feeder, and a bypass pipe quantitative feeder, and a microwave dynamic moisture meter is installed on the reducing agent conveyor belt, the laterite nickel ore conveyor belt, the dry ore quantitative feeder, and the bypass pipe quantitative feeder to measure the moisture content of the dry ore in real time; the automatic control system designs a logical algorithm for the high-precision weighing scale for laterite nickel ore, the reducing agent quantitative feeder, the bypass pipe quantitative feeder, and the microwave dynamic moisture meter to ensure that the amount of reducing agent (dry basis) is adjusted in real time as the amount of dry ore (dry basis) entering the rotary kiln changes, thereby achieving the purpose of accurate ore blending; in addition, the use of the microwave dynamic moisture meter can also monitor the dryness of the dry ore in real time, which is beneficial to the guidance of production management.

[0027] Beneficial effects

[0028] Compared with the prior art, the present invention has the following advantages:

[0029] (1) The flow direction of the high-temperature flue gas in the drying kiln is opposite to the movement direction of the laterite nickel ore, which increases the contact area and contact time between the high-temperature flue gas and the laterite nickel ore, thereby making full use of the waste heat of the high-temperature flue gas in the rotary kiln and maximizing the dry ore output.

[0030] (2) The dry ore produced by this method is not stored on the ground, but directly enters the rotary kiln for roasting and pre-reduction. This can fully utilize the sensible heat of the dry ore and reduce the energy consumption of the rotary kiln roasting and pre-reduction sections. It can also reduce the frequency of dry ore falling to the ground and being transported, thereby reducing dust pollution.

[0031] (3) The drying and blending processes of laterite nickel ore were merged, which shortened the process flow and reduced construction investment and operating costs.

[0032] (4) By adopting a specially designed connecting cover, it is possible to achieve effective docking of the drying kiln production capacity and the rotary kiln consumption capacity. More importantly, the preliminary mixing can be completed in the connecting cover to ensure that the reducing agent and the dry material are mixed evenly, especially when the material contains a certain amount of moisture and carries a certain temperature (). At this time, the moisture will form a layer of water vapor in the particles. When the reducing agent is introduced, the reducing agent will break this layer of water vapor and use this moisture to evenly mix with the dry rolling and rotating minerals.

[0033] (5) Utilize the real-time monitoring and interlocking of metering instruments to achieve accurate ore allocation and material supply and demand balance through the automatic control system. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 This is the connection relationship and workflow diagram of the device designed for the present invention.

[0035] Figure 2This is a structural diagram of the connection cover designed for the present invention.

[0036] Description of Reference Numerals

[0037] 1 is a drying kiln; 2 is a connecting cover; 3 is a rotary kiln; 4 is a chute; 5 is a bypass pipe; 6 is a bypass silo; 7 is a reducing agent silo; 8 is a flue gas duct; 9 is a high-precision belt scale for red nickel earth ore; 10 is a dry ore quantitative feeder; 11 is a reducing agent quantitative feeder A; 12 is a reducing agent quantitative feeder B; 13 is a bypass pipe quantitative feeder; 14 is a reducing agent microwave dynamic moisture meter; 15 is a dry ore microwave dynamic moisture meter; 16 is a red nickel earth ore microwave dynamic moisture meter; 17 is a bypass pipe microwave dynamic moisture meter; 201 is a dry ore drop pipe; 202 is a connecting cover shell; 203 is a reducing agent drop pipe; 204 is a safety net; 205 is an observation hole. DETAILED DESCRIPTION

[0038] The following embodiments are intended only to illustrate the technical concepts and features of the present invention. Their purpose is to enable those skilled in the art to understand the present invention and implement it accordingly. They are not intended to limit the scope of protection of the present invention. Any equivalent changes or modifications made based on the spirit of the present invention are intended to be covered by the scope of protection of the present invention.

[0039] Example 1

[0040] like Figure 1 This device and its application demonstrate a shortened process for drying and pre-reducing laterite nickel ore. The laterite nickel ore is weighed in the wet ore yard by a high-precision belt scale and then transported to a drying kiln via a belt conveyor. The kiln is tilted at a 6° angle. After entering the kiln, the laterite nickel ore moves in opposite directions from the hot flue gas from the rotary kiln, which enters through the kiln discharge port. The hot flue gas enters the kiln at a temperature of 375±25°C. As the kiln rotates axially, the lifting plates inside the kiln churn the laterite nickel ore. The hot flue gas from the rotary kiln passes through the gaps in the lifted laterite nickel ore. The counter-current movement of the laterite nickel ore and the hot flue gas from the rotary kiln increases the contact area and duration, maximizing the utilization of waste heat from the rotary kiln flue gas and the yield of dried ore. Before entering the kiln, the laterite nickel ore has a free water content of approximately 40% by weight, a temperature within the room temperature range, and a particle size of ≤50 mm. After drying in the kiln, the resulting dried ore has a free water content of approximately 20% by weight and a temperature between 90°C and 95°C. After the dry ore is discharged from the drying kiln, it enters the connecting cover with sensible heat; at the same time, the reducing agent entering from the reducing agent bin through the reducing agent drop pipe reserved on the top of the connecting cover mixes together in the chute inside the connecting cover and then slides into the rotary kiln together for the next process of roasting and pre-reduction, thereby maximizing the sensible heat utilization of the dry ore and reducing the frequency of dry ore falling to the ground, thereby reducing the energy consumption and smoke pollution of roasting and pre-reduction in the rotary kiln.

[0041] Under the same inlet flue gas flow rate and temperature, and the moisture content and temperature of the laterite nickel ore, when the flue gas and the laterite nickel ore move in opposite directions and the dry ore output per unit time is 80 tons, the output dry ore temperature is 88°C, and the flue gas temperature discharged from the drying kiln is 128°C. This flue gas can be reused. When the flue gas and the laterite nickel ore move in the same direction and the dry ore output per unit time is 80 tons, the output dry ore temperature is 78°C, and the flue gas temperature discharged from the drying kiln is 131°C. Due to the high dry ore temperature of the present invention, the energy used in subsequent reduction is significantly reduced.

[0042] Assuming the same free water content in the dry ore, the same 80 tons of dry ore enters the rotary kiln for calcination. When the flue gas and laterite nickel ore move in opposite directions, the dry ore produced has a temperature of 88°C. This ore enters the rotary kiln directly and mixes with the reducing agent added directly to the kiln. The resulting sand has a temperature of 750°C, consuming 6.3 tons of fuel coal. When the flue gas and laterite nickel ore move in the same direction, the dry ore produces a temperature of 78°C, but is transferred to the batching plant and then mixed with the reducing agent before entering the rotary kiln for calcination. At this point, the dry ore temperature has dropped from 78°C to room temperature (approximately 25°C). When the sand reaches 750°C after entering the rotary kiln, 9.8 tons of fuel coal is consumed. This translates to an energy saving of (9.8 - 6.3) / 9.8 * 100% = 35.7% for the production of 80 tons of dry ore.

[0043] Example 2

[0044] like Figure 1 The device and application of a short-process laterite nickel ore drying and pre-reduction are shown. When the dry ore output exceeds the demand of the rotary kiln, the excess dry ore is discharged through the bypass pipe in the hood and stored in the ore blending workshop. When the dry ore output is insufficient to meet the demand of the rotary kiln, the previously stored dry ore is mixed with a reducing agent from the ore blending workshop and sent to the rotary kiln through a spare belt conveyor as supplementary raw material, thereby achieving a balanced supply and demand adjustment of materials in the drying, calcining and pre-reduction sections.

[0045] When the demand for dried ore in the rotary kiln is less than the kiln's supply, to minimize heat loss from the kiln's flue gases, the kiln's ore intake is not reduced. Instead, the excess dry ore output beyond what meets the kiln's needs is discharged through a bypass pipe into a bypass silo, from which it is transported by truck to the dry ore stockpile. The adjusted dry ore discharge volume is manually calculated by combining feed rate data from a high-precision laterite nickel ore scale on the kiln's feeder conveyor with the kiln's demand for dried ore. This adjustment is achieved by opening a regulating valve on the bypass pipe and manually inputting a command for the dry ore discharge weight to the bypass feeder. Upon receiving this command, the bypass feeder automatically adjusts its operating speed to achieve a quantitative discharge of dry ore.

[0046] When the demand for dry ore in the rotary kiln is greater than the supply of the drying kiln, increasing the amount of ore fed into the drying kiln will inevitably cause the temperature of the output dry ore to drop. Therefore, the dry ore previously stored in the dry ore yard is mixed with a reducing agent and then directly added to the chute through the dry ore discharge pipe to meet the demand of the rotary kiln.

[0047] Example 3

[0048] like Figure 1 As shown, a laterite nickel ore drying and pre-reduction device equipped with a high-precision laterite nickel ore belt scale, a reducing agent quantitative feeder, a bypass pipe quantitative feeder, and a microwave dynamic moisture meter can measure information such as laterite nickel ore feed rate, dry ore discharge volume, and dry ore moisture content in real time. The automatic control system, in turn, incorporates these instruments into a logic algorithm. Ultimately, the reducing agent dosage is adjusted in real time based on changes in the amount of dry ore entering the rotary kiln and its moisture content, thereby achieving precise ore blending.

Claims

1. Application of a short-process laterite nickel ore drying and pre-reduction device, characterized in that: The following steps are involved: S1. Counter-smoke drying: The laterite nickel ore to be dried is fed into the drying kiln from the feed port of the drying kiln; at the same time, the high-temperature flue gas from the rotary kiln is fed into the drying kiln from the air inlet of the drying kiln; the flow direction of the high-temperature flue gas is opposite to the movement direction of the laterite nickel ore to be dried, that is, the high-temperature flue gas and the laterite nickel ore to be dried are in counter-movement; S2, ore blending and reduction: Monitor the flow rate of laterite nickel ore in the drying kiln and add reducing agent or reducing agent and additional dry ore according to the output of the dried ore in the drying kiln; the reducing agent and dry ore are preliminarily mixed in the connecting hood and fed into the rotary kiln, where they are then reduced; The short-process laterite nickel ore drying and pre-reduction device comprises a drying kiln and a connecting cover; the feed port and air inlet of the drying kiln are respectively located at two ends of the drying kiln, so that when the drying kiln is in operation, the flow direction of the high-temperature flue gas is opposite to the movement direction of the laterite nickel ore; the discharge port and air inlet of the drying kiln are located at the same end of the drying kiln; and the discharge port of the drying kiln is connected to the connecting cover; The rotary kiln and the drying kiln are connected as one with a connecting cover; The top of the connecting cover is provided with an opening, which is connected to the discharge port of the drying kiln. At the same time, the top of the connecting cover is also reserved for a reducing agent drop pipe connected to the reducing agent bin and a dry ore drop pipe for directly adding additional dry ore. The bottom and / or side of the connecting cover are designed with at least two outlets, at least one of which is connected to the rotary kiln and at least one is connected to the bypass silo. A chute and a bypass pipe are provided in the connecting cover; the chute is connected to the rotary kiln, and the bypass pipe is connected to the bypass silo; The drying kiln is designed to be inclined, with an inclination angle of 5° to 6°; The distance between the plane where the rotary kiln feed port is located and the horizontal plane is greater than the distance between the plane where the bypass silo feed port is located and the horizontal plane; the bypass silo feed port is connected to the outlet on the connecting cover.

2. The application of a short-process laterite nickel ore drying and pre-reduction device according to claim 1, characterized in that: In step S1, the laterite nickel ore stored in the wet ore yard is transported to the drying kiln feed port by a belt conveyor. After entering the drying kiln, the laterite nickel ore moves in the opposite direction to the high-temperature flue gas from the rotary kiln entering from the drying kiln air inlet. As the drying kiln rotates axially, the high-temperature flue gas from the rotary kiln passes through the gaps in the churning laterite nickel ore to achieve drying. The dried ore is discharged from the discharge port and directly falls into the connecting cover.

3. The application of a short-process laterite nickel ore drying and pre-reduction device according to claim 1, characterized in that: When the dry ore output exceeds the demand or is in short supply, the corresponding adjustment device will be used to respond in real time; the specific adjustment method is: when the dry ore output exceeds the demand of the rotary kiln, the excess dry ore will be discharged through the bypass pipe in the connecting hood; the bypass pipe quantitative feeder will adjust the discharge volume of the dry ore in real time, and after being transferred through the bypass silo, it will be stored in the ore blending workshop; when the dry ore output is less than the demand of the rotary kiln, the dry ore previously stored in the ore blending workshop will be mixed with the reducing agent, and then transported to the rotary kiln through the dry ore drop pipe by the spare belt conveyor as a supplementary raw material.

4. The application of a short-process laterite nickel ore drying and pre-reduction device according to claim 1, characterized in that: In order to achieve a more accurate ore blending purpose, the device is equipped with a high-precision belt scale for laterite nickel ore, a reducing agent quantitative feeder, and a bypass pipe quantitative feeder, and a microwave dynamic moisture meter is installed on the reducing agent conveyor belt, the laterite nickel ore conveyor belt, the dry ore quantitative feeder, and the bypass pipe quantitative feeder to measure the free water content of the dry ore in real time; the automatic control system designs a logical algorithm for the high-precision belt scale for laterite nickel ore, the reducing agent quantitative feeder, the bypass pipe quantitative feeder, and the microwave dynamic moisture meter to ensure that the amount of reducing agent is adjusted in real time as the amount of dry ore entering the rotary kiln and the moisture content in the dry ore change, thereby achieving the purpose of accurate ore blending; in addition, the use of the microwave dynamic moisture meter can also monitor the dryness of the dry ore in real time.

5. The application of a short-process laterite nickel ore drying and pre-reduction device according to claim 1, characterized in that: The free water content of the dry ore produced from the drying kiln outlet is 18wt%-22wt% and the temperature is 90℃-95℃.

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