Potassium chloride last mother liquor purification device

Abstract

The utility model relates to the technical field of production equipment, and discloses a potassium chloride last mother liquor purification device which comprises a reaction tank, a filter pressing pump, a filter, a filtrate tank, a transfer pump, a resin column, a connecting pipeline, a control valve instrument and the like, according to the device, potassium carbonate and potassium hydroxide respectively react with calcium ions and magnesium ions in the mother liquor to generate calcium carbonate precipitates and magnesium hydroxide precipitates, and the precipitates are removed through filtration; chelating resin functional atoms and metal ions are subjected to a coordination reaction to form a stable structure similar to a small molecule chelate, and sodium ions and heavy metal ions are selectively removed; the device has the advantages of convenience in processing and manufacturing, simplicity in operation, wide application range, convenience in industrial and automatic operation and the like, and has a good popularization value.

Description

Technical Field

[0001] The utility model relates to the technical field of production equipment, in particular to a potassium chloride final mother liquor purification device. Background Art

[0002] Potassium chloride is a colorless, elongated rhombus or cubic crystal or white crystalline powder, odorless, salty, easily soluble in water, soluble in glycerol, and slightly soluble in ethanol. With the improvement of people's living standards, the demand for high-grade refined potassium chloride, especially food-grade and pharmaceutical-grade potassium chloride, is increasing.

[0003] At present, the production process of food-grade potassium chloride at home and abroad is basically based on the evaporation crystallization process of the 1990s. The process generally includes dissolution, impurity removal, crystallization, separation and drying. Although this method can produce potassium chloride that meets the quality requirements, each batch of products will have excessive metal impurities such as calcium and magnesium in the later stage of production. This is because metal impurities such as calcium and magnesium will gradually accumulate in the mother liquor during the production process of potassium chloride. After multiple cycles, qualified edible potassium chloride products can no longer be crystallized. This part of the mother liquor is called the final mother liquor, which can only be used to produce industrial-grade potassium chloride, affecting the economic benefits of the enterprise.

[0004] If the final mother liquor produced in the potassium chloride production process can be purified and the metal impurities such as calcium and magnesium in this mother liquor can be removed to the maximum extent, and then reused in the production of food-grade potassium chloride, it will be beneficial to stabilize the quality of food-grade potassium chloride products, increase the yield of food-grade potassium chloride, and improve the economic benefits of the enterprise.

[0005] The utility model is based on the solubility product (Ksp) principle, using potassium carbonate to react with calcium ions in the mother liquor to generate calcium carbonate precipitate, potassium hydroxide to react with magnesium ions in the mother liquor to produce magnesium hydroxide precipitate, and the precipitate is removed by filtration; the mechanism of chelating resin adsorbing metal ions is that the functional atoms on the resin react with metal ions to form a stable structure similar to a small molecule chelate, which can selectively remove sodium ions and heavy metal ions; the purified potassium chloride final mother liquor can be fully reused in the production of food-grade potassium chloride. The device has many advantages such as convenient processing and manufacturing, simple operation, wide application range, and convenient industrialization and automation operation, and has good promotion value. Utility Model Content

[0006] 1. Technical issues to be resolved

[0007] In view of the deficiencies in the prior art, the utility model provides a device for purifying a final mother liquor of potassium chloride.

[0008] (II) Technical solution

[0009] To achieve the above-mentioned purpose, the utility model provides the following technical solutions: a potassium chloride final mother liquor purification device, comprising: a reaction tank, a filter pressure pump, a filter, a filtrate tank, a filtrate pump, a resin column, connecting pipes and control valve instruments and other components, the reaction tank, the filter pressure pump, the filter, the filtrate tank, the filtrate pump and the resin column are connected in sequence through the connecting pipe, and a control valve instrument is provided on each component;

[0010] Among them, the reaction tank is used for the calcium and magnesium ions in the final potassium chloride mother liquor to fully react and precipitate with potassium carbonate and potassium hydroxide;

[0011] Among them, the filter press pump is used to provide power for the transmission of liquid in the connecting pipe between the reaction tank and the filter;

[0012] Among them, the filter is used to remove the precipitate and impurities produced by the reaction to obtain a clarified filtrate;

[0013] The filtrate tank is used to store the filtrate from the filter to ensure that there is enough filtrate for the resin column.

[0014] Among them, the filtrate pump is used to provide power for the transmission of liquid in the connecting pipeline between the filtrate tank and the resin column;

[0015] Among them, the resin column uses the functional atoms of the chelating resin to react with metal ions to form a stable structure similar to a small molecule chelate, which can selectively remove sodium ions and heavy metal ions, and remove other metal impurities in the filtrate.

[0016] Preferably, the reaction tank is composed of a tank body, a transmission device, a stirring device, an online pH meter, an online thermometer, a heating device and other components.

[0017] The reaction tank is set up to provide a place for calcium, magnesium ions and the like in the final mother liquor of potassium chloride to fully react and precipitate with potassium carbonate and potassium hydroxide, so that the calcium and magnesium ions in the mother liquor react with potassium carbonate and potassium hydroxide to form insoluble calcium carbonate and magnesium hydroxide precipitates. The filter is used to remove the precipitate and impurities produced by the reaction to obtain a clarified filtrate. The resin column uses the functional atoms of the chelating resin to react with metal ions to form a stable structure similar to a small molecule chelate, which can selectively remove sodium ions and heavy metal ions, and remove other metal impurities in the filtrate. The filtrate tank is used to store the filtrate from the filter, and keep enough filtrate for the resin column to ensure the continuous and stable operation of the resin column.

[0018] Preferably, the lower part of the tank body is an elliptical head, and the upper part is a circular cylinder with a flat cover; the flat cover is provided with a potassium carbonate inlet, a potassium hydroxide inlet, a mother liquor inlet, an exhaust port and a manhole, and a transmission device is installed in the middle of the flat cover.

[0019] Preferably, the tank body is equipped with an online pH meter and an online thermometer, which can realize online detection of pH and temperature; a discharge port is provided at the bottom of the lower head;

[0020] A first discharge valve for controlling flow is provided on the connecting pipe of the tank body discharge port;

[0021] The stirring device is composed of a stirring shaft and a stirrer, and the stirrer is installed on the stirring shaft;

[0022] The transmission device is composed of a motor, a reducer, and a frame, and the transmission device is connected to the stirring device through a coupling;

[0023] The heating device is an inner coil heating device installed inside the tank;

[0024] A heat medium inlet is provided on the side of the tank body, and a heat medium outlet is provided on the bottom. A heat medium inlet pipe and a heat medium outlet pipe are connected to the heat medium inlet and the heat medium outlet.

[0025] Preferably, the filter press pump is a single-stage centrifugal pump, the pump inlet is connected to the discharge port of the reaction tank through a connecting pipe, the pump outlet is connected to the feed port of the filter through a connecting pipe, and a control valve is installed on the inlet and outlet connecting pipes.

[0026] Preferably, the filter is a box-type undercurrent plate and frame filter press, the filter feed port is connected to the filter press pump outlet through a connecting pipe, and the filter discharge port is connected to the filtrate tank feed port through a connecting pipe.

[0027] Preferably, the filtrate tank is a vertical storage tank with elliptical heads at the upper and lower parts, the upper head is equipped with a feed port, an exhaust port and a manhole, the lower head is equipped with a discharge port, and the lower part of the intermediate tank body is equipped with an online liquid level gauge for observing the height of the liquid level;

[0028] The second discharge valve for controlling the two discharge valves is installed on the connecting pipe on the discharge port of the filtrate tank.

[0029] Preferably, the filtrate pump is a single-stage centrifugal pump, the filtrate pump inlet is connected to the filtrate tank discharge port through a connecting pipe, and the filtrate pump outlet transports the filtrate to the resin column through a filtrate inlet pipe.

[0030] Preferably, the resin column is composed of a column body, a filter cloth, a perforated plate and a lower head;

[0031] The column is a circular cylinder with a flange at the lower end and an open upper end. A filtrate inlet pipe connected to a filtrate pump is installed in the open upper end of the column. A flow regulating valve and a mass flow meter are installed on the filtrate inlet pipe to control and measure the flow of the filtrate entering the resin column. A resin regeneration liquid inlet pipe is also installed at the open upper end.

[0032] Among them, the filter cloth is a special filter cloth resistant to acid and alkali corrosion;

[0033] Among them, the orifice plate is a circular orifice plate with many through holes;

[0034] The lower head is an elliptical head with a flange at the upper end and a discharge port at the lower end. The discharge port is connected to a three-way pipe, and control valves are installed at both ends of the three-way pipe.

[0035] The three-way pipe at the bottom of the column is connected with a purified liquid outlet pipeline and a regeneration liquid outlet pipeline, and the purified liquid outlet pipeline and the regeneration liquid outlet pipeline are respectively connected with a purified liquid outlet control valve and a regeneration liquid outlet control valve.

[0036] Preferably, the column is connected to the head through a flange, the orifice plate is located between the column flange and the lower head flange, and the filter cloth is located above the orifice plate;

[0037] The orifice plate and the head flange, and the filter cloth and the column flange are sealed with sealing rings;

[0038] The column is equipped with a chelating resin, and the height of the chelating resin is three quarters of the height of the column.

[0039] Preferably, the stirrer comprises blades, the blades are evenly provided with engaging grooves, a pipe is movably installed in the engaging groove, and the upper and lower ends of the pipe are both connected and installed with a mixing component;

[0040] The mixing component is a cylinder, a first communication hole is symmetrically opened on the circumferential surface of the mixing component, and a second communication hole is opened on the top of the mixing component;

[0041] The first communicating hole, the second communicating hole and the pipeline are connected to each other;

[0042] The mixing components are evenly arranged on the upper and lower surfaces of the blades.

[0043] (III) Beneficial effects

[0044] Compared with the prior art, the utility model provides a potassium chloride final mother liquor purification device, which has the following beneficial effects:

[0045] 1. The potassium chloride final mother liquor purification device can effectively remove calcium and magnesium ions and other metal impurities in the potassium chloride final mother liquor. The purified potassium chloride final mother liquor can be fully reused in the production of food-grade potassium chloride, which improves the quality rate of the product and increases economic benefits. The device has many advantages such as convenient processing and manufacturing, simple operation, wide application range, and convenient industrialization and automation operation, and has good promotion value.

[0046] 2. In the potassium chloride final mother liquor purification device, the blades rotate with the stirring shaft, and the mixed liquid in the reaction tank is stirred by the blades to accelerate the reaction. When the blades stir, the mixed liquid enters the first connecting hole and the second connecting hole, and is moved out from the other end at the same time. At the same time, the mixed liquid also enters the pipeline. The liquid is stirred by the first connecting hole and the second connecting hole through stirring, so as to achieve a better stirring effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] Figure 1 This is a schematic diagram of the structure of the first embodiment of the utility model;

[0048] Figure 2 This is a schematic diagram of the structure of the agitator in the second embodiment of the utility model;

[0049] Figure 3 This is a schematic diagram of the structure of the mixing component of the second embodiment of the utility model;

[0050] Figure 4 This is a schematic diagram of the structure of the mixing component of the second embodiment of the present utility model.

[0051] In the figure: 1, reaction tank; 2, filter press pump; 3, filter; 4, filtrate tank; 5, filtrate pump; 6, resin column; 11, stirring device; 12, online thermometer; 13, online pH meter; 14, heating device; 15, discharge valve; 16, transmission device; 21, control valve; 41, online liquid level gauge; 42, discharge valve; 61, flow regulating valve; 62, mass flow meter; 63, resin regeneration liquid inlet pipe; 64, chelating resin; 65, filter cloth; 66, orifice plate; 67, purified liquid outlet control valve; 68, regeneration liquid outlet control valve; 71, blade; 72, engaging groove; 73, mixing component; 74, pipeline; 75, first connecting hole; 76, second connecting hole. DETAILED DESCRIPTION

[0052] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0053] Embodiment 1

[0054] See also Figure 1A potassium chloride final mother liquor purification device comprises: a reaction tank 1, a filter pressure pump 2, a filter 3, a filtrate tank 4, a filtrate pump 5, a resin column 6, connecting pipes and control valve instruments and other components. The reaction tank 1, the filter pressure pump 2, the filter 3, the filtrate tank 4, the filtrate pump 5 and the resin column 6 are connected in sequence through the connecting pipe, and a control valve instrument is provided on each component;

[0055] Among them, reaction tank 1 is used for the calcium and magnesium ions in the final potassium chloride mother liquor to fully react and precipitate with potassium carbonate and potassium hydroxide;

[0056] The filter press pump 2 is used to provide power for the transmission of liquid in the connecting pipe between the reaction tank 1 and the filter 3;

[0057] Among them, the filter 3 is used to remove the precipitate and impurities produced by the reaction to obtain a clarified filtrate;

[0058] The filtrate tank 4 is used to store the filtrate from the filter to keep enough filtrate for the resin column;

[0059] The filtrate pump 5 is used to provide power for the transmission of liquid in the connecting pipe between the filtrate tank 4 and the resin column 6;

[0060] The resin column 6 utilizes the functional atoms of the chelating resin to react with metal ions to form a stable structure similar to a small molecule chelate, which can selectively remove sodium ions and heavy metal ions, and remove other metal impurities in the filtrate.

[0061] The reaction tank 1 is composed of a tank body, a transmission device 16, a stirring device 11, an online pH meter 13, an online thermometer 12 and a heating device 14.

[0062] The lower part of the tank body is an elliptical head, and the upper part is a circular cylinder with a flat cover; the flat cover is provided with a potassium carbonate inlet, a potassium hydroxide inlet, a mother liquor inlet, an exhaust port and a manhole, and a transmission device 16 is installed in the middle of the flat cover.

[0063] The tank body is equipped with an online pH meter 13 and an online thermometer 12, which can realize online detection of pH and temperature; a discharge port is provided at the bottom of the lower head;

[0064] A first discharge valve 15 for controlling flow is provided on the connecting pipe of the tank discharge port;

[0065] The stirring device 11 is composed of a stirring shaft and a stirrer, and the stirrer is installed on the stirring shaft;

[0066] The transmission device 16 is composed of a motor, a reducer, and a frame, and the transmission device 16 is connected to the stirring device 11 through a coupling;

[0067] The heating device 14 is an inner coil heating device installed inside the tank;

[0068] A heat medium inlet is provided on the side of the tank body, and a heat medium outlet is provided on the bottom. A heat medium inlet pipe 17 and a heat medium outlet pipe 18 are connected to the heat medium inlet and the heat medium outlet.

[0069] The filter press pump 2 is a single-stage centrifugal pump, the pump inlet is connected to the discharge port of the reaction tank 1 through a connecting pipe, the pump outlet is connected to the feed port of the filter 3 through a connecting pipe, and a control valve is installed on the inlet and outlet connecting pipes.

[0070] The filter 3 is a box-type undercurrent plate-frame filter press, the feed port of the filter 3 is connected to the outlet of the filter press pump 2 through a connecting pipe, and the discharge port of the filter 3 is connected to the feed port of the filtrate tank 4 through a connecting pipe.

[0071] The filtrate tank 4 is a vertical storage tank with elliptical heads at the upper and lower parts. The upper head is equipped with a feed port, an exhaust port and a manhole, and the lower head is equipped with a discharge port. An online liquid level gauge 41 is installed at the lower part of the intermediate tank body for observing the height of the liquid level.

[0072] The second discharge valve 42 for controlling the discharge port is installed on the connecting pipe of the filtrate tank 4.

[0073] The filtrate pump 5 is a single-stage centrifugal pump. The inlet of the filtrate pump 5 is connected to the discharge port of the filtrate tank 4 through a connecting pipe, and the outlet of the filtrate pump 5 transports the filtrate to the resin column 6 through the filtrate inlet pipe.

[0074] The resin column 6 is composed of a column body, a filter cloth 65, a perforated plate 66 and a lower head;

[0075] The column is a circular cylinder with a flange at the lower end and an open upper end. A filtrate inlet pipe connected to the filtrate pump 5 is installed in the open upper end of the column. A flow regulating valve 61 and a mass flow meter 62 are installed on the filtrate inlet pipe to control and measure the flow of the filtrate entering the resin column. A resin regeneration liquid inlet pipe 63 is also installed at the open upper end.

[0076] Among them, the filter cloth 65 is a special filter cloth resistant to acid and alkali corrosion;

[0077] Among them, the orifice plate 66 is a circular orifice plate with many through holes;

[0078] The lower head is an elliptical head with a flange at the upper end and a discharge port at the lower end. The discharge port is connected to a three-way pipe, and control valves are installed at both ends of the three-way pipe.

[0079] The three-way pipe at the bottom of the column is connected to a purified liquid outlet pipeline and a regenerated liquid outlet pipeline, and the purified liquid outlet pipeline and the regenerated liquid outlet pipeline are respectively connected to a purified liquid outlet control valve 67 and a regenerated liquid outlet control valve 68.

[0080] The column and the head are connected by flanges, the orifice plate 66 is located between the column flange and the lower head flange, and the filter cloth 65 is located on the orifice plate 66;

[0081] The orifice plate 66 and the head flange, and the filter cloth 65 and the column flange are sealed with sealing rings;

[0082] The column is provided with a chelating resin 64, and the height of the chelating resin 64 is three quarters of the height of the column.

[0083] Operation process and steps

[0084] In the first step, a proper amount of potassium chloride final mother liquor is placed in the reaction tank 1, and the transmission device 16 is turned on. The transmission device 16 drives the stirring device 11 to rotate through the coupling and is adjusted to an appropriate speed. The control valves on the heat medium inlet pipe 17 and the heat medium outlet pipe 18 are opened, and the heat medium is passed into the inner coil heating device 14 to heat the mother liquor to 80-85°C.

[0085] In the second step, appropriate amounts of solid potassium carbonate and 48% liquid potassium hydroxide are added into the reaction tank 1 to adjust the pH of the mother liquor to 9.5; when the mother liquor turns white, the transmission device 16 is turned off to allow the precipitates such as calcium carbonate and magnesium hydroxide generated in the reaction tank 1 to fully precipitate.

[0086] The third step is to reopen the transmission device 16, open the discharge valve 15 after 2 minutes, start the filter press pump 2, and transport the mother liquid after reaction and precipitation in the reaction tank 4 to the filter 3. At this time, after the mother liquid is filtered by the filter 3, the clear filtrate enters the filtrate tank 4, and the precipitate is intercepted by the filter medium (filter cloth) of the filter 3. When the liquid reaches the specified level, the fourth step is performed.

[0087] The fourth step is to open the discharge valve 42, the flow regulating valve 61, and the filtrate pump 5 to transport the filtrate through the filtrate inlet pipe to the resin column 6 for chelation treatment of metal impurity ions until the liquid level in the resin column reaches a specified height (about 10 cm higher than the resin).

[0088] The fifth step is to open the purification liquid control valve 67 and adjust the opening of the flow regulating valve 61 to the flow rate specified by the mass flow meter 62; the opening of the purification liquid control valve 67 is adjusted to keep the liquid level of the resin column stable.

[0089] The sixth step is to take samples to test various physical and chemical indicators of the purified liquid, and adjust the opening of the purified liquid control valve 67 and the flow regulating valve 61 to make the various physical and chemical indicators of the purified liquid meet the specified requirements.

[0090] Embodiment 2

[0091] On the basis of the first embodiment, the stirrer comprises a blade 71, and the blade 71 is evenly provided with a clamping groove 72, and a pipe 74 is movably installed in the clamping groove 72, and the upper and lower ends of the pipe 74 are both connected and installed with a mixing component 73;

[0092] The mixing component 73 is a cylinder, and a first communication hole 75 is symmetrically opened on the circumferential surface of the mixing component 73, and a second communication hole 76 is opened on the top of the mixing component 73;

[0093] The first communicating hole 75, the second communicating hole 76 and the pipe 74 are connected to each other;

[0094] The mixing elements 73 are evenly arranged on the upper and lower surfaces of the blade 71 .

[0095] The blade 71 rotates with the stirring shaft, and the mixed liquid in the reaction tank 1 is stirred by the blade 71 to accelerate the reaction. When the blade 71 stirs, the mixed liquid enters the first connecting hole 75 and the second connecting hole 76, and moves out from the other end. At the same time, the mixed liquid also enters the pipeline 74. The liquid is stirred by the first connecting hole 75 and the second connecting hole 76 through stirring, thereby achieving a better stirring effect.

[0096] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A potassium chloride final mother liquor purification device, comprising: The method comprises a reaction tank (1), a filter pressure pump (2), a filter (3), a filtrate tank (4), a filtrate pump (5), a resin column (6), connecting pipes and control valve instruments, wherein the reaction tank (1), the filter pressure pump (2), the filter (3), the filtrate tank (4), the filtrate pump (5) and the resin column (6) are connected in sequence through connecting pipes, and control valve instruments are provided on each component; The reaction tank (1) is used for fully reacting and precipitating the calcium and magnesium ions in the final potassium chloride mother liquor with potassium carbonate and potassium hydroxide; The filter press pump (2) is used to provide power for the transmission of liquid in the connecting pipe between the reaction tank (1) and the filter (3); The filter (3) is used to remove the precipitate and impurities produced by the reaction to obtain a clarified filtrate; The filtrate tank (4) is used to store the filtrate from the filter to ensure that there is enough filtrate for the resin column. The filtrate pump (5) is used to provide power for the transmission of liquid in the connecting pipe between the filtrate tank (4) and the resin column (6); The resin column (6) utilizes the functional atoms of the chelating resin to react with metal ions to form a stable structure similar to a small molecule chelate, which can selectively remove sodium ions and heavy metal ions and remove metal impurities in the filtrate.

2. A potassium chloride final mother liquor purification device according to claim 1, characterized in that: The reaction tank (1) is composed of a tank body, a transmission device (16), a stirring device (11), an online pH meter (13), an online thermometer (12) and a heating device (14); The lower part of the tank body is an elliptical head, and the upper part is a circular cylinder with a flat cover; the flat cover is provided with a potassium carbonate inlet, a potassium hydroxide inlet, a mother liquor inlet, an exhaust port and a manhole, and a transmission device (16) is installed in the middle of the flat cover.

3. A potassium chloride final mother liquor purification device according to claim 2, characterized in that: The tank body is equipped with an online pH meter (13) and an online thermometer (12), which can realize online detection of pH and temperature; a discharge port is provided at the bottom of the lower head; A first discharge valve (15) for controlling flow rate is provided on the connecting pipe of the tank body discharge port; The stirring device (11) is composed of a stirring shaft and a stirrer, and the stirrer is installed on the stirring shaft; The transmission device (16) is composed of an electric motor, a reducer, and a frame, and the transmission device (16) is connected to the stirring device (11) via a coupling; The heating device (14) is an inner coil heating device installed inside the tank; The side of the tank body is provided with a heat medium inlet, and the bottom is provided with a heat medium outlet, and the heat medium inlet and the heat medium outlet are connected to a heat medium inlet pipe (17) and a heat medium outlet pipe (18).

4. A potassium chloride final mother liquor purification device according to claim 1, characterized in that: The filter press pump (2) is a single-stage centrifugal pump, the pump inlet is connected to the discharge port of the reaction tank (1) through a connecting pipe, the pump outlet is connected to the feed port of the filter (3) through a connecting pipe, and a control valve is installed on the inlet and outlet connecting pipes.

5. A potassium chloride final mother liquor purification device according to claim 1, characterized in that: The filter (3) is a box-type undercurrent plate-frame filter press, the feed port of the filter (3) is connected to the outlet of the filter press pump (2) via a connecting pipe, and the discharge port of the filter (3) is connected to the feed port of the filtrate tank (4) via a connecting pipe.

6. A potassium chloride final mother liquor purification device according to claim 1, characterized in that: The filtrate tank (4) is a vertical storage tank with elliptical heads at the upper and lower parts, the upper head is equipped with a feed port, an exhaust port and a manhole, the lower head is equipped with a discharge port, and the lower part of the intermediate tank body is equipped with an online liquid level meter (41) for observing the height of the liquid level; A second discharge valve (42) for controlling the two discharge ports is installed on the connecting pipe on the discharge port of the filtrate tank (4).

7. A potassium chloride final mother liquor purification device according to claim 1, characterized in that: The filtrate pump (5) is a single-stage centrifugal pump. The inlet of the filtrate pump (5) is connected to the discharge port of the filtrate tank (4) through a connecting pipe, and the outlet of the filtrate pump (5) transports the filtrate to the resin column (6) through a filtrate inlet pipe.

8. A potassium chloride final mother liquor purification device according to claim 1, characterized in that: The resin column (6) is composed of a column body, a filter cloth (65), a perforated plate (66) and a lower head; The column is a circular cylinder with a flange at the lower end and an open upper end. A filtrate inlet pipe connected to a filtrate pump (5) is installed in the open upper end of the column. A flow regulating valve (61) and a mass flow meter (62) are installed on the filtrate inlet pipe for controlling and measuring the flow of the filtrate entering the resin column. A resin regeneration liquid inlet pipe (63) is also installed at the open upper end. Wherein, the filter cloth (65) is a filter cloth resistant to acid and alkali corrosion; The orifice plate (66) is a circular orifice plate with a plurality of through holes; The lower head is an elliptical head with a flange at the upper end and a discharge port at the lower end. The discharge port is connected to a three-way pipe, and control valves are installed at both ends of the three-way pipe. The three-way pipe at the bottom of the column is connected to a purified liquid outlet pipeline and a regeneration liquid outlet pipeline, and the purified liquid outlet pipeline and the regeneration liquid outlet pipeline are respectively connected to a purified liquid outlet control valve (67) and a regeneration liquid outlet control valve (68).

9. A potassium chloride final mother liquor purification device according to claim 8, characterized in that: The column and the head are connected via a flange, the orifice plate (66) is located between the column flange and the lower head flange, and the filter cloth (65) is located above the orifice plate (66); The orifice plate (66) and the head flange, and the filter cloth (65) and the column flange are sealed with sealing rings; A chelating resin (64) is installed in the column, and the height of the chelating resin (64) is three quarters of the height of the column.

10. A potassium chloride final mother liquor purification device according to claim 3, characterized in that: The stirrer comprises a blade (71), the blade (71) is evenly provided with engaging grooves (72), a pipe (74) is movably installed in the engaging groove (72), and a mixing component (73) is installed at both the upper and lower ends of the pipe (74); The mixing component (73) is a cylinder, a first communication hole (75) is symmetrically provided on the circumferential surface of the mixing component (73), and a second communication hole (76) is provided at the top end of the mixing component (73); The first communicating hole (75), the second communicating hole (76) and the pipeline (74) are connected to each other; The mixing components (73) are evenly arranged on the upper and lower surfaces of the blades (71).

Images