A molybdenum concentrate dehydration and desulfurization system and process

Abstract

The present invention discloses a molybdenum concentrate dehydration and desulfurization system and process thereof, which belongs to the technical field of metal smelting raw material processing, and includes a rotary kiln and a heat exchange type mixing and drying device based on the heat utilization of the rotary kiln; the heat exchange type mixing and drying device utilizes the waste heat of the tail gas of the rotary kiln to mix and dry the molybdenum concentrate raw material. The present invention utilizes the tail gas generated in the process of molybdenum oxide generation to dry the stored granular molybdenum oxide, and utilizes the waste heat in the tail gas to remove the moisture in the granular molybdenum oxide, so as to ensure that the molybdenum oxide does not need to be dried again during the subsequent ferro-molybdenum alloy smelting, and the tail gas is treated by utilizing the waste heat and using a silicon dioxide absorption filter plate, so as to achieve the waste heat utilization, and at the same time, the sulfur dioxide gas can be treated in the medium term, so as to reduce the burden of tail gas treatment and the equipment installation cost, and the granular molybdenum oxide on the upper layer is used to absorb the moisture in the air, so as to avoid the powdered molybdenum oxide on the lower layer from being damp and agglomerated, so as to ensure the overall quality of the molybdenum oxide.

Description

Technical Field

[0001] The present invention relates to the technical field of metal smelting raw material processing, and in particular to a molybdenum concentrate dehydration and desulfurization system and a process thereof. Background Art

[0002] At present, the roasting production process for molybdenum concentrate is to put the molybdenum concentrate into an internal combustion rotary kiln, use the heat generated by coal ignition to oxidize the molybdenum concentrate in the kiln and emit heat, and then complete the oxidation reaction in the kiln. The generated molybdenum oxide is transported to the molybdenum oxide warehouse by a closed chain plate, and is crushed by a hammer crusher for standby use;

[0003] Molybdenum oxide is mainly used as a raw material for ferromolybdenum alloy smelting. During the ferromolybdenum alloy smelting process, aluminothermic reduction method is used for smelting, and automatic reaction is carried out without adding fuel and other substances. Therefore, the dryness requirement of molybdenum oxide is extremely high. Molybdenum oxide powder is easy to absorb water and moisture during storage, resulting in a large water content. Therefore, it is currently necessary to dry the molybdenum oxide before smelting ferromolybdenum alloy. The sufficient drying of molybdenum oxide causes a waste of resources. In order to optimize the process, and in the current molybdenum oxide generation process, the amount of sulfur dioxide contained in its tail gas in the early stage is relatively small, and a large amount of sulfur dioxide gas will be generated in the middle stage. This requires that the tail gas desulfurization treatment device needs to be designed to meet the treatment capacity of a large amount of sulfur dioxide gas in the middle stage, resulting in a significant increase in cost. For this reason, a molybdenum concentrate dehydration and desulfurization system and process thereof are proposed. Summary of the invention

[0004] The purpose of the present invention is to solve the problems existing in the prior art and to propose a molybdenum concentrate dehydration and desulfurization system and process thereof.

[0005] In order to achieve the above object, the present invention adopts the following technical solutions:

[0006] A molybdenum concentrate dehydration and desulfurization system and process thereof, comprising:

[0007] High temperature roasting unit: including a rotary kiln and a heat exchange type mixing and drying device based on the heat utilization of the rotary kiln; the rotary kiln is used for high temperature roasting of molybdenum oxide ore, and the heat exchange type mixing and drying device utilizes the waste heat of the tail gas of the rotary kiln to mix and dry the molybdenum concentrate raw materials;

[0008] Tail gas desulfurization treatment unit: dehydration device, desulfurization device and silica treatment device;

[0009] The dehydration device is connected to the rotary kiln tail gas discharge device, and the dehydration device is connected to the desulfurization device and the silicon dioxide treatment device through the control valve.

[0010] Molybdenum oxide storage unit: comprising a composite storage chamber, wherein the bottom of the composite storage chamber is used to store molybdenum oxide powder, the middle part stores molybdenum oxide particles, and the upper part is provided with a silicon dioxide adsorbent for adsorbing sulfur dioxide gas and moisture in the waste heat utilization gas;

[0011] Molybdenum oxide processing unit: a crushing device, a screening device and a crushing and mixing device. The crushing device is connected to the rotary kiln, and is used to receive the molybdenum oxide in the rotary kiln and crush it. The crushed molybdenum oxide is divided into molybdenum oxide particles and molybdenum oxide powder by the screening device. The crushing and mixing device is connected to the composite storage chamber, and the stored molybdenum oxide particles are crushed and mixed with the molybdenum oxide powder for transportation.

[0012] Preferably, the composite storage chamber comprises a storage annular cover arranged on the surface of the rotary kiln, a storage annular cavity is provided inside the storage annular cover, and the inner wall of the storage annular cavity is connected to a plurality of isolation plates located inside via a driving device.

[0013] Preferably, the silica treatment device comprises an air injection channel arranged on the bottom isolation plate, the air injection channel is connected to the dehydration device in the tail gas desulfurization treatment unit through a waste heat utilization pipeline, and a silica absorption filter plate is arranged on the isolation plate located above.

[0014] Preferably, the driving device includes a driving motor arranged on the storage annular cover, the isolation plate is connected to the inner wall of the storage annular cover through a connecting rotating ring, the output end of the driving motor is fixedly connected with an adjusting gear, the connecting rotating ring is meshingly connected with the adjusting gear, and the meshing part thereof is provided with a sealing cover.

[0015] Preferably, a heating and reduction chamber is provided at the top of the storage annular cover, a resistive heating device is provided at the bottom of the heating and reduction chamber, and a gas delivery channel leading to a dehydration device is provided in the heating and reduction chamber.

[0016] Preferably, the isolation plate is densely provided with ventilation filters, and the ventilation filters located at the top and the ventilation filters located at the bottom are staggered.

[0017] Preferably, the silica absorption filter plate is densely distributed with porous silica particles for adsorbing sulfur dioxide gas.

[0018] A molybdenum concentrate dehydration and desulfurization process comprises the following steps:

[0019] S1. Mixing and drying: using the tail gas generated by the rotary kiln to dry the molybdenum concentrate, and mixing the molybdenum concentrate through a mixing device;

[0020] S2. High-temperature roasting: The mixed molybdenum concentrate is fed into a rotary kiln for roasting. During the roasting process, the main component of the molybdenum concentrate, molybdenum dioxide, is oxidized into molybdenum trioxide. The roasting temperature is generally controlled below 600°C. The sulfur content of the molybdenum trioxide obtained after roasting is controlled below 0.065%. The sulfur in the molybdenum concentrate is oxidized into sulfur dioxide tail gas, and the generated sulfur dioxide tail gas is treated by a tail gas desulfurization treatment unit;

[0021] S3, crushing and screening: the calcined molybdenum oxide is beaten and crushed, and the crushed molybdenum oxide is sieved to be molybdenum oxide particles and molybdenum oxide powder;

[0022] S4, layered storage: the molybdenum oxide powder is transported to the bottom layer of the composite storage chamber for storage, and the molybdenum oxide particles are transported to the isolation plate on the composite storage chamber for storage. During the storage process, the molybdenum oxide particles in the upper layer are in direct contact with the air, and absorb water during storage, resulting in an increase in water content;

[0023] S5. Drying with waste heat from tail gas: When molybdenum oxide is used as a raw material for ferromolybdenum smelting, the tail gas generated in the high-temperature roasting stage is transported to the isolation plate through a waste heat utilization pipeline. When the tail gas flows through the molybdenum oxide particles on the isolation plate, the waste heat generated will carry the moisture in the molybdenum oxide particles upward, and the molybdenum oxide is dried by the tail gas;

[0024] S6, tail gas absorption: tail gas containing moisture and sulfur dioxide gas will be transported upward, and the silica absorption filter plate on the upper isolation plate will absorb the moisture and sulfur dioxide in the tail gas, and the tail gas after absorption will be sent to the exhaust pipe for discharge;

[0025] S7, reduction and return: The sulfur dioxide in the silicon dioxide absorption filter plate that absorbs moisture and sulfur dioxide exists as sulfur. When the rotary kiln is working, the silicon dioxide absorption filter plate can be heated to oxidize the adsorbed moisture and sulfur into sulfur dioxide again and transport it to the tail gas desulfurization treatment unit for unified tail gas treatment;

[0026] S8. Mixed transportation: The molybdenum oxide particles are crushed into powder by a crusher, and are evenly mixed with the original molybdenum oxide powder for transportation.

[0027] Compared with the prior art, the present invention has the following beneficial effects:

[0028] 1. The present invention stores the molybdenum oxide processed by the rotary kiln by setting up a composite storage chamber, and uses an isolation plate to store the granular molybdenum oxide and the powdered molybdenum oxide in layers. The granular molybdenum oxide in the upper layer is used to absorb moisture in the air, thereby preventing the powdered molybdenum oxide in the lower layer from getting damp and agglomerating, thereby ensuring the overall quality of the molybdenum oxide.

[0029] 2. The present invention utilizes the tail gas generated during the production of molybdenum oxide to dry the stored granular molybdenum oxide, and utilizes the residual heat in the tail gas to remove the moisture in the granular molybdenum oxide, thereby ensuring that the molybdenum oxide does not need to be dried again during the subsequent ferro-molybdenum alloy smelting. The tail gas is treated by using the residual heat and then passing through a silicon dioxide absorption filter plate. While realizing the utilization of the residual heat, a portion of the sulfur dioxide gas can be treated in the medium term, thereby reducing the burden of tail gas treatment and reducing the cost of equipment installation.

[0030] 3. The present invention absorbs sulfur dioxide gas and moisture through a silicon dioxide absorption filter plate, and during the roasting process in a rotary kiln, the heat of the rotary kiln is used to heat the silicon dioxide absorption filter plate, and the absorbed sulfur dioxide gas and moisture are discharged into the exhaust gas treatment device. The heated silicon dioxide absorption filter plate can be restored to meet the next use, thereby effectively solving the problem of molybdenum oxide dehydration through redox reaction conversion. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 A schematic diagram of a molybdenum concentrate dehydration and desulfurization system proposed by the present invention;

[0032] Figure 2 This is a schematic diagram of the assembly structure of a composite storage chamber in a molybdenum concentrate dehydration and desulfurization system proposed by the present invention;

[0033] Figure 3 This is a schematic diagram of the structure of a driving device in a molybdenum concentrate dehydration and desulfurization system proposed by the present invention;

[0034] Figure 4 The present invention provides a schematic flow diagram of a molybdenum concentrate dehydration and desulfurization process.

[0035] In the figure: 1. Rotary kiln; 2. Heat exchange type mixing and drying device; 3. Dehydration device; 4. Desulfurization device; 5. Composite storage chamber; 501. Storage annular cover; 502. Isolation plate; 503. Waste heat utilization pipeline; 504. Silica absorption filter plate; 505. Driving motor; 506. Connecting rotating ring; 507. Adjusting gear; 508. Heating reduction chamber; 509. Gas delivery channel; 510. Ventilation filter port; 6. Molybdenum oxide processing unit. DETAILED DESCRIPTION

[0036] The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0037] In the description of the present invention, it should be noted that the terms "upper", "lower", "inner", "outer", "top / bottom" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific position, be constructed and operated in a specific position, and therefore cannot be understood as limiting the present invention. In addition, the terms "first" and "second" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance.

[0038] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "provided with", "mounted / connected", "connected", etc. should be understood in a broad sense. For example, "connected" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0039] Example, see Figures 1 to 4 , a molybdenum concentrate dehydration and desulfurization system and process thereof, comprising:

[0040] High temperature roasting unit: comprising a rotary kiln 1 and a heat exchange type mixing and drying device 2 based on the heat utilization of the rotary kiln 1; the rotary kiln 1 is used for high temperature roasting of molybdenum oxide ore, and the heat exchange type mixing and drying device 2 utilizes the waste heat of tail gas of the rotary kiln 1 to mix and dry the molybdenum concentrate raw materials;

[0041] Flue gas desulfurization treatment unit: dehydration device 3, desulfurization device 4 and silicon dioxide treatment device;

[0042] The dehydration device 3 is connected to the tail gas discharge device of the rotary kiln 1, and the dehydration device 3 is connected to the desulfurization device 4 and the gas inlet end of the silicon dioxide treatment device through the control valve;

[0043] The molybdenum oxide storage unit comprises a composite storage chamber 5, wherein the bottom of the composite storage chamber 5 is used to store molybdenum oxide powder, the middle part stores molybdenum oxide particles, and the upper part is provided with a silicon dioxide adsorbent for adsorbing sulfur dioxide gas and moisture in the waste heat utilization gas;

[0044] The molybdenum oxide processing unit 6 includes a crushing device, a screening device and a crushing and mixing device. The crushing device is connected to the rotary kiln 1, and is used to receive the molybdenum oxide in the rotary kiln 1 and crush it. The crushed molybdenum oxide is divided into molybdenum oxide particles and molybdenum oxide powder by the screening device. The crushing and mixing device is connected to the composite storage chamber 5, and the stored molybdenum oxide particles are crushed and mixed with the molybdenum oxide powder for transportation.

[0045] The composite storage chamber 5 includes a storage annular cover 501 arranged on the surface of the rotary kiln 1, a storage annular cavity is opened inside the storage annular cover 501, and the inner wall of the storage annular cavity is connected to a plurality of isolation plates 502 located inside through a driving device, and ventilation filters 510 are densely distributed on the isolation plates 502, and the ventilation filters 510 located above and the ventilation filters 510 located below are staggered.

[0046] The staggered structure can achieve a sealing effect when they are close to each other, ensuring that sulfur dioxide gas will not escape downward during the heating process.

[0047] The silica treatment device includes an injection channel arranged on a bottom isolation plate 502, and the injection channel is connected to a dehydration device 3 in a tail gas desulfurization treatment unit through a waste heat utilization pipeline 503. A silica absorption filter plate 504 is arranged on the upper isolation plate 502, and the interior of the silica absorption filter plate 504 is densely distributed with porous silica particles for adsorbing sulfur dioxide gas.

[0048] The tail gas generated during the production of molybdenum oxide is used to dry the stored granular molybdenum oxide, and the residual heat in the tail gas is used to remove the moisture in the granular molybdenum oxide, thereby ensuring that the molybdenum oxide does not need to be dried again during the subsequent ferro-molybdenum alloy smelting. The tail gas is treated by the silicon dioxide absorption filter plate 504 through the use of the residual heat, which can achieve the utilization of the residual heat and treat a part of the sulfur dioxide gas in the medium term, thereby reducing the burden of tail gas treatment and reducing the cost of equipment installation.

[0049] The driving device includes a driving motor 505 arranged on the storage annular cover 501, the isolation plate 502 is connected to the inner wall of the storage annular cover 501 through a connecting rotating ring 506, the output end of the driving motor 505 is fixedly connected with an adjusting gear 507, the connecting rotating ring 506 is meshingly connected with the adjusting gear 507, and the meshing part is provided with a sealing cover.

[0050] A heating and reducing chamber 508 is provided at the top of the storage annular cover 501 . A resistive heating device is provided at the bottom of the heating and reducing chamber 508 . A gas conveying channel 509 leading to the dehydration device 3 is provided in the heating and reducing chamber 508 .

[0051] A molybdenum concentrate dehydration and desulfurization process, including mixed material drying, high temperature roasting, crushing and screening, layered storage, tail gas waste heat drying, tail gas absorption, reduction return and mixed transportation, etc., specifically including the following:

[0052] The tail gas generated by the rotary kiln 1 is used to dry the molybdenum concentrate, and the molybdenum concentrate is mixed and processed by a mixing device;

[0053] The mixed molybdenum concentrate is fed into a rotary kiln 1 for roasting. During the roasting process, the main component of the molybdenum concentrate, molybdenum dioxide, is oxidized into molybdenum trioxide. The roasting temperature is generally controlled below 600° C. The sulfur content of the molybdenum trioxide obtained after roasting is controlled below 0.065%. The sulfur in the molybdenum concentrate is oxidized into sulfur dioxide tail gas, and the generated sulfur dioxide tail gas is treated by a tail gas desulfurization treatment unit;

[0054] The calcined molybdenum oxide is beaten and crushed, and the crushed molybdenum oxide is sieved to be divided into molybdenum oxide particles and molybdenum oxide powder;

[0055] The molybdenum oxide powder is transported to the bottom layer of the composite storage chamber 5 for storage, and the molybdenum oxide particles are transported to the isolation plate 502 on the composite storage chamber 5 for storage. During the storage process, the molybdenum oxide particles in the upper layer are in direct contact with the air, and will absorb water from the air during storage, causing the water content to increase;

[0056] When molybdenum oxide is used as a raw material for ferromolybdenum smelting, the tail gas generated in the high-temperature roasting stage is transported to the isolation plate 502 through the waste heat utilization pipeline 503. When the tail gas flows through the molybdenum oxide particles on the isolation plate 502, the waste heat generated will carry the moisture in the molybdenum oxide particles upward, and the molybdenum oxide is dried by the tail gas.

[0057] The tail gas containing moisture and sulfur dioxide gas will be transported upward, and the silicon dioxide absorption filter plate 504 on the upper isolation plate 502 will absorb the moisture and sulfur dioxide in the tail gas, and the tail gas after absorption will be sent to the exhaust pipe for discharge;

[0058] The sulfur dioxide in the silicon dioxide absorption filter plate 504 that absorbs moisture and sulfur dioxide exists as sulfur. When the rotary kiln 1 is working, the silicon dioxide absorption filter plate 504 can be heated to oxidize the absorbed moisture and sulfur into sulfur dioxide again and transport it to the tail gas desulfurization treatment unit for unified tail gas treatment.

[0059] The molybdenum oxide processed by the rotary kiln 1 is stored by setting up a composite storage chamber 5, and the granular molybdenum oxide and the powdered molybdenum oxide are stored in layers by using the isolation plate 502. The granular molybdenum oxide in the upper layer is used to absorb moisture in the air, thereby preventing the powdered molybdenum oxide in the lower layer from getting damp and agglomerated, thereby ensuring the overall quality of the molybdenum oxide.

[0060] The molybdenum oxide particles are crushed into powder by a crusher and mixed evenly with the original molybdenum oxide powder for transportation.

[0061] The sulfur dioxide gas and moisture are absorbed by the silicon dioxide absorption filter plate 504, and during the roasting process in the rotary kiln 1, the heat of the rotary kiln 1 is used to heat the silicon dioxide absorption filter plate 504, and the absorbed sulfur dioxide gas and moisture are discharged into the exhaust gas treatment device. The heated silicon dioxide absorption filter plate 504 can be reduced to meet the next use, thereby effectively solving the problem of molybdenum oxide dehydration through redox reaction conversion.

[0062] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A molybdenum concentrate dehydration and desulfurization system, characterized in that: include: The high-temperature roasting unit comprises a rotary kiln (1) and a heat exchange type mixing and drying device (2) based on heat utilization of the rotary kiln (1); the rotary kiln (1) is used for high-temperature roasting of molybdenum oxide ore, and the heat exchange type mixing and drying device (2) utilizes the waste heat of tail gas from the rotary kiln (1) to mix and dry the molybdenum concentrate raw materials; Tail gas desulfurization treatment unit: a dehydration device (3), a desulfurization device (4) and a silicon dioxide treatment device; The dehydration device (3) is connected to the tail gas discharge device of the rotary kiln (1), and the dehydration device (3) is connected to the desulfurization device (4) and the gas inlet end of the silicon dioxide treatment device through a control valve; The molybdenum oxide storage unit comprises a composite storage chamber (5), wherein the bottom of the composite storage chamber (5) is used to store molybdenum oxide powder, the middle part stores molybdenum oxide particles, and the upper part is provided with a silicon dioxide adsorption element for adsorbing sulfur dioxide gas and moisture in the waste heat utilization gas; A molybdenum oxide processing unit (6): a crushing device, a screening device and a crushing and mixing device, wherein the crushing device is connected to the rotary kiln (1) and is used to receive the molybdenum oxide in the rotary kiln (1) and crush it, and the crushed molybdenum oxide is separated into molybdenum oxide particles and molybdenum oxide powder by the screening device, and the crushing and mixing device is connected to the composite storage chamber (5) to crush the stored molybdenum oxide particles and mix them with the molybdenum oxide powder for transportation; The composite storage chamber (5) comprises a storage annular cover (501) arranged on the surface of the rotary kiln (1), a storage annular cavity is provided inside the storage annular cover (501), and a plurality of isolation plates (502) located inside the storage annular cavity are connected to the inner wall of the storage annular cavity via a driving device; The silicon dioxide treatment device comprises an air injection channel arranged on a bottom isolation plate (502), the air injection channel being connected to a dehydration device (3) in a tail gas desulfurization treatment unit via a waste heat utilization pipeline (503), and a silicon dioxide absorption filter plate (504) being arranged on the isolation plate (502) located above.

2. A molybdenum concentrate dehydration and desulfurization system according to claim 1, characterized in that: The driving device comprises a driving motor (505) arranged on the storage annular cover (501); the isolation plate (502) is connected to the inner wall of the storage annular cover (501) via a connecting rotating ring (506); an adjusting gear (507) is fixedly connected to the output end of the driving motor (505); the connecting rotating ring (506) is meshingly connected to the adjusting gear (507); and a sealing cover is provided at the meshing portion thereof.

3. A molybdenum concentrate dehydration and desulfurization system according to claim 2, characterized in that: A heating and reducing chamber (508) is provided at the top of the storage annular cover (501), a resistive heating device is provided at the bottom of the heating and reducing chamber (508), and a gas conveying channel (509) leading to the dehydration device (3) is provided in the heating and reducing chamber (508).

4. A molybdenum concentrate dehydration and desulfurization system according to claim 3, characterized in that: The isolation plate (502) is densely provided with ventilation filters (510), and the ventilation filters (510) located at the top and the ventilation filters (510) located at the bottom are arranged in a staggered manner.

5. A molybdenum concentrate dehydration and desulfurization system according to claim 4, characterized in that: The silica absorption filter plate (504) is densely distributed with porous silica particles for adsorbing sulfur dioxide gas.

6. A molybdenum concentrate dehydration and desulfurization process according to a molybdenum concentrate dehydration and desulfurization system according to any one of claims 1 to 5, characterized in that: The following steps are involved: S1, mixing and drying: using the tail gas generated by the rotary kiln (1) to dry the molybdenum concentrate, and mixing the molybdenum concentrate through a mixing device; S2, high temperature roasting: the mixed molybdenum concentrate is fed into a rotary kiln (1) for roasting. During the roasting process, the main component of the molybdenum concentrate, molybdenum dioxide, is oxidized into molybdenum trioxide. The roasting temperature is generally controlled below 600° C. The sulfur content of the molybdenum trioxide obtained after roasting is controlled below 0.065%. The sulfur in the molybdenum concentrate is oxidized into sulfur dioxide tail gas. The generated sulfur dioxide tail gas is treated by a tail gas desulfurization treatment unit; S3, crushing and screening: the calcined molybdenum oxide is beaten and crushed, and the crushed molybdenum oxide is sieved to be molybdenum oxide particles and molybdenum oxide powder; S4, layered storage: the molybdenum oxide powder is transported to the bottom layer of the composite storage chamber (5) for storage, and the molybdenum oxide particles are transported to the isolation plate (502) on the composite storage chamber (5) for storage. During the storage process, the molybdenum oxide particles in the upper layer are in direct contact with the air and absorb water during storage, causing the water content to increase; S5, drying with waste heat of tail gas: when molybdenum oxide is used as a raw material for ferromolybdenum smelting, the tail gas generated in the high-temperature roasting stage is transported to the isolation plate (502) through the waste heat utilization pipeline (503). When the tail gas flows through the molybdenum oxide particles on the isolation plate (502), the waste heat generated will carry the moisture in the molybdenum oxide particles upward, and the molybdenum oxide is dried by the tail gas; S6, tail gas absorption: tail gas containing moisture and sulfur dioxide gas will be transported upward, and the silicon dioxide absorption filter plate (504) on the upper isolation plate (502) will absorb the moisture and sulfur dioxide in the tail gas, and the tail gas after absorption treatment will be sent to the exhaust pipe for discharge; S7, reduction and return: the sulfur dioxide in the silicon dioxide absorption filter plate (504) that absorbs moisture and sulfur dioxide exists as sulfur. When the rotary kiln (1) is working, the silicon dioxide absorption filter plate (504) can be heated to oxidize the adsorbed moisture and sulfur into sulfur dioxide again and transport it to the tail gas desulfurization treatment unit for unified tail gas treatment; S8. Mixed transportation: The molybdenum oxide particles are crushed into powder by a crusher, and are evenly mixed with the original molybdenum oxide powder for transportation.

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