System for recovering and preparing sodium nitrate from nitrification waste liquid

Abstract

The system comprises a nitrification waste liquid pretreatment unit, a rectification deamination unit, a multi-effect evaporation and concentration unit, a crystallization and separation unit and a drying and quantitative packaging unit which are connected in sequence, and the drying and quantitative packaging unit comprises a vibrated fluidized bed dryer and an automatic packaging machine; the automatic packaging machine comprises a finished sodium nitrate storage tank, a discharging opening is formed in the bottom end of the finished sodium nitrate storage tank, a dredging mechanism is arranged in the discharging opening, a mounting platform is fixed to the bottom end of the finished sodium nitrate storage tank, and a first rotating shaft and a second rotating shaft are rotationally mounted on the mounting platform. The driving mechanism can drive the first rotating shaft to intermittently rotate, so that the first through holes in the discharging disc are sequentially aligned with the discharging opening, sodium nitrate crystals are quantitatively poured into the material storage pipe, then materials are accurately poured into a packaging barrel through the material storage pipe, efficient quantitative packaging is achieved, and the packaging efficiency is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of nitrification waste liquid recovery, and particularly to a system for recovering and preparing sodium nitrate from nitrification waste liquid. Background Art

[0002] Sodium nitrate is an inorganic compound with the chemical formula NaNO 3 , which is a hygroscopic colorless transparent trigonal crystal. It decomposes when heated to 380 °C. It is extremely soluble in water and liquid ammonia, soluble in methanol and ethanol, very slightly soluble in acetone, and slightly soluble in glycerol. It absorbs heat when dissolved in water, making the solution cold, and the aqueous solution is neutral. It is used to make nitric acid and sodium nitrite, as a component in the glass, match, enamel or ceramic industry, fertilizer, and a catalyst in the sulfuric acid industry, etc.

[0003] In the production process of molybdenum and tungsten chemical industry and flame retardants, nitrification reactions often produce waste liquids containing nitrates (such as ammonium nitrate solution). Direct discharge will cause environmental pollution and waste of resources. Traditional treatment methods mostly use neutralization or evaporation crystallization, but there are problems such as high energy consumption, low product purity, and low ammonia nitrogen recovery rate. In the prior art, there is a lack of systematic integration design for the recovery of sodium nitrate from nitrification waste liquid, resulting in scattered process steps and low efficiency. Therefore, there is an urgent need for an efficient and environmentally friendly integrated system to achieve the high-value recovery of sodium nitrate from nitrification waste liquid.

[0004] In the prior art, in the drying and quantitative packaging link, existing devices may have problems such as poor feeding and inaccurate quantification, which affect production efficiency and packaging quality. For example, during the discharging process of the finished sodium nitrate storage tank, the material is prone to blockage at the discharging port, resulting in discontinuous discharging and affecting the continuity of production; at the same time, it is difficult to ensure the accuracy of quantitative packaging, which may cause inconsistent packaging weights of products, bringing inconvenience to the sales and use of products.

[0005] Therefore, it is of great practical significance and broad application prospects to develop a system that can efficiently and environmentally recover and prepare high-purity sodium nitrate from nitrification waste liquid, and at the same time solve the problems of existing devices in aspects such as pretreatment, drying and quantitative packaging, and energy utilization. Summary of the Invention

[0006] To solve the problems mentioned in the above background art, the present invention provides a system for recovering and preparing sodium nitrate from nitrification waste liquid.

[0007] To achieve the above object, the present invention adopts the following technical solutions: A system for recovering and preparing sodium nitrate from nitrification waste liquid, comprising a nitrification waste liquid pretreatment unit, a rectification and ammonia removal unit, a multi-effect evaporation and concentration unit, a crystallization and separation unit, and a drying and quantitative packaging unit connected in sequence. The drying and quantitative packaging unit includes a vibrating fluidized bed dryer and an automatic packaging machine; The automatic packaging machine includes a finished sodium nitrate storage tank, a discharge port is provided at the bottom end of the finished sodium nitrate storage tank, a dredging mechanism is provided inside the discharge port, a mounting platform is fixed at the bottom end of the finished sodium nitrate storage tank, a first rotating shaft and a second rotating shaft are rotatably mounted on the mounting platform, the second rotating shaft is hollow, the first rotating shaft is mounted inside the second rotating shaft, a driving mechanism is mounted on the mounting platform, the driving mechanism drives the first rotating shaft to rotate intermittently, a feeding disc is fixed at the bottom end of the first rotating shaft, the top end of the feeding disc is in sliding contact with the discharge port, and a plurality of first through holes are equidistantly provided on the feeding disc, a storage pipe is fixed at the bottom end of the feeding disc and at a position corresponding to the first through hole, a fixed disc is provided on the ground directly below the feeding disc, a second through hole is provided on the fixed disc, and the position of the second through hole is staggered with the discharge port.

[0008] Preferably, the nitration waste liquid pretreatment unit comprises a neutralization adjustment tank and a purification reactor, and the distillation deamination unit comprises a distillation tower.

[0009] Preferably, the multiple-effect evaporation concentration unit includes a triple-effect evaporator, and the crystallization and separation unit includes a vacuum crystallization tank and a centrifuge.

[0010] Preferably, the driving mechanism drives the second rotating shaft to rotate continuously, and the exterior of the second rotating shaft is fixed with an inclined spatial ring, and the interior of the discharge port is movably equipped with a lifting and dredging column, on which a horizontal connecting shaft is fixed.

[0011] Preferably, one end of the horizontal connecting shaft extends to the outside of the discharge port through the vertical opening and is fixed with an arc-shaped baffle, two clamping columns are fixed on the arc-shaped baffle, and the space ring is clamped between the two clamping columns.

[0012] Preferably, the length of the arc-shaped baffle plate ensures that it can block the vertical opening when it is raised to the highest position and the lowest position.

[0013] Preferably, a connecting ring frame is fixed to the top of the lifting dredging column, a first dredging distributor is fixed to the top of the connecting ring frame, and the first dredging distributor is evenly distributed in a ring shape around the connecting ring frame.

[0014] Preferably, a second dredging device is fixed to the bottom end of the lifting dredging column, and a plurality of dredging branches are fixed to the outside of the second dredging device.

[0015] Preferably, the driving mechanism includes a rotating motor and a vertical mounting column, the output shaft of the rotating motor is fixed with a first gear and a driving disc, the outside of the second rotating shaft is fixed with a second gear, the first gear is meshed with the second gear, a third gear is fixed on the first rotating shaft, and a first semicircular arc and a second semicircular arc are respectively provided on the driving disc, the first semicircular arc and the second semicircular arc are smoothly connected, and the diameter of the first semicircular arc is smaller than the diameter of the second semicircular arc.

[0016] Preferably, a first pin shaft is fixedly installed at the top of the driving disc deviating from the circular position. The top of the first pin shaft is rotatably installed with a first connecting rod. A rack is fixedly installed at one end of the first connecting rod away from the first pin shaft. The rack is correspondingly matched with the third gear. The vertical installation column is fixed on the installation platform. A second connecting rod is rotatably installed on the vertical installation column. One end of the second connecting rod is fixedly installed with a second pin shaft. One end of the second pin shaft extends into the first semi-circular arc or the second semi-circular arc movably. The other end of the second connecting rod is rotatably connected with a third pin shaft. A third connecting rod is rotatably connected to the third pin shaft. A slider is fixedly installed on the third connecting rod. The slider is slidably installed on the back side of the rack.

[0017] Preferably, a first moving rod is slidably installed on the installation platform through a slide rail. Limit rods and locking rods are respectively fixedly installed at both ends of the first moving rod. Waist-shaped holes are formed in the limit rods. The third pin shaft penetrates through the limit rods through the waist-shaped holes. A limit tooth is fixedly installed on the locking rod. The limit tooth is correspondingly matched with the third gear.

[0018] Compared with the prior art, the beneficial effects of the present invention are as follows: 1. The driving mechanism can drive the first rotating shaft to rotate intermittently, so that the first through holes on the blanking disc are sequentially aligned with the discharging ports, quantitatively pour sodium nitrate crystals into the storage pipe, and then accurately pour the materials into the packaging barrel through the storage pipe, realizing efficient quantitative packaging and improving the packaging efficiency.

[0019] 2. The nitrification waste liquid pretreatment unit adjusts the pH value through the neutralization adjustment tank to avoid equipment corrosion, and the purification reactor removes heavy metal ions, effectively purifying the sodium nitrate solution; the rectification tower in the rectification and ammonia removal unit volatilizes ammonia gas by steam heating, and a low-ammonia sodium nitrate solution can be obtained, ensuring the quality of subsequent production.

[0020] 3. The triple-effect evaporator in the multi-effect evaporation and concentration unit adopts a series and countercurrent evaporation mode to concentrate the sodium nitrate solution to a saturated concentration, saving more than 30% of energy; in the crystallization and separation unit, sodium nitrate crystals are promoted to generate in the vacuum crystallization tank by controlling the temperature and negative pressure, and the centrifuge separates the crystals from the mother liquor, and the mother liquor can be recycled, improving the utilization rate of raw materials.

[0021] 4. When the driving mechanism drives the second rotating shaft to rotate continuously, it drives the space ring to rotate, and then makes the lifting and dredging column move up and down reciprocally. The first dredging divider at its top can stir the materials near the bottom inside the finished sodium nitrate storage tank, improving the fluidity of the materials; the second dredger at the bottom can dredge the discharging port, ensuring that the materials flow smoothly into the storage pipe and preventing blockage.

[0022] 5. The driving mechanism can convert the continuous output power of the rotating motor into the force for intermittently rotating the first rotating shaft, and the rotation angle each time is fixed. At the same time, through structures such as a slide rail, a first moving rod, a limiting rod, a locking rod, and limiting teeth, the third gear is automatically locked during the intermittent rotation of the first rotating shaft, making the stop position of the blanking disc more accurate, avoiding deviation and misalignment, and ensuring that the first through hole is accurately aligned with the discharge port. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0024] Figure 1 Structural schematic diagram of the automatic packaging machine of the present invention; Figure 2 Main perspective sectional view of the discharge port position of the finished sodium nitrate storage tank of the present invention; Figure 3 Enlarged sectional view of the discharge port position of the finished sodium nitrate storage tank of the present invention; Figure 4 Schematic diagram of the cooperation relationship between the fixed disc and the blanking disc of the present invention; Figure 5 Enlarged detail view of the blanking disc of the present invention; Figure 6 First perspective three-dimensional view of the driving mechanism of the present invention; Figure 7 Second perspective three-dimensional view of the driving mechanism of the present invention; Figure 8 Top view of the driving mechanism of the present invention; Figure 9 Flow chart of the present invention; In the figure: 1. finished sodium nitrate storage tank; 101. discharge port; 2. fixed disc; 202. packing barrel; 3. installation platform; 301. first rotating shaft; 3011. third gear; 302. blanking disc; 303. first through hole; 304. storage pipe; 305. second rotating shaft; 3051. second gear; 306. space ring; 4. lifting dredging column; 401. second dredger; 402. connecting ring frame; 403. first dredging divider; 404. horizontal connecting shaft; 405. arc baffle; 406. clamping column; 5. rotating motor; 501. first gear; 502. driving disc; 503. first semi-circular arc; 504. second semi-circular arc; 6. first pin shaft; 601. first connecting rod; 602. rack; 7. vertical installation column; 701. second connecting rod; 702. second pin shaft; 703. third pin shaft; 704. third connecting rod; 705. slider; 8. slide rail; 801. first moving rod; 802. limiting rod; 803. waist-shaped hole; 804. locking rod; 805. limiting tooth. Detailed implementation manners

[0025] To make the objectives, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Apparently, the described embodiments are some but not all of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0026] Embodiment 1

[0027] Refer to Figures 1-9 , a system for recovering and preparing sodium nitrate from nitrification waste liquid, comprising a nitrification waste liquid pretreatment unit, a rectification and ammonia removal unit, a multi-effect evaporation and concentration unit, a crystallization and separation unit, and a drying and quantitative packaging unit connected in sequence. The drying and quantitative packaging unit includes a vibrating fluidized bed dryer and an automatic packaging machine; The wet material is dried by the fluidized bed dryer to obtain finished sodium nitrate crystals, and the finished sodium nitrate crystals are added to the finished sodium nitrate storage tank 1 for quantitative packaging; The automatic packaging machine includes a finished sodium nitrate storage tank 1. A discharge port 101 is provided at the bottom end of the finished sodium nitrate storage tank 1. A dredging mechanism is provided inside the discharge port 101. An installation platform 3 is fixed at the bottom end of the finished sodium nitrate storage tank 1. A first rotating shaft 301 and a second rotating shaft 305 are rotatably installed on the installation platform 3. The second rotating shaft 305 is hollow, and the first rotating shaft 301 is installed inside the second rotating shaft 305. A driving mechanism is installed on the installation platform 3. The driving mechanism drives the first rotating shaft 301 to rotate intermittently. A blanking disc 302 is fixed at the bottom end of the first rotating shaft 301. The top end of the blanking disc 302 is in sliding contact with the discharge port 101, and a plurality of first through holes 303 are equidistantly arranged on the blanking disc 302. A storage pipe 304 is fixed at the position corresponding to the first through holes 303 at the bottom end of the blanking disc 302. On the ground, a fixed disc 2 is provided directly below the blanking disc 302. A second through hole is provided on the fixed disc 2, and the position of the second through hole is offset from the discharge port 101. A packaging barrel 202 is provided directly below the second through hole below the fixed disc 2; The driving mechanism drives the first rotating shaft 301 to rotate intermittently. Each rotation just aligns one of the first through holes 303 with the discharge port 101, so as to pour sodium nitrate crystals into the storage pipe 304. Through the continuous intermittent rotation of the first rotating shaft 301, sodium nitrate crystals can be cyclically poured into each storage pipe 304. The second through hole just corresponds to the position where one of the storage pipes 304 stays. When the storage pipe 304 filled with materials rotates directly above the second through hole, the materials can be quantitatively poured into the packaging barrel 202, thus achieving the effect of efficient quantitative packaging.

[0028] Among them, the nitrification waste liquid pretreatment unit includes a neutralization and adjustment tank and a purification reaction kettle. The rectification and ammonia removal unit includes a rectification tower. The neutralization and adjustment tank is used to receive nitrification waste liquid (including ammonium nitrate, acidic extraction liquid, etc.), and the pH is adjusted to neutral (6.5 - 7.5) by adding sodium hydroxide or nitric acid to avoid corrosion of subsequent equipment. A flocculant (such as activated magnesium oxide) is added to the purification reaction kettle to remove heavy metal ions, and impurities are separated by a filter press to obtain a preliminarily purified sodium nitrate solution. The sodium nitrate solution enters the rectification and ammonia removal unit. Multiple layers of packing are arranged inside the rectification tower, and ammonia gas is volatilized by steam heating (80 - 100 °C), ammonia water is condensed and recovered at the top, and a low-ammonia sodium nitrate solution (ammonia content ≤ 15 ppm) is output at the bottom.

[0029] Among them, the multi-effect evaporation and concentration unit includes a triple-effect evaporator. The crystallization and separation unit includes a vacuum crystallization tank and a centrifuge. The triple-effect evaporator adopts a series design and a countercurrent evaporation mode (the temperature of the first effect is 105 - 112 °C, and the temperature of the last effect is 63 - 68 °C), and the sodium nitrate solution is concentrated to a saturated concentration (40 - 45% w / w), saving more than 30% of energy; The temperature of the vacuum crystallization tank is controlled at 50 - 60 °C, and sodium nitrate crystals are promoted to form under a negative pressure environment (-0.08 ~ -0.06 MPa). Then, the crystals and mother liquor are separated by a centrifuge. The mother liquor returns to the evaporation unit for recycling, and the crystals enter the drying section.

[0030] Example 2

[0031] Refer to Figures 1-8 , the difference between this example and Example 1 is that the driving mechanism drives the second rotating shaft 305 to rotate continuously, and a spatial ring 306 is fixedly and obliquely arranged outside the second rotating shaft 305. A lifting dredging column 4 is movably installed inside the discharge port 101. A horizontal connecting shaft 404 is fixed on the lifting dredging column 4. One end of the horizontal connecting shaft 404 extends outside the discharge port 101 through a vertical opening and is fixed with an arc-shaped baffle 405. Two clamping columns 406 are fixed on the arc-shaped baffle 405, and the spatial ring 306 is clamped between the two clamping columns 406; When the second rotating shaft 305 rotates continuously, it can drive the spatial ring 306 to rotate continuously. Since the spatial ring 306 is clamped between the two clamping columns 406, as the spatial ring 306 rotates, it will drive the arc-shaped baffle 405 and the lifting dredging column 4 to move up and down reciprocally; A connecting ring frame 402 is fixed at the top end of the lifting dredging column 4, and a first dredging divider 403 is fixed at the top end of the connecting ring frame 402. The first dredging dividers 403 are evenly distributed annularly around the connecting ring frame 402. The reciprocating up and down movement of the first dredging dividers 403 can stir the materials at the position near the bottom end inside the finished sodium nitrate storage tank 1, improve the fluidity of the materials, and ensure that the materials can continuously enter the discharge port 101. A second dredging device 401 is fixed at the bottom end of the lifting dredging column 4, and multiple dredging branches are fixed outside the second dredging device 401. The second dredging device 401 can dredge the discharge port 101 to ensure that the materials can flow smoothly and continuously into the storage pipe 304, and ensure that the storage pipe 304 can be filled with materials during the stay period.

[0032] Among them, the length of the arc-shaped baffle 405 ensures that it can block the vertical opening in both the highest and lowest positions. The arc-shaped baffle 405 can block the vertical opening to prevent the materials from flowing out through the vertical opening.

[0033] Example 3

[0034] Refer to Figures 1-8, The difference between this embodiment and Embodiment 2 is that the driving mechanism includes a rotating motor 5 and a vertically installed column 7. A first gear 501 and a driving disc 502 are fixed to the output shaft of the rotating motor 5. A second gear 3051 is fixed to the outside of the second rotating shaft 305. The first gear 501 meshes with the second gear 3051. A third gear 3011 is fixed to the first rotating shaft 301. The driving disc 502 is respectively provided with a first semi-circular arc 503 and a second semi-circular arc 504. The first semi-circular arc 503 and the second semi-circular arc 504 are smoothly connected, and the diameter of the first semi-circular arc 503 is smaller than the diameter of the second semi-circular arc 504; When the rotating motor 5 is turned on, the rotating motor 5 drives the first gear 501 to rotate, and the second rotating shaft 305 can be driven to rotate continuously through the meshing of the first gear 501 and the second gear 3051.

[0035] Among them, a first pin shaft 6 is fixed to the top of the driving disc 502 deviating from the circular position. The top of the first pin shaft 6 is rotatably installed with a first connecting rod 601. A rack 602 is fixed to the end of the first connecting rod 601 away from the first pin shaft 6. The rack 602 corresponds to and matches the third gear 3011. The vertically installed column 7 is fixed to the installation platform 3. A second connecting rod 701 is rotatably installed on the vertically installed column 7. A second pin shaft 702 is fixed to one end of the second connecting rod 701. One end of the second pin shaft 702 extends into the first semi-circular arc 503 or the second semi-circular arc 504. The other end of the second connecting rod 701 is rotatably connected to a third pin shaft 703. A third connecting rod 704 is rotatably connected to the third pin shaft 703. A slider 705 is fixed to the third connecting rod 704. The slider 705 is slidably installed on the back side of the rack 602; When the rotating motor 5 is turned on to drive the driving disc 502 to rotate continuously, since the rack 602 is rotatably installed on the first pin shaft 6 through the first connecting rod 601, the driving disc 502 will push and pull the rack 602 during the rotation process. And because the second pin shaft 702 at one end of the second connecting rod 701 is stuck in the first semi-circular arc 503 or the second semi-circular arc 504, so when the second pin shaft 702 is stuck in the first semi-circular arc 503, the second connecting rod 701 (refer to Figure 8), one end of the second connecting rod 701 close to the second pin shaft 702 rotates to a position farther away from the rack 602. On the contrary, the third pin shaft 703 will be closer to the rack 602. Then, the rack 602 can be pushed towards the third gear 3011 through the third connecting rod 704 and the slider 705, ensuring that the rack 602 remains in meshing with the third gear 3011 during the process of pulling the rack 602. Therefore, the third gear 3011 can be driven to rotate by an angle. When the driving disc 502 continues to rotate and the second pin shaft 702 moves into the first semi-circular arc 503, since the diameter of the first semi-circular arc 503 is smaller than that of the second semi-circular arc 504, the second connecting rod 701 will rotate counterclockwise by an angle, thus pulling the rack 602 away from the third gear 3011. At this time, the first rotating shaft 301 will stop rotating until the second pin shaft 702 re-enters the second semi-circular arc 504 and then rotates by an angle again, thereby converting the continuous output power of the rotating motor 5 into the force for driving the intermittent rotation of the first rotating shaft 301, and the angle of each rotation is certain.

[0036] Wherein, a first moving rod 801 is slidably mounted on the mounting platform 3 through a slide rail 8. Limit rods 802 and locking rods 804 are respectively fixed at both ends of the first moving rod 801. A kidney-shaped hole 803 is formed in the limit rod 802. The third pin shaft 703 passes through the limit rod 802 through the kidney-shaped hole 803. A limit tooth 805 is fixed on the locking rod 804, and the limit tooth 805 corresponds to and matches the third gear 3011; Since the third pin shaft 703 is stuck in the kidney-shaped hole 803 on the limit rod 802, when the second connecting rod 701 rotates, the first moving rod 801 can be pulled to slide horizontally along the slide rail 8. When the second connecting rod 701 rotates and pulls the rack 602 away from the third gear 3011, the first moving rod 801 will be pulled to move and drive the locking rod 804 closer to the third gear 3011, so that the limit tooth 805 is stuck on the third gear 3011, ensuring that the third gear 3011 will not rotate. Thus, the purpose of automatically locking the third gear 3011 during the intermittent rotation of the third gear 3011 can be achieved, making the stop position of the blanking disc 302 more accurate. When the blanking disc 302 stops, one of the first through holes 303 can accurately align with the discharge port 101 without offset or misalignment.

[0037] In the description of the present invention, it should be understood that the orientation or positional relationship indicated by the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation to the present invention.

[0038] In the present invention, unless otherwise clearly defined and limited, the terms "set", "install", "connect", "couple", "fix", etc. should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or integrated; it can be a mechanical connection, a direct connection, or an indirect connection through an intermediate medium, and it can be the communication inside two elements or the interaction relationship between two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0039] The control mode of the present invention is automatically controlled by a controller. The control circuit of the controller can be realized by simple programming by those skilled in the art. The provision of power also belongs to the common knowledge in the art. And the present invention is mainly used to protect mechanical devices, so the control mode and circuit connection of the present invention will not be explained in detail.

[0040] The above are only the preferred specific embodiments of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present invention, according to the technical solution of the present invention and its inventive concept, makes equivalent substitutions or changes, and should be covered by the protection scope of the present invention.

Claims

1. A system for recovering sodium nitrate from nitration waste liquid, comprising a nitration waste liquid pretreatment unit, a distillation deamination unit, a multi-effect evaporation concentration unit, a crystallization and separation unit, and a drying and quantitative packaging unit connected in sequence, characterized in that: The drying and quantitative packaging unit includes a vibrating fluidized bed dryer and an automatic packaging machine; The automatic packaging machine comprises a finished sodium nitrate storage tank (1), wherein a discharge port (101) is provided at the bottom end of the finished sodium nitrate storage tank (1), a dredging mechanism is provided inside the discharge port (101), a mounting platform (3) is fixed at the bottom end of the finished sodium nitrate storage tank (1), a first rotating shaft (301) and a second rotating shaft (305) are rotatably mounted on the mounting platform (3), the second rotating shaft (305) is hollow, the first rotating shaft (301) is mounted inside the second rotating shaft (305), and a driving mechanism is mounted on the mounting platform (3), the driving mechanism drives the first rotating shaft (301) to rotate. 01) intermittently rotates, a feeding disc (302) is fixed at the bottom end of the first rotating shaft (301), the top end of the feeding disc (302) is in sliding contact with the discharge port (101), and a plurality of first through holes (303) are equidistantly provided on the feeding disc (302), a material storage pipe (304) is fixed at the bottom end of the feeding disc (302) and at positions corresponding to the first through holes (303), a fixed disc (2) is provided on the ground directly below the feeding disc (302), a second through hole is provided on the fixed disc (2), and the position of the second through hole is staggered with the discharge port (101).

2. A system for recovering sodium nitrate from nitration waste liquid according to claim 1, characterized in that: The nitration waste liquid pretreatment unit comprises a neutralization adjustment tank and a purification reactor, and the distillation deamination unit comprises a distillation tower.

3. A system for recovering sodium nitrate from nitration waste liquid according to claim 1, characterized in that: The multi-effect evaporation concentration unit comprises a triple-effect evaporator, and the crystallization and separation unit comprises a vacuum crystallization tank and a centrifuge.

4. A system for recovering sodium nitrate from nitration waste liquid according to claim 1, characterized in that: The driving mechanism drives the second rotating shaft (305) to rotate continuously, and the outer portion of the second rotating shaft (305) is fixed with a tilted space ring (306), and the inner portion of the discharge port (101) is movably provided with a lifting dredging column (4), and a horizontal connecting shaft (404) is fixed on the lifting dredging column (4).

5. A system for recovering sodium nitrate from nitration waste liquid according to claim 4, characterized in that: One end of the horizontal connecting shaft (404) extends to the outside of the discharge port (101) through a vertical opening and is fixed with an arc-shaped baffle (405), on which two clamping columns (406) are fixed, and the space ring (306) is clamped between the two clamping columns (406).

6. A system for recovering sodium nitrate from nitration waste liquid according to claim 5, characterized in that: The length of the arc-shaped baffle (405) ensures that it can block the vertical opening when it is raised to the highest position or the lowest position.

7. A system for recovering sodium nitrate from nitration waste liquid according to claim 4, characterized in that: A connecting ring frame (402) is fixed to the top of the lifting dredging column (4), and a first dredging distributor (403) is fixed to the top of the connecting ring frame (402). The first dredging distributor (403) is evenly distributed in a ring shape around the connecting ring frame (402).

8. A system for recovering sodium nitrate from nitration waste liquid according to claim 7, characterized in that: A second dredging device (401) is fixed to the bottom end of the lifting dredging column (4), and a plurality of dredging branches are fixed to the outside of the second dredging device (401).

9. A system for recovering sodium nitrate from nitration waste liquid according to claim 4, characterized in that: The driving mechanism comprises a rotating motor (5) and a vertical mounting column (7); a first gear (501) and a driving disc (502) are fixed to the output shaft of the rotating motor (5); a second gear (3051) is fixed to the outside of the second rotating shaft (305); the first gear (501) is meshed with the second gear (3051); a third gear (3011) is fixed to the first rotating shaft (301); a first semicircular arc (503) and a second semicircular arc (504) are respectively provided on the driving disc (502); the first semicircular arc (503) and the second semicircular arc (504) are smoothly connected, and the diameter of the first semicircular arc (503) is smaller than the diameter of the second semicircular arc (504).

10. A system for recovering sodium nitrate from nitration waste liquid according to claim 9, characterized in that: A first pin shaft (6) is fixed at a position deviating from the circle at the top of the driving disc (502); a first connecting rod (601) is rotatably mounted at the top of the first pin shaft (6); a rack (602) is fixed at one end of the first connecting rod (601) away from the first pin shaft (6); the rack (602) corresponds to and matches the third gear (3011); a vertical mounting column (7) is fixed on the mounting platform (3); a second connecting rod (701) is rotatably mounted on the vertical mounting column (7); and the second connecting rod (701) is rotatably mounted on the second connecting rod (701). A second pin shaft (702) is fixed to one end of the rod (701), one end of the second pin shaft (702) movably extends into the first semicircular arc (503) or the second semicircular arc (504), the other end of the second connecting rod (701) is rotatably connected to a third pin shaft (703), the third connecting rod (704) is rotatably connected to the third pin shaft (703), a slider (705) is fixed to the third connecting rod (704), and the slider (705) is slidably mounted on the back side of the rack (602).

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