A device and method for extracting phosphoric acid from high-silicon and low-phosphate ore

Abstract

The present invention discloses a device and method for extracting phosphoric acid from high-silicon and low-phosphate ore, and relates to the technical field of phosphoric acid production. The device includes an extraction tank, in which a stirring paddle is provided, and a heat transfer tube is also provided on the extraction tank. Both ends of the heat transfer tube are located in the extraction tank, and the heat transfer tube is adapted to be able to introduce the solution in the extraction tank from the first end and then flow through a motor and then be re-exported from the second end. The extraction tank is also provided with a pump mechanism, and the pump mechanism can drive the solution to form a circulating flow path between the extraction tank and the heat transfer tube. The solution forms a circulating flow path between the extraction tank and the heat transfer tube through the pump mechanism, and because the circulating flow path flows through the motor, the heat generated during the operation of the motor can be used for auxiliary heating of the solution, thereby reducing the energy consumption burden of the heating device. Compared with the prior art, the present invention can use the heat of the motor to assist in heating the solution through the cooperation of the pump mechanism and the heat transfer tube, thereby reducing the energy consumption and cost of producing phosphoric acid.

Description

Technical Field

[0001] The present invention relates to the technical field of phosphoric acid production, and in particular to a device and method for extracting phosphoric acid from a high-silicon and low-phosphate ore. Background Art

[0002] Phosphoric acid and its compounds and phosphates play a very important role in many sectors of the national economy. They are widely used in agriculture, industry and daily life and play a great role. In recent years, many new application fields have been opened up in frontier science, cutting-edge technology and emerging industries. They play an irreplaceable role in military industry, aerospace and people's livelihood industry. For example, the research and industry of lithium iron phosphate, the main raw material for high-function and high-power batteries that adapt to the gasoline-to-electric vehicle industry, is booming. It can be expected that the phosphorus compound and phosphate industry based on phosphoric acid will play a greater role in the national economy and emerging science and technology in the future.

[0003] Because of the above reasons, the development of phosphate resources has been unprecedentedly strengthened in recent years, resulting in the near exhaustion of high-grade phosphate ores and single, well-selected and available phosphate ores, resulting in a shortage of phosphate resources, which has formed a sharp contradiction with production and market demand. On the other hand, a large number of poor phosphate ores, multi-element associated and symbiotic phosphate ores, especially high-silicon and low-phosphate ores, are difficult to effectively develop and utilize.

[0004] At present, industrial phosphoric acid is divided into two categories: thermal phosphoric acid and wet phosphoric acid. Thermal phosphoric acid mainly uses coke to reduce phosphate rock into yellow phosphorus, then burns yellow phosphorus into phosphorus pentoxide, and then absorbs water to generate phosphoric acid. Wet phosphoric acid is mainly produced by reacting sulfuric acid with phosphate rock. Due to high energy consumption and high pollution, thermal phosphoric acid has a tendency to be gradually replaced by wet phosphoric acid. In addition, the wet phosphoric acid process can effectively utilize this low-grade phosphate rock resource, improve the overall utilization rate of phosphorus resources, and reduce dependence on high-quality phosphate rock.

[0005] In the preparation process of wet phosphoric acid from high-silicon and low-phosphate ore, it is necessary to add phosphate slurry and sulfuric acid into the extraction tank for extraction. The main reaction conditions of extraction depend on temperature, time and stirring effect, among which the temperature control mainly depends on the heating device, such as the heating device can be a jacket or an electromagnetic heater. In other words, the heat required for extraction is only provided by the heating device, which increases energy consumption to a certain extent, causing the production cost of phosphoric acid to rise. Summary of the invention

[0006] The first object of the present invention is to overcome the deficiencies of the prior art and provide a phosphoric acid extraction device for high-silicon and low-phosphate ore.

[0007] The first object of the present invention is achieved by the following technical solutions:

[0008] A high-silicon, low-phosphate ore phosphoric acid extraction device comprises an extraction tank, wherein a stirring paddle is arranged in the extraction tank, and the stirring paddle is rotatably driven by a motor, and a heat transfer tube is also arranged on the extraction tank, both ends of the heat transfer tube are located in the extraction tank, and the heat transfer tube is adapted to be able to introduce the solution in the extraction tank from the first end and then flow through the motor and then be re-exported from the second end, and a pump mechanism is also arranged on the extraction tank, and the pump mechanism can drive the solution to form a circulation flow path between the extraction tank and the heat transfer tube.

[0009] Preferably, a pump liquid box is provided on the top of the extraction tank, the heat transfer tube is connected to the pump liquid box, the connecting shaft of the agitator paddle passes through the pump liquid box and extends into the extraction tank, and the pump mechanism is arranged on the side wall of the connecting shaft of the agitator paddle located in the pump liquid box.

[0010] Preferably, the pump mechanism comprises an impeller or a screw.

[0011] Preferably, the motor is arranged on the top surface of the pump liquid tank.

[0012] Preferably, an abutment plate is provided on the side wall of the connecting shaft of the stirring paddle located in the extraction tank, the diameter of the abutment plate is larger than the diameter of the stirring blades of the stirring paddle, and the abutment plate is used to abut the heat transfer tube to drive the heat transfer tube away from the stirring blades of the stirring paddle.

[0013] Preferably, the abutment disk includes a plurality of abutment portions along the circumferential direction, and the eccentricities of the plurality of abutment portions are different.

[0014] Preferably, each of the abutting portions is connected to the abutting plate via an elastic member.

[0015] Preferably, the extraction tank is also connected to a premixing box, and the heat transfer pipe is arranged so that the circulation flow path can flow through the outer wall of the premixing box.

[0016] Preferably, a heat preservation component is provided on the outer wall of the premixing box, a temperature regulating tube is provided on the heat transfer tube at the pump outlet end of the pump mechanism, the temperature regulating tube extends into the heat preservation component, and the liquid inlet end and the liquid outlet end of the temperature regulating tube are both connected to the heat transfer tube, a closing plate is movably provided in the heat transfer tube between the liquid inlet end and the liquid outlet end of the temperature regulating tube, an elastic component is connected to the closing plate, the closing plate is adapted to open the passage of the heat transfer tube under the impact of the fluid with a threshold momentum, and pressure-type one-way valves are provided in the liquid inlet end and the liquid outlet end of the temperature regulating tube.

[0017] The second object of the present invention is to overcome the deficiencies of the prior art and provide a method for extracting phosphoric acid from a high-silicon, low-phosphate ore.

[0018] The second object of the present invention is achieved through the following technical solutions:

[0019] A method for extracting phosphoric acid from a high-silicon and low-phosphate ore, comprising the above-mentioned high-silicon and low-phosphate ore phosphoric acid extraction device, and further comprising the following steps:

[0020] S1, putting high silicon and low phosphorus ore into a crusher for crushing, and then slurrying the crushed ore through a ball mill to obtain phosphate ore slurry;

[0021] S2, putting phosphate slurry into the extraction tank, and premixing sulfuric acid and returned phosphoric acid in the premixing box before putting the phosphate slurry into the extraction tank to extract the phosphate slurry to obtain phosphoric acid; in the extraction process of S2, the extraction tank is heated by a heating device, and the extraction device is selected to perform the following operation modes according to the progress of the extraction reaction: a low heat compensation mode, in which the stirring paddle stirs the solution in the extraction tank at a first speed, the pump mechanism pumps out a solution with a threshold momentum, and pushes the closing plate to open the passage of the heat transfer tube, and at this time the solution only flows through the motor and is then reintroduced into the extraction tank; a high heat compensation mode, in which the stirring paddle stirs the solution in the extraction tank at a second speed, the pump mechanism pumps out a solution with a momentum lower than the threshold, the closing plate keeps the passage of the heat transfer tube closed, and at this time the solution flows through the motor and the outer wall of the premixing box and is then reintroduced into the extraction tank; wherein the first speed is greater than the second speed.

[0022] The beneficial effects of the present invention are:

[0023] 1. The solution forms a circulation path between the extraction tank and the heat transfer tube through the pump mechanism, and because the circulation path flows through the motor, the heat generated during the operation of the motor can be used to assist in heating the solution, thereby reducing the energy consumption burden of the heating device. Compared with the prior art, the present invention can use the heat of the motor to assist in heating the solution through the cooperation of the pump mechanism and the heat transfer tube, thereby reducing the energy consumption and cost of producing phosphoric acid.

[0024] 2. The pump mechanism uses a motor as a power to pump out the solution, thereby reducing the system control complexity of the device.

[0025] 3. The present invention has multiple operating modes, and in particular, the selection of low heat compensation mode and high heat compensation mode can meet the different heat requirements of the solution during the extraction process, and can further reduce the energy consumption burden of the heating device. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 It is a structural schematic diagram of an embodiment;

[0027] Figure 2 for Figure 1A magnified view of part A;

[0028] Figure 3 is a schematic diagram of the top view of the abutment plate;

[0029] Figure 4 Schematic diagram of switching from a high thermal compensation mode to a low thermal compensation mode according to an embodiment (the flow path of the solution is indicated by solid arrows).

[0030] Figure numerals: 1, extraction tank; 2, stirring paddle; 3, motor; 4, heat transfer tube; 5, first end; 6, second end; 7, pump mechanism; 8, pump liquid box; 9, connecting shaft; 10, abutment plate; 11, stirring blade; 12, abutment part; 13, premixing box; 14, insulation component; 15, temperature regulating tube; 16, liquid inlet end; 17, liquid outlet end; 18, closing plate; 19, pressure-type one-way valve. DETAILED DESCRIPTION

[0031] The technical solution of the present invention will be clearly and completely described below in conjunction with the embodiments. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present invention.

[0032] Embodiment 1:

[0033] like Figures 1 to 4 As shown, a high-silicon low-phosphate ore phosphoric acid extraction device includes an extraction tank 1, a motor 3 is arranged on the top of the extraction tank 1, and a stirring paddle 2 extending into the extraction tank 1 is connected to the output shaft of the motor 3. Specifically, the stirring paddle 2 may include a connecting shaft 9 and a stirring blade 11 arranged on the side wall of the connecting shaft 9, wherein the connecting shaft 9 is fixedly connected to the output shaft of the motor 3, and the stirring blade 11 is placed in the extraction tank 1.

[0034] The top of the extraction tank 1 is also connected to a premixing box 13. During extraction, the returned phosphoric acid and sulfuric acid can be placed in the premixing box 13 for premixing, and then the acid in the premixing box 13 is put into the extraction tank 1 for extraction with the phosphate rock slurry. The returned phosphoric acid and sulfuric acid can release heat during premixing, thereby avoiding the situation where the local temperature in the extraction tank 1 is too high and affects the extraction effect.

[0035] In order to ensure the stability of the extraction, a heating device (not shown) may be provided on the extraction tank 1, for example, the heating device may be a jacket or an electromagnetic heater. It can be understood that the main reaction conditions of the extraction depend on the temperature, time and stirring effect, and generally a higher temperature can accelerate the reaction rate, but may also lead to the occurrence of side reactions or the decomposition of the extractant; sufficient reaction time can ensure the full progress of the extraction process, but too long a reaction time may increase energy consumption and production costs; stirring can promote mixing and mass transfer between reactants, thereby improving the extraction efficiency. Therefore, selecting appropriate temperature, time and stirring speed is a key factor in ensuring the effect of the extraction reaction.

[0036] In the process of phosphate rock extraction, there is a certain interaction between stirring speed and temperature. On the one hand, the appropriate stirring speed can promote the mixing and contact between the extractant and the phosphate rock particles, thereby compensating for the effect of insufficient temperature on the extraction efficiency to a certain extent. On the other hand, when the temperature is high, the extraction reaction rate is accelerated, and the stirring speed can be appropriately reduced to save energy and reduce equipment wear.

[0037] However, in the prior art, the heat required for extraction is only provided by a heating device, which increases energy consumption to a certain extent and increases the production cost of phosphoric acid.

[0038] In view of the above technical problems, in the present disclosure, a heat transfer tube 4 is further provided on the extraction tank 1, and the heat transfer tube 4 has a first end 5 and a second end 6 opposite to each other, and both ends are located in the extraction tank 1. In addition, the heat transfer tube 4 is specifically arranged to extend through the above motor 3, and the extension through the motor 3 here means that the heat transfer tube 4 can allow the solution in the extraction tank 1 to be introduced from the first end 5, flow through the motor 3, and then be discharged from the second end 6 again, and the so-called flow through means that the solution can flow through the space where the motor 3 is located, for example, the heat transfer tube 4 can be directly attached to the outer shell of the motor 3 to achieve the above-mentioned flow through.

[0039] For example, the extraction tank 1 is also provided with a pump mechanism 7, through which the solution in the extraction tank 1 can be driven to form a circulation path between the extraction tank 1 and the heat transfer tube 4 to flow through the motor 3. As a possible embodiment, the pump mechanism 7 can be a water pumping device such as a water pump driven by an additional driving source. Therefore, the solution can carry away the heat generated during the operation of the motor 3 during the flow process, that is, the heat generated during the operation of the motor 3 can be used for auxiliary heating of the solution, thereby reducing the energy consumption burden of the heating device.

[0040] In a possible example, extraction can be performed by increasing the stirring speed and lowering the temperature. At this time, the solution's temperature requirement is reduced, and the motor 3 will emit more heat to ensure a faster stirring speed of the stirring blade 11. For example, as those skilled in the art know, the temperature range of the motor 3 of the mixer is usually between 60°C and 80°C. This part of the heat can be used for auxiliary heating of the solution, thereby further reducing the heating temperature of the heating device or achieving a better extraction effect at the same temperature.

[0041] In some embodiments, a pump liquid box 8 is also provided on the top of the extraction tank 1, and the motor 3 is arranged on the pump liquid box 8 so that the motor 3 can directly guide the heat to one side of the pump liquid box 8, and the connecting shaft 9 passes through the pump liquid box 8 and extends into the extraction tank 1. The heat transfer tube 4 includes two parts connected to the two sides of the pump liquid box 8, that is, the first end 5 and the second end 6 are respectively formed on the two parts. The pump mechanism 7 is arranged on the side wall of the connecting shaft 9 located in the pump liquid box 8. For example, the pump mechanism 7 may include an impeller or a screw, or other structures that complete the pumping of liquid by rotation.

[0042] Therefore, while the motor 3 drives the stirring paddle 2 to stir the solution, the pump mechanism 7 will simultaneously pump the solution under the drive of the motor 3, thereby achieving auxiliary heat dissipation of the solution by the heat emitted by the motor 3. In this example, the pump mechanism 7 uses the motor 3 as the pumping power of the solution without the need for an additional driving source, and simultaneously achieves auxiliary heating of the solution while stirring the solution, greatly reducing the complexity of the system control disclosed in the present invention.

[0043] In a preferred example, an abutment disk 10 is provided on the side wall of the connecting shaft 9 in the extraction tank 1, and the diameter of the abutment disk 10 is larger than the diameter of the stirring blade 11. In other words, in vertical projection, the stirring blade 11 will fall into the abutment disk 10, and the two parts of the heat transfer tube 4 extending into the extraction tank 1 will abut against the side wall of the abutment disk 10, thereby achieving isolation from the stirring blade 11.

[0044] Under the action of the abutment plate 10, on the one hand, the heat transfer tube 4 and the stirring blade 11 can be prevented from interfering and entangled, and on the other hand, the heat transfer tube 4 can assist in heating the solution in the stirring blind area outside the stirring blade 11, which will be more conducive to the uniformity of the solution reaction in the extraction tank 1, so that the extraction effect is improved. Among them, the mixing effect of the solution in the area directly stirred by the stirring blade 1 is the best, so the solution in this area has a lower temperature requirement; and a stirring blind area may be formed between the outside of the stirring blade 11 and the inner wall of the extraction tank 1. Since the solution in this area has a poor mixing effect, targeted auxiliary heat dissipation can achieve a better extraction effect.

[0045] For example, the abutment disk 10 specifically includes a plurality of abutment portions 12 along the circumferential direction, and the eccentricities of the plurality of abutment portions 12 are different. In addition, each abutment portion 12 is also connected to the abutment disk 10 through an elastic member. It can be understood that, since the eccentricities of the plurality of abutment portions 12 are different, during the rotation of the stirring paddle 2, the abutment portions 12 with different eccentricities abut against the heat transfer tube 4 in sequence, and the heat transfer tube 4 will exhibit a dual movement of radial movement and vertical movement, so that the solution at different positions in the stirring blind area can be pumped, thereby achieving more uniform auxiliary heating of the solution.

[0046] When the rotation speed of the stirring paddle 2 changes, for example, when the rotation speed of the stirring paddle 2 is increased to obtain a better stirring effect, the stirring force of the stirring paddle 2 on the solution changes. At this time, the stirring blind area is further compressed, and under the action of the elastic part on the abutment portion 12, the abutment portion 12 will stretch the elastic part under the action of centrifugal force, that is, the overall diameter of the abutment plate 10 will be further increased, thereby driving the heat transfer tube 4 to always be located in the stirring blind area to achieve the above-mentioned auxiliary heating effect.

[0047] In some embodiments, the heat transfer tube 4 is further arranged so that the circulation flow path can flow through the outer wall of the premixing tank 13, so that the heat generated when the return phosphoric acid and sulfuric acid are premixed can be used to assist in heating the solution.

[0048] For example, a heat preservation member 14 may be provided on the outer wall of the premixing box 13, and the heat generated when the return phosphoric acid and sulfuric acid are premixed is preserved by the heat preservation member 14. The heat preservation member 14 may be, for example, heat preservation foam or heat storage bricks. A thermostatic tube 15 is provided on the part of the heat transfer tube 4 located at the pump outlet of the pump mechanism 7. The thermostatic tube 15 extends into the heat preservation member 14, and its liquid inlet end 16 and liquid outlet end 17 are both connected to the heat transfer tube 4. More specifically, a closing plate 18 is also movably provided between the liquid inlet end 16 and the liquid outlet end 17 of the thermostatic tube 15 in the heat transfer tube 4. The closing plate 18 is also connected to an elastic member that can drive the closing plate 18 to close the passage of the heat transfer tube 4 in a natural state. Therefore, by selecting the elastic force of the elastic member, the closing plate 18 can be moved under the impact of the fluid with a threshold momentum to open the passage of the heat transfer tube 4. In addition, pressure-type one-way valves 19 are disposed in both the liquid inlet end 16 and the liquid outlet end 17 of the temperature regulating tube 15 .

[0049] In a preferred example, the closing plate 18 can be connected to the heat transfer tube 4 by a torsion spring rotation connection, and an elastic sealing member such as a rubber ring can be provided on the side wall of the closing plate 18. Under the action of the elastic member, the closing plate 18 can be deflected to close the passage of the heat transfer tube 4.

[0050] According to the control of the stirring rate of the stirring paddle 2, the extraction device disclosed in the present invention can have at least two operating modes as follows:

[0051] In the low heat compensation mode, the stirring blade 2 stirs the solution in the extraction tank 1 at a first speed. At the same time, the pump mechanism 7 pumps out the solution with a threshold momentum and pushes the sealing plate 18 to open the passage of the heat transfer tube 4. At this time, the solution only flows through the motor 3 and then is reintroduced into the extraction tank 1.

[0052] In the high heat compensation mode, the stirring blade 2 stirs the solution in the extraction tank 1 at the second speed. At the same time, the pump mechanism 7 pumps out the solution with a momentum below the threshold, and the sealing plate 18 keeps the passage of the heat transfer tube 4 closed. At this time, the solution flows through the motor 3 and the outer wall of the premixing box 13 and is then re-introduced into the extraction tank 1.

[0053] Specifically, the first speed is greater than the second speed. When the stirring paddle 2 stirs at the first speed, due to the high rotation speed of the connecting shaft 9, the pump mechanism 7 will pump out the solution with a threshold momentum, so that the solution will impact the sealing plate 18 and flow directly into the extraction tank 1; when the stirring paddle 2 stirs at the second speed, due to the low rotation speed of the connecting shaft 9, the pump mechanism 7 will pump out the solution with a momentum lower than the threshold, and the sealing plate 18 is not easy to deflect and keeps the passage of the heat transfer tube 4 closed. At this time, the pressure of the solution on the side of the liquid inlet end 16 of the temperature regulating tube 15 increases until it passes through the pressure-type one-way valve 19 and flows through the outer wall of the premixing box 13 and is re-introduced into the extraction tank 1.

[0054] In the low heat compensation mode, the stirring paddle 2 has a high rotation speed, so the solution's temperature requirement is reduced, and at this time, the solution can be assisted in cooling only by the heat dissipated by the motor 3; while in the high heat compensation mode, the stirring paddle 2 has a low rotation speed, and the solution's temperature requirement is increased, and at this time, the solution can be assisted in cooling by the heat dissipated by the motor 3 and the heat stored by the heat preservation member 14 to meet the solution's temperature requirement. That is, the heat use of the heat preservation member 14 can be dynamically released according to the requirements of the extraction reaction, thereby further reducing the energy consumption burden of the heating device.

[0055] Embodiment 2:

[0056] A method for extracting phosphoric acid from a high-silicon, low-phosphate ore, comprising the high-silicon, low-phosphate ore phosphoric acid extraction device of embodiment 1, and further comprising the following steps:

[0057] S1, putting high silicon and low phosphorus ore into a crusher for crushing, and then slurrying the crushed ore through a ball mill to obtain phosphate ore slurry;

[0058] S2, putting the phosphate slurry into the extraction tank 1, and premixing sulfuric acid and returned phosphoric acid in the premixing box 13, and then putting it into the extraction tank 1 to extract the phosphate slurry to obtain phosphoric acid;

[0059] During the extraction process of S2, the extraction tank 1 is heated by a heating device, and the extraction device is selected to execute a low heat compensation mode or a high heat compensation mode according to the progress of the extraction reaction.

[0060] The above is only a preferred embodiment of the present invention. It should be understood that the present invention is not limited to the form disclosed herein, and should not be regarded as excluding other embodiments, but can be used in various other combinations, modifications and environments, and can be modified within the scope of the concept described herein through the above teachings or the technology or knowledge of the relevant field. The changes and modifications made by those skilled in the art shall not deviate from the spirit and scope of the present invention, and shall be within the scope of protection of the claims attached to the present invention.

Claims

1. A phosphoric acid extraction device for high-silicon and low-phosphate ore, comprising an extraction tank (1), wherein a stirring paddle (2) is arranged in the extraction tank (1), and the stirring paddle (2) is rotatably driven by a motor (3), wherein: The extraction tank (1) is also provided with a heat transfer tube (4), both ends of which are located in the extraction tank (1), and the heat transfer tube (4) is adapted to be able to introduce the solution in the extraction tank (1) from the first end (5) and then flow through the motor (3) and then be discharged again from the second end (6). The extraction tank (1) is also provided with a pump mechanism (7), and the pump mechanism (7) is able to drive the solution to form a circulation flow path between the extraction tank (1) and the heat transfer tube (4); A pump liquid box (8) is arranged on the top of the extraction tank (1), the heat transfer pipe (4) is connected to the pump liquid box (8), the connecting shaft (9) of the stirring paddle (2) passes through the pump liquid box (8) and extends into the extraction tank (1), and the pump mechanism (7) is arranged on the side wall of the connecting shaft (9) of the stirring paddle (2) located inside the pump liquid box (8); A connecting shaft (9) of the stirring paddle (2) is provided with an abutment plate (10) on the side wall of the extraction tank (1), the diameter of the abutment plate (10) being larger than the diameter of the stirring blade (11) of the stirring paddle (2), and the abutment plate (10) is used to abut the heat transfer tube (4) to drive the heat transfer tube (4) away from the stirring blade (11) of the stirring paddle (2).

2. The high-silicon and low-phosphate ore phosphoric acid extraction device according to claim 1 is characterized in that: The pump mechanism (7) comprises an impeller or a screw.

3. The high-silicon and low-phosphate ore phosphoric acid extraction device according to claim 1 is characterized by: The motor (3) is arranged in close contact with the top surface of the pump liquid box (8).

4. The high-silicon and low-phosphate ore phosphoric acid extraction device according to claim 1 is characterized by: The abutment disk (10) comprises a plurality of abutment portions (12) along the circumferential direction, and the eccentricities of the plurality of abutment portions (12) are different.

5. The high-silicon and low-phosphate ore phosphoric acid extraction device according to claim 4 is characterized in that: Each of the abutting portions (12) is connected to the abutting plate (10) via an elastic member.

6. The high-silicon and low-phosphate ore phosphoric acid extraction device according to any one of claims 1 to 5, characterized in that: The extraction tank (1) is also connected to a premixing box (13), and the heat transfer pipe (4) is arranged so that the circulation flow path can flow through the outer wall of the premixing box (13).

7. The high-silicon and low-phosphate ore phosphoric acid extraction device according to claim 6 is characterized by: A heat preservation member (14) is provided on the outer wall of the premixing box (13); a temperature regulating tube (15) is provided on the heat transfer tube (4) at the pump outlet end of the pump mechanism (7) and is connected thereto; the temperature regulating tube (15) extends into the heat preservation member (14); and both the liquid inlet end (16) and the liquid outlet end (17) of the temperature regulating tube (15) are connected to the heat transfer tube (4); a closing plate (18) is movably provided in the heat transfer tube (4) between the liquid inlet end (16) and the liquid outlet end (17) of the temperature regulating tube (15); an elastic member is connected to the closing plate (18); the closing plate (18) is adapted to open the passage of the heat transfer tube (4) under the impact of a fluid with a threshold momentum; and pressure-type one-way valves (19) are provided in both the liquid inlet end (16) and the liquid outlet end (17) of the temperature regulating tube (15).

8. A method for extracting phosphoric acid from a high-silicon, low-phosphate ore, comprising the device for extracting phosphoric acid from a high-silicon, low-phosphate ore according to claim 7, characterized in that: The following steps are also included: S1, putting high silicon and low phosphorus ore into a crusher for crushing, and then slurrying the crushed ore through a ball mill to obtain phosphate ore slurry; S2, putting the phosphate slurry into the extraction tank (1), and premixing sulfuric acid and returned phosphoric acid in the premixing tank (13), and then putting the phosphate slurry into the extraction tank (1) to extract the phosphate slurry, so as to obtain phosphoric acid; During the extraction process of S2, the extraction tank (1) is heated by a heating device, and the extraction device is selected to perform the following operation modes according to the progress of the extraction reaction: a low heat compensation mode, in which the stirring paddle (2) stirs the solution in the extraction tank (1) at a first speed, the pump mechanism (7) pumps out the solution with a threshold momentum, and pushes the sealing plate (18) to open the passage of the heat transfer tube (4), and the solution only flows through the motor (3) and is then reintroduced into the extraction tank (1); a high heat compensation mode, in which the stirring paddle (2) stirs the solution in the extraction tank (1) at a second speed, the pump mechanism (7) pumps out the solution with a momentum below a threshold value, the sealing plate (18) keeps the passage of the heat transfer tube (4) closed, and the solution flows through the motor (3) and the outer wall of the premixing box (13) and is then reintroduced into the extraction tank (1); Wherein, the first speed is greater than the second speed.

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