Brine bromine extraction device

Abstract

The utility model relates to a device for extracting bromine from brine, and belongs to the technical field of brine resource utilization. A ceramic membrane is arranged at the lower part of the reaction tank, and one side of a membrane layer of the ceramic membrane is connected with a gas source; the reaction tank is also connected with an acid liquor adding pipe and a sodium hypochlorite adding pipe; one side of the membrane layer of the ceramic membrane is also connected with the vacuum pump; a gas outlet pipeline is arranged on the reaction tank, is connected to the absorption tank and is used for absorbing the generated bromine gas; and the pipeline for connecting the ceramic membrane and the vacuum pump is also connected to a lithium adsorbent bed layer.

Description

TECHNICAL FIELD

[0001] The utility model relates to a kind of brine bromine extraction device, belong to brine resource utilization technical field. BACKGROUND

[0002] Bromine, known as "marine element", has strong oxidizing property and high flame retardant characteristics, and can be used for water disinfection and sterilization, active additives in rubber, synthetic fiber and dye industries, and fire and explosion prevention in fields such as construction, fuel and electronic products. Bromine-containing compounds and their derivatives can be used as intermediates for organic synthesis and catalytic reactions, and are widely used in the pharmaceutical field. With the rapid development of China's economy and technology, the demand for fine chemicals related to bromine and bromide is increasing year by year, so on the one hand, more bromine sources need to be found, and on the other hand, new bromine extraction technology needs to be developed.

[0003] Bromine elements mainly exist in the form of bromide ions in the ocean, salt lakes and underground brine. The content of bromide ions in seawater is relatively low, about 65 mg / L. The bromine content in underground brine and salt lake brine is much higher than that in seawater, about 0.1-2 g / L, but the resources are relatively dispersed.

[0004] In view of the above situation, the most important bromine extraction method in industrial application is air blowing method and steam distillation method. Air blowing method has low requirement on raw material concentration, and is easy to control automatically, but its product purity is low, the equipment occupies large area, and the safety and environmental protection cost is high. Steam distillation method is suitable for high concentration brine, and the process flow is simple, and the raw material consumption is less, but the steam consumption is huge, resulting in high cost, and high temperature steam causes bromine hydrolysis, resulting in low bromine yield. In recent years, emerging bromine extraction methods include solvent extraction, resin adsorption, membrane separation and electrochemical oxidation, but each has problems such as environmental pollution of extractant, short service life and poor selectivity of adsorbent, serious membrane pollution, long time consumption and low absorption rate, which makes it difficult to realize industrialization in the short term.

[0005] The technology of extracting bromine by using oxidizing agent is also being researched and promoted. This technology can oxidize bromide ions in brine into bromine gas through the oxidizing property of the agent. This technology has the advantages of simple operation, fast reaction and low energy consumption, and has great research significance and development prospect. However, uneven distribution of aeration also leads to instability of bromine gas production and absorption process, affecting the separation effect. SUMMARY

[0006] In order to solve the above technical problems, the patent proposes a brine bromine extraction process, which uses a ceramic membrane as an aeration device, can continuously release micro-nano bubbles, and uniformly contacts with the brine, so that the amount of bromine gas generated is larger; at the same time, after the bromine extraction is completed, the ceramic membrane can be used as a filter material to filter and remove impurities in the brine, and further sent to the adsorption-nanofiltration process for reseparation of lithium, realizing one membrane for two purposes.

[0007] Technical scheme

[0008] The brine bromine extraction device comprises:

[0009] A reaction tank is provided with a ceramic membrane at the lower part, one side of the membrane layer of the ceramic membrane is connected with a gas source; an acid liquid adding pipe and a sodium hypochlorite adding pipe are further connected to the reaction tank;

[0010] One side of the membrane layer of the ceramic membrane is also connected with a vacuum pump;

[0011] A gas outlet pipeline is arranged on the reaction tank and connected with an absorption tank, for absorbing the generated bromine gas;

[0012] The pipeline connected with the vacuum pump and the ceramic membrane is further connected with a lithium adsorbent bed layer.

[0013] The desorption liquid outlet of the lithium adsorbent bed layer is connected with the feed inlet of the nanofiltration membrane.

[0014] The pore size of the ceramic membrane ranges from 50nm to 500nm.

[0015] The material of the ceramic membrane is alumina, zirconia or titanium oxide.

[0016] The ceramic membrane is a tubular or multi-channel structure.

[0017] The vacuum pump and / or the gas source are connected to one side of the channel of the ceramic membrane.

[0018] The ceramic membrane is located at the bottom of the reaction tank and is horizontally placed.

[0019] The method has the advantages of uniform aeration and high bromine extraction rate, and the bromine extraction process is optimized; in addition, the ceramic membrane can perform two operation modes of aeration and filtration, and has the advantage of one membrane for two purposes. BRIEF DESCRIPTION OF DRAWINGS

[0020] Figure 1 It is a device drawing of the utility model.

[0021] Figure 2 It is the corresponding bromine extraction rate when different medicaments are oxidized and bromine is extracted.

[0022] Figure 3The bromine extraction rate corresponding to different molar ratios of sodium hypochlorite and bromide ions.

[0023] Figure 4 The absorption rate corresponding to different volume ratios of lye and reaction liquid.

[0024] 1, reaction tank; 2, ceramic membrane; 3, gas source; 4, acid liquid adding pipe; 5, sodium hypochlorite adding pipe; 6, vacuum pump; 7, absorption tank; 8, lithium adsorbent bed; 9, nanofiltration membrane. DETAILED DESCRIPTION

[0025] The technical process of the application is shown as follows:

[0026] Step 1, adding an oxidizing agent into the bromine-containing brine;

[0027] Step 2, adjusting the pH of the bromine-containing brine solution to be acidic to promote the oxidizing agent to oxidize bromide ions into bromine gas;

[0028] Step 3, blowing the bromine gas into an alkaline solution by an air pump to obtain a sodium bromide solution.

[0029] The brine is any solution containing impurity ions and bromide ions, such as concentrated seawater, salt lake brine, underground brine, oil and gas field brine, and mother liquor after seawater salt making. The impurity ions in the bromine-containing brine include but are not limited to Li + , Na + , K + , Ca 2+ , Mg 2+ , Co3 2- , Cl - ; the concentration of bromide ions in the brine is 100 mg / L to 5 g / L. The pH of the brine adjusted by acid ranges from 2 to 5, and is further preferably from 2 to 3.

[0030] The pH of the bromine-containing brine is adjusted to be acidic by acid, on the one hand, because the oxidizing agent is more likely to react with bromide ions in the brine under acidic conditions; on the other hand, it is to avoid the bromine gas generated by oxidation from being disproportionated into Br - and BrO3 - under neutral or alkaline conditions, so as to ensure that the bromine gas is blown into the alkaline absorption liquid as much as possible. By comparing the bromine removal effects under different conditions of using different reagents and molar ratios of bromide ions, different concentrations (volumes) of absorption liquid, and different reaction times and gas blowing amounts, the best experimental conditions for oxidizing and extracting bromine by the reagent are obtained.

[0031] The acid is selected from one or a mixture of several of sulfuric acid, hydrochloric acid, nitric acid, citric acid, and acetic acid, and is further preferably hydrochloric acid.

[0032] The medicament includes one or a mixture of several of ozone, sodium hypochlorite or hydrogen peroxide, and the molar ratio of the medicament to bromine ions in the bromine-containing brine is 1:1-6:1.

[0033] The absorption liquid (alkali liquid) is a mixture of one or several of sodium hydroxide, sodium carbonate, urea and sodium bicarbonate solution, and is further preferably a mixed solution of sodium carbonate and urea. The alkali liquid has a concentration equal to, greater than the concentration of bromine ions in the bromine-containing brine and saturated alkali liquid, and is further preferably greater than the concentration of bromine ions in the bromine-containing brine. The volume ratio of the alkali liquid to the reaction liquid is 1:100-1:10.

[0034] The air pump has an aeration amount ranging from 10 mL / min to 100 mL / min, and is further preferably 20 mL / min.

[0035] The aeration process uses a ceramic membrane, and compressed air is supplied to one side of the ceramic membrane, so that micro-nano bubbles are discharged from the other side of the ceramic membrane. The pore size of the ceramic membrane is 50-500 nm.

[0036] The oxidation reaction time is 0.5 h-3 h, and is further preferably 1 h.

[0037] After the bromine extraction is completed, the air source is turned off, and the vacuum pump is turned on to apply negative pressure to the ceramic membrane. When the brine is filtered through the ceramic membrane, suspended particles and the like are removed, and purified brine is obtained. The brine filtered by negative pressure suction enters the lithium adsorbent bed layer to adsorb lithium, and the desorption liquid of the adsorption is sent to the nanofiltration membrane for deep calcium and magnesium removal treatment, thereby further extracting lithium from the brine.

[0038] Based on the above process principle, the device structure used in the patent includes:

[0039] The reaction tank 1 is provided with a ceramic membrane 2 at the lower part, one side of the membrane layer of the ceramic membrane 2 is connected with an air source 3, and an acid liquid adding pipe 4 and a sodium hypochlorite adding pipe 5 are further connected to the reaction tank 1.

[0040] One side of the membrane layer of the ceramic membrane 2 is also connected with a vacuum pump 6.

[0041] The reaction tank 1 is provided with a gas outlet pipeline connected to an absorption tank 7 for absorbing the generated bromine gas.

[0042] The pipeline connected with the vacuum pump 6 of the ceramic membrane 2 is further connected to a lithium adsorbent bed layer 8.

[0043] The desorption liquid outlet of the lithium adsorbent bed layer 8 is connected to the feed inlet of a nanofiltration membrane 9.

[0044] The pore size of the ceramic membrane 2 ranges from 50 nm to 500 nm.

[0045] The material of the ceramic membrane 2 is alumina, zirconia or titania.

[0046] The ceramic membrane 2 is in a tubular or multi-channel structure.

[0047] The vacuum pump 6 and / or the air source are connected to one side of the channel of the ceramic membrane 2.

[0048] The ceramic membrane 2 is located at the bottom of the reaction tank 1 and is horizontally placed.

[0049] The present application relates to a method for extracting bromine from brine containing high-concentration impurity ions and low-concentration (less than 1 g / L) bromide ions, in particular to a safe, pollution-free and low-energy-consumption method for extracting bromine from brine containing impurity ions and bromide ions and producing high-economic-value sodium bromide product, which provides a new method for brine bromine extraction / bromine removal, solves the problems of high cost and low yield of traditional bromine extraction methods, and explores the optimal process conditions of the reagent oxidation method for extracting bromine, so as to achieve the purpose of high bromine extraction rate.

[0050] The ions to be extracted in the brine in the present application are bromide ions, and the raw material sources of the brine can be concentrated seawater, salt lake brine, underground brine, oil and gas field brine and seawater mother liquor after salt making. In China, industrial production of bromine extraction from bromide-containing brine mainly adopts air blowing method and water vapor distillation method, but the problems of low safety, high production cost and large energy consumption cannot be solved for a long time, so it is an inevitable trend to actively develop new bromine extraction technology and realize its industrial production as soon as possible.

[0051] The technical concept of the present application is that in the process of oxidizing bromide ions in brine into bromine gas by using oxidizing reagents, the amount of acid and reagent can be reasonably controlled to selectively oxidize bromide ions, thereby avoiding waste of reagent resources and generation of other by-products, reducing bromine extraction production cost and environmental pollution, and greatly reducing energy consumption due to short reaction time and high bromine extraction rate.

[0052] Example 1

[0053] The bromine-containing brine used in this example is a light yellow transparent liquid, which contains main ions of lithium ion, sodium ion, potassium ion, calcium ion, boron element, bromide ion, chloride ion and carbonate, with ion concentrations of 57.47 mg / L, 127.6 g / L, 1.663 g / L, 37.19 mg / L, 113.7 mg / L, 502 mg / L, 155.687 g / L and 2.411 g / L, respectively, and a pH of 13. 1000 mL of bromine-containing brine is placed in a reaction tank, sodium hypochlorite solution is added according to a molar ratio of sodium hypochlorite to bromide ion of 2:1, then hydrochloric acid is used to adjust the pH to 2-3, pressure aeration is carried out through a ceramic membrane with a pore size of 200 nm, and the aeration amount is 20 mL / min. After 1 h of aeration, the process is stopped. The highest bromine extraction rate can reach 85%. After bromine extraction is completed, the gas source is turned off, a vacuum pump is started to suck the ceramic membrane under negative pressure, the brine is filtered to remove suspended particles, then enters the lithium adsorbent bed for lithium adsorption, and after desorption, the elution solution is treated by a nanofiltration membrane to remove calcium and magnesium in depth, and a lithium salt-containing solution is obtained.

[0054] Comparative Example 1

[0055] The difference from Example 1 is that the medicament used in this comparative example is hydrogen peroxide, and the highest bromine extraction rate is only 15%.

[0056] Comparative Example 2

[0057] The difference from Example 1 is that the medicament used in this comparative example is ozone, and the highest bromine extraction rate is only 12%. Example 2

[0058] The bromine-containing brine used in this example is the same as that in Example 1. 1000 mL of bromine-containing brine is placed in a reaction tank, corresponding sodium hypochlorite solution is added according to a molar ratio of sodium hypochlorite to bromide ion of 1:1, 1.5:1, 2:1, 3:1, 4.5:1 and 6:1, then hydrochloric acid is used to adjust the pH to 2-3, pressure aeration is carried out through a ceramic membrane with a pore size of 200 nm, and the aeration amount is 20 mL / min. After 1 h of aeration, the process is stopped. The corresponding bromine extraction rates under different ratios are 60%, 79%, 82%, 85%, 89% and 90%, respectively. Under the condition of ensuring a high bromine extraction rate, the consumption of medicament is reduced as much as possible, and the best molar ratio of sodium hypochlorite to bromide ion is selected as 2:1. After bromine extraction is completed, the gas source is turned off, a vacuum pump is started to suck the ceramic membrane under negative pressure, the brine is filtered to remove suspended particles, then enters the lithium adsorbent bed for lithium adsorption, and after desorption, the elution solution is treated by a nanofiltration membrane to remove calcium and magnesium in depth, and a lithium salt-containing solution is obtained. Example 3

[0059] The bromine-containing brine used in the example is the same as that in Example 1. 1000 mL of bromine-containing brine is placed in a reaction tank. Sodium hypochlorite solution is added according to a molar ratio of sodium hypochlorite to bromide ions of 2:1. Then, hydrochloric acid is used to adjust the pH to 2-3. Pressurized aeration is performed through a ceramic membrane with a pore size of 200 nm. The aeration amount is 20 mL / min, and the aeration is stopped after 1 h. The volume ratio of lye to reaction liquid is 1:100, 1:50, and 1:10 to absorb the generated bromine gas. The corresponding absorption rates under each absorption liquid ratio are 61%, 85%, and 89%, respectively. In order to facilitate the subsequent refining of sodium bromide products and reduce water consumption, the optimal volume ratio of lye to reaction liquid is selected to be 1:50. After the bromine extraction is completed, the gas source is turned off, and a vacuum pump is started to perform negative pressure suction on the ceramic membrane. The brine is filtered to remove suspended particles and then enters the lithium adsorbent bed layer for lithium adsorption. After desorption, the elution liquid is treated by nanofiltration membrane to remove calcium and magnesium in depth, and a lithium salt-containing solution is obtained.

Claims

1. A device for bromine extraction from brine, characterized in that, The application relates to a ceramic membrane reactor for producing bromine, which comprises the following parts: a reaction tank (1) with a ceramic membrane (2) arranged at the lower part of the reaction tank (1), wherein one side of the membrane layer of the ceramic membrane (2) is connected with a gas source (3); an acid liquid adding pipe (4) and a sodium hypochlorite adding pipe (5) are further connected with the reaction tank (1); the membrane layer side of the ceramic membrane (2) is also connected with a vacuum pump (6); a gas outlet pipe is arranged on the reaction tank (1) and connected with an absorption tank (7) for absorbing the generated bromine; a pipe connected with the vacuum pump (6) and the ceramic membrane (2) is further connected with a lithium adsorbent bed layer (8).

2. The brine bromine extraction plant of claim 1, wherein The desorption liquid outlet of the lithium adsorbent bed layer (8) is connected with the feed inlet of a nanofiltration membrane (9).

3. The brine bromine extraction plant of claim 1, wherein The pore size of the ceramic membrane (2) is 50-500nm.

4. The brine bromine extraction plant of claim 1, wherein The material of the ceramic membrane (2) is alumina, zirconia or titania.

5. The brine bromine extraction plant of claim 1, wherein The ceramic membrane (2) is in a tubular or multi-channel structure.

6. The brine bromine extraction plant of claim 1, wherein The vacuum pump (6) and / or the gas source are connected with one side of the channel of the ceramic membrane (2).

7. The brine bromine extraction plant of claim 1, wherein The ceramic membrane (2) is horizontally arranged at the bottom of the reaction tank (1).

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