High temperature acid digestion apparatus and method for a uranium-containing polymetallic silicate ore

Abstract

The application provides a high-temperature acidolysis device and method for uranium-containing polymetallic silicate ore, and relates to the technical field of hydrometallurgy. The device is used for high-temperature acidolysis of uranium-containing polymetallic silicate ore, the function structure of a slurry preparation tank is designed, and material is added in batches in sections, so that the risk of slurry tank overflow is reduced, and the time for slurry preparation is shortened; the reaction heat and dilution heat are used to make the material mature in the stirring tank, so that the energy consumption is reduced, and the reaction time in the subsequent high-temperature acidolysis process is shortened. The solidification of the slurry and the high-temperature acidolysis equipment are modularized and connected in series, and are carried out in the paddle stirring equipment, so that the rapid solidification of the slurry and the fine control of the high-temperature acidolysis process are realized, the technical problems of material caking and scarring in the high-temperature acidolysis are effectively solved, the energy consumption is reduced, the amount of waste gas generated in the acidolysis process is reduced, and the equipment floor area is saved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of hydrometallurgy, and particularly relates to a high-temperature acidolysis device and method for uranium-containing polymetallic silicate ore. BACKGROUND

[0002] Rare earth concentrate is generally prepared into various rare earth compound products through processes such as acid and alkali strengthening decomposition, leaching, purification, concentration or calcination. Baotou mixed rare earth ore composed of bastnaesite and monazite is mainly treated by acid method and alkali method. 90% of Baotou rare earth ore adopts the third generation of sulfuric acid method smelting, and the device used is an internal heating rotary kiln. This method has low production cost and has been widely used in recent years, and has achieved certain economic benefits. However, the use of internal heating rotary kiln will cause scabbing and ring formation at the feeding end, resulting in discontinuous production. In order to reduce the scabbing and ring formation at the kiln head, a large amount of sulfuric acid is added for flushing during process operation, resulting in a serious excess of sulfuric acid.

[0003] The uranium-containing polymetallic ore has many mineral types, isomorphism and mineral inclusion phenomena, and the conventional uranium hydrometallurgy method is difficult to effectively extract target elements. The sulfation roasting technology utilizes the strong corrosion and oxidation of sulfuric acid under high temperature conditions to realize the decomposition of difficult-to-crack minerals and improve the extraction rate of valuable metals in difficult-to-treat ores. The use of sulfation roasting technology effectively solves the problem of target metal extraction rate in complex and difficult-to-treat polymetallic ores, but some impurities in the ore can easily form eutectic compounds during high-temperature acidolysis, causing mineral inclusion and material caking. On the one hand, this reduces the extraction rate of target metals, and on the other hand, it causes scabbing and ring formation in the rotary kiln during engineering production, resulting in discontinuous production.

[0004] To address the aforementioned issues, Chinese patent CN111411219A discloses a method and apparatus for low-temperature acid roasting of rare earth concentrates. This method employs an external constant-temperature mixer for material mixing, followed by adding the mixture to a rotary acidifier for acidification. A portion of the rare earth acidified clinker generated during the acidification reaction is returned to the feed end of the indirect-heated rotary acidifier via a reverse conveying structure to mix with the raw acid material, thus resolving the scaling and ring formation issues at the feed end of the cylinder. However, its drawbacks include the continued use of a rotary acidification device, which limits the equipment's processing capacity due to its limited loading capacity; and the adoption of an external circulation return system, resulting in a large material conveying volume and high power and heat consumption. Chinese patent CN104988330A discloses a continuous production method for solidifying, crushing, and maturing sulfation roasting slag. The method involves mixing sulfation roasting slag with a sulfuric acid solution, solidifying the mixture on a first conveyor belt, crushing the solidified material by rolling it down an inclined plate, and then naturally drying the crushed solidified material on a second conveyor belt. The dried solidified material is then fed into a third conveyor belt for maturation to obtain the maturated material. This method solves the problems of long production time and large space requirements associated with traditional gold concentrate technologies. However, this method suffers from issues such as a relatively low maturation temperature (80–120℃) and the continued presence of agglomerates in the maturate. Summary of the Invention

[0005] In view of this, the purpose of this invention is to provide a high-temperature acid leaching apparatus and method for uranium-containing polymetallic silicate ores. Using the high-temperature acid leaching apparatus provided by this invention for high-temperature acid leaching of uranium-containing polymetallic silicate ores results in low energy consumption, large processing capacity, no "overflow" phenomenon during the slurry preparation process, short acid leaching time, and reduced agglomeration during high-temperature acid leaching.

[0006] To achieve the above-mentioned objectives, the present invention provides the following technical solution:

[0007] This invention provides a high-temperature acid leaching apparatus for uranium-containing polymetallic silicate ores, comprising:

[0008] Metering screw conveyor 2;

[0009] A slurry preparation tank 3 is connected to the outlet of the metering screw conveyor 2. The slurry preparation tank 3 includes a mixing tank, and the mixing tank is equipped with a stirrer and an acid spraying system 3-3. The stirrer includes a stirring shaft, an I-shaped paddle 3-1 connected to the top of the stirring shaft, and a propeller 3-2 connected to the bottom of the stirring shaft. The top of the slurry preparation tank 3 is provided with a mineral powder inlet and an acid feed pipe, the acid feed pipe being connected to the acid spraying system 3-3. The bottom of the slurry preparation tank 3 is provided with a slurry outlet.

[0010] A solidification unit 5 in communication with the slurry outlet of the slurry preparation tank 3, the solidification unit 5 comprising a barrel, a spiral distribution pipe 5-1 and a stirring device arranged in the barrel, the stirring device 5-2 comprising a set of counter-rotating hollow heating shafts and hollow paddles in communication with the holes in the hollow heating shafts, the solidification unit 5 further being provided with a discharge pipe 5-3; the spiral distribution pipe 5-1 being provided with more than three discharge outlets; the barrel further being provided with an outer shell jacket;

[0011] A high-temperature acidolysis device 6 in communication with the discharge pipe 5-3 of the solidification unit 5, the high-temperature acidolysis device 6 comprising N acidolysis units connected in series; each acidolysis unit having the same structure as the solidification unit 5; adjacent two acidolysis units being in communication through a discharge pipe, the Nth acidolysis unit being provided with a discharge outlet; the value of N being ≥ 2;

[0012] A heating system 8 in communication with the solidification unit 5 and each acidolysis unit, respectively, the heating system 8 comprising a heating medium, the heating medium flowing in the outer shell jacket of the solidification unit 5 and each acidolysis unit, the holes in the hollow heating shafts and the hollow paddles.

[0013] Preferably, the height-diameter ratio of the slurry preparation tank 3 is 2-3.5:1;

[0014] The diameter ratio of the propeller 3-2 to the stirring tank is 0.3-0.5:1;

[0015] The height ratio of the I-shaped paddle 3-1 to the material height in the stirring tank is 0.3-1:1, the length ratio of the I-shaped paddle 3-1 to the diameter of the stirring tank is 0.6-0.8:1; the installation height of the I-shaped paddle 3-1 to the distance from the top of the stirring tank is 0.3-0.5 m.

[0016] Preferably, the value of N is an integer between 2 and 5;

[0017] The number of discharge outlets provided on the spiral distribution pipe 5-1 is 3-10;

[0018] The height ratio of the discharge pipe 5-3 to the solidification unit 5 is 0.7-0.8:1.

[0019] Preferably, the heating medium of the heating system 8 comprises heat-conducting oil, hot air or steam, and the temperature of the heating medium is 200-450℃;

[0020] The flow mode of the heating medium comprises parallel flow, counter flow or single control;

[0021] The parallel flow is that the heating medium sequentially passes through the solidification unit 5, the first acidolysis unit and the Nth acidolysis unit;

[0022] The countercurrent type is that the heating medium sequentially passes through the N-th acidolysis unit to the first acidolysis unit and the solidification unit 5;

[0023] The single-control type is that the heating medium respectively enters the solidification unit 5, the first acidolysis unit to the N-th acidolysis unit.

[0024] Preferably, the high-temperature acidolysis device further comprises a feeding screw 4, which is in communication with the slurry outlet of the slurry preparation tank 3 and the feeding port of the solidification unit 5, respectively.

[0025] Preferably, the high-temperature acidolysis device further comprises a tail gas treatment device 7, which is in communication with the solidification unit 5.

[0026] The application provides a high-temperature acidolysis method for uranium-containing polymetallic silicate ore, which is performed by using the high-temperature acidolysis device.

[0027] The first part of concentrated sulfuric acid is added to the slurry preparation tank 3 through the acid feeding pipe and the acid spraying system 3-3, and the uranium-containing polymetallic silicate concentrate powder is added to the slurry preparation tank 3 through the mineral powder inlet and the metering screw conveyor 2 under the first stirring condition, and the second part of concentrated sulfuric acid is added through the acid spraying system 3-3, and the remaining concentrated sulfuric acid is added through the acid spraying system 3-3 after the addition of the uranium-containing polymetallic silicate concentrate powder is completed, and then the mixture is stirred, and then the slurry is obtained by aging under the second stirring condition.

[0028] The slurry is transported to the solidification unit 5, and the solidification is performed under the third stirring condition to obtain the solidified material.

[0029] The solidified material is fed into the high-temperature acidolysis device 6 through the discharging pipe 5-3 to perform N-stage high-temperature acidolysis, and the uranium-containing polymetallic silicate ore high-temperature acidolysis material is obtained; the temperature of each stage of high-temperature acidolysis is independently greater than or equal to 180 DEG C.

[0030] The heat of the solidification and acidolysis is provided by the heating system 8.

[0031] Preferably, the mass ratio of the uranium-containing polymetallic silicate concentrate powder to the total amount of concentrated sulfuric acid is 1:0.6-2.

[0032] The first part of concentrated sulfuric acid accounts for 50-80% of the total mass of the total concentrated sulfuric acid, the second part of concentrated sulfuric acid accounts for 10-40% of the total mass of the total concentrated sulfuric acid, and the remaining concentrated sulfuric acid accounts for 10-20% of the total mass of the total concentrated sulfuric acid.

[0033] The mass concentration of the concentrated sulfuric acid is 90-98%.

[0034] The feeding time of the uranium-containing polymetallic silicate concentrate powder is 20-40 min.

[0035] The adding time of the remaining concentrated sulfuric acid is 5-20 min.

[0036] The rotating speed of the first stirring is 350-600 rpm, and the mixing time is 5-20 min.

[0037] The temperature of the ripening is 40-80℃, the time is 0.5-3 h, and the second stirring speed is 50-300 rpm.

[0038] Preferably, the temperature of the solidification unit 5 is 180-260℃, and the solidification time is 3-20 min.

[0039] The mass ratio of the slurry added into the solidification unit 5 to the solidified hot dry material existing in the solidification unit 5 is preferably 0.1-0.4:1.

[0040] Preferably, the temperature of each high-temperature acidolysis of the N segments is independently 180-300℃, the time of each high-temperature acidolysis is independently 5-240 min, and the temperature difference of the material between the inlet and the outlet of each acidolysis unit is independently <10℃.

[0041] The particle size of the high-temperature acidolysis material of the uranium-containing polymetallic silicate ore is ≤3 mm.

[0042] The high-temperature acidolysis device for the uranium-containing polymetallic silicate ore provided by the present application is used for high-temperature acidolysis of the uranium-containing polymetallic silicate ore, and through the functional structure design of the slurry preparation tank 3 and the process control of the segmented and batched addition of the material, the risk of slurry tanking is reduced, and the time of slurry preparation is shortened; the reaction heat and the dilution heat are utilized to make the material ripen in the stirring tank, so that the energy consumption is reduced, and the reaction time of the subsequent high-temperature acidolysis process is shortened. The solidification and high-temperature acidolysis process of the slurry are carried out in the paddle stirring type equipment, through the optimized design of the process and the equipment structure, and through the comprehensive adoption of the multi-point feeding (three or more than three discharge outlets arranged on the spiral feeding pipe 5-1), the paddle stirring, and the paddle coupling self-cleaning process and equipment structure, the rapid solidification of the slurry is realized, and the technical problems of material caking and scarring are effectively solved. The rapid solidification and high-temperature acidolysis equipment modules of the slurry of the uranium-containing polymetallic silicate ore after ripening are connected in series, the fine control of the high-temperature acidolysis process is realized, the energy consumption is reduced, the amount of waste gas generated in the acidolysis process is reduced, and the equipment floor area is saved. BRIEF DESCRIPTION OF DRAWINGS

[0043] Fig. 1 It is a structural schematic diagram of the high-temperature acidolysis device for the uranium-containing polymetallic silicate ore.

[0044] Fig. 2 It is a structural schematic diagram of the solidification unit.

[0045] Figs. 1-2In the figure, 1 is a bunker, 2 is a metering screw conveyor, 3 is a slurry preparation tank, 3-1 is an I-shaped paddle, 3-2 is a propeller, 3-3 is an acid spraying system, 4 is a feeding screw, 5 is a solidification unit, 5-1 is a spiral distribution pipe, 5-2 is a stirring device, 5-3 is a discharging pipe, 6 is a high-temperature acidolysis device, 6-1 is a first acidolysis unit, 6-2 is a second acidolysis unit, 6-3 is a third acidolysis unit, 6-4 is a fourth acidolysis unit, 6-5 is a fifth acidolysis unit, 7 is a tail gas treatment device, and 8 is a heating system. DETAILED DESCRIPTION

[0046] The application provides a high-temperature acidolysis device for uranium-containing polymetallic silicate ore, which comprises the following components:

[0047] a metering screw conveyor 2;

[0048] a slurry preparation tank 3 in communication with the outlet of the metering screw conveyor 2, wherein the slurry preparation tank 3 comprises a stirring tank, a stirrer and an acid spraying system 3-3 arranged in the stirring tank; the stirrer comprises a stirring shaft, an I-shaped paddle 3-1 connected to the top of the stirring shaft, and a propeller 3-2 connected to the bottom of the stirring shaft; the top of the slurry preparation tank 3 is provided with a mineral powder inlet and an acid feeding pipe, the acid feeding pipe is in communication with the acid spraying system 3-3, and the bottom of the slurry preparation tank 3 is provided with a slurry outlet;

[0049] a solidification unit 5 in communication with the slurry outlet of the slurry preparation tank 3, wherein the solidification unit 5 comprises a cylinder, a spiral distribution pipe 5-1 and a stirring device 5-2 arranged in the cylinder, the stirring device comprises a group of hollow heating shafts rotating in opposite directions and hollow paddles 5-2 in communication with the holes in the hollow heating shafts, and the solidification unit 5 is further provided with a discharging pipe 5-3; the spiral distribution pipe 5-1 is provided with more than three discharge ports; the cylinder is further provided with an outer shell jacket;

[0050] a high-temperature acidolysis device 6 in communication with the discharging pipe 5-3 of the solidification unit 5, wherein the high-temperature acidolysis device 6 comprises N acidolysis units connected in series; each acidolysis unit has the same structure as the solidification unit 5; adjacent two acidolysis units are in communication through a discharging pipe, and the Nth acidolysis unit is provided with a discharge port; the value of N is greater than or equal to 2;

[0051] a heating system 8 in communication with the solidification unit 5 and each acidolysis unit, respectively, wherein the heating system 8 comprises a heating medium, and the heating medium flows in the outer shell jacket of the solidification unit 5 and each acidolysis unit, the holes in the hollow heating shafts and the hollow paddles.

[0052] Fig. 1 a high-temperature acidolysis device structure diagram for uranium-containing polymetallic silicate ore, Fig. 2For the details of the solidification unit, the following is combined with Figs. 1-2 The high-temperature acidolysis device for uranium-containing polymetallic silicate ore is described in detail.

[0053] The high-temperature acidolysis device for uranium-containing polymetallic silicate ore provided by the present application comprises a metering screw conveyor 2, which is used to meter the uranium-containing polymetallic silicate ore powder delivered into a slurry preparation tank 3.

[0054] The high-temperature acidolysis device for uranium-containing polymetallic silicate ore provided by the present application preferably further comprises an ore bin 1, and the outlet of the ore bin 1 is communicated with the metering screw conveyor 2.

[0055] The high-temperature acidolysis device for uranium-containing polymetallic silicate ore provided by the present application comprises a slurry preparation tank 3, which comprises a stirring tank, and a stirrer and an acid spraying system 3-3 are arranged in the stirring tank; the stirrer comprises a stirring shaft, a I-shaped paddle 3-1 connected to the top of the stirring shaft, and a propeller 3-2 connected to the bottom of the stirring shaft; the top of the slurry preparation tank 3 is provided with an ore powder inlet and an acid feeding pipe, the acid feeding pipe is communicated with the acid spraying system 3-3, and the bottom of the slurry preparation tank 3 is provided with a slurry outlet; the ore powder inlet is communicated with the outlet of the metering screw conveyor 2. In the present application, the bottom of the slurry preparation tank 3 is preferably further provided with a valve, when the valve is opened, the slurry flows out through the slurry outlet; the opening degree of the valve is preferably 30-100%, more preferably 40-60%, and the present application controls the slurry outflow speed by controlling the opening degree of the valve. In the present application, the height-diameter ratio of the slurry preparation tank 3 is preferably 2-3.5:1, more preferably 2.5-3:1; the diameter ratio of the propeller 3-2 to the stirring tank is preferably 0.3-0.5:1, more preferably 0.4-0.5:1; the height ratio of the I-shaped paddle 3-1 to the material height in the stirring tank is preferably 0.3-1:1, more preferably 0.5-0.8:1; the length ratio of the I-shaped paddle 3-1 to the diameter of the stirring tank is preferably 0.6-0.8:1, more preferably 0.7-0.8:1; the distance between the installation height of the I-shaped paddle 3-1 and the top of the stirring tank is preferably 0.3-0.5 m, more preferably 0.3-0.4 m, and further preferably 0.3-0.35 m; the installation height of the I-shaped paddle 3-1 is preferably above the material liquid level in the stirring tank, and the I-shaped paddle 3-1 is used for defoaming.

[0056] The slurry preparation tank 3 is used for ripening in the present application, which can effectively eliminate the problem of foam overflowing in the slurry preparation stage, and ripen the material by using the reaction heat and the dilution heat of concentrated sulfuric acid, thereby shortening the subsequent high-temperature acidolysis time.

[0057] The high-temperature acidolysis device for uranium-containing polymetallic silicate ore provided by the application preferably further comprises a feeding screw 4 in communication with the slurry outlet of the slurry preparation tank 3 and the feeding inlet of the solidification unit 5, respectively, and the speed and amount of the slurry entering the solidification unit 5 are controlled by controlling the opening degree of the valve and the rotating speed of the feeding screw 4. In the application, the rotating speed of the feeding screw 4 is preferably 10-120 rpm, more preferably 30-80 rpm, and particularly preferably 30 rpm, 50 rpm and 80 rpm.

[0058] The high-temperature acidolysis device for uranium-containing polymetallic silicate ore provided by the application comprises a solidification unit 5, which comprises a barrel, a spiral feeding pipe 5-1 and a stirring device 5-2 arranged in the barrel, the stirring device 5-2 comprises a group of hollow heating shafts rotating in opposite directions and hollow paddles in communication with the middle holes of the hollow heating shafts, and the number of the group is preferably 2; the solidification unit 5 is further provided with a discharging pipe 5-3, and the height ratio of the discharging pipe 5-3 to the solidification unit 5 is preferably 0.7-0.8:1, more preferably 0.75-0.8:1; the spiral feeding pipe 5-1 is provided with more than three discharge outlets, and the number of the discharge outlets is preferably 3-10, and particularly preferably 3, 4, 5, 6, 7, 8, 9 or 10; the barrel is further provided with an outer shell jacket and a feeding inlet, and the feeding inlet is in communication with the slurry outlet of the slurry preparation tank 3. In the application, the material level height in the solidification unit 5 can be adjusted by adjusting the height of the discharging pipe 5-3. In the application, the hollow heating shafts are preferably double helical shafts. In the application, the shape of the hollow paddles 5-2 is preferably wedge-shaped. In the application, the stirring device preferably consists of two hollow paddles rotating in opposite directions, the rotation of the hollow paddles can stir the slurry, strengthen the heat transfer effect of the material, and at the same time, the solidified material can be crushed and finely ground; the heating medium can enter the hollow paddles through the middle holes of the hollow stirring shafts with middle holes to heat the slurry; the barrel has a double-layer structure, and the heating medium is introduced into the outer shell jacket to heat the slurry, so that the slurry is rapidly solidified. The device provided by the application comprehensively adopts the processes and equipment structures of multi-point feeding, paddle stirring, wedge-shaped paddle coupling self-cleaning, etc., realizes the rapid solidification of the slurry, and effectively solves the technical problems of material caking and scarring.

[0059] The high-temperature acidolysis device for uranium-containing polymetallic silicate ore provided by the present application comprises a high-temperature acidolysis device 6, the feed inlet of the high-temperature acidolysis device 6 is communicated with the discharging pipe 5-3 of the solidification unit 5, the high-temperature acidolysis device 6 comprises N acidolysis units in series, the value of N is greater than or equal to 2, more preferably an integer between 2 and 5, and specifically preferably 2, 3, 4 or 5; the structure of each acidolysis unit is the same as that of the solidification unit 5; adjacent two acidolysis units are communicated through a discharging pipe, and the Nth acidolysis unit is provided with a discharge port. In the present application, the high-temperature acidolysis device 6 is stacked below the solidification unit 5. In the present application, the height ratio of the discharging pipe to the acidolysis unit is preferably 0.7-0.8:1, and more preferably 0.75-0.8:1. In the present application, when the material in the acidolysis unit falls to one end of the lower acidolysis unit higher than the height of the discharging pipe, it is stirred and pushed to the other end of the discharge port by the paddle, and so on, and the material is discharged from the discharge port of the Nth (the last) acidolysis unit after acidolysis. In the high-temperature acidolysis process using the high-temperature acidolysis device provided by the present application, the stirring and rotating action of the paddle strengthens the mixing and heat transfer effect of the material, and shortens the traditional acidolysis time by 5-10%. The high-temperature acidolysis device of the present application uses an indirect heating method (the heating medium does not contact the material) in the acidolysis process of uranium-containing polymetallic silicate ore, produces less tail gas and carries less dust, saves tail gas treatment cost and reduces tail gas heat loss.

[0060] The high-temperature acidolysis device for uranium-containing polymetallic silicate ore provided by the present application preferably further comprises a tail gas treatment device 7, which is communicated with the solidification unit 5. In the present application, according to the flow direction of the tail gas, the tail gas treatment device preferably comprises a top bag-type dust collector, a tail gas absorption tower, a draft fan and a chimney communicated in sequence.

[0061] The high-temperature acidolysis apparatus for uranium-containing polymetallic silicate ore provided by the present invention further includes a heating system 8, which is connected to the solidification unit 5 and each acidolysis unit. The heating system 8 includes a heating medium that flows in the outer jacket, the central hole of the hollow heating shaft, and the hollow blades of the solidification unit 5 and each acidolysis unit. In the present invention, the heating medium preferably includes heat transfer oil, hot air, or steam; the temperature of the heating medium is preferably 200–450°C, more preferably 250–400°C, and even more preferably 300–350°C. In the present invention, the flow mode of the heating medium includes parallel flow, counter-flow, or single-controlled flow. In the present invention, the parallel flow is preferably where the heating medium sequentially passes through the solidification unit 5, the first acidolysis unit, and the Nth acidolysis unit. Taking N=5 as an example, the heating medium sequentially passes through the solidification unit 5, the first acidolysis unit 6-1, the second acidolysis unit 6-2, the third acidolysis unit 6-3, the fourth acidolysis unit 6-4, and the fifth acidolysis unit 6-5. In this invention, the counter-current type is preferably where the heating medium sequentially passes through the Nth acidolysis unit to the first acidolysis unit and the curing unit 5. Taking N=5 as an example, the heating medium sequentially passes through the fifth acidolysis unit 6-5, the fourth acidolysis unit 6-4, the third acidolysis unit 6-3, the second acidolysis unit 6-2, the first acidolysis unit 6-1, and the curing unit 5. In this invention, the single-control type involves the heating medium entering the curing unit 5, the first acidolysis unit, and then the Nth acidolysis unit. Taking N=5 as an example, the heating medium enters the curing unit 5, the first acidolysis unit 6-1, the second acidolysis unit 6-2, the third acidolysis unit 6-3, the fourth acidolysis unit 6-4, and the fifth acidolysis unit 6-5.

[0062] This invention provides a high-temperature acid leaching method for uranium-containing polymetallic silicate ores, which utilizes the high-temperature acid leaching apparatus described above and includes the following steps:

[0063] The first part of concentrated sulfuric acid is added to the slurry preparation tank 3 through the acid feeding pipe and the acid spraying system 3-3. Under the first stirring condition, the uranium-containing polymetallic silicate concentrate powder is added to the slurry preparation tank 3 through the mineral powder inlet via the metering screw conveyor 2. At the same time, the second part of concentrated sulfuric acid is added through the acid spraying system 3-3. After the uranium-containing polymetallic silicate concentrate powder is added, the remaining concentrated sulfuric acid is added through the acid spraying system 3-3 and stirred and mixed. Then, under the second stirring condition, it is matured to obtain the slurry.

[0064] The slurry is transported to the curing unit 5 and cured under the third stirring condition to obtain a cured material;

[0065] The solidified material is fed into the high-temperature acid hydrolysis device 6 through the feed pipe 5-3 for N-stage high-temperature acid hydrolysis to obtain uranium-containing polymetallic silicate ore high-temperature acid hydrolysis material; the temperature of each stage of high-temperature acid hydrolysis is independently ≥180℃;

[0066] The heat of the solidification and acidolysis is provided by the heating system 8.

[0067] In the present application, the materials and equipment used are commercially available in the art, unless otherwise specified.

[0068] In the present application, the first part of concentrated sulfuric acid is added into the slurry preparation tank 3 through the acid spraying system 3-3, and the uranium-containing polymetallic silicate concentrate powder is added into the slurry preparation tank 3 through the metering screw conveyor 2 under the first stirring condition, while the second part of concentrated sulfuric acid is added through the acid spraying system 3-3, and after the addition of the uranium-containing polymetallic silicate concentrate powder is completed, the remaining concentrated sulfuric acid is added through the acid spraying system 3-3 for stirring and mixing, and then the slurry is obtained under the second stirring condition.

[0069] In the present application, the uranium-containing polymetallic silicate concentrate powder is not particularly limited, and any uranium-containing polymetallic silicate concentrate powder known to those skilled in the art can be used, such as bastnaesite and mix-type rare earth concentrate, silicate uranium rare earth, uranium beryllium, and uranium niobium polymetallic ore. In the specific embodiments of the present application, the uranium-containing polymetallic silicate concentrate powder includes rare earth concentrate powder containing hydroxylsilicate beryllium yttrium, bastnaesite, and monazite minerals (the uranium grade is preferably 0.085wt%, and the rare earth oxide content is preferably 26wt%), or uranium-containing beryllohydroxylsilicate concentrate powder (the uranium content is preferably 0.156wt%, the rare earth oxide content is preferably 8wt%, and the beryllium oxide content is preferably 9.8wt%), or uranium-containing niobium rare earth polymetallic concentrate powder containing monazite, bastnaesite, and niobite minerals (the uranium content is preferably 0.108wt%, the rare earth oxide content is preferably 4.8wt%, and the niobium pentoxide content is preferably 3.5wt%). In the present application, the particle size of the uranium-containing polymetallic silicate concentrate powder is preferably 0.035-0.15mm, and more preferably 0.074-0.1mm.

[0070] In the present application, the mass ratio of the total amount of the uranium-containing polymetallic silicate concentrate powder to concentrated sulfuric acid is preferably 1:0.6-2, more preferably 1:0.8-1.5, and specifically preferably 1:0.6, 1:1.0, or 1:1.2.

[0071] In the present application, the first part of concentrated sulfuric acid preferably accounts for 50-80% of the total mass of the total concentrated sulfuric acid, more preferably 50%, 70% or 80%; the second part of concentrated sulfuric acid accounts for 10-40% of the total mass of the total concentrated sulfuric acid, more preferably 10%, 15% or 40%; and the remaining concentrated sulfuric acid accounts for 10-20% of the total mass of the total concentrated sulfuric acid, more preferably 10-15%, and more preferably 10% or 15%. In the present application, the mass concentration of the concentrated sulfuric acid is preferably 90-98%, and more preferably 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97% or 98%.

[0072] In the present application, the rotation speed of the first stirring is preferably 350-600 rpm, more preferably 400-550 rpm, and more preferably 450-500 rpm.

[0073] In the present application, the feeding time of the uranium-containing polymetallic silicate concentrate powder and the second part of concentrated sulfuric acid is the same, and is preferably 20-40 min, more preferably 25-40 min, and more preferably 25 min or 40 min.

[0074] In the present application, the addition time of the remaining concentrated sulfuric acid is preferably 5-20 min, more preferably 10-20 min, and more preferably 15-20 min.

[0075] In the present application, the stirring and mixing time is preferably 5-20 min, more preferably 10-20 min, and more preferably 15-20 min; and the stirring and mixing rotation speed is preferably 350-600 rpm, more preferably 400-550 rpm, and more preferably 450-500 rpm.

[0076] In the present application, the temperature of the ripening is preferably 40-80°C, more preferably 50-70°C, and more preferably 60°C; the ripening time is preferably 0.5-3 h, more preferably 1-2.5 h, and more preferably 1.5-2 h; and the second stirring speed during the ripening is preferably 50-300 rpm, more preferably 100-250 rpm, and more preferably 100-200 rpm.

[0077] After obtaining the slurry, the present application delivers the slurry to the solidification unit 5 for solidification under the third stirring condition to obtain a solidified material; and the heat for the solidification is provided by the heating system 8.

[0078] In the present application, the mass ratio of the slurry added into the solidification unit 5 to the solidified hot dry material existing in the solidification unit 5 is preferably 0.1-0.4:1, more preferably 0.2-0.3:1. In the present application, when the high-temperature acidolysis device for uranium-containing polymetallic silicate ore is initially operated, part of the ore powder is first added into the solidification unit 5, then the slurry is input, and the slurry is solidified in the solidification unit 5 to form the solidified hot dry material; after the material is higher than the discharge pipe 5-3, the solidification unit 5 is basically filled with the solidified hot dry material, and then the feeding valve of the slurry is opened to normally input the slurry. In the present application, the addition amount of the part of the ore powder is preferably at the position where the mass ratio of the slurry added into the solidification unit 5 to the solidified hot dry material existing in the solidification unit 5 is 0.1-0.4:1. In the present application, the height of the material layer in the solidification unit 5 is adjusted by controlling the height of the discharge pipe 5-3, and then the storage amount of the material in the solidification unit 5 is controlled to adjust the height of the solidified hot dry material in the solidification unit 5 (that is, the storage amount of the solidified hot dry material in the solidification unit 5 is controlled), and at the same time, the addition flow of the slurry is controlled by the feeding screw 4 to realize the mass ratio of the slurry to the solidified material, and then to ensure that the addition amount of the wet slurry matches the amount of the solidified hot dry material existing in the solidification unit 5, and to ensure that the slurry is mixed with the solidified hot dry material and quickly solidified. Moreover, the present application realizes the dispersion of feeding through the three or more discharge ports arranged on the discharge pipe 5-3, and realizes the rapid mixing and solidification through the addition of medium and stirring.

[0079] In the present application, the temperature of the solidification unit 5 is preferably 180-260℃, more preferably 200-260℃, and further preferably 230-260℃; the solidification time is preferably 3-20min, more preferably 10-18min; and the rotation speed of the third stirring is preferably 10-150rpm, more preferably 20-80rpm.

[0080] After the solidification, the present application preferably further includes tail gas treatment of the solidification tail gas obtained by the solidification, and the tail gas treatment preferably includes dust removal through a top bag-type dust remover, absorption through a tail gas absorption tower, and discharge through a chimney by an induced draft fan after reaching the standard.

[0081] After obtaining the solidified material, the present application inputs the solidified material into the high-temperature acidolysis device 6 through the discharge pipe 5-3 to perform N-stage high-temperature acidolysis, and obtains high-temperature acidolysis material of uranium-containing polymetallic silicate ore; and the heat of the acidolysis is provided by the heating system 8.

[0082] In the present application, the temperature of each high-temperature acidolysis in the N-stage high-temperature acidolysis is independently ≥180℃, preferably 180-300℃, and more preferably 200-250℃; and the time of each high-temperature acidolysis is independently preferably 5-240min, more preferably 10-100min, and specifically preferably 30min, 50min or 90min. In the present application, the temperature difference of the material at the inlet and the outlet of each acidolysis unit is independently <10℃.

[0083] In the present application, the particle size of the uranium-containing polymetallic silicate ore high-temperature acidolysis material is preferably ≤3 mm, more preferably ≤2.5 mm.

[0084] In order to further illustrate the present application, the high-temperature acidolysis device and method of the uranium-containing polymetallic silicate ore are described in detail below in conjunction with the accompanying drawings and examples, but they should not be understood as limiting the scope of protection of the present application.

[0085] Example 1

[0086] The uranium-containing polymetallic silicate ore is a rare earth concentrate containing hydroxyl-silicate beryllium yttrium, fluorocarbon cerium, monazite and other minerals, with a uranium grade of 0.085wt% and a rare earth oxide content of 26wt%.

[0087] (1) Slurry preparation and ripening: The slurry preparation and ripening are carried out in the slurry preparation tank 3. The height-diameter ratio of the slurry preparation tank 3 is 3.5:1; the lower part of the stirring shaft of the stirrer is connected to the propeller 3-2, and the diameter of the propeller 3-2 is 0.3 times the diameter of the stirring tank; the upper part of the stirring shaft is connected to the I-shaped slurry 3-1, and the height of the I-shaped slurry 3-1 is 0.8 times the height of the slurry layer in the stirring tank, the length is 0.6 times the diameter of the stirring tank, and the installation height is above the final liquid surface, 0.5m from the top of the tank. Uranium-containing polymetallic silicate ore powder (particle size 0.035-0.15mm) and concentrated sulfuric acid (mass concentration 90wt%) are prepared into a slurry in a mass ratio of 1:1.2. First, add concentrated sulfuric acid to the slurry preparation tank through the acid feeding pipe, and the amount of concentrated sulfuric acid added is 50wt% of the total amount of concentrated sulfuric acid. After the addition of concentrated sulfuric acid is completed, the stirring is started. The uranium-containing rare earth polymetallic ore powder in the ore bin 1 is added to the slurry preparation tank 3 through the metering screw conveyor 2, and the remaining 40wt% of the total amount of concentrated sulfuric acid is added through the acid spraying system 3-3 in a spraying manner; the feeding time of the ore powder is controlled within 40min, and the stirring speed during the feeding process is 600rpm. After the feeding of the ore powder is completed, the stirring speed is 500rpm, and the remaining concentrated sulfuric acid is continuously added by spraying, and the addition time is 20min; after the addition of concentrated sulfuric acid is completed, the stirrer continues to stir at a speed of 500rpm for 20min; then, the stirring speed is adjusted to 150rpm, and the ripening is carried out for 3h. During the slurry preparation and ripening stage, the reaction heat and the dilution heat of concentrated sulfuric acid can keep the slurry temperature at 80℃.

[0088] (2) Slurry rapid solidification: The solidification unit 5 is composed of a stirring device 5-2 and a cylinder. The stirring device 5-2 is composed of two counter-rotating hollow heating shafts and two hollow wedge-shaped paddles in communication with the middle holes of the hollow heating shafts. The rotation of the hollow wedge-shaped paddles can stir the slurry, strengthen the material heat transfer effect, and at the same time can crush and finely grind the solidified material. The rotation speed of the hollow wedge-shaped paddles is 20 rpm. The heating medium can enter the hollow paddles through the hollow heating shafts to heat the slurry. The cylinder has a double-layer structure, and the heating medium can also be introduced into the jacket to heat the slurry.

[0089] After the slurry is matured, the bottom valve of the slurry preparation tank 3 is opened, the slurry is added into the solidification unit 5 through the feeding screw 4 and the spiral distribution pipe 5-1 (5 feeding points are provided), the opening degree of the valve is controlled at 60%, and the rotation speed of the feeding screw 4 is 30 rpm, so that the mass ratio of the wet slurry to the solidified hot dry material in the solidification unit 5 is 0.2. The wet slurry is contacted and mixed with the high-temperature solid (i.e. the solidified hot dry material) to realize rapid solidification. The temperature of the heating medium is 300°C, the feeding speed is controlled to ensure that the temperature of the rapid solidification unit 5 is 260°C, and the material solidification time is 10 min.

[0090] (3) High-temperature acidolysis: The high-temperature acidolysis device 6 is provided with two layers of acidolysis units (6-1 and 6-2). The structure of each layer of acidolysis unit is the same as that of the solidification unit 5 and is stacked below the solidification unit 5. The solidification unit 5, the first acidolysis unit 6-1 and the second acidolysis unit are connected through the internal discharge pipe of the equipment, and the height of the discharge pipe is 0.8 times the height of the unit equipment. The upper material falls to one end of the lower acidolysis unit and is stirred and slowly pushed to the discharge port at the other end by the stirring device. In this way, the final reaction material is discharged from the discharge port of the last high-temperature acidolysis unit 6-2. The residence time of the material in each section is adjusted by the feeding speed and the rotation speed of the screw, and the single-section residence time is 1.5 h. The temperature of the high-temperature acidolysis material is controlled at 250°C.

[0091] Due to the stirring and rotation of the stirring device in the high-temperature acidolysis process, the mixing and heat transfer effect of the material are strengthened, the acidolysis process time is shortened by 10%, the decomposition rates of uranium and rare earth in the uranium-containing polymetallic silicate ore are 86% and 98% respectively, and the material discharge particle size is-2.5 mm.

[0092] The heating medium is selected as heat-conducting oil, the temperature of the heating medium is 320°C, and the heating medium adopts a parallel flow type: sequentially passing through the solidification unit 5, the first acidolysis unit 6-1 and the second acidolysis unit 6-2.

[0093] The slurry solidification and high-temperature acidolysis tail gas is treated by the equipment top bag-type dust collector-tail gas absorption tower-induced draft fan-chimney to meet the emission standard.

[0094] Example 2

[0095] A uranium-containing hydroxyl-silicon beryl ore concentrate with a uranium content of 0.156 wt%, a rare earth oxide content of 8 wt%, and a beryllium oxide content of 9.8 wt%.

[0096] (1) Slurry preparation and maturation: The slurry preparation and maturation are performed in a slurry preparation tank 3. The height-diameter ratio of the slurry preparation tank 3 is 2:1; the lower part of the stirring shaft of the stirrer is connected to a propeller 3-2, and the diameter of the propeller 3-2 is 0.4 times the diameter of the stirring tank; the upper part of the stirring shaft adopts an I-shaped paddle 3-1, the height of the I-shaped paddle 3-1 is 0.5 times the height of the slurry layer in the stirring tank, the length is 0.8 times the diameter of the stirring tank, and the installation height is above the final liquid level, 0.3 m from the top of the tank. Uranium-containing polymetallic silicate ore powder (particle size of 0.035-0.15 mm) and concentrated sulfuric acid (mass concentration of concentrated sulfuric acid is 92 wt%) are prepared into a slurry according to a mass ratio of ore to acid of 1:1.0. First, add concentrated sulfuric acid into the slurry preparation tank through the acid feeding pipe, and the amount of concentrated sulfuric acid added is 70 wt% of the total amount of concentrated sulfuric acid. After the addition of concentrated sulfuric acid is completed, the stirring is started. The uranium-containing rare earth polymetallic ore powder in the ore bin 1 is added into the slurry preparation tank 3 through the metering screw conveyor 2, and at the same time, 15 wt% of the total amount of concentrated sulfuric acid is added in the form of spraying through the acid spraying system 3-3. The feeding time of the ore powder is controlled to be 25 min, and the stirring speed during the feeding process is 550 rpm. After the feeding of the ore powder is completed, the stirring speed is 550 rpm, and the remaining concentrated sulfuric acid is continuously added by spraying, and the addition time is 10 min. After the addition of concentrated sulfuric acid is completed, the stirrer continues to stir at a speed of 550 rpm for 10 min. Then, the stirring speed is adjusted to 300 rpm, and the maturation is performed for 1 h. During the slurry preparation and maturation stage, the reaction heat and the dilution heat of concentrated sulfuric acid can keep the slurry temperature at 60°C.

[0097] (2) Rapid solidification of the slurry: After the slurry is matured, the bottom valve of the slurry preparation tank 3 is opened, and the slurry is added into the solidification unit 5 through the feeding screw 4 and the screw distribution pipe 5-1 (provided with 3 feeding points). By controlling the valve opening degree to be 40% and the rotation speed of the feeding screw 4 to be 50 rpm, the mass ratio of the wet slurry to the solidified hot material in the solidification unit 5 is 0.1, so that the wet slurry is contacted and mixed with the high-temperature solidified material, and the stirring device rotates at a speed of 50 rpm, thereby realizing the rapid solidification. The temperature of the heating medium is 280°C, the feeding speed is controlled to ensure that the temperature of the solidification unit 5 is 230°C, and the solidification time of the material is 20 min.

[0098] (3) High temperature acidolysis: The high temperature acidolysis device 6 is provided with 5 layers of high temperature acidolysis units (6-1, 6-2, 6-3, 6-4 and 6-5), each layer of acidolysis unit has the same structure as the solidification unit 5 and is stacked below the solidification unit 5. The solidification unit 5 and the first acidolysis unit 6-1 and the acidolysis units are in communication through the internal discharge pipe of the device, and the height of the discharge pipe is 0.7 times the height of the unit device. The upper material is higher than the height of the discharge pipe and falls to one end of the lower acidolysis unit, and is stirred and slowly pushed to the discharge port at the other end by the stirring device. In this way, the material after the final reaction is discharged from the discharge port of the last high temperature acidolysis unit. The residence time of the material in each section can be adjusted by the feeding speed, screw rotation speed, etc., and the single section residence time is 30 min. The high temperature acidolysis material is controlled at 200℃.

[0099] Compared with the traditional rotary kiln device, the new method shortens the acidolysis process time by 8%, and the decomposition rates of uranium, rare earth and beryllium in the uranium-containing hydroxyl silicon beryl ore concentrate are 95%, 94% and 96%, respectively; the material discharge particle size is less than 3 mm.

[0100] The heating medium is hot air, the heating medium temperature is 450℃, and the heating medium adopts single control type: entering the solidification unit 5, the first acidolysis unit 6-1, the second acidolysis unit 6-2, the third acidolysis unit 6-3, the fourth acidolysis unit 6-4 and the fifth acidolysis unit 6-5 respectively.

[0101] The slurry solidification and high temperature acidolysis tail gas is treated by the equipment top bag type dust collector-tail gas absorption tower-induced draft fan-chimney to meet the emission standard.

[0102] Example 3

[0103] The uranium-containing niobium rare earth multi-metal concentrate containing monazite, bastnaesite, niobite and other minerals has a uranium content of 0.108wt%, a rare earth oxide content of 4.8wt%, and a niobium pentoxide niobium content of 3.5wt%.

[0104] (1) Slurry preparation and maturation: The slurry preparation and maturation were carried out in the slurry preparation tank 3. The height-diameter ratio of the slurry preparation tank 3 was 2.5:1; the lower part of the stirring shaft of the stirrer was connected with the propeller 3-2, the diameter of the propeller 3-2 was 0.5 times the diameter of the stirring tank; the upper part of the stirring shaft was connected with the I-shaped paddle 3-1, the height of the I-shaped paddle 3-1 was 0.4 times the height of the material layer in the stirring tank, the length was 0.7 times the diameter of the stirring tank, and the installation height was above the final liquid level, 0.35 m from the top of the tank. The uranium-containing polymetallic silicate ore powder (particle size 0.035-0.15 mm) was prepared into a slurry with concentrated sulfuric acid (mass concentration of concentrated sulfuric acid 95wt%) according to the mass ratio of ore to acid 1:0.6. First, the concentrated sulfuric acid was added to the slurry preparation tank 3 through the acid feeding pipe, and the amount of addition was 80wt% of the total amount of concentrated sulfuric acid. After the addition of concentrated sulfuric acid was completed, the stirring was started. The uranium-containing rare earth polymetallic ore powder in the ore bin 1 was added to the slurry preparation tank 3 through the metering screw conveyor 2, and at the same time, 10wt% of the total amount of concentrated sulfuric acid was added through the acid spraying system 3-3 in the form of spraying; the feeding time of the ore powder was 25 min, and the stirring speed during the feeding process was 400 rpm. After the feeding of the ore powder was completed, the stirring speed was maintained at 600 rpm, and the remaining concentrated sulfuric acid was continuously added by spraying, and the addition time was 20 min; after the addition of concentrated sulfuric acid was completed, the stirrer continued to stir at a speed of 600 rpm for 20 min; then, the stirring speed was adjusted to 100 rpm, and the maturation was continued for 3 h. During the slurry preparation and maturation stage, the reaction heat and the dilution heat of concentrated sulfuric acid can keep the slurry temperature at 50℃.

[0105] (2) Rapid solidification of slurry: After the maturation of the slurry, the bottom valve of the slurry preparation tank 3 was opened, and the slurry was added to the solidification unit 5 through the screw distribution pipe 5-1 (provided with 8 feeding points) by the feeding screw 4. By controlling the valve opening degree to be 40% and the rotation speed of the feeding screw 4 to be 80 rpm, the mass ratio of the wet slurry to the solidified hot material in the solidification unit 5 was 0.4, so that it was contacted and mixed with the high-temperature solidified material, and the double propeller blade rotation speed was 80 rpm, thereby realizing the rapid solidification. The temperature of the heating medium was 200℃, the feeding speed was controlled to ensure that the temperature of the solidification unit 5 was 180℃, and the material solidification time was 18 min.

[0106] (3) high-temperature acidolysis: the high-temperature acidolysis device 6 is provided with three layers of acidolysis units (6-1, 6-2 and 6-3), each layer of acidolysis unit has the same structure as the solidification unit 5 and is stacked below the solidification unit 5. The solidification unit 5 and the first acidolysis unit 6-1 and the acidolysis units are communicated through the blanking pipe inside the device, and the blanking pipe height is 0.8 times the height of the unit device. The upper layer material is higher than the blanking pipe height and falls to one end of the lower layer acidolysis unit, and is stirred and slowly pushed to the discharge port at the other end by the stirring device. In this way, the material after the final reaction is discharged from the discharge port of the last acidolysis unit 6-3. The residence time of the material in each section can be adjusted by the feeding speed and the screw rotation speed, and the single-section residence time is 50 min. The high-temperature acidolysis material is controlled at 180℃.

[0107] Compared with the traditional rotary kiln device, the acidolysis process time provided by the device and method of the application is shortened by 3%, and the decomposition rates of uranium, rare earth and niobium in the uranium-niobium rare earth multi-metal concentrate are 90%, 96% and 92%, respectively; the material discharge particle size is less than 3 mm.

[0108] The heating medium is steam, the heating medium temperature is 210℃, and the heating medium adopts the countercurrent type: sequentially passing through the third acidolysis unit 6-3, the second acidolysis unit 6-2, the first acidolysis unit 6-1 and the solidification unit 5.

[0109] The slurry solidification and high-temperature acidolysis tail gas is treated by the equipment top bag type dust collector-tail gas absorption tower-induced draft fan-chimney to meet the emission standard.

[0110] In summary, the application overcomes the shortcomings in the prior art and provides a high-temperature acidolysis method for uranium-containing polymetallic silicate ore. Through the comprehensive application of process steps and devices, fine control of the high-temperature acidolysis process is realized, the amount of waste gas generated is reduced, the energy consumption is reduced, the equipment processing capacity is improved, and technical problems such as "slagging" during slurry preparation of uranium-containing polymetallic silicate ore, long acidolysis time and easy caking during high-temperature acidolysis are solved.

[0111] Although the above embodiment has made a detailed description of the application, it is only a part of the embodiments of the application, not all the embodiments, and other embodiments can be obtained by people according to the embodiments of the application without creative labor, which belong to the protection scope of the application.

Claims

1. A high-temperature acidolysis apparatus for uranium-containing polymetallic silicate ore, comprising: Metering screw conveyor (2); A slurry preparation tank (3) is connected to the outlet of the metering screw conveyor (2). The slurry preparation tank (3) includes a mixing tank, and a stirrer and an acid spraying system (3-3) are provided inside the mixing tank. The stirrer includes a stirring shaft, an I-shaped paddle (3-1) connected to the top of the stirring shaft, and a propeller (3-2) connected to the bottom of the stirring shaft. A mineral powder inlet and an acid feed pipe are provided at the top of the slurry preparation tank (3). The acid feed pipe is connected to the acid spraying system (3-3). A slurry outlet is provided at the bottom of the slurry preparation tank (3). A curing unit (5) is connected to the slurry outlet of the slurry preparation tank (3). The curing unit (5) includes a cylinder, a spiral feeding pipe (5-1), and a stirring device (5-2) disposed inside the cylinder. The stirring device (5-2) includes a set of hollow heating shafts rotating in opposite directions and hollow blades connected to the central hole of the hollow heating shafts. The curing unit (5) is also provided with a discharge pipe (5-3). The spiral feeding pipe (5-1) is provided with more than three discharge ports. The cylinder is also provided with an outer shell jacket. A high-temperature acid hydrolysis device (6) is connected to the feed pipe (5-3) of the curing unit (5). The high-temperature acid hydrolysis device (6) includes N acid hydrolysis units connected in series. The structure of each acid hydrolysis unit is the same as that of the curing unit (5). Adjacent acid hydrolysis units are connected through feed pipes. The Nth acid hydrolysis unit is provided with a discharge port. The value of N is ≥2. A heating system (8) is connected to the curing unit (5) and each acidolysis unit respectively. The heating system (8) includes a heating medium that flows in the outer jacket of the curing unit (5) and each acidolysis unit, the central hole of the hollow heating shaft and the hollow blade.

2. The high-temperature acidolysis apparatus according to claim 1, characterized in that, The height-to-diameter ratio of the slurry preparation tank (3) is 2~3.5:1; The diameter ratio of the propeller (3-2) to the mixing tank is 0.3~0.5:1; The ratio of the height of the I-shaped paddle (3-1) to the height of the material in the mixing tank is 0.3~1:1, the ratio of the length of the I-shaped paddle (3-1) to the diameter of the mixing tank is 0.6~0.8:1, and the distance between the installation height of the I-shaped paddle (3-1) and the top of the mixing tank is 0.3~0.5m.

3. The high-temperature acidolysis apparatus according to claim 1, characterized in that, The value of N is an integer between 2 and 5; The spiral feeding tube (5-1) has 3 to 10 discharge ports. The height ratio of the feed pipe (5-3) to the curing unit (5) is 0.7~0.8:

1.

4. The high-temperature acidolysis apparatus according to claim 1, characterized in that, The heating medium of the heating system (8) includes heat transfer oil, hot air or steam, and the temperature of the heating medium is 200~450℃; The flow mode of the heating medium includes parallel flow, counterflow, or single control; The parallel flow type is where the heating medium passes sequentially through the curing unit (5), the first acidolysis unit, and the Nth acidolysis unit; The counter-current type is that the heating medium passes through the Nth acidolysis unit to the first acidolysis unit and the curing unit (5) in sequence. The single-control type means that the heating medium enters the curing unit (5), the first acidolysis unit and the Nth acidolysis unit respectively.

5. The high-temperature acidolysis apparatus according to any one of claims 1 to 4, characterized in that, The high-temperature acid hydrolysis device also includes a feeding screw (4), which is connected to the slurry outlet of the slurry preparation tank (3) and the inlet of the curing unit (5).

6. The high-temperature acidolysis apparatus according to claim 5, characterized in that, The high-temperature acid hydrolysis device also includes an exhaust gas treatment device (7); the exhaust gas treatment device (7) is connected to the curing unit (5).

7. A method for high-temperature acid leaching of uranium-containing polymetallic silicate ore, characterized in that, The process, using the high-temperature acidolysis apparatus according to any one of claims 1 to 6, includes the following steps: The first part of concentrated sulfuric acid is added to the slurry preparation tank (3) through the acid feeding pipe and the acid spraying system (3-3). Under the first stirring condition, the uranium-containing polymetallic silicate concentrate powder is added to the slurry preparation tank (3) through the mineral powder inlet via the metering screw conveyor (2). At the same time, the second part of concentrated sulfuric acid is added through the acid spraying system (3-3). After the uranium-containing polymetallic silicate concentrate powder is added, the remaining concentrated sulfuric acid is added through the acid spraying system (3-3) and stirred. Then, under the second stirring condition, it is matured to obtain the slurry. The slurry is transported to the curing unit (5) and cured under the third stirring condition to obtain a cured material; The solidified material is fed into the high-temperature acid hydrolysis device (6) through the feed pipe (5-3) for N-stage high-temperature acid hydrolysis to obtain uranium-containing polymetallic silicate ore high-temperature acid hydrolysis material; the temperature of each stage of high-temperature acid hydrolysis is ≥180℃ independently; The heat for the curing and acidification is provided by the heating system (8).

8. The method according to claim 7, characterized in that, The mass ratio of the uranium-containing polymetallic silicate concentrate powder to the total amount of concentrated sulfuric acid is 1:0.6~2; The first portion of concentrated sulfuric acid accounts for 50-80% of the total mass of concentrated sulfuric acid, the second portion of concentrated sulfuric acid accounts for 10-40% of the total mass of concentrated sulfuric acid, and the remaining concentrated sulfuric acid accounts for 10-20% of the total mass of concentrated sulfuric acid. The concentrated sulfuric acid has a mass concentration of 90-98%; The feeding time for the uranium-containing polymetallic silicate concentrate is 20-40 minutes; The remaining concentrated sulfuric acid is added over a period of 5 to 20 minutes. The first stirring speed is 350~600 rpm; the mixing time is 5~20 min; The ripening temperature is 40~80℃, the time is 0.5~3h, and the second stirring speed is 50~300rpm.

9. The method according to claim 7, characterized in that, The temperature of the curing unit (5) is 180~260℃, and the curing time is 3~20min; The mass ratio of the slurry added to the curing unit (5) to the curing heat dry material present in the curing unit (5) is 0.1~0.4:

1.

10. The method according to claim 7, characterized in that, The temperature of each of the N-stage high-temperature acid hydrolysis stages is independently 180~300℃, the time of each stage is independently 5~240min, and the material temperature difference between the inlet and outlet of each acid hydrolysis unit is independently <10℃. The particle size of the high-temperature acid hydrolysis material of the uranium-containing polymetallic silicate ore is ≤3mm.

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