Agricultural potassium sulfate preparation system based on potassium feldspar powder

Abstract

The invention relates to the technical field of potash fertilizer production, and discloses an agricultural potassium sulfate preparation system based on potassium feldspar powder, which comprises a rotary kiln, a reaction kettle, an evaporator and a dryer, adding the clinker powder into a reaction kettle, carrying out water leaching and filter pressing treatment to obtain a potassium-containing mother solution, introducing CO2 into the potassium-containing mother solution through a CO2 supply unit to realize carbon component acidification treatment to obtain a potassium-sodium mixed salt solution, and evaporating and crystallizing the potassium-sodium mixed salt solution through an evaporator to obtain a potassium-rich solution; stirring and mixing the potassium-rich solution with concentrated sulfuric acid in a dryer to obtain a potassium sulfate suspension, and drying the potassium sulfate suspension to obtain an agricultural potassium sulfate product. According to the preparation system, rich water-insoluble potassium ore resources in China can be fully utilized, and the defect that soluble potassium resources are extremely lacked in China is effectively overcome, so that the problem of potassium fertilizer shortage in China is solved, and an important guarantee is provided for agricultural production.

Description

Technical Field

[0001] The invention relates to the technical field of potash fertilizer production, and in particular to an agricultural potassium sulfate preparation system based on potassium feldspar powder. Background Art

[0002] Potash fertilizer is one of the indispensable fertilizers in agricultural production, but due to the extreme shortage of water-soluble potassium resources in my country, the output is far from meeting the needs of agricultural production. However, my country's insoluble potassium resources, especially potassium feldspar, are extremely rich in reserves. Therefore, the rational development of insoluble potassium to make potash fertilizer can make up for the shortage of soluble potassium resources in China to a certain extent, which is of great significance for solving the shortage of potash fertilizer in my country and ensuring agricultural production. For this reason, it is urgent to provide an agricultural potassium sulfate preparation system based on potassium feldspar powder. Summary of the invention

[0003] In view of this, the purpose of the present invention is to provide an agricultural potassium sulfate preparation system based on potassium feldspar powder to solve the problem of potassium fertilizer shortage in my country and provide important guarantee for agricultural production.

[0004] An agricultural potassium sulfate preparation system based on potassium feldspar powder, comprising:

[0005] A rotary kiln, the rotary kiln comprising a shell, a feeding cylinder arranged inside the shell, and a heating chamber arranged around the outer peripheral side of the feeding cylinder, a first heating assembly being arranged between the heating chamber and the inner wall opposite surfaces of the shell, two ends of the feeding cylinder respectively extending along the center line direction of the shell to closely fit with the inner wall of the shell, a rotating shaft being arranged inside the feeding cylinder, two ends of the rotating shaft respectively extending to be rotatably connected with the inner wall of the shell, one end of the rotating shaft passing through the inner wall of the shell to be connected with the output shaft of the motor, a plurality of flipping plates being evenly installed on the outer periphery of the rotating shaft, and one end of the flipping plate extending away from the rotating shaft to be connected with the inner wall of the feeding cylinder;

[0006] A reaction kettle, the reaction kettle comprising a kettle body, a stirring drum arranged inside the kettle body, and a reaction chamber arranged between the outer peripheral side of the stirring drum and the opposite surface of the inner wall of the kettle body, a magnetic stirrer is arranged at the bottom of the stirring drum, a magnetic stirring block is rotatably mounted at the bottom end of the inner wall of the stirring drum, a filter hole is arranged on the inner wall of the stirring drum, the filter hole is connected to the reaction chamber, a filter press and a water supply unit are arranged on the top of the stirring drum, and a CO2 supply unit is connected to the top of the reaction chamber;

[0007] an evaporator, wherein a feed port of the evaporator is connected to the bottom of the inner wall of the reaction chamber through a pipeline and a first water pump, and a second heating component is arranged in the evaporator;

[0008] A dryer, wherein the feed end of the dryer is connected to the bottom of the inner wall of the evaporator through a pipeline and a second water pump, an acid supply unit and a stirring mechanism are arranged on the top of the dryer, the output end of the stirring mechanism extends to the bottom of the inner wall near the dryer, and a third heating assembly is arranged in the dryer.

[0009] Optionally, the first heating component has:

[0010] An inner liner, the inner liner is arranged between the shell and the feeding barrel, the two ends of the inner liner are respectively extended to be connected with the inner wall of the shell, the side of the inner liner close to the feeding barrel forms the heating chamber, the side of the inner liner close to the shell forms an installation chamber, a plurality of groups of hollow bricks are arranged in the installation chamber at equal intervals along the annular direction, and the opposite sides of the hollow bricks are respectively connected with the inner wall of the shell and the outer wall of the inner liner;

[0011] A heating pipe is arranged on the mid-vertical line of each group of hollow bricks;

[0012] The resistance wire is installed on each of the heating tubes.

[0013] Optionally, a plurality of lining plates are evenly installed along the circumference of the feeding cylinder, and one end of the lining plate away from the feeding cylinder is slidably connected to the inner wall of the inner container, and the lining plate divides the heating chamber into a plurality of heat storage cavities;

[0014] A plurality of heat exchange holes are circumferentially arranged on the inner tank, and the two ends of the heat exchange holes are respectively connected to the installation chamber and the heating chamber. An electronic valve is installed in the heat exchange hole so that the electronic valve is opened when the prepared raw materials in the feeding barrel are calcined, so that the feeding barrel can flow the hot air in the installation chamber through the heat exchange holes into each of the heat storage cavities in turn during the rotation process, so as to achieve uniform heating of the prepared raw materials.

[0015] Optionally, two adjacent heat storage cavities are connected near adjacent ends of the shell, and air supply ports and exhaust ports are provided at both ends of the heating chamber along the diagonal direction. A one-way valve and an induced draft fan are installed at the air inlet end in sequence, and a pressure relief valve and a waste heat recovery system are installed at the air outlet end in sequence, and a heat output end of the waste heat recovery system is connected to a heat input end of the second heating component and a heat input end of the third heating component through a pipeline.

[0016] Optionally, the waste heat recovery system is a spiral plate heat exchanger, the heat input end of the spiral plate heat exchanger is connected to the exhaust port through a pipe, the heat output end of the spiral plate heat exchanger is connected to the heat input end of the second heating component and the heat input end of the third heating component through a pipe, the cold input end of the spiral plate heat exchanger is connected to the output end of the liquid storage unit through a pipe, the cold output end of the spiral plate heat exchanger is connected to the exhaust gas treatment unit, and the cold output end of the second heating component and the cold output end of the third heating component are respectively connected to the input end of the liquid storage unit.

[0017] Optionally, the second heating component and the third heating component both have:

[0018] A heat exchange tube, wherein the heat exchange tube is arranged in the evaporator or the dryer, the liquid inlet of the heat exchange tube is connected to the heat output end of the spiral plate heat exchanger through a pipeline, and the liquid outlet of the heat exchange tube is connected to the reflux port of the liquid storage unit through a pipeline;

[0019] A temperature control valve, the temperature control valve is installed in the liquid inlet of the heat exchange tube;

[0020] An electric heater is installed at the cold input end of the spiral plate heat exchanger.

[0021] Optionally, the first heating component, the second heating component and the third heating component all have a temperature adjustment unit, and the temperature adjustment unit includes:

[0022] A setting module is used to set the current heating temperature of the heating component;

[0023] A temperature detection sensor, used to detect the actual heating temperature of the heating component;

[0024] A controller, connected to the setting module and the temperature detection sensor, is used to control the first heating component, the second heating component or the third heating component to start heating, and when the temperature detection sensor detects that the actual heating temperature reaches the current heating temperature, controls the corresponding heating component to stop heating.

[0025] Optionally, a self-unloading structure is provided at the bottom of the housing, and the self-unloading structure has:

[0026] A support platform, wherein the top of the support platform is protruding upward and is provided with an arc-shaped support portion, and the bottom of the shell is tightly fitted with the inner concave surface of the arc-shaped support portion;

[0027] An articulated seat, one end of which is mounted on the bottom of the shell and located close to the discharge port of the rotary kiln, and the other end of which is mounted on the top of the support platform;

[0028] A lifting mechanism is installed on the top of the support platform, and the output end of the lifting mechanism is hinged to the bottom of the shell and located near the feeding port of the rotary kiln, so that the lifting mechanism is extended upward to drive the discharge port of the rotary kiln to tilt downward, and the discharge port of the rotary kiln is opened to realize automatic unloading of the rotary kiln.

[0029] Optionally, a collection trough is provided below the discharge port of the rotary kiln, a screw feeder is provided between the collection trough and the reactor, a feed end of the screw feeder is connected to the bottom of the collection trough, and a discharge end of the screw feeder passes through the outer surface of the reactor and extends to be connected to the inner wall of the mixing drum.

[0030] Optionally, the filter press comprises a telescopic member, the telescopic member is mounted on the top of the kettle body, the output end of the telescopic member passes through the top of the kettle body and extends to the mixing drum where a filter press plate is mounted, and the outer periphery of the filter press plate is slidably connected to the inner wall of the mixing drum;

[0031] The filter press plate is located above the discharge end of the spiral feeder, and the mesh aperture of the filter press plate is smaller than the aperture of the filter hole.

[0032] The beneficial effects that the present invention can produce include:

[0033] The invention provides an agricultural potassium sulfate preparation system based on potassium feldspar powder. The preparation system uses potassium feldspar powder as a preparation raw material for calcination, so that the potassium in the calcined clinker powder is converted into soluble potassium, and then the clinker powder is subjected to filter pressing, carbonization, crystallization and drying to prepare an agricultural potassium sulfate product. The abundant non-water-soluble potassium ore resources in my country can be fully utilized. Moreover, the preparation raw materials are widely available, the resource utilization rate is high, the product cost is low, and the economic benefits are remarkable, thereby effectively making up for the shortage of soluble potassium resources that are extremely scarce in China, solving the problem of potassium fertilizer shortage in my country and providing important guarantees for agricultural production. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 This is a schematic structural diagram of a system for preparing agricultural potassium sulfate based on potassium feldspar powder according to the present invention;

[0035] Figure 2 For the present invention Figure 1 The structural diagram of the rotary kiln;

[0036] Figure 3 For the present invention Figure 2 A transverse cross-sectional view of

[0037] In the figure: 1, rotary kiln, 2, reactor, 3, evaporator, 4, dryer, 5, shell, 6, heating chamber, 7, liner, 8, hollow brick, 9, heating tube, 10, resistance wire, 11, electronic valve, 12, shaft, 13, motor, 14, turning plate, 15, feeding cylinder, 16, kettle, 17, stirring cylinder, 18, reaction chamber, 19, filter hole, 20, telescopic part, 21, filter press plate, 22, water supply unit, 23, magnetic stirrer, 24, CO2 supply Unit, 25. first water pump, 26. second heating component, 27. second water pump, 28. third heating component, 29. acid supply unit, 30. stirring mechanism, 31. air supply port, 32. exhaust port, 33. induced draft fan, 34. waste heat recovery system, 35. temperature control valve, 36. electric heater, 37. support platform, 38. articulated seat, 39. lifting mechanism, 40. collecting trough, 41. screw feeder, 42. lining plate, 43. liquid storage unit, 44. discharge pipe. DETAILED DESCRIPTION

[0038] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0039] See also Figure 1-3As shown, the present invention provides an agricultural potassium sulfate preparation system based on potassium feldspar powder, the preparation system comprises a rotary kiln 1, a reactor 2, an evaporator 3 and a dryer 4, wherein the rotary kiln 1 comprises a shell 5, a feeding cylinder 15 arranged inside the shell 5 and a heating chamber 6 arranged around the outer peripheral side of the feeding cylinder 15, a first heating component is arranged between the heating chamber 6 and the inner wall opposite surface of the shell 5, two ends of the feeding cylinder 15 extend respectively along the center line direction of the shell 5 to be closely fitted with the inner wall of the shell 5, a rotating shaft 12 is arranged in the feeding cylinder 15, and the rotating shaft 1 The two ends of the rotating shaft 12 extend to the inner wall of the shell 5 for rotation connection, one end of the rotating shaft 12 penetrates the inner wall of the shell 5 and is connected to the output shaft of the motor 13, the motor 13 is fixedly mounted on the shell 5 through a frame, a plurality of turning plates 14 are uniformly welded on the outer periphery of the rotating shaft 12, and the turning plates 14 extend to the inner wall of the feeding barrel 15 for welding at one end away from the rotating shaft 12. The rotary kiln 1 is used to add the raw materials containing potassium feldspar powder into the feeding barrel 15, and heat the raw materials to 700-900℃ through the first heating component and calcine them for 0.2-2.5h to obtain clinker powder, and then the clinker powder is passed into the reactor 2 for further processing; the reactor 2 has a reactor body 16, a stirring drum 17 arranged inside the reactor body 16, and a reaction chamber 18 arranged between the outer peripheral side of the stirring drum 17 and the inner side wall opposite to the reactor body 16, a magnetic stirrer 23 is arranged at the bottom of the stirring drum 17, a magnetic stirring block is rotatably installed at the bottom end of the inner wall of the stirring drum 17, a filter hole 19 is arranged on the inner side wall of the stirring drum 17, the filter hole 19 is connected to the reaction chamber 18, and a filter press is arranged on the top of the stirring drum 17 The top of the reaction chamber 18 is connected with a CO2 supply unit 24, so that the clinker powder is added into the mixing drum 17, water is added into the clinker powder through the water supply unit 22, and the magnetic stirring block is driven by the magnetic stirrer 23 to rotate to stir and mix the water and the clinker powder to achieve water immersion treatment, and then the mixed solution in the mixing drum 17 is filtered by the filter press to obtain a filter cake and a potassium-containing mother liquor, so that the potassium-containing mother liquor flows into the top of the filter press and the reaction chamber 18, and then the potassium-containing mother liquor is supplied to the mixing drum 17 by the CO2 supply unit 24. CO2 is introduced into the reaction chamber to realize carbonation and acidification treatment, thereby obtaining a potassium-sodium mixed salt solution; the feed port of the evaporator 3 is connected to the bottom of the inner wall of the reaction chamber 18 through a pipeline and a first water pump 25, and a second heating component 26 is provided in the evaporator 3; so that the first water pump 25 pumps the potassium-sodium mixed salt solution into the evaporator 3, and a mixed product of sodium bicarbonate crystals, potassium-sodium complex salt crystals and potassium-rich solution is obtained through evaporation and crystallization by the second heating component 26; the feed end of the dryer 4 is connected to the bottom of the inner wall of the evaporator 3 through a pipeline and a second water pump 27, and the dryer 4 An acid supply unit 29 and a stirring mechanism 30 are provided at the top, and the output end of the stirring mechanism 30 extends to the bottom of the inner wall near the dryer 4. A third heating component 28 is provided in the dryer 3, so that the second water pump 27 pumps the potassium-rich solution into the dryer 4, and concentrated sulfuric acid is added to the potassium-rich solution through the acid supply unit 29, and the potassium-rich solution and concentrated sulfuric acid are stirred and mixed by the stirring mechanism 30 to obtain a potassium sulfate suspension, and then the potassium sulfate suspension is dried by the third heating component 28 inside the dryer 4 to obtain an agricultural potassium sulfate product. The above-mentioned preparation system uses potassium feldspar powder as a preparation raw material for calcination, so that the potassium in the calcined clinker powder is converted into soluble potassium, and then the clinker powder is subjected to filter pressing, carbonization, crystallization, and drying to produce agricultural potassium sulfate products, which can fully utilize my country's abundant non-water-soluble potassium ore resources. In addition, the preparation raw materials are widely available, with high resource utilization, low product cost, and significant economic benefits, thereby effectively making up for the shortage of soluble potassium resources in China, solving the problem of potassium fertilizer shortage in my country and providing important guarantees for agricultural production.

[0040] In one of the above-mentioned embodiments, there is one flipping plate 14, and the flipping plate 14 covers one side of the inner wall of the feeding barrel 15, so that during the rotation of the rotating shaft 12, the prepared raw materials on the bottom side of the feeding barrel 15 are lifted to the top side of the feeding barrel 15 by the flipping plate 14, and then fall to the bottom side of the feeding barrel 15 through the top side of the feeding barrel 15, so that the prepared raw materials are continuously flipped when the flipping plate 14 rotates continuously, thereby ensuring the uniformity of the prepared raw materials during the calcination process.

[0041] In another embodiment described above, Figure 2 and Figure 3 As shown, there are three flipping plates 14, and the angle between two adjacent flipping plates 14 is 120°, and a strip-shaped discharge port is provided on the side of the flipping plate 14 close to the rotating shaft 12 along the axial direction of the rotating shaft 12, so that when the flipping plate 14 lifts the prepared raw materials on the bottom side of the feeding barrel 15 to a level exceeding the rotating shaft 12, the raw materials fall back to the bottom side of the feeding barrel 15 from the discharge port, so that the prepared raw materials are continuously flipped by the three flipping plates 14, which can improve the flipping effect of the prepared raw materials, further ensure the uniformity of the prepared raw materials during the calcination process, and enhance the structural strength of the feeding barrel 15.

[0042] In the above, the first heating component has an inner tank 7, a heating tube 9 and a resistance wire 10. The inner tank 7 is arranged between the shell 5 and the feeding barrel 15. The two ends of the inner tank 7 extend to connect with the inner wall of the shell 5 respectively. The side of the inner tank 7 close to the feeding barrel 15 forms a heating chamber 6, and the side of the inner tank 7 close to the shell 5 forms an installation chamber. A plurality of groups of hollow bricks 8 are arranged at equal intervals along the circumferential direction in the installation chamber. The opposite sides of the hollow bricks 8 are respectively connected to the inner wall of the shell 5 and the outer wall of the inner tank 7. The heating tube 9 is passed through the mid-vertical line of each group of hollow bricks 8, and the resistance wire 10 is installed on each heating tube 9; when the prepared raw materials are calcined, the resistance wire 10 is energized to heat the heating tube 9 to the set temperature, so that the heating tube 9 transfers heat to the hollow bricks 8 to evenly heat the air inside the installation chamber, thereby evenly transferring heat to the heating chamber 6 to evenly calcine the prepared raw materials loaded in the feeding barrel 15. Furthermore, a plurality of lining plates 42 are evenly installed along the circumference of the feeding barrel 15, and one end of the lining plate 42 away from the feeding barrel 15 is slidably connected to the inner wall of the inner tank 7, and the lining plate 42 divides the heating chamber 6 into a plurality of heat storage cavities; a plurality of heat exchange holes are arranged along the circumference of the inner tank 7, and the two ends of the heat exchange holes are respectively connected to the installation chamber and the heating chamber 6, and an electronic valve 11 is installed in the heat exchange hole, so that the electronic valve 11 is opened when the prepared raw materials in the feeding barrel 15 are calcined, so that the motor 13 drives the feeding barrel 15 to flow the hot air in the installation chamber through the heat exchange holes into each heat storage cavity in turn during the rotation process, so as to achieve uniform heating of the prepared raw materials.

[0043] In the above, two adjacent heat storage cavities are connected near the adjacent ends of the shell 5, and the two ends of the heating chamber 6 are provided with air supply ports 31 and exhaust ports 32 along the diagonal direction. The air inlet end of the air supply port 31 is successively installed with a one-way valve and an induced draft fan 33, and the air outlet end of the exhaust port 32 is successively installed with a pressure relief valve and a waste heat recovery system 34. The heat output end of the waste heat recovery system 34 is connected to the heat input end of the second heating component 26 and the heat input end of the third heating component 28 through a pipeline. When the clinker powder is cooled, the electronic valve 11 is closed to separate the installation chamber from the heating chamber 6, so that the induced draft fan 33 passes the external cold air into the heating chamber 6 through the one-way valve to cool the clinker powder, and passes the hot air after heat exchange into the waste heat recovery system 34 through the pressure relief valve, which is used to supply heat to the second heating component 26 or the third heating component 28 to realize the recovery and utilization of waste heat. It should be noted that the thermal conductivity of the feeding barrel 15 is greater than that of the inner tank 7, thereby avoiding the removal of a large amount of residual heat of the first heating component in the installation chamber during the cooling process, so that when calcining the next batch of prepared raw materials, it can quickly reach the set temperature, thereby improving production efficiency and reducing production costs.

[0044] Specifically, the waste heat recovery system 34 is a spiral plate heat exchanger, the heat input end of the spiral plate heat exchanger is connected to the exhaust port 32 through a pipeline, the heat output end of the spiral plate heat exchanger is connected to the heat input end of the second heating component 26 and the heat input end of the third heating component 28 through a pipeline, the cold input end of the spiral plate heat exchanger is connected to the output end of the liquid storage unit 43 through a pipeline, and the cold output end of the spiral plate heat exchanger is connected to the exhaust gas treatment unit; when supplying heat to the second heating component 26 and the third heating component 28, the cold source in the liquid storage unit 43 is passed to the cold source of the spiral plate heat exchanger. The input end allows the hot air flow discharged from the exhaust port 32 to flow into the heat input end of the spiral plate heat exchanger to heat the cold source, and then the heat source after heat exchange is transported from the heat output end of the spiral plate heat exchanger to the second heating component 26 and the third heating component 28, so as to realize the recovery and utilization of waste heat, and at the same time, it can reduce the temperature of the hot air flow discharged into the atmosphere and reduce environmental pollution; and the cold output end of the second heating component 26 and the cold output end of the third heating component 28 are respectively connected to the input end of the liquid storage unit 43, so as to return the cold source after heat exchange to the liquid storage unit 43 for recycling.

[0045] In the above, the second heating component 26 and the third heating component 28 both have a heat exchange tube, a temperature control valve 35 and an electric heater 36, wherein the heat exchange tube is arranged in the evaporator 3 or the dryer 4, the liquid inlet of the heat exchange tube is connected to the heat output end of the spiral plate heat exchanger through a pipeline, and the liquid outlet of the heat exchange tube is connected to the reflux port of the liquid storage unit 43 through a pipeline, so that the heat source returns to the liquid storage unit 43 for recycling after heat exchange, and the temperature control valve 35 is installed in the liquid inlet of the heat exchange tube, so that the corresponding temperature control valve 35 can be opened according to the use requirements to transport the heat source to the second heating component 26 or the third heating component 28, and the electric heater 36 is installed at the cold input end of the spiral plate heat exchanger, so that when the heat source cannot meet the heating requirements of the second heating component 26 or the third heating component 28, the cold source is heated by the electric heater 36, thereby providing the required heat to the second heating component 26 and the third heating component 28 according to the use requirements.

[0046] In the above, the first heating component, the second heating component 26 and the third heating component 28 all have a temperature regulating unit, and the temperature regulating unit includes a setting module, a temperature detection sensor and a controller (single-chip microcomputer), the setting module is used to set the current heating temperature of the heating component, and the temperature detection sensor is used to detect the actual heating temperature of the heating component; the controller is connected to the setting module and the temperature detection sensor, and is used to control the first heating component, the second heating component 26 or the third heating component 28 to start heating, and when the temperature detection sensor detects that the actual heating temperature reaches the current heating temperature, the corresponding heating component is controlled to stop heating; specifically, when the first heating component is heated, the controller controls the resistance wire 10 to be energized and the electronic valve 11 to be opened, until the temperature detection sensor located inside the heating chamber 6 detects that the actual heating temperature reaches the current heating temperature, the controller controls the resistance wire 10 to be de-energized and the electronic valve 11 to be closed; when the second heating component 26 is heated, the controller controls the heat exchange tube connected to the evaporator 3 to be The temperature control valve 35 is opened, and the heat source is passed into the evaporator 3 to evaporate and crystallize the potassium-containing mother liquor. If the actual heating temperature detected by the temperature detection sensor inside the evaporator 3 does not reach the current heating temperature, the electric heater 36 is controlled to heat the cold source supplied by the liquid storage unit 43 until the temperature detection sensor detects that the actual heating temperature inside the evaporator 3 reaches the current heating temperature, and the controller controls the temperature control valve 35 to close and controls the heater to stop heating; when the third heating component 28 is heated, the controller controls the temperature control valve 35 of the heat exchange tube connected to the dryer 4 to open, and the heat source is passed into the dryer 4 to dry the potassium sulfate suspension. If the actual heating temperature detected by the temperature detection sensor inside the dryer 4 does not reach the current heating temperature, the electric heater 36 is controlled to heat the cold source supplied by the liquid storage unit 43 until the temperature detection sensor detects that the actual heating temperature inside the dryer 4 reaches the current heating temperature, and the controller controls the temperature control valve 35 to close and controls the heater to stop heating.

[0047] Furthermore, a self-unloading structure is provided at the bottom of the shell 5, and the self-unloading structure has a support platform 37, an articulated seat 38 and a lifting mechanism 39. The top of the support platform 37 is protruding upward and is provided with an arc-shaped support portion, and the bottom of the shell 5 is tightly fitted with the inner concave surface of the arc-shaped support portion; one end of the articulated seat 38 is welded to the bottom of the shell 5 and is located on the side close to the discharge port of the rotary kiln 1, and the other end of the articulated seat 38 is welded to the top of the support platform 37; the lifting mechanism 39 is installed on the top of the support platform 37, and the output end of the lifting mechanism 39 is hinged to the bottom of the shell 5 and is located on the side close to the feeding port of the rotary kiln 1, so that the lifting mechanism 39 extends upward to drive the discharge port of the rotary kiln 1 to tilt downward, and the discharge port of the rotary kiln 1 is opened, thereby realizing automatic unloading of the rotary kiln 1. Specifically, a collecting trough 40 is provided below the discharge port of the rotary kiln 1 for collecting clinker powder, and a screw feeder 41 is provided between the collecting trough 40 and the reactor 2. The feed end of the screw feeder 41 is connected to the bottom of the collecting trough 40, and the discharge end of the screw feeder 41 passes through the outer surface of the reactor 2 and extends to be connected to the inner wall of the mixing drum 17, so that after the rotary kiln 1 automatically unloads, the clinker powder is transported to the mixing drum 17 through the screw feeder 41, thereby completing automatic feeding and improving processing efficiency.

[0048] In the above-mentioned embodiment, the lifting mechanism 39 is as follows Figure 2 and Figure 3 As shown, it includes two groups of hydraulic cylinders, a fixing ring and a connecting piece. The fixing ring is welded to the outer periphery of the shell 5. Hinge holes are respectively arranged on opposite sides of the fixing ring. One end of the connecting piece is hingedly installed with the hinge hole through a pin shaft. The other end of the connecting piece is hingedly connected to the output end of one group of hydraulic cylinders. The hydraulic cylinder is tiltedly installed on the support platform 37 toward the side close to the hinge seat, so that when the hydraulic cylinder outputs, it drives the shell 5 to rotate along the hinge end of the hinge seat 38, thereby driving the discharge port of the rotary kiln 1 to tilt downward, which is convenient for unloading.

[0049] In the above, the filter press includes a telescopic member 20, which is installed on the top of the kettle body 16. The output end of the telescopic member 20 passes through the top of the kettle body 16 and extends to the mixing drum 17, where a filter press plate 21 is installed. The outer periphery of the filter press plate 21 is slidably connected to the inner wall of the mixing drum 17. The filter press plate 21 is located above the discharge end of the spiral feeder 41, and the mesh aperture of the filter press plate 21 is smaller than the aperture of the filter hole 19. The telescopic member 20 can be an electric push rod, a cylinder or a hydraulic cylinder, so that after the water immersion treatment of the clinker powder is completed, the telescopic member 20 is started to push the filter press plate 21 downward along the inner wall of the mixing drum 17, thereby performing a filter press treatment on the mixed solution of the clinker powder and water, so that the solution is pressed out from the side of the filter hole 19 to obtain a filter cake and a potassium-containing solution.

[0050] In the above, a discharge pipe 44 is provided on one side of the bottom of the mixing drum 17 and the evaporator 3, and a valve is provided at the feed end of the discharge pipe 44, which is used to open the valve after the reaction is completed to collect the filter cake or sodium bicarbonate crystals and potassium sodium complex salt crystals. It should be further explained that a pressure relief valve is provided on the top of the evaporator 3 and the dryer 4 to ensure the stability of the internal air pressure of the evaporator 3 and the dryer 4.

Claims

1. A system for preparing agricultural potassium sulfate based on potassium feldspar powder, characterized in that: include: A rotary kiln (1), the rotary kiln (1) comprising a shell (5), a feeding cylinder (15) arranged inside the shell (5), and a heating chamber (6) arranged around the outer peripheral side of the feeding cylinder (15); a first heating component is arranged between the heating chamber (6) and the inner wall opposite to the shell (5); the two ends of the feeding cylinder (15) respectively extend along the center line direction of the shell (5) to be tightly fitted with the inner wall of the shell (5); a rotating shaft (12) is arranged inside the feeding cylinder (15); the two ends of the rotating shaft (12) respectively extend to be rotatably connected with the inner wall of the shell (5); one end of the rotating shaft (12) penetrates the inner wall of the shell (5) and is connected to the output shaft of a motor (13); a plurality of turning plates (14) are evenly installed on the outer periphery of the rotating shaft (12); the turning plate (14) extends from one end of the rotating shaft (12) to be connected with the inner wall of the feeding cylinder (15); A reaction kettle (2), the reaction kettle (2) comprising a kettle body (16), a stirring drum (17) arranged inside the kettle body (16), and a reaction chamber (18) arranged between the outer peripheral side of the stirring drum (17) and the inner side wall opposite to the kettle body (16), a magnetic stirrer (23) being arranged at the bottom of the stirring drum (17), a magnetic stirring block being rotatably mounted at the bottom end of the inner wall of the stirring drum (17), a filter hole (19) being arranged on the inner side wall of the stirring drum (17), the filter hole (19) being connected to the reaction chamber (18), a filter press and a water supply unit (22) being arranged at the top of the stirring drum (17), and a CO2 supply unit (24) being connected to the top of the reaction chamber (18); An evaporator (3), wherein a feed port of the evaporator (3) is connected to the bottom of the inner wall of the reaction chamber (18) via a pipeline and a first water pump (25), and a second heating component (26) is arranged in the evaporator (3); A dryer (4), wherein the feed end of the dryer (4) is connected to the bottom of the inner wall of the evaporator (3) through a pipeline and a second water pump (27), an acid liquid supply unit (29) and a stirring mechanism (30) are arranged on the top of the dryer (4), the output end of the stirring mechanism (30) extends to the bottom of the inner wall of the dryer (4), and a third heating component (28) is arranged in the dryer (3).

2. The agricultural potassium sulfate preparation system based on potassium feldspar powder according to claim 1, characterized in that: The first heating component has: An inner liner (7), wherein the inner liner (7) is arranged between the shell (5) and the feeding barrel (15), and the two ends of the inner liner (7) are respectively extended to be connected to the inner wall of the shell (5), and the side of the inner liner (7) close to the feeding barrel (15) forms the heating chamber (6), and the side of the inner liner (7) close to the shell (5) forms an installation chamber, and a plurality of groups of hollow bricks (8) are arranged at equal intervals in the circumferential direction in the installation chamber, and the opposite sides of the hollow bricks (8) are respectively connected to the inner wall of the shell (5) and the outer wall of the inner liner (7); A heating pipe (9) is arranged on the mid-vertical line of each group of hollow bricks (8); A resistance wire (10) is installed on each of the heating tubes (9).

3. The agricultural potassium sulfate preparation system based on potassium feldspar powder according to claim 2, characterized in that: A plurality of lining plates (42) are evenly installed along the circumferential direction on the outer circumference of the feeding cylinder (15); one end of the lining plate (42) away from the feeding cylinder (15) is slidably connected to the inner wall of the inner container (7); and the lining plate (42) divides the heating chamber (6) into a plurality of heat storage cavities; A plurality of heat exchange holes are arranged in a circumferential direction on the inner container (7), and two ends of the heat exchange holes are respectively connected to the installation chamber and the heating chamber (6), and an electronic valve (11) is installed in the heat exchange hole.

4. The agricultural potassium sulfate preparation system based on potassium feldspar powder according to claim 3, characterized in that: Two adjacent heat storage cavities are connected near adjacent ends of the shell (5), and air supply ports (31) and exhaust ports (32) are provided at two ends of the heating chamber (6) along the diagonal direction. A one-way valve and an induced draft fan (33) are installed in sequence at the air inlet end of the air supply port (31), and a pressure relief valve and a waste heat recovery system (34) are installed in sequence at the air outlet end of the exhaust port (32). The heat output end of the waste heat recovery system (34) is connected to the heat input end of the second heating component (26) and the heat input end of the third heating component (28) through a pipeline.

5. The agricultural potassium sulfate preparation system based on potassium feldspar powder according to claim 4, characterized in that: The waste heat recovery system (34) is a spiral plate heat exchanger, wherein the heat input end of the spiral plate heat exchanger is connected to the exhaust port (32) via a pipeline, the heat output end of the spiral plate heat exchanger is connected to the heat input end of the second heating component (26) and the heat input end of the third heating component (28) via a pipeline, the cold input end of the spiral plate heat exchanger is connected to the output end of the liquid storage unit (43) via a pipeline, the cold output end of the spiral plate heat exchanger is connected to the exhaust gas treatment unit, and the cold output end of the second heating component (26) and the cold output end of the third heating component (28) are respectively connected to the input end of the liquid storage unit (43).

6. The agricultural potassium sulfate preparation system based on potassium feldspar powder according to claim 5, characterized in that: The second heating component (26) and the third heating component (28) both have: a heat exchange tube, the heat exchange tube being arranged in the evaporator (3) or the dryer (4), the liquid inlet of the heat exchange tube being connected to the heat output end of the spiral plate heat exchanger through a pipeline, and the liquid outlet of the heat exchange tube being connected to the reflux port of the liquid storage unit (43) through a pipeline; A temperature control valve (35), the temperature control valve (35) being installed in the liquid inlet of the heat exchange tube; An electric heater (36) is installed at the cold input end of the spiral plate heat exchanger.

7. The agricultural potassium sulfate preparation system based on potassium feldspar powder according to claim 6, characterized in that: The first heating component, the second heating component (26) and the third heating component (28) all have a temperature adjustment unit, and the temperature adjustment unit includes: A setting module is used to set the current heating temperature of the heating component; A temperature detection sensor, used to detect the actual heating temperature of the heating component; A controller, connected to the setting module and the temperature detection sensor, is used to control the first heating component, the second heating component (26) or the third heating component (28) to start heating, and when the temperature detection sensor detects that the actual heating temperature reaches the current heating temperature, controls the corresponding heating component to stop heating.

8. The agricultural potassium sulfate preparation system based on potassium feldspar powder according to claim 1, characterized in that: A self-unloading structure is provided at the bottom of the housing (5), and the self-unloading structure has: A support platform (37), wherein the top of the support platform (37) is protruding upward and is provided with an arc-shaped support portion, and the bottom of the shell (5) is tightly fitted with the inner concave surface of the arc-shaped support portion; an articulated seat (38), one end of the articulated seat (38) being mounted on the bottom of the shell (5) and located close to the discharge port of the rotary kiln (1), and the other end of the articulated seat (38) being mounted on the top of the support platform (37); A lifting mechanism (39) is installed on the top of the support platform (37), and the output end of the lifting mechanism (39) is hinged to the bottom of the shell (5) and is located close to the feeding port of the rotary kiln (1).

9. The agricultural potassium sulfate preparation system based on potassium feldspar powder according to claim 8, characterized in that: A material collecting trough (40) is provided below the discharge port of the rotary kiln (1), and a screw feeder (41) is provided between the material collecting trough (40) and the reaction kettle (2). The feed end of the screw feeder (41) is connected to the bottom of the material collecting trough (40), and the discharge end of the screw feeder (41) passes through the outer surface of the reaction kettle (2) and extends to be connected to the inner wall of the mixing drum (17).

10. The agricultural potassium sulfate preparation system based on potassium feldspar powder according to claim 9, characterized in that: The filter press comprises a telescopic member (20), the telescopic member (20) is installed on the top of the kettle (16), the output end of the telescopic member (20) passes through the top of the kettle (16) and extends to the mixing drum (17) where a filter press plate (21) is installed, and the outer periphery of the filter press plate (21) is slidably connected to the inner wall of the mixing drum (17); The filter press plate (21) is located above the discharge end of the spiral feeder (41), and the mesh aperture of the filter press plate (21) is smaller than the aperture of the filter hole (19).

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