A high-purity barium hydroxide octahydrate purification production system and method

Abstract

The present invention discloses a high-purity barium hydroxide octahydrate purification production system and method, belonging to the technical field of barium hydroxide octahydrate purification. It includes a raw material bin, a mother liquor tank, a dissolution tank, a precision filter, a transfer tank, a DTB crystallization system, a thickener, a centrifugal separator, a dryer, a jet mill, and an automatic packaging machine that are connected in sequence. The entire processing process is continuous, and the production process is completed in a closed system, improving the efficiency and making the entire operation process safer.

Description

Technical Field

[0001] The present invention relates to the technical field of purification of barium hydroxide octahydrate, and particularly to a high-purity barium hydroxide octahydrate purification production system and method. Background Art

[0002] Barium hydroxide octahydrate Ba(OH)₂·8H₂O is an important raw material for chemical production, and is mostly used in industries such as chemical industry, light industry, and medicine. For example, it is used as a multi-functional additive in the petroleum industry, for refining barium-based grease and oils, and for producing plastic stabilizers, etc. High-quality barium hydroxide octahydrate is mainly used for the production of high-purity barium titanate by hydrothermal method and for experimental purposes.

[0003] The conventional production process of high-quality pure barium hydroxide octahydrate usually only uses physical filtration, lacking means for removing soluble ions, and the product purity is not high. It adopts single-tank batch operation, with a high operation frequency and a relatively high labor intensity for workers. Barium hydroxide is toxic, and the leakage and steam entrainment in the device are extremely likely to endanger the health of workers.

[0004] Based on solving the above problems, technical research and experiments have been carried out, and the present high-purity barium hydroxide octahydrate purification production system and method have been developed. Summary of the Invention

[0005] The purpose of the present invention is to provide a high-purity barium hydroxide octahydrate purification production system and method, which have the advantages of improving the purification efficiency and being safer in operation.

[0006] To achieve the above purpose, the technical solution adopted by the present invention is: a high-purity barium hydroxide octahydrate purification production system, including a raw material bin, a mother liquor tank, a dissolution tank, a precision filter, a transfer tank, a DTB crystallization system, a thickener, a centrifuge separator, a dryer, a jet mill, and an automatic packing machine that are connected in sequence.

[0007] Among them, the raw material bin is connected to the melting tank through a metering belt, and the mother liquor tank, the dissolution tank, the precision filter, the transfer tank, the DTB crystallization system, the thickener, the centrifuge separator, the dryer, the jet mill, and the automatic packing machine are connected in sequence through pipelines.

[0008] The top of the dissolution tank is provided with a feed inlet for receiving the materials output by the metering belt. The top of the dissolution tank is connected to a strontium removal agent storage tank through a pipeline, and the top of the dissolution tank is also connected to the mother liquor tank through a pipeline for transporting the mother liquor into the dissolution tank to dissolve the raw materials in the dissolution tank. Pumps and valves for controlling the normal transportation of materials are provided on all pipelines.

[0009] Among them, the dissolution tank includes a primary dissolution tank and a secondary dissolution tank. The feed inlet is arranged at the top of the primary dissolution tank. The strontium removal agent storage tank is communicated with the primary dissolution tank. The output ends of the primary dissolution tank and the secondary dissolution tank are connected to the input end of the precision filter through pipelines. An overflow outlet is arranged on the side wall of the primary dissolution tank, and an overflow inlet is arranged on the side wall of the secondary dissolution tank. The overflow outlet is communicated with the overflow inlet, and the height of the overflow inlet is not higher than that of the overflow outlet.

[0010] Preferably, both the side walls of the primary dissolution tank and the secondary dissolution tank are provided with interlayers. Steam inlets for allowing steam to enter the interlayers and condensate outlets for allowing the condensate in the interlayers to flow out are arranged on the side walls of the primary dissolution tank and the secondary dissolution tank.

[0011] Preferably, the side wall of the precision filter is provided with an interlayer. A steam inlet for allowing steam to enter the interlayer and a condensate outlet for allowing the condensate in the interlayer to flow out are arranged on the side wall of the precision filter.

[0012] Preferably, a serpentine pipe is arranged in the transfer tank. One end of the serpentine pipe is for steam to enter, and the other end is for condensate to discharge.

[0013] Preferably, the DTB crystallization system includes a DTB crystallizer, a crystallization cooler, a crystallization circulation pump, a crystal extraction pump and a liquid outlet pump;

[0014] The bottom of the DTB crystallizer is connected to the crystallization circulation pump through a pipeline. The output end of the crystallization circulation pump is communicated with the input end of the crystallization cooler. The output end of the transfer tank is communicated with the input end of the crystallization cooler through a pipeline. The output end of the crystallization cooler is communicated with the input end of the DTB crystallizer through a pipeline. The bottom of the DTB crystallizer is connected to the thickener through a pipeline, and a crystal extraction pump is arranged on this pipeline.

[0015] Preferably, a clear liquid overflow pipe is communicated and arranged on the side wall of the thickener. The other end of the clear liquid overflow pipe is communicated with the mother liquor tank. The liquid phase output end of the centrifuge is communicated with the mother liquor tank through a pipeline. The solid phase output end of the centrifuge is communicated with the dryer through a pipeline.

[0016] Preferably, the air flow crusher includes a feed bin, a nitrogen crusher, a cyclone collector and a pulse bag filter. The input end of the feed bin is communicated with the output end of the dryer through a pipeline. The output end of the feed bin is communicated with the input end of the nitrogen crusher. The output end of the nitrogen crusher is communicated with the input end of the cyclone collector through a pipeline. The discharge port of the cyclone collector is communicated with the input end of the automatic packaging machine through a pipeline. The air outlet end of the cyclone collector is communicated with the input end of the pulse bag filter through a pipeline. The output end of the pulse bag filter is communicated with the automatic packaging machine through a pipeline.

[0017] A purification production method of high-purity barium hydroxide octahydrate as described in claim 1, comprising the following steps:

[0018] S1. Manually transfer industrial-grade barium hydroxide octahydrate Ba(OH)₂·8H₂O to the raw material bin, measure it through a metering belt, and transport it into the first-stage dissolution tank. At the same time, transport the mother liquor in the mother liquor tank to the first-stage dissolution tank through a pipeline and stir and dissolve it with industrial-grade barium hydroxide octahydrate according to a certain mass ratio. The mass ratio of industrial-grade barium hydroxide octahydrate to the mother liquor is 9:10. After the mixed slurry stays in the first-stage dissolution tank for a period of time, it overflows into the second-stage dissolution tank for temporary storage;

[0019] S2. During the stirring and dissolution process in the first-stage dissolution tank, continuously dropwise add a liquid impurity remover, which forms precipitates with strontium, calcium, etc. in the solution;

[0020] S3. After the completely dissolved barium hydroxide solution is pressurized by a pump body, it is sent to a precision filter to filter out insoluble impurities, and the filtered solution is put into a transfer tank for temporary storage;

[0021] S4. Send the liquid in the transfer tank into a DTB crystallizer system for recrystallization to remove soluble ions;

[0022] S5. Send the crystallized barium hydroxide octahydrate into a centrifugal separator for wet-dry separation, and transport the separated solid phase to a dryer for drying. The drying is carried out under vacuum, and the temperature is controlled at 60°C;

[0023] S6. Send the dried barium hydroxide octahydrate into a jet mill for crushing, and finally transport it into an automatic packaging machine for packaging.

[0024] Preferably, in step S1, during the dissolution process, control the saturation concentration batching at 80°C, and then send it forward after heating to 90°C;

[0025] Preferably, in step S4, the temperature of the DTB crystallizer system is set at 40°C ± 2°C

[0026] Compared with the prior art, the advantages of the present invention are as follows:

[0027] First, using DTB recrystallization as a means to separate soluble ions. After multiple recrystallizations, the soluble impurities in the mother liquor increase by dozens of times, and for some control indicators in the product, it is necessary to reach the thousandth level. In this case, on the one hand, it is necessary to crystallize large particles to form the smallest ratio of crystal area to volume, reduce the entrainment of impurities on the crystal surface, and on the other hand, during the crystal growth process, it is necessary to be stably formed to avoid the entrainment of internal impurities. The DTB continuous crystallization system is equipped with on-line precision inspection instruments and regulating valves to control the flow rate, temperature, and residence time of the system, so as to achieve an ideal crystallization effect;

[0028] II. The formation process of impurity barium carbonate mainly occurs in the solid state of the material, that is, after centrifugal separation, during the drying and crushing steps. The solid is dried using a closed vacuum dryer and crushed using a nitrogen gas stream to avoid contact with carbon dioxide in the air and prevent the formation of barium carbonate.

[0029] III. Due to differences in the particle size of crystallization, the water content on the crystal surface and the internal water content, and its tendency to agglomerate, there are some slight differences in the component water content of barium hydroxide octahydrate after drying. These differences can affect the formulation accuracy of certain downstream products of customers. Therefore, an air classifier is used to crush it to a small particle size. After crushing, the barium hydroxide octahydrate system is balanced and not prone to agglomeration, achieving a mixing effect in batches, and the water content on the inner and outer surfaces of the crystal is more balanced.

[0030] IV. In traditional technologies, pipe blockage and equipment blockage often occur, especially in the filtration step. The reason is that the saturation concentration and heat preservation are not well controlled. In this technology, the saturation concentration is controlled during the dissolution step at 80°C for batching, and then heated to 90°C before being sent further. For the equipment and pipelines involved, steam tracing is used, which ensures that the material does not precipitate before entering the DTB crystallization kettle, solving the problem of pipe blockage in traditional devices.

[0031] V. Barium hydroxide is a toxic medium, so the production process is completed in a closed system. A gas collection hood is set at the feeding step to prevent dust from flying and improve the safety factor.

[0032] VI. For the heating step, it is controlled at 90°C instead of boiling the solution, and a tail gas extraction pipe is set to prevent the escape of toxic water vapor and improve the safety factor. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 is a schematic structural diagram of this embodiment;

[0034] Figure 2 is a schematic structural diagram of the dissolution tank of this embodiment;

[0035] Figure 3 is a schematic structural diagram of the precision filter of this embodiment;

[0036] Figure 4 is a schematic structural diagram of the DTB crystallization system of this embodiment;

[0037] Figure 5 is a schematic structural diagram of the thickener of this embodiment;

[0038] Figure 6 is a schematic structural diagram of the centrifugal separator of this embodiment;

[0039] Figure 7 is a schematic structural diagram of the dryer of this embodiment;

[0040] Figure 8 This is a schematic structural diagram of the airflow crusher in this embodiment. Specific implementation manner

[0041] The present invention will be further described below.

[0042] Embodiment:

[0043] As Figure 1 shown, a high-purity barium hydroxide octahydrate purification production system includes a raw material bin, a mother liquor tank, a dissolution tank, a precision filter, a transfer tank, a DTB crystallization system, a thickener, a centrifugal separator, a dryer, an airflow crusher, and an automatic packaging machine that are connected in sequence. Among them, the raw material bin is connected to the dissolution tank through a metering belt, and the mother liquor tank, the dissolution tank, the precision filter, the transfer tank, the DTB crystallization system, the thickener, the centrifugal separator, the dryer, the airflow crusher, and the automatic packaging machine are connected in sequence through pipelines. Pumps and valves for controlling the normal transportation of materials are provided on the pipelines. In this embodiment, heat-insulating layers are provided on the outer sides of the pipelines to insulate the transported slurry and prevent crystals from precipitating in the pipelines.

[0044] A butterfly valve is provided at the output end of the raw material bin. The metering belt is located directly below the output end of the raw material bin, and the output end of the metering belt is located at the feed inlet at the top of the dissolution tank to transport the material into the dissolution tank for dissolution. In this embodiment, a gas hood is provided in this feeding link to prevent dust from flying. The top of the dissolution tank is connected to the mother liquor tank through a pipeline. The pump on the pipeline at this place has a metering function and is signal-connected to the control center to control the input amount of the mother liquor, so as to cooperate with the input industrial-grade barium hydroxide octahydrate for dissolution.

[0045] In this embodiment, in order to accurately control the solution concentration in the dissolution tank, the control center is used to control the metering belt and the pump with a metering function at the pipeline for transporting the mother liquor. The metering belt is interlocked with the on-line flowmeter for the returned mother liquor. The control center adjusts the running speed of the metering belt according to the flow rate of the mother liquor, so as to control the amount of material added to the dissolution tank, and calculate the ratio accordingly.

[0046] As Figure 1 、 2As shown in the figure, in order to remove strontium ions in the dissolution tank, a strontium removal agent storage tank is connected to the top of the dissolution tank through a pipeline. A valve body with a flow meter function and a flow regulation function is provided at this pipeline to control the addition amount of the strontium removal agent. During the dissolution process, a quantitative strontium removal agent is added dropwise to form a precipitate with the strontium in the solution. In this embodiment, the valve body on this pipeline is signal-connected to the control center, and the control center calculates and controls the addition rate and total amount of the strontium removal agent according to the obtained information. In order to achieve better dissolution and reaction effects, there is a stirring paddle in the dissolution tank to stir the solution. The side wall of the dissolution tank is provided with a sandwich layer, as well as a steam inlet for steam to enter the sandwich layer and a condensate outlet for the condensate in the sandwich layer to flow out, so that the dissolution and reaction are sufficient.

[0047] Since the solubility of barium hydroxide increases with the increase of temperature, but it takes a certain time to heat up and dissolve. In this application, the dissolution tank includes a primary dissolution tank and a secondary dissolution tank. The feed inlet is arranged at the top of the primary dissolution tank. The strontium removal agent storage tank is connected to the primary dissolution tank. The output ends of the primary dissolution tank and the secondary dissolution tank are connected to the input end of the precision filter through a pipeline. An overflow outlet is opened on the side wall of the primary dissolution tank. An overflow inlet is opened on the side wall of the secondary dissolution tank. The overflow outlet is communicated with the overflow inlet. The height of the overflow inlet is not higher than the height of the overflow outlet. The side walls of both the primary dissolution tank and the secondary dissolution tank are provided with sandwich layers. The side walls of both the primary dissolution tank and the secondary dissolution tank are provided with a steam inlet for steam to enter the sandwich layer and a condensate outlet for the condensate in the sandwich layer to flow out. The setting of the secondary dissolution tank increases the heat exchange area and can also control the solid content. In this embodiment, a thermometer is arranged in the primary dissolution tank and the secondary dissolution tank and is signal-connected to the control system to monitor the temperature in the primary dissolution tank and the secondary dissolution tank in real time. When the temperature is about 80 °C, ensuring that the solid is just completely dissolved and is lower than the boiling point of the material.

[0048] As Figure 1 、 3As shown, the solution after the dissolution reaction is heated to 90°C and then transported by the pump body to the precision filter to filter insoluble impurities, such as silicon dioxide, dust impurities, calcium strontium precipitation, etc. Since the content of insoluble impurities is originally very small and the product purity requirements are high, ordinary filtering means can no longer meet the requirements. In this embodiment, an advanced microporous filter is used with a filtration accuracy of 2μm. At the same time, in order to prevent crystal precipitation from clogging the micropores during the filtration process, causing the filtration work to be unable to proceed normally, the side wall of the precision filter is provided with an interlayer, and the side wall of the precision filter is provided with a steam inlet for steam to pass into the interlayer and a condensed water outlet for condensed water in the interlayer to flow out, so as to keep the interior of the entire precision filter warm and prevent crystal precipitation after cooling and clogging the filter element. In this embodiment, in order to enable the precision filter to be used for a long time, the side wall of the precision filter is connected with a backwashing pipe and a forward flushing pipe, and the backwashing pipe is connected with a backwashing water inlet pipe and a backwashing nitrogen inlet pipe, and valves are provided on the backwashing water inlet pipe and the backwashing nitrogen inlet pipe. The positive flushing pipeline is connected with a positive flushing water inlet pipe and a positive blowing nitrogen inlet pipe, and valves are arranged on the positive flushing water inlet pipe and the positive blowing nitrogen inlet pipe. When a certain amount of slag is accumulated, the precision filter is used to blow out the liquid in the forward direction through nitrogen, and the slag is discharged in the reverse direction, and the filter can be reused.

[0049] The filtered solution is transported to a transfer tank for temporary storage. A serpentine tube is provided in the transfer tank. One end of the serpentine tube is for steam to enter, and the other end is for condensed water to discharge. The serpentine tube is used to insulate the liquid in the transfer tank to prevent crystals from precipitating in the transfer tank.

[0050] like Figure 1 , 4 As shown, the solution is then sent to the DTB crystallization system for recrystallization. The DTB crystallization system includes a DTB crystallizer, a crystallization cooler, a crystallization circulation pump, a crystal extraction pump and a liquid outlet pump. The bottom of the DTB crystallizer is connected to the crystallization circulation pump through a pipeline, and the output end of the crystallization circulation pump is connected to the input end of the crystallization cooler. The output end of the transfer tank is connected to the input end of the crystallization cooler through a pipeline. The output end of the crystallization cooler is connected to the input end of the DTB crystallizer through a pipeline. The bottom of the DTB crystallizer is connected to the thickener through a pipeline, and a crystal extraction pump is provided on the pipeline. The introduced barium hydroxide solution is mixed with the barium hydroxide slurry at the bottom of the DTB crystallizer, and then sent to the crystallization cooler through a pipeline by the crystallization circulation pump for circulation heat exchange and cooling recrystallization. After cooling, the solubility of barium hydroxide decreases, and crystals are precipitated. The temperature of the entire system is maintained at about 40°C. The purpose of recrystallization is to remove soluble ionic impurities, such as Ca 2+ , K + 、Na + , Sr 2+ , CL - 、SO42- etc. The impurity content in this part is originally very small. When the solution cools down and barium hydroxide reaches the saturated concentration and precipitates, the impurities are far from reaching the precipitation concentration, so the soluble ions are left in the mother liquor, and pure barium hydroxide octahydrate crystals are separated. After multiple recrystallization cycles, various impurity ions in the mother liquor will be enriched in the middle, and the quality of the precipitated barium hydroxide will gradually decrease. When it reaches a certain level, the mother liquor is discharged to the next process for treatment, and fresh water is added again. Usually, carbonate is added to the high-impurity mother liquor to precipitate and recover barium salts, and the remaining waste liquid is treated by evaporating salt.

[0051] After recrystallization, the barium hydroxide slurry is continuously extracted from the bottom of the DTB crystallizer by the crystal extraction pump. In this embodiment, the DTB crystallization system also includes corresponding detection and control instruments such as liquid level, temperature, and flow rate. These detection and control instruments are all connected to the control system by signals, and the obtained signals are reflected to the control system, and the overall operation is controlled by the controller.

[0052] A regulating valve and a flowmeter are interlocked at the outlet of the crystallization feed pump to control the feed flow rate and residence time. The longer the residence time, the larger the crystal particles. A regulating valve is set for the pipeline used for circulation of the crystallization cooler and is interlocked with the on-line thermometer of the DTB crystallizer to achieve the purpose of controlling the system temperature. The temperature of the crystallizer system also determines the crystallization speed and crystal nucleus size. The higher the temperature, the slower the crystallization but the denser the crystal form. The lower the temperature, the faster the crystallization but the more fragmented the crystal form. It is necessary to select a suitable temperature to balance the production energy consumption and product quality. By controlling the extraction ratio of the crystal extraction pump and the liquid discharge pump, the solid content in the DTB system is controlled, and the crystal growth interval is adjusted. Through the above means and analysis and sampling, the crystallization process is stabilized to form large and dense barium hydroxide crystal forms.

[0053] Such as Figure 1 、 5 As shown, the barium hydroxide slurry is continuously extracted from the bottom of the DTB crystallizer and sent into the thickener for thickening. A clear liquid overflow pipe is connected to the side wall of the thickener. In this embodiment, the other end of the clear liquid overflow pipe is connected to the mother liquor tank, and the clear liquid directly overflows from the top of the thickener to the mother liquor tank for reuse.

[0054] Such as Figure 1 、 6 As shown, the moisture in the thickened slurry has been greatly reduced. At this time, it can be transported to the centrifugal separator for solid-liquid separation. The solid-phase output end of the centrifugal separator is connected to the dryer through a pipeline. In this embodiment, in order to reuse the mother liquor, the liquid-phase output end of the centrifugal separator is connected to the mother liquor tank through a pipeline.

[0055] Such as Figure 1 、 7As shown, the wet barium hydroxide solid after solid-liquid separation is fed into a dryer for drying. Since the melting point of barium hydroxide octahydrate is 78°C and dehydration starts at 100°C. The temperature of conventional electric heating and steam drying is around 120°. To prevent caking and dehydration of the barium hydroxide octahydrate solid, in this embodiment, a vacuum drying method at 60°C is adopted to ensure that the quality of the barium hydroxide octahydrate solid will not be damaged during the drying process.

[0056] As Figure 1 , 8 shown, the dried barium hydroxide solid is fed into a jet mill and crushed to 10 μm. In this embodiment, the jet mill includes a feed bin, a nitrogen jet mill, a cyclone collector and a pulse jet bag filter. The input end of the feed bin is connected to the output end of the dryer through a pipeline, the output end of the feed bin is connected to the input end of the nitrogen jet mill, the output end of the nitrogen jet mill is connected to the input end of the cyclone collector through a pipeline, the discharge port of the cyclone collector is connected to the input end of an automatic packaging machine through a pipeline, the air outlet end of the cyclone collector is connected to the input end of the pulse jet bag filter through a pipeline, and the output end of the pulse jet bag filter is connected to the automatic packaging machine through a pipeline. Nitrogen is used as the circulating gas in the jet mill to prevent the formation of barium carbonate. The crushed barium hydroxide octahydrate becomes powdery and is collected by the cooperation of the cyclone collector and the pulse jet bag filter. The crushed barium hydroxide octahydrate is powdery and the particle sizes are not uniform. The diameter of the barium hydroxide octahydrate particles collected by the cyclone collector is larger than that of the barium hydroxide octahydrate particles collected by the pulse jet bag filter. The barium hydroxide octahydrate collected by the cyclone collector and the pulse jet bag filter is mixed and then transported into the automatic packaging machine for packing, so that the uniformity of the barium hydroxide octahydrate particles in the same batch is basically the same, in order to reduce the impact on the formulation accuracy of some downstream customers caused by the difference in particle size of the barium hydroxide octahydrate in different packaging bags. And the cooperation of the cyclone collector and the pulse jet bag filter is used for collection, with high collection efficiency, very uniform composition and not easy to cake. The collected barium hydroxide octahydrate solid is directly transported into the automatic packaging machine for packing, completing the purification and packing process of the whole barium hydroxide octahydrate. The whole process is continuous and efficient, and the operator does not need to directly contact with barium hydroxide.

[0057] In this embodiment, exhaust gas discharge pipes are connected to the tops of the primary dissolution tank, the secondary dissolution tank and the mother liquor tank. The exhaust gas discharge pipes discharge the exhaust gas to a supporting scrubbing tower for treatment and then discharge it to the atmosphere.

[0058] The whole production process is continuously operated and can be fully automated through a designed control system, improving production efficiency while reducing the labor intensity of operators. At the same time, all raw materials are produced in a closed environment during the whole production process, effectively reducing the contact between barium hydroxide and operators and improving the safety factor of the working environment of operators.

[0059] A purification production method of high-purity barium hydroxide octahydrate as described in claim 1, comprising the following steps:

[0060] S1. Manually transfer industrial-grade barium hydroxide octahydrate Ba(OH)₂·8H₂O to the raw material bin, measure it through a metering belt, and transport it into the first-stage dissolution tank. At the same time, transport the mother liquor in the mother liquor tank to the first-stage dissolution tank through a pipeline and stir and dissolve it with industrial-grade barium hydroxide octahydrate according to a certain mass ratio. The mass ratio of industrial-grade barium hydroxide octahydrate to the mother liquor is 9:10, and a slurry with a concentration of 27% is obtained by mixing and dissolving. After the mixed slurry stays in the first-stage dissolution tank for a period of time, it overflows into the second-stage dissolution tank for temporary storage. During the dissolution process, the temperature in the first-stage dissolution tank and the second-stage dissolution tank is controlled at 80°C. At this time, the solids in the dissolution tank are just completely dissolved. When transportation is required, set the temperature in the first-stage dissolution tank and the second-stage dissolution tank to 90°C ± 2°C and then transport it to make the solution in an unsaturated state, preventing crystals from precipitating due to temperature drop during pipeline transportation and blocking the pipeline and equipment;

[0061] S2. During the stirring and dissolution process in the first-stage dissolution tank, continuously dropwise add a liquid strontium removal agent. In this embodiment, the selected strontium removal agent is ammonium fluoride solution. After the strontium removal agent enters the first-stage dissolution tank, due to the combination of cations and fluoride ions and the solubility difference, fluoride ions preferentially combine with strontium and calcium ions to form strontium fluoride and calcium fluoride precipitates, removing strontium ions and calcium ions in the original solution;

[0062] S3. The completely dissolved barium hydroxide solution is pressurized by a pump body and sent to a precision filter to filter out insoluble impurities. The filtered solution is put into a transfer tank for heat preservation and temporary storage to avoid crystal precipitation in the transfer tank;

[0063] S4. Send the liquid in the transfer tank into the DTB crystallizer system for recrystallization to remove soluble ions. The temperature of the DTB crystallizer system is set at 40°C ± 2°C;

[0064] S5. Send the crystallized barium hydroxide octahydrate into a centrifugal separator for dry-wet separation, and transport the separated solid phase to a dryer for drying. The drying is carried out by vacuum drying, and the temperature is controlled at 60°C;

[0065] S6. Send the dried barium hydroxide octahydrate into an air flow crusher for crushing, and finally transport it to an automatic packaging machine for packaging.

[0066] The present invention uses industrial-grade barium hydroxide as raw material (first-class product index of "HG / T 2566-2014 Industrial Barium Hydroxide", 97% purity), and through a series of processes such as dissolution, chemical impurity removal, filtration, recrystallization, drying, and crushing, removes insoluble impurities and soluble ions in the raw material, and improves the purity to more than 99.5% to obtain high-purity barium hydroxide octahydrate.

[0067] Using this process technology, the achieved product quality is high (≥99.5%), far superior to the first-class product standard of ≥98% in "HGT2629-2011 Chemical Reagent Barium Hydroxide Octahydrate (Barium Hydroxide)" currently on the market.

[0068] In this article, specific examples are used to elaborate on the principles and implementation modes of the present invention. The descriptions of the above embodiments are only used to help understand the method and its core idea of the present invention; at the same time, for those of ordinary skill in the art, according to the idea of the present invention, there will be changes in the specific implementation modes and application scopes. It is possible to make changes and improvements to the present invention without exceeding the concept and scope defined by the appended claims. In summary, the content of this specification should not be construed as a limitation to the present invention.

Claims

1. A high-purity barium hydroxide octahydrate purification and production system, characterized in that: It includes a raw material bin, a mother liquor tank, a dissolution tank, a precision filter, a transfer tank, a DTB crystallization system, a thickener, a centrifugal separator, a dryer, a jet mill and an automatic packaging machine that are connected in sequence; The raw material bin is connected to the dissolution tank through a metering belt, and the mother liquor tank, the dissolution tank, the precision filter, the transfer tank, the DTB crystallization system, the thickener, the centrifugal separator, the dryer, the jet mill and the automatic packaging machine are connected in sequence through pipelines; The jet mill includes a feed bin, a nitrogen jet mill, a cyclone collector and a pulse bag filter. The input end of the feed bin is connected to the output end of the dryer through a pipeline, the output end of the feed bin is connected to the input end of the nitrogen jet mill, the output end of the nitrogen jet mill is connected to the input end of the cyclone collector through a pipeline, the discharge port of the cyclone collector is connected to the input end of the automatic packaging machine through a pipeline, the air outlet end of the cyclone collector is connected to the input end of the pulse bag filter through a pipeline, and the output end of the pulse bag filter is connected to the automatic packaging machine through a pipeline. The top of the dissolution tank is provided with a feed port for receiving the materials output by the metering belt. The top of the dissolution tank is connected to a strontium removal agent storage tank through a pipeline. The top of the dissolution tank is also connected to the mother liquor tank through a pipeline for transporting the mother liquor into the dissolution tank to dissolve the raw materials in the dissolution tank. Pumps and valves for controlling the normal transportation of materials are provided on all pipelines; Among them, the dissolution tank includes a primary dissolution tank and a secondary dissolution tank. The feed port is arranged at the top of the primary dissolution tank. The strontium removal agent storage tank is connected to the primary dissolution tank. The output ends of the primary dissolution tank and the secondary dissolution tank are connected to the input end of the precision filter through a pipeline. An overflow outlet is provided on the side wall of the primary dissolution tank. An overflow inlet is provided on the side wall of the secondary dissolution tank. The overflow outlet is connected to the overflow inlet. The height of the overflow inlet is not higher than the height of the overflow outlet; A clear liquid overflow pipe is connected to the side wall of the thickener, and the other end of the clear liquid overflow pipe is connected to the mother liquor tank. The liquid phase output end of the centrifugal separator is connected to the mother liquor tank through a pipeline, and the solid phase output end of the centrifugal separator is connected to the dryer through a pipeline.

2. The high-purity barium hydroxide octahydrate purification production system according to claim 1, characterized in that, Both the side walls of the primary dissolution tank and the secondary dissolution tank are provided with interlayers. Both the side walls of the primary dissolution tank and the secondary dissolution tank are provided with a steam inlet for steam to enter the interlayer and a condensate outlet for the condensate in the interlayer to flow out.

3. A high-purity barium hydroxide octahydrate purification production system according to claim 1, characterized in that, The side wall of the precision filter is provided with an interlayer. The side wall of the precision filter is provided with a steam inlet for steam to enter the interlayer and a condensate outlet for the condensate in the interlayer to flow out.

4. A high-purity barium hydroxide octahydrate purification and production system according to claim 1, characterized in that, A serpentine pipe is arranged in the transfer tank. One end of the serpentine pipe is for steam to enter, and the other end is for condensate to discharge.

5. A high-purity barium hydroxide octahydrate purification production system according to claim 1, characterized in that, The DTB crystallization system includes a DTB crystallizer, a crystallization cooler, a crystallization circulation pump, a crystal extraction pump and a liquid outlet pump; The bottom of the DTB crystallizer is connected to a crystallization circulation pump through a pipeline. The output end of the crystallization circulation pump is communicated with the input end of a crystallization cooler. The output end of the transfer tank is communicated with the input end of the crystallization cooler through a pipeline. The output end of the crystallization cooler is communicated with the input end of the DTB crystallizer through a pipeline. The bottom of the DTB crystallizer is communicated with a thickener through a pipeline, and a crystal extraction pump is provided on this pipeline.

6. A method for purifying and producing high-purity barium hydroxide octahydrate according to claim 1, characterized in that, It includes the following steps: S1. Manually transfer industrial-grade barium hydroxide octahydrate Ba(OH)₂·8H₂O to the raw material bin, measure it through a metering belt, and transport it into the first-stage dissolution tank. At the same time, transport the mother liquor in the mother liquor tank into the first-stage dissolution tank through a pipeline and stir and dissolve it with industrial-grade barium hydroxide octahydrate according to a certain mass ratio. The mass ratio of industrial-grade barium hydroxide octahydrate to the mother liquor is 9:

10. After the mixed slurry stays in the first-stage dissolution tank for a period of time, it overflows into the second-stage dissolution tank for temporary storage. S2. During the stirring and dissolution process of the first-stage dissolution tank, continuously dropwise add a liquid impurity remover, and this impurity remover forms precipitates with strontium and calcium in the solution. S3. The completely dissolved barium hydroxide solution is pressurized by a pump body and then sent to a precision filter to filter out insoluble impurities. The filtered solution is put into the transfer tank for temporary storage. S4. Send the liquid in the transfer tank into the DTB crystallizer system for recrystallization to remove soluble ions. S5. Send the crystallized barium hydroxide octahydrate into a centrifugal separator for dry-wet separation, and transport the separated solid phase to a dryer for drying. The drying is carried out under vacuum, and the temperature is controlled at 60°C. S6. Send the dried barium hydroxide octahydrate into an air flow crusher for crushing, and finally transport it into an automatic packaging machine for packaging.

7. A method for purifying and producing high-purity barium hydroxide octahydrate according to claim 6, characterized in that, In step S1, during the dissolution process, control the saturation concentration batching at 80°C, and then send it forward after heating to 90°C.

8. A method for purifying and producing high-purity barium hydroxide octahydrate according to claim 6, characterized in that, In step S4, the temperature of the DTB crystallizer system is set at 40°C ± 2°C.

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