A continuous production system of high-purity basic zinc carbonate
By combining a static mixer, a continuous purifier, and a continuous zinc precipitation reactor, the problems of insufficient purity and high cost in the production of basic zinc carbonate are solved, achieving efficient and low-cost one-stop production, which is suitable for industrial applications.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- SICHUAN KERUI ENVIRONMENTAL PROTECTION TECH CO LTD
- Filing Date
- 2025-08-05
- Publication Date
- 2026-07-03
AI Technical Summary
Existing basic zinc carbonate production processes suffer from problems such as insufficient product purity, numerous byproducts, and high production costs. In particular, the metathesis and precipitation methods face technical bottlenecks in terms of purity and cost.
A combined system of static mixer, continuous purifier and continuous zinc precipitation reactor is adopted. The raw materials, neutralizer and impurity remover are mixed by static mixer, and ultrasonic energy is used for deep treatment. Combined with inclined plate sedimentation and reflux technology, one-stop production of basic zinc carbonate is realized.
It enables efficient and continuous production of basic zinc carbonate, significantly improving product purity and processing efficiency, reducing production costs, and making it suitable for large-scale industrial applications.
Smart Images
Figure CN224443026U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to a continuous production system for high-purity basic zinc carbonate, specifically a highly efficient supporting production system for preparing industrial high-purity basic zinc carbonate by precipitation method, belonging to the field of chemical production technology. Background Technology
[0002] There are two main production processes for basic zinc carbonate: the metathesis method and the precipitation method. The metathesis method involves adding zinc sulfate to a solution and using ammonium bicarbonate as a precipitant to generate basic zinc carbonate. The product is then filtered, washed, and dried to obtain the final product. This method uses ammonium carbonate as a precipitant, resulting in relatively low cost, but the precipitate may contain many impurities, leading to low purity of the obtained basic zinc carbonate. The precipitation method uses zinc sulfate mother liquor obtained from low-grade zinc oxide ore powder as raw material, reacting it with soda ash at high temperature (78–85°C). This method has a fast reaction rate, but existing technologies using this method to produce basic zinc carbonate generate many byproducts that are difficult to remove, requiring multiple washings to remove sulfates and causing equipment corrosion during production, which is detrimental to production. Furthermore, the raw materials used in the precipitation method, such as zinc sulfate and sodium carbonate, are relatively expensive. It is evident that the basic zinc carbonate prepared by the metathesis or precipitation method still suffers from insufficient product purity. Therefore, optimizing the production process and designing a matching high-efficiency production system remain key technical challenges that urgently need to be addressed in this field.
[0003] Chinese patent CN217921503U discloses a production system for basic zinc carbonate. This system includes a purification system, a washing system, and an MVR evaporation system. The purification system removes various metallic impurities from the raw materials, facilitating the production of a purer product. The MVR evaporation system treats the sodium sulfate mother liquor. In this system, a preheater preheats the mother liquor, a heater heats it, and a separator separates sodium sulfate and other impurities such as water. The resulting concentrated sodium sulfate solution is then collected in a buffer tank, concentrating the mother liquor produced during the production of basic sodium carbonate to a concentration suitable for sale. The washing system further removes impurities from the finished product. However, the purification system in this patent is relatively complex, potentially increasing the complexity of the processing flow and requiring higher operational and monitoring standards, thus raising production costs. Furthermore, the patent specifies that the raw material is a zinc sulfate solution, the byproduct is sodium sulfate, and it is concentrated using MVR. The main innovative technology of this patent is a continuous purification and continuous zinc precipitation production system for zinc-containing materials. It is fundamentally different from the basic zinc carbonate production system disclosed in patent CN217921503U. Utility Model Content
[0004] The purpose of this invention is to provide a continuous production system for high-purity basic zinc carbonate. This system uses a static mixer, a continuous purifier, and a continuous zinc precipitation reactor for the precipitation process of industrial basic zinc carbonate, enabling one-stop production of basic zinc carbonate and facilitating process control.
[0005] A continuous production system for high-purity basic zinc carbonate includes a static mixer, a continuous purifier, and a continuous zinc precipitation reactor. The static mixer is equipped with a raw material inlet, a neutralizing agent inlet, a removing agent inlet, a weighting agent inlet, and a mixed liquid outlet. The mixed liquid outlet is connected to the feed inlet of the continuous purifier via a pipeline. The overflow outlet of the continuous purifier is connected to the material inlet of the continuous zinc precipitation reactor via a material pipe. A dynamic mixer is installed on the material pipe, and the dynamic mixer is equipped with a precipitant inlet. The material outlet of the continuous zinc precipitation reactor is connected to a drying device via a discharge pipe, and a solid-liquid separation device is also installed on the discharge pipe.
[0006] The raw material inlet of the static mixer is connected to a zinc source storage tank, and the slag discharge port of the continuous purifier is connected to the raw material inlet of the static mixer through a purification circulation pipe; the purification circulation pipe is equipped with a circulation pump.
[0007] The static mixer is a tubular structure, with one end of the tubular structure being the raw material inlet and the other end being the mixture outlet. The sidewall of the tubular structure is provided with neutralizing agent inlet, impurity removal agent inlet, and weighting agent inlet. Multiple left-handed and right-handed blades are arranged inside the tubular structure, with the left-handed and right-handed blades alternately arranged along the sidewall of the tubular structure; the left-handed and right-handed blades are arranged in 8-12 layers respectively.
[0008] The continuous purifier includes an ultrasonic zone and a settling zone. The feed inlet and overflow outlet of the continuous purifier are respectively located at both ends along the length of the continuous purifier. The ultrasonic zone is located on the side of the continuous purifier near the feed inlet, and the settling zone is located on the side of the continuous purifier near the overflow outlet. The ultrasonic zone is equipped with a heating device and an ultrasonic generator, and the ultrasonic generator is evenly distributed in the middle of the reactor.
[0009] The ultrasonic zone is also equipped with mixing baffles. Multiple mixing baffles are arranged at the bottom of the ultrasonic zone along the direction of liquid flow. The spacing between the mixing baffles is ≥200mm. The mixing baffles are made of PP material.
[0010] The settling zone is an inclined plate settling device. The inclination angle of the inclined plate settling device is 55-65°, the spacing between the inclined plates is 50-100mm, and the inclined plates are made of PP material.
[0011] The inclined plate settler is also provided with a PAM feeding port on the side near the ultrasonic zone; the bottom of the inclined plate settler is a cone-shaped structure, and the slag discharge port is located at the bottom of the cone-shaped structure; a first centrifuge is provided at the slag discharge port, and the liquid outlet of the first centrifuge is connected to the raw material inlet of the static mixer through a purification circulation pipe; the first centrifuge is a flat plate centrifuge or a horizontal screw centrifuge.
[0012] The dynamic mixer is equipped with a first agitator; the continuous zinc precipitation reactor is equipped with a second agitator; a reflux device is provided between the continuous zinc precipitation reactor and the dynamic mixer; the reflux device includes a reflux pipe and a reflux pump; the two ends of the reflux pipe are respectively connected to the bottom of the continuous zinc precipitation reactor and the top of the dynamic mixer; and the reflux pump is installed on the reflux pipe.
[0013] The inner wall of the continuous zinc precipitation reactor is equipped with a rhomboid baffle plate located below the material inlet. The width of the rhomboid baffle plate is 1 / 12 to 1 / 10 of the reactor diameter, and the height of the baffle plate is 80% to 85% of the total height of the continuous zinc precipitation reactor.
[0014] The solid-liquid separation device is a second centrifuge, which is a horizontal screw discharge sedimentation centrifuge; the drying device is a vibrating fluidized bed, a belt dryer, or a flash dryer.
[0015] Compared with the prior art, this utility model has the following advantages and beneficial effects:
[0016] 1. This utility model combines a static mixer, a continuous purifier, and a continuous zinc precipitation reactor to handle both metathesis and precipitation methods for the production of industrial basic zinc carbonate, enabling one-stop production of basic zinc carbonate while facilitating process control. The static mixer is simple, highly reliable, and uniformly mixes liquids of different components; it boasts high and consistent mixing efficiency, providing highly repeatable and uniform mixing results, unaffected by operator intervention.
[0017] 2. This invention uses a static mixer to mix raw materials, neutralizing agent, impurity remover, and weighting agent, followed by purification in a continuous purifier. The purified liquid and separated impurities are continuously discharged from different outlets. This significantly improves processing efficiency, is suitable for large-scale industrial production, and avoids the waiting time of batch processing.
[0018] 3. In this invention, ultrasonic energy is used for deep treatment of materials. Cavitation energy can accelerate chemical reactions and promote mass transfer reactions, which is beneficial for the additive to capture heavy metal ions in the solution. The ultrasonic generators are evenly distributed in the middle of the reactor to ensure that there are no dead zones in the solution during the ultrasonic process. Attached Figure Description
[0019] Figure 1 This is a schematic diagram of the structure of the continuous production system for high-purity basic zinc carbonate in this utility model.
[0020] Figure 2 This is a schematic diagram of the static mixer and continuous purifier in this utility model.
[0021] Figure 3 This is a schematic diagram of the continuous zinc precipitation reactor in this utility model.
[0022] Figure 4 This is a schematic diagram of the baffle plate in this utility model.
[0023] The components include: 1. Static mixer; 2. Continuous purifier; 3. Continuous zinc precipitation reactor; 4. Dynamic mixer; 5. Drying device; 6. Solid-liquid separation device; 7. Zinc source storage tank.
[0024] 11. Raw material inlet; 12. Neutralizing agent inlet; 13. Impurity remover inlet; 14. Weighting agent inlet; 15. Mixture outlet; 16. Purification circulation pipe; 17. Circulation pump; 18. Left-handed impeller; 19. Right-handed impeller;
[0025] 21. Feed inlet; 22. Overflow outlet; 23. Ultrasonic zone; 24. Settling zone; 25. Heating device; 26. Ultrasonic generator; 27. Mixing baffle; 28. Inclined plate; 29. PAM feed inlet; 210. Slag discharge outlet; 211. First centrifuge;
[0026] 31. Material inlet; 32. Material pipe; 33. Material outlet; 34. Second agitator; 35. Reflux device; 36. Reflux pipe; 37. Reflux pump; 38. Rhomboid baffle plate;
[0027] 41. Precipitator inlet; 42. First stirrer. Detailed Implementation
[0028] The present invention will be further described in detail below with reference to the embodiments, but the implementation of the present invention is not limited thereto.
[0029] Example 1
[0030] This embodiment provides a method such as Figure 1The high-purity basic zinc carbonate continuous production system shown includes a static mixer 1, a continuous purifier 2, and a continuous zinc precipitation reactor 3. The static mixer 1 is equipped with a raw material inlet 11, a neutralizing agent inlet 12, a purification agent inlet 13, a weighting agent inlet 14, and a mixed liquid outlet 15. The mixed liquid outlet 15 is connected to the feed inlet 21 of the continuous purifier 2 through a pipeline. The overflow outlet 22 of the continuous purifier 2 is connected to the material inlet 31 of the continuous zinc precipitation reactor 3 through a material pipe 32. A dynamic mixer 4 is installed on the material pipe 32. The dynamic mixer 4 is equipped with a precipitant inlet 41. The material outlet 33 of the continuous zinc precipitation reactor 3 is connected to a drying device 5 through a discharge pipe. A solid-liquid separation device 6 is also installed on the discharge pipe.
[0031] In this embodiment, the zinc source material, neutralizing agent, impurity remover, and weighting agent are mixed in the static mixer 1 and then flow out through the mixed liquid outlet 15 to the continuous purifier 2 for purification. The purified liquid overflows through the overflow port 22 to the dynamic mixer 4, where it is mixed with the precipitant and then reacted in the continuous zinc precipitation reactor 3. After the reaction, it is sent to the solid-liquid separation device 6 for solid-liquid separation. The separated solid is then sent to the drying device 5 for drying before packaging.
[0032] Example 2
[0033] The difference between this embodiment and Embodiment 1 is that, in this embodiment, as... Figure 2 As shown, the static mixer 1 has a raw material inlet 11 connected to a zinc source storage tank 7. The static mixer 1 has a tubular structure, with one end of the tubular structure being the raw material inlet 11 and the other end being the mixed liquid outlet 15. The side wall of the tubular structure is provided with a neutralizing agent inlet 12, a purifying agent inlet 13, and a weighting agent inlet 14. Multiple left-handed and right-handed blades 18 and 19 are provided inside the tubular structure, and the left-handed and right-handed blades 18 and 19 are arranged alternately along the side wall of the tubular structure. The left-handed blades 18 and 19 are provided in 8-12 layers respectively. The rest of the structure is the same as in Example 1.
[0034] In this embodiment, the static mixer 1 is simple and highly reliable, capable of uniformly mixing liquids of different components; it has high and consistent mixing efficiency, providing a highly repeatable and uniform mixing effect, unaffected by the operator.
[0035] The left-hand rotor blade 18 and the right-hand rotor blade 19 are each provided with 8-12 layers; both the left-hand rotor blade 18 and the right-hand rotor blade 19 are twisted metal sheets, and the surface of the blades is treated with anti-corrosion. The blades guide the fluid to form rotation and shearing to divide, reorganize, and rearrange the fluid flow channels. The liquid flow velocity in the static mixer 1 is 0.5m / s-1.5m / s. If the flow velocity is too low, the mixing will be uneven; if the flow velocity is too high, the fluid pressure drop will be large. The static mixer 1 thoroughly mixes the zinc source raw materials (zinc sulfate, zinc chloride, etc.), neutralizing agent (10-20% sodium hydroxide solution), impurity removal agent (sodium persulfate solution, hydrogen peroxide, etc.), and recombinant agent (Na2S solution).
[0036] In this embodiment, those skilled in the art can also install flow meters and electric valves at the raw material inlet 11, neutralizer inlet 12, impurity remover inlet 13, and weighting agent inlet 14 of the static mixer 1, respectively. A pH meter is installed inside the static mixer 1, and an external PLC controller is connected to the flow meter, electric valve, and pH meter respectively. The PLC controller receives the signals from the flow meter and pH meter and processes the data, controls the electric valve to operate, thereby controlling the liquid flow rate and pH value inside the static mixer 1, and controlling the flow ratio of raw materials, neutralizer, impurity remover, and weighting agent.
[0037] Example 3
[0038] Compared with Example 2, the difference in this embodiment is that, in this embodiment, the slag discharge port 210 of the continuous purifier 2 is connected to the raw material inlet 11 of the static mixer 1 through the purification circulation pipe 16; the purification circulation pipe 16 is equipped with a circulation pump 17.
[0039] The continuous purifier 2 includes an ultrasonic zone 23 and a settling zone 24. The feed inlet 21 and the overflow outlet 22 of the continuous purifier 2 are respectively located at both ends along the length of the continuous purifier 2. The ultrasonic zone 23 is located on the side of the continuous purifier 2 near the feed inlet 21, and the settling zone 24 is located on the side of the continuous purifier 2 near the overflow outlet 22. The ultrasonic zone 23 is equipped with a heating device 25 and an ultrasonic generator 26, and the ultrasonic generator 26 is evenly distributed in the middle of the reactor.
[0040] The ultrasonic zone 23 is also provided with a mixing baffle 27. Multiple mixing baffles 27 are provided at the bottom of the ultrasonic zone 23 along the liquid flow direction. The spacing between the mixing baffles 27 is ≥200mm. The mixing baffles 27 are made of PP material.
[0041] The settling zone 24 is an inclined plate settling device. The inclined plate 28 of the inclined plate settling device has an inclination angle of 55°-65°, the spacing between the inclined plates 28 is 50-100mm, and the inclined plate 28 is made of PP material.
[0042] The inclined plate settler is also provided with a PAM feeding port 29 on the side near the ultrasonic zone 23; the bottom of the inclined plate settler is a cone-shaped structure, and the slag discharge port 210 is located at the bottom of the cone-shaped structure; the slag discharge port 210 is provided with a first centrifuge 211, and the liquid outlet of the first centrifuge 211 is connected to the raw material inlet 11 of the static mixer 1 through a purification circulation pipe 16; the first centrifuge 211 is a flat plate centrifuge or a horizontal screw centrifuge; the rest of the structure is the same as in Embodiment 1.
[0043] In this embodiment, the mixed liquid continuously enters from the inlet of the continuous purifier 2, and after being heated, ultrasonicated, and mixed in the ultrasonic zone 23, it enters the sedimentation zone 24 for sedimentation and purification. The purified liquid and the separated impurities are continuously discharged from different outlets. This significantly improves processing efficiency, is suitable for large-scale industrial production, and avoids the waiting time of batch processing. In this embodiment, the heating device 25 is a built-in coil heating device.
[0044] In this embodiment, ultrasonic energy is used to deeply process the material in the ultrasonic zone. The ultrasonic frequency is controlled at 20-40 kHz. Low frequency (20 kHz) results in stronger cavitation, while high frequency (40 kHz) provides a more uniform distribution. Cavitation energy can accelerate chemical reactions, promote mass transfer reactions, and facilitate the capture of heavy metal ions in the solution by the supplementary agent. The ultrasonic generator 26 is evenly distributed in the middle of the reactor to ensure that there are no dead zones in the solution during the ultrasonic process.
[0045] In this embodiment, the mixing baffle 27 forces material mixing and homogenization, increases flow path, or promotes reaction during liquid flow. The baffles are made of acid-resistant PP material, and the spacing between baffles is ≥200mm to avoid excessive pressure drop. Simultaneously, it ensures uniform heating, uniform ultrasonic energy distribution, and sufficient contact and mixing of additives (such as remedial agents and impurity removers) with the main material. It increases turbulence and extends residence time, optimizes flow pattern, and improves heat and mass transfer efficiency. It also promotes particle collision and agglomeration, creating conditions for subsequent sedimentation and separation (forming larger particles).
[0046] In this embodiment, the settling zone 24 is equipped with a settling chamber of sufficient volume and a specific flow channel. The inclined plate settling device has an inclination angle of 55°–65° and a plate spacing of 50–100 mm, and is made of PP material. Simultaneously, a PAM feeding port 29 is located at the front end of the inclined plate settling device. The amount of PAM added is 5–20 ppm of the total volume of the inclined plate settling device, which can further form large flocculent particles from the precipitate. Denser solid particles or heavy phases naturally sink to the bottom under gravity, while the clean, lighter phase flows upward. The bottom of the settling chamber is equipped with a conical hopper for slag discharge, with a discharge cycle of 30–60 minutes per cycle. Large particulate pollutants are separated and filtered by centrifugation using a first centrifuge 211, which can be a flatbed centrifuge or a horizontal screw centrifuge. The centrifuged liquid returns to the raw material inlet 11 of the static mixer 1 for secondary circulation treatment, and the purified liquid after settling in the settling chamber is sent to the dynamic mixer 4 for subsequent zinc precipitation.
[0047] In this embodiment, those skilled in the art can also set a temperature sensor in the ultrasonic zone 23 and a flow sensor in the feed inlet 21 of the continuous purifier 2. The temperature sensor and the flow sensor are respectively connected to the PLC controller. The PLC controller controls the heating device 25 according to the signal of the temperature sensor, thereby controlling the temperature in the ultrasonic zone 23. The PLC controller controls the ultrasonic generator 26 according to the signal of the flow sensor, thereby controlling the ultrasonic time in the ultrasonic zone 23.
[0048] Example 4
[0049] The difference between this embodiment and Embodiment 1 is that, in this embodiment, as... Figure 3 and 4 As shown, the dynamic mixer 4 is equipped with a first agitator 42; the continuous zinc precipitation reactor 3 is equipped with a second agitator 34; a reflux device 35 is provided between the continuous zinc precipitation reactor 3 and the dynamic mixer 4, the reflux device 35 includes a reflux pipe 36 and a reflux pump 37, the two ends of the reflux pipe 36 are respectively connected to the bottom of the continuous zinc precipitation reactor 3 and the top of the dynamic mixer 4, and the reflux pump 37 is installed on the reflux pipe 36; the inner wall of the continuous zinc precipitation reactor 3 is provided with a rhomboid baffle 38, the rhomboid baffle 38 is located below the material inlet 31, the width of the rhomboid baffle 38 is 1 / 12-1 / 10 of the reactor diameter, and the height of the baffle is 80%-85% of the total height of the continuous zinc precipitation reactor 3; the solid-liquid separation device 6 is a second centrifuge, the second centrifuge is a horizontal screw discharge sedimentation centrifuge; the rest of the structure is the same as in Example 1.
[0050] In this embodiment, the dynamic mixer 4 is connected to the overflow port 22 of the continuous purifier 2 and the precipitant pipeline. The mixer is driven by a motor to rotate the rotor, which is mainly spiral in shape. The stirring speed of the rotor is 60-150 r / min. The precipitant is added at a rate of 5-15% of the zinc solution flow rate. The residence time of the mixed basic zinc carbonate slurry in the mixer is controlled at 5-30 s. The mixed slurry enters the precipitation reactor for the next reaction.
[0051] In this embodiment, a rhomboid baffle plate 38 is added inside the continuous zinc deposition reactor 3. The baffle plate can change the flow direction of the fluid, increase the turbulence of the fluid, and prevent the fluid from forming laminar flow in the reactor, thereby improving the reaction efficiency. At the same time, the baffle plate can force the fluid to form a complex flow path in the reactor, increasing the contact area between reactants, thereby increasing the reaction rate.
[0052] In this embodiment, a reflux device 35 is installed between the continuous zinc precipitation reactor 3 and the dynamic mixer 4, with a reflux flow rate of 5-15% of the total feed volume of the continuous zinc precipitation reactor 3. A small amount of slurry is refluxed back to the mixer via the reflux device 35 for reaction. The main purpose of the reflux is:
[0053] 1) The reflux slurry contains pre-formed microcrystals of basic zinc carbonate. These microcrystals in the reflux slurry act as seed crystals, promoting the preferential growth of new substances on the seed crystal surface.
[0054] 2) By controlling the number of seed crystals (controlled by the reflux flow rate) and premixing conditions (mixing intensity, time), the average particle size and particle size distribution of the final product can be better controlled, making it more uniform.
[0055] 3) The reflux liquid carries part of the reaction environment (pH, temperature, ionic strength) of the main reactor back to the premixing point, which helps to buffer the impact of newly added raw materials.
[0056] In this embodiment, the slurry after the reaction in the continuous zinc precipitation reactor 3 is separated by a solid-liquid separation device 6, which is a second centrifuge. A feed pump can be installed on the inlet side of the second centrifuge via the discharge pipe. The feed pump uses frequency conversion control to ensure that the slurry is delivered to the second centrifuge at a constant flow rate and pressure. The second centrifuge is a horizontal screw discharge sedimentation centrifuge. The separated basic zinc carbonate solids are dried and packaged as finished products. The separated mother liquor is used to treat Zn²⁺. + The concentration is monitored; if it is too high, it needs to be returned to the pre-precipitation stage. Qualified mother liquor enters the concentrated brine treatment system for further processing. An MVR evaporator is typically used for evaporation and concentration.
[0057] In this invention, those skilled in the art can choose to use a complete set of drying equipment such as a vibrating fluidized bed, belt dryer, or flash dryer for the drying device 5. In this embodiment, a rotary flash dryer is used for drying, which can directly process the wet material discharged from centrifugation.
[0058] In summary, this invention, through a static mixer 1, a continuous purifier 2, a dynamic mixer 4, and a continuous zinc precipitation reactor 3, can improve the production efficiency of preparing basic zinc carbonate from a zinc source, reduce reaction residence time, lower energy consumption, and save production costs. The raw materials are uniformly mixed with neutralizing agent, impurity remover, and weighting agent in the static mixer 1, and then purified by heating, ultrasonication, and sedimentation in the continuous purifier 2. The purified liquid is then pre-reacted in the dynamic mixer 4 with the addition of a precipitant. After the pre-reaction, the liquid enters the continuous zinc precipitation reactor 3 to react and generate a slurry, which is then separated and dried to finally obtain the finished product, zinc carbonate. This method achieves high efficiency in zinc source pretreatment while ensuring both the efficiency of the zinc source pretreatment and the quality of the subsequent basic zinc carbonate product.
[0059] It should be noted that, Figure 1 and Figure 2 This is only one embodiment of the present invention. Any material conveying involved in the production system can be controlled or adjusted by setting corresponding material conveying pumps, metering pumps, flow meters, temperature sensors, pH meters, etc. as needed. The conventional settings involved in the chemical process flow are not shown one by one in the figure.
[0060] Application Example 1
[0061] In this application example, the raw material (zinc sulfate) is pumped from the zinc source storage tank 7 into the static mixer 1 at a controlled flow rate of 0.8 m / s. Then, a reconstituter, neutralizer, and impurity remover are added to the mixer through different feed ports. The amount of each additive is adjusted according to the flow rate of the zinc source solution. After the materials are completely mixed in the static mixer, they flow by gravity into a continuous purifier for reaction.
[0062] In continuous purifier 2, the feed valve is opened, and the heater is turned on. The heater temperature is set to 70℃. When the solution temperature reaches 70℃, the ultrasonic generator 26 is turned on. The ultrasonic generator 26 has a frequency of 30KHz and an ultrasonic time of 10min. After heating and ultrasonication, before the solution enters the settling chamber, the PAM valve is opened, and 10ppm of PAM is added to the solution.
[0063] After settling in settling zone 24, the purified liquid overflows through overflow port 22 at the top of the impurity removal device. The solid impurities at the bottom of settling zone 24 are transferred to a centrifuge for centrifugal separation. A flat plate centrifuge is used for separation. The separated liquid is returned to the raw material inlet 11 of the static mixer 1, and the separated solid residue is transferred to a special warehouse for temporary storage.
[0064] After settling in settling zone 24, the purified liquid overflows through overflow port 22 and is then pumped into dynamic mixer 4, with the flow rate controlled at 4 m³ / s. 3 At the same time, turn on the stirring switch of the dynamic mixer and control the rotation speed to 100 r / min. Open the precipitant inlet valve 41, and the precipitant flow rate is 15% of the zinc-containing solution flow rate. The mixed slurry is then transferred to the continuous zinc precipitation reactor 3 for reaction.
[0065] After reaction in continuous zinc precipitation reactor 3, the basic zinc carbonate is transferred to the next process. Simultaneously, reflux device 35 is activated, with a reflux rate of 10% of the total mass. The completely reacted basic zinc carbonate slurry is then transferred to a centrifuge for centrifugal separation. The centrifuged basic zinc carbonate filter cake is then dried and packaged in a flash dryer. The concentrated brine after centrifugation is transferred to the MVR evaporation system.
[0066] In this application example, the metal impurity content of the raw materials and the purified liquid after purification by the continuous purifier 2 is shown in Table 1; the performance test results of the basic zinc carbonate prepared in this application example are shown in Table 2.
[0067] Table 1. Metal impurity content of raw materials and purification solutions in application examples.
[0068]
[0069] Table 2. Performance test results of basic zinc carbonate prepared in the application examples.
[0070]
[0071] As can be seen from Tables 1 and 2, in this application example, the raw materials, neutralizing agent, impurity remover, and weighting agent are mixed by a static mixer and then purified in a continuous purifier. The purified liquid and the separated impurities are continuously discharged from different outlets, which can remove most of the metal impurities in the raw materials, facilitating the subsequent acquisition of a purer product. The purity of the basic zinc carbonate product prepared in this application example is far superior to the industry standard HG / T2523-2016. This invention can significantly improve processing efficiency, is suitable for large-scale industrial production, avoids the waiting time of batch processing, improves the purity of basic zinc carbonate, reduces the metal content in the product, and avoids the potential harm of metal elements to human health and the environment.
[0072] Application Example 2
[0073] In this application example, the raw material (zinc chloride) is pumped from the zinc source storage tank 7 into the static mixer 1 at a controlled flow rate of 1.0 m / s. Then, a reconstituter, neutralizer, and impurity remover are added to the mixer through different feed ports. The amount of each additive is adjusted according to the flow rate of the zinc source solution. After the materials are completely mixed in the static mixer, they flow by gravity into a continuous purifier for reaction.
[0074] In continuous purifier 2, the feed valve is opened, and the heater is turned on. The heater temperature is set to 60℃. When the solution temperature reaches 60℃, the ultrasonic generator 26 is turned on. The ultrasonic generator 26 has a frequency of 30KHz and an ultrasonic time of 10min. After heating and ultrasonication, before the solution enters the settling chamber, the PAM valve is opened, and 10ppm of PAM is added to the solution.
[0075] After settling in settling zone 24, the purified liquid overflows through overflow port 22. The solid impurities at the bottom of settling zone 24 are transferred to a centrifuge for centrifugal separation. A flat plate centrifuge is used for separation. The separated liquid is returned to the raw material inlet 11 of the static mixer 1, and the separated solid residue is transferred to a special warehouse for temporary storage.
[0076] After settling in settling zone 24, the purified liquid overflows through overflow port 22 and is then pumped into dynamic mixer 4, with the flow rate controlled at 3m³ / min. 3 At the same time, control the stirring switch of the dynamic mixer to maintain a speed of 100 r / min. Open the precipitant inlet valve 41, and set the precipitant flow rate to 18% of the zinc-containing solution flow rate. The mixed slurry is then transferred to the continuous zinc precipitation reactor 3 for reaction.
[0077] After reaction in continuous zinc precipitation reactor 3, the basic zinc carbonate is transferred to the next process. Simultaneously, reflux device 35 is activated, with a reflux rate of 8% of the total mass. The completely reacted basic zinc carbonate slurry is then transferred to a centrifuge for centrifugal separation. The centrifuged basic zinc carbonate filter cake is then dried and packaged in a flash dryer. The concentrated brine after centrifugation is transferred to the MVR evaporation system.
[0078] The above description is merely a preferred embodiment of the present utility model and is not intended to limit the present utility model in any way. Any simple modifications or equivalent changes made to the above embodiments based on the technical essence of the present utility model shall fall within the protection scope of the present utility model.
Claims
1. A continuous production system for high-purity basic zinc carbonate, characterized in that: The system includes a static mixer (1), a continuous purifier (2), and a continuous zinc precipitation reactor (3). The static mixer (1) is provided with a raw material inlet (11), a neutralizer inlet (12), a purifier inlet (13), a weighting agent inlet (14), and a mixed liquid outlet (15). The mixed liquid outlet (15) is connected to the feed inlet (21) of the continuous purifier (2) through a pipe. The overflow outlet (22) of the continuous purifier (2) is connected to the material inlet (31) of the continuous zinc precipitation reactor (3) through a material pipe (32). A dynamic mixer (4) is provided on the material pipe (32). The dynamic mixer (4) is provided with a precipitant inlet (41). The material outlet (33) of the continuous zinc precipitation reactor (3) is connected to a drying device (5) through a discharge pipe. A solid-liquid separation device (6) is also provided on the discharge pipe.
2. The system for continuous production of high-purity basic zinc carbonate according to claim 1, characterized in that: The raw material inlet (11) of the static mixer (1) is connected to a zinc source storage tank (7), and the slag discharge port (210) of the continuous purifier (2) is connected to the raw material inlet (11) of the static mixer (1) through a purification circulation pipe (16); the purification circulation pipe (16) is equipped with a circulation pump (17).
3. The system for continuous production of high-purity basic zinc carbonate according to claim 1, characterized in that: The static mixer (1) is a tubular structure. One end of the tubular structure is the raw material inlet (11), and the other end of the tubular structure is the mixed liquid outlet (15). The side wall of the tubular structure is provided with a neutralizer inlet (12), a purifier inlet (13), and a weighting agent inlet (14). Multiple left-handed blades (18) and right-handed blades (19) are provided inside the tubular structure. The left-handed blades (18) and right-handed blades (19) are arranged alternately along the side wall of the tubular structure. The left-handed blades (18) and right-handed blades (19) are provided with 8-12 layers respectively.
4. The system for continuous production of high-purity basic zinc carbonate according to claim 1, characterized in that: The continuous purifier (2) includes an ultrasonic zone (23) and a settling zone (24). The feed inlet (21) and overflow outlet (22) of the continuous purifier (2) are respectively located at both ends of the continuous purifier (2) along its length. The ultrasonic zone (23) is located on the side of the continuous purifier (2) near the feed inlet (21), and the settling zone (24) is located on the side of the continuous purifier (2) near the overflow outlet (22). A heating device (25) and an ultrasonic generator (26) are provided in the ultrasonic zone (23). The ultrasonic generator (26) is evenly distributed in the middle of the reactor.
5. The continuous production system for high-purity basic zinc carbonate according to claim 4, characterized in that: The ultrasonic zone (23) is also provided with mixing baffles (27). Multiple mixing baffles (27) are provided at the bottom of the ultrasonic zone (23) along the direction of liquid flow, and the distance between the mixing baffles (27) is ≥200mm.
6. The system for continuous production of high-purity basic zinc carbonate according to claim 4, characterized in that: The settling zone (24) is an inclined plate settling device. The inclined plate (28) of the inclined plate settling device has an inclination angle of 55-65° and a spacing of 50-100mm between the inclined plates (28).
7. The system for continuous production of high-purity basic zinc carbonate according to claim 6, characterized in that: The inclined plate settler is also provided with a PAM feeding port (29) on the side near the ultrasonic zone (23); the bottom of the inclined plate settler is a cone-shaped structure, and the slag discharge port (210) is located at the bottom of the cone-shaped structure; the slag discharge port (210) is provided with a first centrifuge (211), and the liquid outlet of the first centrifuge (211) is connected to the raw material inlet (11) of the static mixer (1) through a purification circulation pipe; the first centrifuge (211) is a flat plate centrifuge or a horizontal screw centrifuge.
8. The system for continuous production of high-purity basic zinc carbonate according to claim 1, characterized in that: The dynamic mixer (4) is equipped with a first agitator (42); the continuous zinc precipitation reactor (3) is equipped with a second agitator (34); a reflux device (35) is provided between the continuous zinc precipitation reactor (3) and the dynamic mixer (4); the reflux device (35) includes a reflux pipe (36) and a reflux pump (37); the two ends of the reflux pipe (36) are respectively connected to the bottom of the continuous zinc precipitation reactor (3) and the top of the dynamic mixer (4); and the reflux pump (37) is installed on the reflux pipe (36).
9. The continuous production system for high-purity basic zinc carbonate according to claim 8, characterized in that: The inner wall of the continuous zinc precipitation reactor (3) is provided with a rhomboid baffle (38). The rhomboid baffle (38) is located below the material inlet (31). The width of the rhomboid baffle (38) is 1 / 12-1 / 10 of the reactor diameter, and the height of the baffle is 80%-85% of the total height of the continuous zinc precipitation reactor (3).
10. The system for continuous production of high-purity basic zinc carbonate according to claim 9, characterized in that: The solid-liquid separation device (6) is a second centrifuge, which is a horizontal screw discharge sedimentation centrifuge; the drying device (5) is a vibrating fluidized bed, a belt dryer, or a flash dryer.