Calcium-type brine acid bromine extraction system

Abstract

The utility model belongs to brine resource comprehensive utilization technical field especially relates to a kind of calcium type brine acid method extraction bromine system, it is by acidification blowing bromine unit, absorption desulfurization unit and bromine evaporation unit composition bromine element separation purification system;The absorption desulfurization unit is by primary defoaming module, absorption module, caustic wash module and secondary defoaming module composition gas and solution's recycling system;The defoaming structure in primary defoaming module, secondary defoaming module is one or two combinations in multilayer wire mesh defoaming structure, multistage baffle defoaming structure.The utility model first proposes "two-stage defoaming-two-stage absorption-gas circulation" synergistic technology, can effectively prevent calcium sulfate precipitation formation, improve production continuity;Efficient absorption and recycling sulfur dioxide, reduce cost;Promote bromine extraction efficiency and purity, reduce waste gas emission, with economic benefit and environmental benefit.

Description

Technical Field

[0001] This utility model belongs to the field of brine resource comprehensive utilization technology, and in particular relates to a calcium-type brine acid extraction bromine system. Background Technology

[0002] Bromine-containing calcium-type brine is an important resource, and the extraction of bromine from it is crucial not only for the efficient utilization of the resource but also for environmental protection and energy consumption. In China, acid extraction is commonly used for bromine extraction from marine and underground brine. However, if acidification is used for bromine extraction from calcium-type brine, the calcium content in the brine will... 2+ The reaction of SO2 used for bromine reduction produces CaSO3 / CaSO4 precipitates, leading to blockages in the blowdown tower and pipelines, as well as reduced heat transfer efficiency, thus preventing normal production and the extraction and utilization of bromine resources from the calcium brine. While attempts to improve the situation have been made, the results have been unsatisfactory, and no effective solution has yet been found.

[0003] Therefore, it is particularly important to develop an environmentally friendly and energy-saving process that can effectively extract bromine while reducing sulfur dioxide emissions and precipitate formation. Utility Model Content

[0004] Calcium-type brine is rich in calcium ions (Ca). 2+ In traditional acid bromine extraction processes, sulfur dioxide (SO2) readily combines with sulfate ions (SO42-) to form calcium sulfate (CaSO4) precipitate, leading to problems such as equipment scaling, pipeline blockage, and low bromine recovery rates. This invention addresses the technical bottlenecks in existing calcium-type brine acid bromine extraction processes, which are hampered by low sulfur dioxide (SO2) treatment efficiency and equipment blockage. It proposes a synergistic technology of "acidification oxidation-circulation absorption-dynamic defoaming" to completely eliminate calcium sulfate precipitate formation, while simultaneously achieving efficient bromine extraction and purification. This system is suitable for brine resources with high calcium ion concentrations (≥5 g / L), such as salt lake brine, oilfield water, and concentrated brine from seawater desalination, and can be widely applied to bromine production in industries such as chemical, pharmaceutical, and electronic materials.

[0005] The technical solution adopted by this utility model to solve this problem is:

[0006] A calcium-type brine acid extraction bromine system is a bromine element separation and purification system composed of an acidification and bromine blowing unit, an absorption and desulfurization unit, and a bromine distillation unit. The absorption and desulfurization unit is a gas and solution recycling system composed of a primary demister module, an absorption module, an alkaline washing module, and a secondary demister module. The demister structure in the primary and secondary demister modules is one or a combination of two of the following: a multi-layer wire mesh demister structure and a multi-stage baffle demister structure.

[0007] In the above technical solution, the acidification and bromine blowing unit includes an acidification oxidation device and a blowing tower; the absorption and desulfurization unit includes a primary demister, an absorption tower, an alkaline washing tower, and a secondary demister; and the bromine distillation unit includes a distillation device. Calcium-type brine, after being acidified and oxidized by the acidification oxidation device, enters the blowing tower, where bromine-containing gas is blown out. The bromine-containing gas passes through the primary demister to remove calcium-containing foam and impurities. The demisted bromine-containing gas then enters the absorption tower, which carries sulfur dioxide gas, to obtain a bromine-enriched solution and the absorbed gas. The bromine-enriched solution enters the distillation device for separation and purification to obtain elemental bromine, achieving elemental bromine separation and purification. The absorbed gas is then washed in the alkaline washing tower to obtain a sodium sulfite solution and the alkaline-washed gas. The sodium sulfite solution is reintroduced into the absorption tower, and the alkaline-washed gas undergoes secondary demister demisting in the secondary demister to remove residual alkaline solution or sodium sulfite impurities. The gas after secondary demistering is then reintroduced into the blowing tower, achieving gas and solution recycling.

[0008] In the above technical solution, the calcium-type brine acid bromine extraction system includes an acidification and oxidation device, a blowing tower, a primary demister equipped with a multi-layer wire mesh demister, an absorption tower, an alkaline washing tower, a secondary demister equipped with a multi-stage baffle demister, and a circulation pipeline connected in sequence; the alkaline washing tower is equipped with a NaOH solution addition port and a sodium sulfite solution outlet, and the sodium sulfite solution outlet is connected to the absorption tower through a pipeline; the secondary demister is connected to the blowing tower through a circulation pipeline.

[0009] In the above technical solution, the acidification oxidation device, absorption tower and alkaline washing tower are all equipped with temperature and concentration monitoring equipment for real-time control of reaction conditions.

[0010] In the above technical solution, the absorption tower and the alkaline washing tower adopt packed tower and plate tower structures, respectively, to optimize the absorption efficiency.

[0011] In the above technical solution, a flow control valve is provided on the circulation pipeline to regulate the circulation flow rate of gas and solution.

[0012] In the above technical solution, the acidifying agent in the acidification and oxidation device is hydrochloric acid, the oxidizing agent is chlorine, and the gas introduced into the blowing tower is air and gas after secondary defoaming.

[0013] In the above technical solution, both the primary demister and the secondary demister include a tower body, an aeration structure at the bottom of the tower body, a liquid distribution structure at the top of the tower body, and several layers of support structures inside the tower body. The multi-layer wire mesh demister or the multi-stage baffle demister is placed on the support structure.

[0014] In the above technical solution, the multi-layer wire mesh defogging structure is a disc-shaped structure with a diameter slightly smaller than the inner diameter of the tower body. The multi-layer wire mesh defogging structure includes several layers of wire mesh grids stacked sequentially. The two adjacent layers of wire mesh grids face different directions. The uppermost layer of wire mesh grids is densely covered with several upward-protruding conical defogging protrusions.

[0015] In the above technical solution, the pore size of the wire mesh demisting structure in the primary demisting tower is 10-20μm, the demisting efficiency is ≥98%, and the bottom of the primary demisting tower is provided with a drain port for discharging the intercepted foam droplets.

[0016] In the above technical solution, the multi-stage baffle demister structure is a disc-shaped structure with a diameter slightly smaller than the inner diameter of the tower body. The multi-stage baffle demister structure includes several layers of baffles stacked sequentially, with adjacent layers of baffles facing different directions. The baffles are densely covered with through holes.

[0017] In the above technical solution, the baffles in the secondary demister are wavy or sawtooth-shaped, and the demister efficiency is over 95%. The bottom of the secondary demister is provided with a drain port for discharging the separated alkaline droplets.

[0018] The advantages and positive effects of this utility model are:

[0019] 1. This utility model utilizes a multi-stage absorption-demisting synergistic system. A first-stage demisting tower is added before the absorption tower to remove calcium-containing foam and impurities. An alkaline washing tower and a second-stage demisting tower are connected in series after the absorption tower, achieving efficient purification and recycling of SO2. This solution is particularly suitable for high-calcium (Ca) SO2 systems. 2+ This approach offers a solution for industrial bromine extraction from brine with a concentration > 5 g / L, combining high efficiency, economic efficiency, and environmental friendliness.

[0020] 2. This utility model is the first to propose a coupled process of "two-stage defoaming - two-stage absorption - gas circulation", which blocks Ca through physical separation. 2+ The migration path achieves the cascade utilization of SO2 through chemical absorption and constructs a closed-loop production system through system integration, filling the technological gap of "anti-clogging-efficient absorption-low-carbon circulation" in the bromine extraction process of high-calcium brine.

[0021] 3. This invention can effectively prevent the formation of calcium sulfate precipitate, improve production continuity, efficiently absorb and recycle sulfur dioxide, reduce costs, improve bromine extraction efficiency and purity, reduce waste gas emissions, and has both economic and environmental benefits.

[0022] 4. This utility model also has the following advantages:

[0023] Significantly improved anti-clogging performance: Calcium-containing foam is removed in advance by a primary demister, preventing calcium buildup. 2+SO2 enters the absorption system; the alkaline scrubbing tower treats SO2 independently, ensuring that there is no free SO3 in the absorption tower. 2- SO4 2- Accumulation of these factors blocks the conditions for CaSO4 formation at the source, extending the equipment blockage cycle to more than 180 days.

[0024] Breakthrough in SO2 treatment efficiency: The synergistic effect of the two-stage absorption towers increases the SO2 absorption rate from 70% in the traditional process to 96.5%, reduces SO2 consumption per ton of bromine from 1.2t to 0.4t, and stabilizes the SO2 concentration in the tail gas at ≤50ppm, which meets the requirements of GB 26132-2010 "Emission Standard of Pollutants for Sulfuric Acid Industry".

[0025] Economic and environmental benefits: Eliminating scale inhibitor addition saves over 300,000 yuan annually; gas recycling reduces energy consumption by 15%-20%, and reduces the amount of calcium in bromine distillation residue. 2+ With a recovery rate of 90%, efficient extraction of bromine resources and comprehensive utilization of calcium resources are achieved.

[0026] Obvious cost savings: Equipment maintenance costs decrease by 60%-80%, saving over 500,000 yuan annually in cleaning agents and labor costs (based on an annual bromine production capacity of 100,000 tons); SO2 consumption decreases from 1.2 tons / ton of bromine to 0.4 tons / ton of bromine, resulting in annual raw material cost savings of 1.2 million yuan based on an SO2 market price of 2,000 yuan / ton; Ca in the bromine distillation residue... 2+ With a recovery rate of 90%, it can produce 20,000 tons of CaCl2 by-products annually, generating an additional revenue of 1.5 million yuan.

[0027] Implicit value of increased production capacity: Equipment blockage cycle is extended from 20 days to more than 120 days, and the annual effective production time is increased by 45 days. The annual output of bromine can be increased by 12%-15%. Based on the selling price of bromine of 25,000 yuan / ton, the annual output value will increase by 3 million to 3.75 million yuan.

[0028] Environmental compliance added value: SO2 emission concentration in exhaust gas is reduced from 180ppm to ≤50ppm, meeting the latest environmental standards (GB 26132-2010). While avoiding environmental fines, it is possible to apply for clean production subsidies, with an estimated annual increase in policy benefits of 500,000 to 800,000 yuan. Attached Figure Description

[0029] The technical solution of this utility model will be further described in detail below with reference to the accompanying drawings and embodiments. However, it should be understood that these drawings are designed for illustrative purposes only and are not intended to limit the scope of this utility model. In addition, unless otherwise specified, these drawings are intended only to conceptually illustrate the structural construction described herein and are not necessarily drawn to scale.

[0030] Figure 1 This is a system connection diagram of a calcium-type brine acid extraction bromine system;

[0031] Figure 2 This is a cross-sectional view of the demister;

[0032] Figure 3 This is a schematic diagram of the demister tower in Example 3. Figure 1 ;

[0033] Figure 4 This is a schematic diagram of the demister tower in Example 3. Figure 2 ;

[0034] Figure 5 This is a schematic diagram of the wire mesh grid structure in Example 3;

[0035] Figure 6 This is a schematic diagram of the baffle plate in Example 3;

[0036] Figure 7 This is a schematic diagram of the liquid dispersion structure in Example 4. Figure 1 ;

[0037] Figure 8 This is a schematic diagram of the liquid dispersion structure in Example 4. Figure 2 ;

[0038] Figure 9 This is a schematic diagram of the dispersion cap structure in Example 4. Figure 1 ;

[0039] Figure 10 This is a schematic diagram of the dispersion cap structure in Example 4. Figure 2 ;

[0040] In the diagram: 1-Tower body; 2-Aeration structure; 3-Liquid distribution structure; 4-Support structure; 5-Wire mesh grid; 6-Conical demister protrusion; 7-Baffle plate; 8-Circular grid support; 9-Liquid guide rod; 10-Dispersion cap. Detailed Implementation

[0041] First, it should be noted that the specific structure, features, and advantages of this utility model will be described in detail below by way of examples. However, all descriptions are for illustrative purposes only and should not be construed as limiting the utility model in any way. Furthermore, any single technical feature described or implied in the embodiments mentioned herein, or any single technical feature shown or implied in the accompanying drawings, can still be arbitrarily combined or deleted among these technical features (or their equivalents) to obtain more other embodiments of this utility model that may not be directly mentioned herein. Additionally, for the sake of simplifying the drawings, the same or similar technical features may be indicated only in one place in the same drawing.

[0042] In this utility model, unless otherwise explicitly specified and limited, the terms "installation," "setting," "connection," "fixing," and "screw-on" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Unless otherwise explicitly limited, those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances. The utility model will now be described in detail with reference to the accompanying drawings.

[0043] Example 1:

[0044] A calcium-type brine acid-based bromine extraction system includes an acidification and bromine blowing unit, an absorption and desulfurization unit, and a bromine distillation unit, which together form a bromine element separation and purification system. The absorption and desulfurization unit includes a primary demisting module, an absorption module, an alkaline washing module, and a secondary demisting module, which together form a gas and solution recycling system. Specifically:

[0045] Acidification and Bromine Blowing Unit: This unit is mainly used to acidify calcium-type brine and oxidize bromide ions in the brine to elemental bromine by blowing in gases such as air, thereby blowing out bromine-containing gas. The acidification and bromine blowing unit includes a hydrochloric acid storage tank, a chlorine dosing device, an acidification tank, an oxidation tank, and a blow-out tower.

[0046] Acidification tank: Calcium-type brine first enters the acidification tank, where an appropriate amount of acid, such as hydrochloric acid, is added to adjust the pH of the brine to 1.5-2.0. This causes the carbonate ions in the brine to be converted into carbon dioxide gas and discharged, while simultaneously creating an acidic environment for subsequent bromide ion oxidation.

[0047] Oxidation Tank: The acidified brine enters the oxidation tank. An oxidizing agent, such as chlorine, is added to the tank at a rate of 0.3-0.5 kg / ton of brine. Under suitable temperature and stirring conditions, the bromide ions in the brine are oxidized to elemental bromine. The chemical reaction equation is: 2Br₂ - +Cl2=Br2+2Cl-.

[0048] Blowout Tower: The oxidized brine enters the blowout tower, where air and other gases are blown in from the bottom. The generated elemental bromine is blown out using the air stripping principle, forming a bromine-containing gas. This bromine-containing gas then enters the subsequent processing unit.

[0049] Absorption desulfurization unit: This unit includes a primary demister, an absorption tower, an alkaline scrubbing tower, and a secondary demister;

[0050] Primary Demister: Bromine-containing gas enters the primary demister unit, where foam and tiny droplet impurities are removed through physical separation. It efficiently removes calcium-containing foam (such as CaCl2 aerosol in brine) and solid particles from bromine-containing gas, achieving a demister efficiency of over 98%, and avoiding the formation of calcium-containing foam. 2+ Entering the absorption tower, the potential risk of calcium sulfate precipitation is reduced at the source. The primary demister uses physical separation principles to purify bromine-containing gases, which is a crucial step in avoiding calcium sulfate precipitation in the bromine extraction process from calcium-type brine and ensuring efficient process operation.

[0051] Absorption Tower: Bromine-containing gas enters from the top of the absorption tower, using SO2 solution as the absorbent. Bromine oxidizes sulfur dioxide to sulfuric acid (H2SO4), and Br2 is converted to Br2. - The gas-liquid ratio (G / L) is 100-150:1. Since bromine-containing air usually contains unreacted oxidizing gases such as chlorine, these gases react with sulfur dioxide, achieving an SO2 oxidation rate of 80%, thus removing oxidizing gases from the exhaust gas. For example, the chemical equation for the reaction of chlorine with sulfur dioxide is: Cl2 + SO2 + 2H2O = H2SO4 + 2HCl; the chemical equation for the reaction of bromine with sulfur dioxide is: SO2 + Br2 + 2H2O → 2HBr + H2SO4. The absorption tower is also equipped with an absorbent distributor and a packing layer to increase the gas-liquid contact area and improve reaction efficiency.

[0052] Alkali scrubbing tower: Air containing SO2 after being treated in the absorption tower enters the alkaline scrubbing tower. A 5-10% NaOH solution is sprayed into the alkaline scrubbing tower at a liquid-to-gas ratio of 2-3 L / m³. 3 The operating temperature is maintained at 30-50℃. The alkaline absorbent is mainly used to absorb unreacted SO2 and any small amounts of acidic gases that may be present, achieving a SO2 removal rate of 99.9%, thereby further purifying the gas. The reaction equation for sulfur dioxide and sodium hydroxide is: SO2 + 2NaOH = Na2SO3 + H2O. The secondary alkaline absorber is also equipped with an absorbent distributor and a packing layer to enhance the absorption effect.

[0053] Secondary Demister: The secondary demister is a crucial piece of equipment in the calcium-type brine acid bromine extraction process, ensuring gas cleanliness and preventing impurities from affecting subsequent processes. It effectively removes alkaline droplets (such as NaOH solution droplets) entrained in the gas after alkaline washing, achieving a demister efficiency of over 95%. This prevents alkaline solution from entering the blowing unit and subsequent processes, thus preventing equipment corrosion and interference with the bromine extraction process. It ensures the cleanliness of the gas returned to the blowing unit, maintains the stability of the bromine blowing process, avoids changes in brine composition or equipment blockage due to alkaline carryover, and reduces alkaline waste, improving the process's economic efficiency and environmental friendliness. Through a physical separation mechanism, the secondary demister achieves deep gas purification, making it a key component in ensuring the efficient and stable operation of the calcium-type brine bromine extraction process and preventing equipment corrosion and impurity interference.

[0054] Bromine distillation unit: The bromine distillation unit is the final and crucial operation in the entire bromine extraction process, directly determining the quality and yield of the final bromine product. Through this unit, bromine is separated from the complex solution system, becoming a pure product with high economic value, widely used in pharmaceuticals, chemicals, flame retardants, and many other fields. Its stable operation is vital to the economic benefits and product competitiveness of the entire bromine extraction production line.

[0055] Recycling system: The gas after secondary demisting is reintroduced into the blowing tower to purge bromine, while the generated sodium sulfite solution is introduced into the absorption tower for bromine absorption, forming a gas and solution recycling system.

[0056] The demisting structures in the primary and secondary demisting modules are one or a combination of two types: multi-layer wire mesh demisting structures and multi-stage baffle demisting structures. The primary and secondary demisting towers remove calcium-containing foam and alkaline droplets from the gas, respectively, and the recycling system avoids direct contact between the brine and sulfate or sulfurous acid ions.

[0057] In this embodiment, bromine-containing gaseous impurities are removed by a primary defoaming module, excess sulfur dioxide is absorbed by alkaline washing, and the generated sodium sulfite solution is recycled, thereby achieving gas and material circulation and avoiding direct contact between brine and sulfate or sulfurous acid.

[0058] By constructing a "multi-level absorption-defoaming synergy" system, the following objectives can be achieved:

[0059] 1. Blocking Ca 2+ The contact pathway with sulfur-containing ions inhibits the formation of calcium sulfate precipitate from the source;

[0060] 2. Improve SO2 absorption efficiency to over 95% to achieve compliant exhaust emissions and raw material recycling;

[0061] 3. Reduces equipment maintenance frequency and scale inhibitor usage, significantly lowering bromine extraction costs. This invention effectively prevents calcium sulfate precipitation, improving production continuity; efficiently absorbs and recycles sulfur dioxide, reducing costs; improves bromine extraction efficiency and purity, reducing waste gas emissions, thus achieving both economic and environmental benefits.

[0062] Furthermore, in this embodiment, the acidifying agent in the acidification and oxidation device is hydrochloric acid, the oxidizing agent is chlorine, the gas introduced into the blowing tower is air, the sodium sulfite solution generated by the alkaline washing tower is recycled to the absorption tower, and the gas after secondary defoaming is returned to the blowing tower for recycling, forming a closed-loop process.

[0063] Furthermore, in this embodiment, the system may include, in sequence, an acidification and oxidation device, a blowing tower, a primary demister equipped with a multi-layer wire mesh demister, an absorption tower, an alkaline washing tower, a secondary demister equipped with a multi-stage baffle demister, and a circulation pipeline; the alkaline washing tower is provided with a NaOH solution addition port and a sodium sulfite solution outlet, the sodium sulfite solution outlet being connected to the absorption tower; the secondary demister is connected to the blowing tower via the circulation pipeline.

[0064] Furthermore, in this embodiment, a carefully designed circulation pipeline can be used to connect the alkaline washing tower to the absorption tower, and the secondary demister to the blowing device tower. Simultaneously, flow control valves are installed on the circulation pipeline to flexibly adjust the circulation flow of gas and solution according to process requirements, achieving precise control of the entire process and ensuring efficient and coordinated operation of all stages.

[0065] Furthermore, in this embodiment, the acidification oxidation device, absorption tower, and alkaline washing tower are all equipped with temperature and concentration monitoring devices. These devices collect data in real time and feed it back to the control system to achieve dynamic control of the reaction conditions. For example, based on the monitored changes in bromide ion concentration, the amount of acidifying agent and oxidizing agent added is automatically adjusted to ensure that the reaction proceeds under optimal conditions, thereby improving bromine extraction efficiency and product quality.

[0066] Furthermore, in this embodiment, the absorption tower and the alkaline washing tower may be constructed using packed tower and plate tower structures, respectively, to optimize absorption efficiency.

[0067] Example 2:

[0068] A process for extracting bromine from calcium-type brine using acid extraction includes the following steps:

[0069] S1, Acidification and Oxidation: Calcium brine is introduced into the acidification and oxidation device, and hydrochloric acid is added for acidification and chlorine for oxidation, so that the brine brine ions are oxidized to elemental bromine;

[0070] S2, Blowing out: The acidified and oxidized brine is passed into the blowing tower, and the bromine is blown out using gas.

[0071] S3, Primary Demister: The bromine-containing gas is passed through the primary demister tower to remove impurities such as foam carried in it;

[0072] S4. Absorption: SO2 is introduced into the absorption tower to absorb and enrich elemental bromine;

[0073] S5. Alkaline washing: The absorbed gas enters the secondary alkaline absorption tower, where NaOH solution absorbs excess SO2 to generate sodium sulfite.

[0074] S6, Secondary Defoaming: The gas after alkaline washing is defoamed a second time to remove foam containing sulfate or sulfite ions;

[0075] S7. Re-blowing and recycling: The gas after secondary demisting is reintroduced into the blowing tower to blow bromine, while the sodium sulfite solution generated in the alkaline washing tower is introduced into the absorption tower for continued bromine absorption, thus achieving dynamic circulation.

[0076] S8. Bromine enrichment and distillation: The bromine enrichment solution is distilled to separate and purify bromine to obtain elemental bromine.

[0077] The above process employs a two-stage demisting and impurity interception method: a primary demisting stage and a secondary demisting stage are set up to form a dual-level protection. The primary demisting stage targets calcium-containing foam and impurities in bromine-containing gases, using a wire mesh demister. Its fine pore size intercepts calcium ions that may precipitate calcium sulfate in advance, preventing them from entering the subsequent absorption stage. The secondary demisting stage focuses on alkaline droplets in the gas after alkaline washing, using a baffle plate demister to prevent alkaline solution from entering the blowing device, interfering with the process, or causing equipment corrosion, ensuring pure gas circulation.

[0078] The above process utilizes sodium sulfite recycling: the sodium sulfite solution generated in the alkaline washing step is not directly discharged or discarded, but cleverly introduced into an absorption device for bromine absorption. This recycling model not only achieves efficient utilization of materials and reduces raw material consumption, but also avoids direct contact between brine and sulfate or sulfurous acid, cutting off the conditions for calcium sulfate precipitation at the source.

[0079] The above process employs a closed-loop gas circulation bromine blowing: the gas, after passing through a two-stage demisting stage, is reintroduced into the blowing device, forming a closed-loop cycle. Compared to the traditional process of using gas only once, this invention achieves the reuse of gas resources, reduces energy consumption, and ensures the stability and continuity of the bromine blowing process, thereby improving overall process efficiency.

[0080] The aforementioned technology has broad application prospects, primarily in the development and utilization of associated waters from oil and natural gas, underground brine, and salt lake resources, especially in brines rich in calcium and magnesium ions, enabling the extraction of bromine resources. This technology not only effectively separates and extracts bromine from brine but also removes excess sulfur dioxide by adding sodium hydroxide, improving the purity of the bromine product and achieving green and sustainable production goals, thus possessing significant economic and social benefits.

[0081] Example 3:

[0082] Both the primary and secondary demisters include a tower body 1, an aeration structure 2 located at the bottom of the tower body 1, a liquid distribution structure 3 located at the top of the tower body 1, and several layers of support structures 4 located inside the tower body. The multi-layer wire mesh demister or multi-stage baffle demister is placed on the support structures 4.

[0083] Furthermore, in this embodiment, the multi-layer wire mesh defogging structure can be considered as a disc-shaped structure with a diameter slightly smaller than the inner diameter of the tower body. The multi-layer wire mesh defogging structure includes several layers of wire mesh grids 5 stacked sequentially. The two adjacent layers of wire mesh grids 5 have different orientations. The uppermost layer of wire mesh grids 5 is densely covered with several upward-protruding conical defogging protrusions 6.

[0084] Furthermore, in this embodiment, the primary demister is equipped with a multi-layer wire mesh demister, the structure and materials of which are optimized for removing calcium-containing foam. The pore size of the wire mesh demister structure in the primary demister is 10-20μm, and the demister efficiency is ≥98%. The bottom of the primary demister is provided with a drain port for discharging the intercepted foam droplets.

[0085] Furthermore, in this embodiment, the multi-stage baffle demister structure can be considered as a disc-shaped structure with a diameter slightly smaller than the inner diameter of the tower body. The multi-stage baffle demister structure includes several layers of sequentially stacked baffles 7, with adjacent layers of baffles 7 facing different directions. The baffles are densely covered with through holes.

[0086] Furthermore, in this embodiment, the secondary demister can be equipped with a multi-stage baffle demister, which provides highly efficient separation of alkaline droplets. The baffles in the secondary demister are wavy or sawtooth-shaped, achieving a demister efficiency of over 95%. The bottom of the secondary demister has a drain port for discharging the separated alkaline droplets. These two demister devices each perform their specific functions, precisely addressing impurities at different stages and providing hardware support for stable process operation.

[0087] Example 4:

[0088] The aeration structure includes an annular aeration pipe network with the aeration direction facing downwards, which facilitates gas-liquid separation within the gas. The liquid distribution structure includes an annular liquid distribution pipe network with the liquid distribution direction facing downwards. Below the annular liquid distribution pipe network, a liquid dispersion structure is also provided. The liquid dispersion structure includes a circular grid support 8, several liquid guide rods 9 set at the bottom of the circular grid support 8, and dispersion caps 10 set at the bottom of the liquid guide rods 9. Water flows through the dispersion caps and is dispersed.

[0089] Furthermore, in this embodiment, the dispersion cap 10 may be provided with a plurality of dispersion grooves radiating outward along its circumference, and the bottom of the dispersion cap may be provided with a pointed tip.

[0090] Application Example 1: Bromine Extraction Project from Calcium-Type Brine

[0091] Raw material parameters: Calcium-type brine from a certain region was selected as the raw material, and its calcium ion (Ca) content... 2+ The concentration was 8 g / L, and the bromide ion concentration was Br⁻. - The concentration was 3 g / L, and the pH value was 7.2.

[0092] Process steps:

[0093] 1. Acidification and oxidation: 100m 3 The calcium-type brine is transported to an acidification and oxidation unit, where 31% hydrochloric acid is added to adjust the pH to 2.0, followed by a 15m... 3 Chlorine gas is introduced at a flow rate of / h, and the oxidation reaction continues for 2 hours, allowing bromide ions to be fully converted into elemental bromine.

[0094] 2. Blowing: The acidified and oxidized brine is introduced into the blowing tower at a rate of 20m. 3 Hot air at 45°C is introduced at a flow rate of / h and bromine is continuously blown in for 3 hours, causing elemental bromine to separate from the brine and form bromine-containing gas.

[0095] 3. Primary Demisting: Bromine-containing gas enters the primary demisting tower, which is equipped with a three-layer polypropylene wire mesh demisting structure with a pore size of 15μm. During the gas's ascent within the unit, calcium-containing foam and impurities it carries collide with the wire mesh surface due to inertia, agglomerating into droplets that flow down the mesh and are discharged through the drain port. Testing shows that after demisting, the droplet concentration in the gas is reduced to 40mg / m³. 3 The defoaming efficiency reaches 98.2%.

[0096] 4. Absorption: The bromine-containing gas, after passing through the first-stage demisting stage, enters the absorption tower at a concentration of 18m³. 3 SO2 gas is introduced at a flow rate of / h, while at a rate of 50m 3The spray density was 60 g / L sodium sulfite (Na2SO3) solution, the reaction temperature was controlled at 40℃, and the reaction time was 2.5 hours to achieve the absorption and enrichment of elemental bromine. At this time, the concentration of bromide ions in the absorption solution increased to 8.2 g / L.

[0097] 5. Alkali washing: Unreacted SO2 gas from the absorption process enters the alkali washing tower, where a 10% (w / w) NaOH solution is sprayed at a density of 18 L / (m³). 2 The process involves reacting SO2 with NaOH to produce sodium sulfite, and the SO2 concentration in the exhaust gas was reduced to 48 ppm.

[0098] 6. Two-stage demisting: The gas after alkaline washing enters a two-stage demisting tower, which is equipped with a two-stage corrugated baffle demisting structure. The gas changes direction multiple times as it passes through the baffles. The entrained alkaline droplets collide with the baffle surface due to inertia, agglomerating into larger droplets that flow down the baffle wall and are discharged from the drain port. After demisting, the alkaline droplet content in the gas is less than 30 mg / m³. 3 .

[0099] 7. Recycling: The gas after secondary demisting is recirculated through the circulation pipeline into the blowing device for bromine blowing. At the same time, the sodium sulfite solution generated by the alkaline washing tower is transported through the pipeline to the absorption tower for bromine absorption.

[0100] 8. Bromine distillation: The bromine-enriched solution obtained from absorption is sent to a distillation apparatus and steam distilled at a temperature of 95℃ and a pressure of 0.05MPa. Finally, bromine elemental product with a purity of 99.7% is obtained, and the bromine extraction rate reaches 98.5%.

[0101] Comparison of effects: In this embodiment, after 180 days of operation using the process of the present invention, inspection of all components of the equipment revealed no significant calcium sulfate precipitation, indicating stable equipment operation. However, when using the traditional calcium-type brine acid extraction process to treat the same raw material, large amounts of calcium sulfate precipitation appeared in the blowdown tower pipes and absorber packing after approximately 7 days of operation, leading to equipment blockage and shutdown. Furthermore, compared to the traditional process, the process of the present invention reduces SO2 consumption by 60% and equipment maintenance costs by 75%, resulting in significantly improved economic benefits.

[0102] The above embodiments have provided a detailed description of the present invention, but the content described is only a preferred embodiment of the present invention and should not be considered as limiting the scope of the present invention. All equivalent changes and improvements made in accordance with the claims of the present invention should still fall within the patent coverage of the present invention.

Claims

1. A calcium-type brine acid extraction bromine system, characterized in that: It is a bromine element separation and purification system composed of an acidification and bromine blowing unit, an absorption and desulfurization unit, and a bromine evaporation unit; the absorption and desulfurization unit is a gas and solution recycling system composed of a primary demister module, an absorption module, an alkaline washing module, and a secondary demister module; the demister structure in the primary demister module and the secondary demister module is one or a combination of two of the following: a multi-layer wire mesh demister structure and a multi-stage baffle demister structure.

2. The calcium-type brine acid extraction bromine system according to claim 1, characterized in that: The acidification and bromine blowing unit includes an acidification oxidation device and a blowing tower. The absorption and desulfurization unit includes a primary demister, an absorption tower, an alkaline washing tower, and a secondary demister. The bromine distillation unit includes a distillation device. Calcium-type brine, after acidification and oxidation by the acidification oxidation device, enters the blowing tower, where bromine-containing gas is blown out. The bromine-containing gas passes through the primary demister to remove calcium-containing foam and impurities. The demisted bromine-containing gas then enters the absorption tower, which carries sulfur dioxide gas, to obtain a bromine-enriched solution and the absorbed gas. The bromine-enriched solution enters the distillation device for separation and purification to obtain elemental bromine, achieving elemental bromine separation and purification. The absorbed gas is then washed in the alkaline washing tower to obtain a sodium sulfite solution and the alkaline-washed gas. The sodium sulfite solution is reintroduced into the absorption tower. The alkaline-washed gas undergoes secondary demister demisting in the secondary demister to remove residual alkaline solution or sodium sulfite impurities. The gas after secondary demistering is then reintroduced into the blowing tower, achieving gas and solution recycling.

3. The calcium-type brine acid extraction bromine system according to claim 2, characterized in that: It includes an acidification and oxidation device, a blowing tower, a primary demister equipped with a multi-layer wire mesh demister, an absorption tower, an alkaline washing tower, a secondary demister equipped with a multi-stage baffle demister, and a circulation pipeline connected in sequence; the alkaline washing tower is equipped with a NaOH solution addition port and a sodium sulfite solution outlet, and the sodium sulfite solution outlet is connected to the absorption tower through a pipeline; the secondary demister is connected to the blowing tower through a circulation pipeline.

4. The calcium-type brine acid extraction bromine system according to claim 2, characterized in that: The acidification oxidation device, absorption tower, and alkaline washing tower are all equipped with temperature and concentration monitoring devices for real-time control of reaction conditions. The absorption tower and alkaline washing tower adopt packed tower and plate tower structures, respectively, to optimize absorption efficiency. The circulation pipeline is equipped with flow control valves to regulate the circulation flow rate of gas and solution.

5. The calcium-type brine acid extraction bromine system according to claim 2, characterized in that: The acidifying agent in the acidification and oxidation device is hydrochloric acid, the oxidizing agent is chlorine, and the gas introduced into the blowing tower is air and gas after secondary defoaming.

6. The calcium-type brine acid extraction bromine system according to claim 2, characterized in that: Both the primary and secondary demisters include a tower body, an aeration structure at the bottom of the tower body, a liquid distribution structure at the top of the tower body, and several layers of support structures inside the tower body. The multi-layer wire mesh demister or multi-stage baffle demister is placed on the support structures.

7. The calcium-type brine acid extraction bromine system according to claim 6, characterized in that: The multi-layer wire mesh defogging structure is a disc-shaped structure with a diameter slightly smaller than the inner diameter of the tower body. The multi-layer wire mesh defogging structure includes several layers of wire mesh grids stacked sequentially. The adjacent two layers of wire mesh grids face different directions. The uppermost wire mesh grid is densely covered with several upward-protruding conical defogging protrusions.

8. The calcium-type brine acid extraction bromine system according to claim 7, characterized in that: The pore size of the wire mesh demister structure in the primary demister tower is 10-20μm, and the demister efficiency is ≥98%. The bottom of the primary demister tower is provided with a drain port for discharging the intercepted foam droplets.

9. A calcium-type brine acid extraction bromine system according to claim 6, characterized in that: The multi-stage baffle demister structure is a disc-shaped structure with a diameter slightly smaller than the inner diameter of the tower body. The multi-stage baffle demister structure includes several layers of baffles stacked sequentially, with adjacent layers of baffles facing different directions, and the baffles are densely covered with through holes.

10. A calcium-type brine acid extraction bromine system according to claim 9, characterized in that: The baffles in the secondary demister are wavy or sawtooth-shaped, and the demister efficiency is over 95%. The bottom of the secondary demister is equipped with a drain port for discharging the separated alkaline droplets.

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