A roasting device and process for preparing oxide material in one step

Abstract

The present invention relates to a roasting device for preparing oxidized materials in one step, comprising a front air collecting hood, a rotating device, a rear air collecting hood, a screening barrel, a diversion smoke structure and a heat preservation structure. The front and rear ends of the rotating device are respectively connected to the front air collecting hood and the rear air collecting hood. The tail of the rotating device in the rear air collecting hood is connected to the screening barrel. The top of the front air collecting hood is provided with a diversion smoke outlet, and the top of the rear air collecting hood is provided with a smoke outlet. The diversion smoke outlet and the smoke outlet are respectively connected to the front air inlet and the rear air inlet of the diversion smoke structure. A movable heat preservation structure is installed on the middle periphery of the rotating device. The device can realize pre-roasting oxidation in one step, utilize the combustion heat of its own combustion and the stirring function of the device itself to achieve the purpose of oxidation, and meet the production process requirements. It saves energy, reduces the production process flow, reduces costs, and improves labor productivity.

Description

Technical Field

[0001] The invention belongs to a roasting technology and relates to the preparation of oxide materials, in particular to a roasting device and a process method for preparing oxide materials in a one-step method. Background Art

[0002] In the process of recycling NdFeB waste resources, the preparation of raw materials mainly adopts the process technology of pre-roasting, crushing and grinding, and oxidation roasting. In this process, the pre-roasting process of the raw materials is carried out by using their spontaneous combustion, while the oxidation roasting is roasted at a certain temperature, which requires external heating of natural gas, and the process flow is long, resulting in increased production costs.

[0003] In addition, the smoke generated during the process is recovered by a cyclone dust collector, and then enters a fan-shaped spray tower for cooling and dust recovery. Finally, after a spray absorption, the exhaust gas is led out through an induced draft fan to meet emission standards.

[0004] Due to internal structural problems, the cyclone dust collector's pipes are blocked by deposited dust, and the internal components are often damaged, which affects the dust collection effect. Especially after the components are damaged, the internal smoke and dust reaches a certain temperature and suddenly catches fire after contact with the air, causing an explosion, which is very dangerous.

[0005] The smoke dust recovered after water spraying is cleaned regularly in the recovery pool. The labor intensity is very high, the wet materials on site are dirty and the environment is difficult to ensure cleanliness.

[0006] Therefore, the original process has the disadvantages of long process, high cost, high risk, high labor intensity, poor on-site environment, high equipment maintenance requirements, no waste heat utilization, no equipment insulation, poor on-site working environment, etc., and the on-site environment is not good due to leakage. According to the problems of the original process, the smoke recovery process deleted the cyclone dust removal and water spray recovery process of smoke dust, and studied the device and process technology of one-step preparation of oxidized materials. The oxidized materials meet the process requirements, the equipment maintenance is simple, the waste heat of smoke is utilized, the cost is greatly reduced, the problems of furnace smoke and high temperature are solved, and the on-site working environment is very good. Summary of the invention

[0007] The purpose of the present invention is to overcome the shortcomings of the prior art and provide a roasting device and process method for preparing oxide materials in one step, which is reasonably designed, energy-saving, environmentally friendly and easy to operate. The device and process are particularly suitable for providing qualified oxide raw materials through the roasting process of NdFeB waste. The oxide material is very consistent with the production technology of extracting and recovering valuable elements from NdFeB waste.

[0008] The present invention solves the technical problem by adopting the following technical solutions:

[0009] A roasting device for preparing oxidized materials in one step, characterized in that it includes a front air collecting hood, a rotating device, a rear air collecting hood, a screening barrel, a diverter smoke structure and a heat preservation structure, the front and rear ends of the rotating device are respectively connected to the front air collecting hood and the rear air collecting hood, the tail of the rotating device in the rear air collecting hood is connected to the screening barrel, the top of the front air collecting hood is formed with a diverter smoke outlet, the top of the rear air collecting hood is formed with a smoke outlet, the diverter smoke outlet and the smoke outlet are respectively connected to the front air inlet and the rear air inlet of the diverter smoke structure; a movable heat preservation structure is installed on the middle periphery of the rotating device.

[0010] The front end of the rotating device is embedded in the rear of the front air collecting hood, refractory bricks are inlaid in the front air collecting hood, and a feeding port is arranged at the front end of the front air collecting hood, which can be closed; a diversion smoke outlet is also formed at the upper end of the front air collecting hood, and a flange is formed at the position of the diversion smoke outlet for connecting with the diversion smoke structure, and a plug plate is installed in the diversion smoke outlet for adjustment.

[0011] The rotating device includes a furnace tube, a transmission gear and a supporting device. The furnace tube is a horizontally arranged cylindrical steel structure, a refractory layer is embedded inside the furnace tube, and the furnace tube is set with a slope of 5° at the horizontal direction, with the front higher and the rear lower. A transmission gear is coaxially installed on the outer periphery of the middle part of the furnace tube, and the transmission gear is connected to the motor gearbox; supporting devices are respectively installed on the outer peripheries of the front and rear sides of the furnace tube.

[0012] The supporting device includes a rotating wheel, a tugwheel and a base. The base is fixed on the ground. Two tugwheels that can rotate freely are installed in parallel on the base through a bracket. The two tugwheels jointly support the rotating wheel. The tugwheel and the rotating wheel are both formed with mutually meshing teeth. The rotating wheel is sleeved on the outer periphery of the furnace tube and rotates with the furnace tube.

[0013] The furnace tube is divided into three parts from front to back: a feeding section, a combustion section and an oxidation cooling section. Three convex edges are evenly distributed in annular intervals in the furnace tube of the combustion section, which can lift and stir the materials in the combustion section when rotating.

[0014] The furnace tube is provided with flanges at both the front and rear ends. The flanges at the front and rear ends are respectively inserted into the mounting holes of the front and rear air collecting hoods and are embedded with the front and rear air collecting hoods to prevent smoke from overflowing and provide oxygen. The flange at the rear end is also used to connect with the screening barrel.

[0015] The tail of the rotating device is embedded in the rear air collecting hood, and the tail of the rotating device in the rear air collecting hood is coaxially connected to the sub-screening barrel through a flange. The feeding end of the sub-screening barrel is provided with a flange matching the rear end flange of the furnace tube, and the front end of the sub-screening barrel is provided with a front discharge port to discharge fine materials that meet the process requirements. A sub-screening port is provided in the rear air collecting hood below the rear end of the sub-screening barrel for collecting large particle materials screened by the sub-screening barrel.

[0016] The split flue gas structure comprises a heat exchange pipe, a front smoke pipe, a rear smoke pipe, a heat exchange water cooling jacket and a water cooling jacket. The heat exchange pipe is arranged horizontally and transversely. The front and rear ends of the heat exchange pipe are respectively connected to the vertically arranged front smoke pipe and rear smoke pipe. The heat exchange pipe is wrapped with a heat exchange water cooling jacket, and the rear smoke pipe is wrapped with a water cooling jacket.

[0017] The lower end of the front smoke pipe is provided with a front air inlet, which is connected to the split smoke outlet at the upper end of the front air collecting hood, and the upper end of the front smoke pipe is closed; the lower end of the rear smoke pipe is provided with a rear air inlet, which is connected to the smoke outlet at the upper end of the rear air collecting hood, and the upper end of the rear smoke pipe is provided with a smoke outlet connected to the main flue;

[0018] The rear lower end of the heat exchange water cooling jacket is provided with a heat exchange water inlet, and the front upper end of the heat exchange water cooling jacket is provided with a heat exchange water outlet; the lower part of the water cooling jacket is provided with a water cooling water inlet, and the upper part of the water cooling jacket is provided with a water cooling water outlet.

[0019] The thermal insulation structure includes a thermal insulation sleeve, a thermal insulation layer, an inner lining tube and rollers. Radially symmetrical thermal insulation sleeves are arranged on both radial sides of the middle part of the furnace tube. The upper part of the thermal insulation sleeve is provided with an arc groove that can be embedded in the furnace tube on one side facing the furnace tube. The interior of the thermal insulation sleeve is filled with a thermal insulation layer, and a plurality of inner lining tubes are embedded in the thermal insulation layer at intervals; a plurality of rollers are arranged at the lower end of the thermal insulation sleeve.

[0020] A one-step roasting process for preparing an oxide material, the steps are as follows:

[0021] First, start the transmission device to make the rotating device rotate;

[0022] Then, the mixed material is added, and the mixed material passes through the feeding port of the front air collecting hood and enters the feeding area in the rotating device, and the material is ignited;

[0023] The material moves forward along the axis under the inclination of the rotating device into the combustion zone, where it spontaneously combusts violently at a temperature of 800-900°C. Whenever the burning material encounters a convex edge, it is lifted up and fully contacts with oxygen.

[0024] After the combustion zone, the material enters the oxidation cooling zone, and according to the actual operation situation, auxiliary oxygen is blown in to make the oxidation more complete. As the rotating device rotates, the material moves along the axis to the screening barrel at the tail of the device;

[0025] Finally, the screening barrel rotates with the rotating device, and the oxide materials that meet the process requirements are discharged from the screening barrel front material outlet into the front material box, and sent to the next process for rare earth extraction and recovery; the materials with larger particles that do not meet the process requirements continue to move along the axis to the screening barrel rear material outlet and are discharged into the rear material box, and then transferred to the crushing device for crushing, and then returned for roasting treatment;

[0026] During the combustion process and the process of raising materials, high-temperature smoke and dust are generated, which will flow to the tail smoke inlet pipe and then flow towards the main flue. The supersaturated smoke enters the front smoke pipe through the diversion smoke outlet of the front wind collecting hood.

[0027] The advantages and positive effects of the present invention are:

[0028] 1. This device can realize pre-baking oxidation in one step, using the combustion heat of its own combustion and the stirring function of the device itself to achieve the purpose of oxidation, which meets the production process requirements.

[0029] 2. The present invention enables the waste heat generated during processing to be reasonably utilized in production and life.

[0030] 3. The present invention reduces the ambient temperature to near normal temperature, and the operating environment is good.

[0031] 4. The present invention naturally provides the oxygen required for combustion and provides auxiliary strong oxygen supply according to the process requirements, and the design is reasonable.

[0032] 5. The present invention saves energy, reduces production process flow, reduces costs and improves labor productivity. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 It is the overall structural diagram of the device;

[0034] Figure 2 It is a schematic diagram of the furnace structure;

[0035] Figure 3 It is a schematic diagram of the diversion smoke structure;

[0036] Figure 4 It is a schematic diagram of the insulation structure;

[0037] Figure 5 for Figure 4 Left view of . DETAILED DESCRIPTION

[0038] The present invention will be further described in detail below with reference to the accompanying drawings and through specific embodiments. The following embodiments are only illustrative and not restrictive, and the protection scope of the present invention cannot be limited thereto.

[0039] A roasting device for preparing oxidized materials in one step comprises a front air collecting hood 2, a rotating device, a rear air collecting hood 5, a screening barrel 10, a diverting smoke structure and a heat preservation structure 8, wherein the front and rear ends of the rotating device are respectively connected to the front air collecting hood and the rear air collecting hood, the tail end of the rotating device in the rear air collecting hood is connected to the screening barrel, the front air collecting hood and the rear air collecting hood are respectively fixed on the ground, a diverting smoke outlet is formed on the top of the front air collecting hood, a smoke outlet is formed on the top of the rear air collecting hood, the diverting smoke outlet and the smoke outlet are respectively connected to the front air inlet and the rear air inlet of the diverting smoke structure; a movable heat preservation structure is installed on the middle periphery of the rotating device.

[0040] The diverter flue gas structure is externally connected to an induced draft dust removal system (not shown in the figure), and the diverter flue gas structure and the insulation structure are respectively connected to a circulating water system (not shown in the figure). The induced draft dust removal system and the circulating water system are both existing technologies and are not described in detail herein.

[0041] The structure of each part is described in detail as follows:

[0042] See attached Figure 2 As shown, the front end of the rotating device is embedded in the rear part of the front air collecting hood, the lower end bracket of the front air collecting hood is fixed on the ground, the upper part of the front air collecting hood is a horizontally arranged cylindrical structure, the diameter of the cylindrical structure is 1.55 meters and the width is 1.2 meters, and refractory bricks are inlaid in the front air collecting hood to cooperate with the rotating device to prevent smoke from overflowing, and a feeding port is arranged at the front end of the front air collecting hood, and the feeding port can be closed; a split smoke outlet is also formed at the upper end of the front air collecting hood, and a flange is formed at the position of the split smoke outlet for connecting with the split smoke structure, and a plug plate (not numbered in the figure) is installed in the split smoke outlet for adjustment, and the insertion depth of the adjusting plug plate can adjust the size of the split according to the production process;

[0043] The rotating device includes a furnace tube 6, a transmission gear 7 and a supporting device. The furnace tube is a horizontally arranged cylindrical steel structure with a refractory layer embedded inside. The furnace tube has a diameter of 1.2m and a length of 30m. The furnace tube is provided with a slope of 5° with a high front and a low rear and a horizontal direction to facilitate the movement of materials from front to back; a transmission gear 7 is coaxially installed on the outer periphery of the middle part of the furnace tube, and the transmission gear is connected to the gearbox and the motor to drive the furnace tube to rotate; supporting devices are respectively installed on the outer peripheries of the front and rear sides of the furnace tube, and the supporting device includes a rotating wheel 9, a tugwheel 16 and a base 17. The base is fixed on the ground, and two tugwheels that can rotate freely are installed in parallel on the base through a bracket. The two tugwheels jointly support the rotating wheel, and the tugwheel and the rotating wheel are both provided with mutually meshing teeth. The rotating wheel is sleeved on the outer periphery of the furnace tube and rotates with the furnace tube;

[0044] The furnace tube is divided into three parts from front to back, namely the feeding section, the combustion section and the oxidation cooling section. The lengths of the three parts are 2m, 18m and 10m respectively. Among them, three convex edges are evenly distributed in annular intervals inside the furnace tube of the combustion section. The convex edges are 18000mm long, 80mm wide and 45mm high. When rotating, they have a lifting and stirring effect on the materials in the combustion section.

[0045] The front and rear ends of the furnace tube are equipped with flanges (flange size is φ1500mm*15mm), and the flanges are equipped with 24 holes with a diameter of 22mm. The front and rear end flanges are respectively inserted into the mounting holes of the front and rear air collecting hoods and are embedded with the front and rear air collecting hoods to prevent smoke from overflowing and provide oxygen. The rear end flange is also used to connect with the screening barrel.

[0046] The tail of the rotating device is embedded in the rear air collecting hood, and the tail of the rotating device in the rear air collecting hood is coaxially connected to the screening barrel 10 through a flange 18. The diameter of the screening barrel is 1200mm and the length is 1100mm. The feeding end of the screening barrel is provided with a flange matching the flange at the rear end of the furnace tube. The front end of the screening barrel is provided with a front discharge port to discharge fine materials that meet the process requirements. A screening port 11 is provided in the rear air collecting hood below the rear end of the screening barrel to collect large particles screened by the screening barrel. The large particles are collected through a material box, sent for crushing, and then returned for re-roasting.

[0047] The lower bracket of the rear air hood is fixed on the ground. The upper part of the rear air hood is a horizontally arranged cylindrical structure with a diameter of 1.5 meters and a width of 2.2 meters. A material inlet is provided at the front end of the rear air hood, which is connected with the oxidation cooling section of the rotating device. The inner diameter of the material inlet is 1410mm and the outer diameter is 1550mm to prevent smoke leakage. Refractory bricks are inlaid in the cylindrical structure of the rear air hood. A smoke outlet is provided at the upper end of the rear air hood, and an adjustable plug plate is installed at the smoke outlet position. The smoke discharge volume can be adjusted by adjusting the insertion depth of the plug plate. The rear air hood is also connected to a blower to provide oxygen according to process needs.

[0048] See attached Figure 3 As shown, the split flue gas structure includes a heat exchange pipe 3, a front smoke pipe 4, a rear smoke pipe 1, a heat exchange water cooling jacket 19 and a water cooling jacket. The heat exchange pipe is horizontally arranged, and the front and rear ends of the heat exchange pipe are respectively connected to the vertically arranged front smoke pipe and rear smoke pipe. The heat exchange pipe is wrapped with a heat exchange water cooling jacket 19, and the rear smoke pipe is wrapped with a water cooling jacket (not numbered in the figure).

[0049] The lower end of the front smoke pipe is provided with a front air inlet, which is connected to the split smoke outlet at the upper end of the front air collecting hood, and the upper end of the front smoke pipe is closed; the lower end of the rear smoke pipe is provided with a rear air inlet, which is connected to the smoke outlet at the upper end of the rear air collecting hood, and the upper end of the rear smoke pipe is provided with a smoke outlet connected to the main flue;

[0050] A heat exchange water inlet 14 is formed at the rear lower end of the heat exchange water cooling jacket, and a heat exchange water outlet 15 is formed at the front upper end of the heat exchange water cooling jacket; a water cooling water inlet 13 is formed at the lower part of the water cooling jacket, and a water cooling water outlet 12 is formed at the upper part of the water cooling jacket; the heat exchange water inlet, the heat exchange water outlet, the water cooling water inlet and the water cooling water outlet are respectively connected to a circulating water system (not shown in the figure).

[0051] See attached Figure 4 , 5 As shown, the insulation structure includes an insulation sleeve 8, an insulation layer 22, an inner lining pipe 20 and a roller 21. Radially symmetrical insulation sleeves are arranged on both radial sides of the middle of the furnace tube. The upper side of the insulation sleeve facing the furnace tube is provided with an arc groove that can be embedded in the furnace tube. The interior of the insulation sleeve is filled with an insulation layer, and a plurality of inner lining pipes are embedded in the insulation layer at intervals. The inner lining pipes are connected to a circulating water system through pipelines (not shown in the figure).

[0052] In order to facilitate movement and position adjustment, a plurality of rollers are provided at the lower end of the heat insulation sleeve.

[0053] The processing steps of this process are as follows:

[0054] First, the transmission device is started to rotate the rotating device; the transmission device is equipped with a gearbox, and the speed is adjustable according to the process requirements. In this embodiment, the speed is conventionally set to 2 rpm;

[0055] Add the mixed material (the mixing ratio of the material and the waste material is proportioned according to the material characteristics and process requirements), the mixed material passes through the feeding port of the front air collecting hood and enters the feeding area in the rotating device, and the material is ignited; the material moves forward along the axis under the inclination of the rotating device and enters the combustion zone, and violent spontaneous combustion occurs in the combustion zone, the temperature is 800 ~ 900 ℃, the burning material is lifted up every time it encounters a convex edge, and fully contacts with oxygen, and the material is lifted up every time it encounters a convex edge, so that the material is oxidized more completely; after passing the combustion zone, the material enters the oxidation cooling zone, and according to the actual operation situation, auxiliary oxygen is blown in to make the oxidation more complete, and moves along the axis to the sub-screening barrel at the tail of the device as the rotating device rotates;

[0056] The screening barrel rotates with the rotating device, and the oxide materials that meet the process requirements are discharged from the screening barrel front material outlet into the front material box, and sent to the next process for rare earth extraction and recovery; the materials with larger particles that do not meet the process requirements continue to move along the axis to the screening barrel rear material outlet and are discharged into the rear material box, and then transferred to the crushing device for crushing, and then returned for roasting treatment;

[0057] During the combustion process and the process of lifting materials, high-temperature smoke and dust will flow to the tail smoke inlet pipe and then flow towards the main flue. However, due to the fluctuation of combustion, auxiliary blowing will occur. When the combustion is intense, the smoke volume reaches or exceeds the saturation state. In addition to entering the dust removal system along the tail smoke inlet pipe at the upper end of the rear wind hood, the supersaturated smoke enters the front smoke duct through the diverter smoke outlet of the front wind hood to ensure the normal operation of the entire system (or the smoke and dust are directly connected to the waste heat boiler of the circulating water system for waste heat utilization).

[0058] Turn on the induced draft dust removal system to allow the smoke to move along the pipe into the main flue; at the same time, turn on the cooling water so that the smoke passing through the pipe is cooled down through heat exchange, and the water temperature of the circulation device reaches above 80°C and is sent to the environmental protection workshop for wastewater evaporation.

[0059] The heat generated by the furnace body is insulated and isolated by the thermal insulation system. The heat is used to heat the circulating water for domestic use through heat exchange and ensure the indoor temperature is at a normal level.

[0060] In order to more effectively recover the heat of high-temperature flue gas in the flue gas, the heat exchange pipe and the tail flue gas inlet pipe are equipped with cooling water jackets for heat exchange. Water enters the cooling water jacket from the low-level water inlet, exchanges heat with the water jacket heated by the high-temperature flue gas, and then comes out from the high-level water outlet and returns to the circulating water system. The temperature of the smoke dust after the heat exchange of the water cooling jacket is greatly reduced, generally below 150°C, which is conducive to the effective and normal operation of the dust removal later. The cooling water temperature can reach above 80°C and is provided to the environmental protection treatment workshop for wastewater evaporation and recycling, achieving the purpose of waste heat utilization and greatly saving energy.

[0061] The outer shell of the furnace tube has a temperature of about 200°C and is insulated with a thermal insulation layer. An annular liner pipe is embedded in the insulation layer. Cooling water flows through the pipe. Water enters from the water inlet, exchanges heat with the heated annular water pipe, and then flows out from the water outlet and returns to the circulating water device, realizing the utilization of waste heat, achieving the purpose of cooling the furnace body, and greatly improving the operating environment.

[0062] Although the embodiments and drawings of the present invention are disclosed for illustrative purposes, those skilled in the art will appreciate that various substitutions, changes and modifications are possible without departing from the spirit and scope of the present invention and the appended claims. Therefore, the scope of the present invention is not limited to the contents disclosed in the embodiments and drawings.

Claims

1. A roasting device for preparing an oxidized material in one step, characterized in that: It includes a front air collecting hood, a rotating device, a rear air collecting hood, a screening barrel, a flue gas diversion structure and a heat preservation structure. The rotating device includes a furnace tube, a transmission gear and a supporting device. The furnace tube is a horizontally arranged cylindrical steel structure. A refractory layer is embedded inside the furnace tube. The furnace tube is provided with a slope of 5° from the horizontal direction with a front high and a rear low. A transmission gear is coaxially installed on the outer periphery of the middle part of the furnace tube, and the transmission gear is connected to the motor gearbox. Support devices are respectively installed on the outer periphery of the front and rear sides of the furnace tube. The furnace tube is divided into three parts from front to back: a feeding section, a combustion section and an oxidation cooling section. Three convex edges are evenly distributed in an annular space inside the furnace tube of the combustion section, which can lift and stir the materials in the combustion section when rotating. The front and rear ends of the rotating device are respectively connected to the front air collecting hood and the rear air collecting hood, the tail of the rotating device in the rear air collecting hood is connected to a sub-screening barrel, the top of the front air collecting hood is provided with a diverted smoke outlet, the top of the rear air collecting hood is provided with a smoke outlet, the diverted smoke outlet and the smoke outlet are respectively connected to the front air inlet and the rear air inlet of the diverted smoke structure; a movable thermal insulation structure is installed on the outer periphery of the middle part of the rotating device; the tail of the rotating device is embedded in the rear air collecting hood, and the tail of the rotating device in the rear air collecting hood is coaxially connected to the sub-screening barrel through a flange, the feeding end of the sub-screening barrel is provided with a flange matching the rear end flange of the furnace tube, the front end of the sub-screening barrel is provided with a front discharge port to discharge fine materials that meet the process requirements, and a sub-feeding port is provided in the rear air collecting hood below the rear end of the sub-screening barrel to collect large particles screened out by the sub-screening barrel; The split flue gas structure comprises a heat exchange pipe, a front smoke pipe, a rear smoke pipe, a heat exchange water cooling jacket and a water cooling jacket. The heat exchange pipe is arranged horizontally and transversely. The front and rear ends of the heat exchange pipe are respectively connected to the vertically arranged front smoke pipe and rear smoke pipe. The heat exchange pipe is wrapped with a heat exchange water cooling jacket, and the rear smoke pipe is wrapped with a water cooling jacket. The lower end of the front smoke pipe is provided with a front air inlet, which is connected to the split smoke outlet at the upper end of the front air collecting hood, and the upper end of the front smoke pipe is closed; the lower end of the rear smoke pipe is provided with a rear air inlet, which is connected to the smoke outlet at the upper end of the rear air collecting hood, and the upper end of the rear smoke pipe is provided with a smoke outlet connected to the main flue; The rear lower end of the heat exchange water cooling jacket is provided with a heat exchange water inlet, and the front upper end of the heat exchange water cooling jacket is provided with a heat exchange water outlet; the lower part of the water cooling jacket is provided with a water cooling water inlet, and the upper part of the water cooling jacket is provided with a water cooling water outlet; The supporting device includes a rotating wheel, a tug wheel and a base, the base is fixed on the ground, two tug wheels that can rotate freely are installed in parallel on the base through a bracket, the two tug wheels jointly support the rotating wheel, the tug wheel and the rotating wheel are both formed with mutually meshing teeth, and the rotating wheel is sleeved on the outer periphery of the furnace tube and rotates with the furnace tube; A one-step roasting process for preparing an oxide material, the steps are as follows: First, start the transmission device to make the rotating device rotate; Then, the mixed material is added, and the mixed material passes through the feeding port of the front air collecting hood and enters the feeding area in the rotating device, and the material is ignited; The material moves forward along the axis under the inclination of the rotating device into the combustion zone, where it spontaneously combusts violently at a temperature of 800-900°C. Whenever the burning material encounters a convex edge, it is lifted up and fully contacts with oxygen. After the combustion zone, the material enters the oxidation cooling zone, and according to the actual operation situation, auxiliary oxygen is blown in to make the oxidation more complete. As the rotating device rotates, the material moves along the axis to the screening barrel at the tail of the device; Finally, the screening barrel rotates with the rotating device, and the oxide materials that meet the process requirements are discharged from the screening barrel front material outlet into the front material box, and sent to the next process for rare earth extraction and recovery; the materials with larger particles that do not meet the process requirements continue to move along the axis to the screening barrel rear material outlet and are discharged into the rear material box, and then transferred to the crushing device for crushing, and then returned for roasting treatment; During the combustion process and the lifting of materials, high-temperature smoke and dust will flow to the tail smoke inlet pipe and then flow to the main flue. The supersaturated smoke will enter the front smoke pipe through the split smoke outlet of the front air hood. The front end of the rotating device is embedded in the rear part of the front air collecting hood, and refractory bricks are inlaid in the front air collecting hood. A feeding port is arranged at the front end of the front air collecting hood, and the feeding port can be closed; a diversion smoke outlet is also formed at the upper end of the front air collecting hood, and a flange is formed at the position of the diversion smoke outlet for connecting with the diversion smoke structure, and a plug plate is installed in the diversion smoke outlet for adjustment; flanges are formed at the front and rear ends of the furnace pipe, and the front and rear end flanges are respectively inserted into the mounting holes of the front and rear air collecting hoods and embedded with the front and rear air collecting hoods to prevent smoke overflow and provide oxygen, and the rear end flange is also used to connect with the screening barrel.

2. The roasting device for preparing the oxidized material in one step according to claim 1, characterized in that: The thermal insulation structure includes a thermal insulation sleeve, a thermal insulation layer, an inner lining tube and rollers. Radially symmetrical thermal insulation sleeves are arranged on both radial sides of the middle part of the furnace tube. The upper part of the thermal insulation sleeve is provided with an arc groove that can be embedded in the furnace tube on one side facing the furnace tube. The interior of the thermal insulation sleeve is filled with a thermal insulation layer, and a plurality of inner lining tubes are embedded in the thermal insulation layer at intervals; a plurality of rollers are arranged at the lower end of the thermal insulation sleeve.

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