Method and device for producing lithium bromide

Abstract

The invention belongs to the field of chemical engineering, and discloses a method and device for producing lithium bromide, and the method comprises the following steps: introducing bromine-containing gas into an iron powder suspension to obtain a first mixed solution; filtering the first mixed solution to obtain an iron bromide solution and iron powder; adding lithium carbonate into the ferric bromide solution to obtain a second mixed solution; carrying out filter pressing on the second mixed solution to obtain a lithium bromide solution and a ferric hydroxide solid; and evaporating and drying the lithium bromide solution to obtain a lithium bromide solid product. According to the method, the use of hazardous chemical chlorine in the traditional bromine extraction process is avoided, meanwhile, the use of hazardous chemical bromine is avoided, the problem of byproduct lithium bromate in the traditional lithium bromide production process is avoided, high-purity lithium bromide is prepared, and safe and environment-friendly extraction and utilization of bromine resources are achieved.

Description

Technical Field

[0001] The present invention relates to the field of chemical industry, and in particular to a method and apparatus for producing lithium bromide. Background Art

[0002] Lithium bromide is an inorganic substance that appears as white cubic crystals or granular powder. It is highly soluble in water, ethanol, and ether, slightly soluble in pyridine, and soluble in organic solvents such as methanol, acetone, and ethylene glycol. It is a highly efficient water vapor absorber and air humidity regulator. It can be used as an absorption refrigerant, a hydrogen chloride remover in organic chemistry, a fiber bulking agent, a hypnotic and sedative in medicine, and is also used in the photographic industry, as an analytical chemical reagent, and as an electrolyte in certain high-energy batteries.

[0003] Currently, lithium bromide is commonly produced industrially by using lithium hydroxide to absorb bromine or by using hydrobromic acid and lithium hydroxide to neutralize bromine. Taking the absorption of bromine by a hot lithium hydroxide solution as an example, the solution is evaporated to dryness to obtain a mixture of lithium bromide and lithium bromate. The lithium bromate in the mixture is then reduced to lithium bromide using carbon powder, and the lithium bromide product is finally obtained through steps such as dissolution, filtration, recrystallization, and drying. However, the lithium bromide produced by these methods produces lithium bromate as an impurity, which needs to be further removed by carbon powder reduction. This greatly increases the process difficulty and production cost, and also prolongs the process cycle. Furthermore, the lithium bromate that is difficult to remove can also reduce the quality of the lithium bromide product.

[0004] Furthermore, the production process of lithium bromide generally uses bromine as a raw material. Currently, bromine production methods include air extraction, steam distillation, extraction, resin adsorption, and membrane separation. Air extraction and steam distillation are the most widely used industrially, with steam distillation accounting for 10% of my country's bromine production, and air extraction accounting for the remaining 90%. Specifically, bromide ions in brine are first acidified and oxidized with chlorine to form elemental bromine. The bromine in the brine is then blown out using air or steam. The bromine in the air is then absorbed and enriched with an absorbent to form a hydrobromic acid solution. Finally, the bromine product is obtained through secondary oxidation with chlorine and distillation. However, these bromine production methods require the use of large amounts of chlorine, and the introduction of hazardous chlorine poses safety risks such as leakage and explosion. Furthermore, the water discharged after bromine extraction becomes acidic, posing a certain risk of environmental pollution.

[0005] Gasfield water, a byproduct of gas field development, often contains salt, sulfur, and organic matter. During gas field development, it is often disposed of as waste, significantly increasing production costs. Preliminary research has shown that some gasfield water contains 200-500 mg / L of bromide ions, 4-10 times the industrial grade, and possesses high extraction and utilization value. Currently, gasfield water is primarily treated for reinjection, with no bromine recovery or utilization achieved, representing a significant waste of bromine resources. Traditional bromine extraction processes involve the use of hazardous chemical chlorine gas, and the product is bromine, making it difficult to implement on-site as part of a hazardous chemical production and storage project.

[0006] Therefore, it is necessary to propose a method and device for producing lithium bromide to realize the green and environmentally friendly extraction and utilization of bromine resources in gas field water, ensure the supply of bromine resources, and realize the efficient recovery of bromine resources in gas field water.

[0007] Application Contents

[0008] In order to overcome the defects of the above-mentioned prior art, the purpose of this application is to provide a method and device for producing lithium bromide, which avoids the use of hazardous chemical chlorine in the traditional bromine extraction process, the serious waste of bromine resources in the existing gas field water treatment process, the traditional chlorine oxidation bromine extraction process involving the use and production of hazardous chemicals, and the high safety and environmental risks, and the traditional lithium bromide production process involving the by-production of lithium bromate. The method avoids the use of hazardous chemical chlorine in the traditional bromine extraction process, and at the same time avoids the hazardous chemical product being bromine, avoids the problem of lithium bromate as a by-product in the traditional lithium bromide production process, prepares higher purity lithium bromide, and realizes the safe and environmentally friendly extraction and utilization of bromine resources.

[0009] To achieve the above objectives, this application provides the following technical solutions:

[0010] A method for producing lithium bromide, comprising:

[0011] Passing bromine-containing gas into the iron powder suspension to obtain a first mixed solution;

[0012] filtering the first mixed liquid to obtain a ferric bromide solution and iron powder;

[0013] adding lithium carbonate to the ferric bromide solution to obtain a second mixed solution;

[0014] The second mixed liquid is filter-pressed to obtain a lithium bromide solution and ferric hydroxide solid;

[0015] The lithium bromide solution is evaporated to dryness to obtain a lithium bromide solid product.

[0016] Furthermore, the preparation method of bromine-containing gas comprises:

[0017] The pH value of the gas field water is adjusted to 1-4 using hydrochloric acid to obtain acidified fluid;

[0018] The acidified solution is electrolyzed to obtain an oxidized solution at the anode;

[0019] The oxidizing liquid is stripped with air to obtain bromine-containing gas.

[0020] Furthermore, the gas-liquid flow ratio of air and oxidizing liquid is 130-260:1.

[0021] Furthermore, the concentration of ferric bromide in the first mixed solution is 20-30 wt %.

[0022] Furthermore, the flow ratio of the bromine-containing gas to the iron powder suspension is 40-100:1.

[0023] Furthermore, the mass ratio of lithium carbonate to ferric bromide solution is 1.5-2.7:1.

[0024] At the same time, the present application also discloses a device for producing lithium bromide, comprising:

[0025] a first mixed liquid obtaining unit, for passing bromine-containing gas into the iron powder suspension to obtain a first mixed liquid;

[0026] a filtration unit, configured to filter the first mixed liquid to obtain a ferric bromide solution and iron powder;

[0027] a second mixed liquid obtaining unit, configured to add lithium carbonate to the ferric bromide solution to obtain a second mixed liquid;

[0028] A filter press unit, used for filter pressing the second mixed liquid to obtain a lithium bromide solution and ferric hydroxide solid;

[0029] The evaporation and drying unit is used to evaporate and dry the lithium bromide solution to obtain a lithium bromide solid product.

[0030] Furthermore, the device also includes a bromine molecule extraction unit for preparing bromine-containing gas using gas field water;

[0031] The bromine molecule extraction unit includes an acid conditioning tank, an electrolytic cell and a stripping tower connected in sequence.

[0032] The acid adjustment tank is used to adjust the pH value of gas field water to 1-4 using hydrochloric acid to obtain acidified liquid;

[0033] The electrolytic cell is used to electrolyze the acidified solution, and the anode obtains the oxidized solution;

[0034] The stripping tower is used to strip the oxidizing liquid with air to obtain bromine-containing gas.

[0035] Furthermore, the first mixed liquid obtaining unit includes an absorption tower;

[0036] The filtration unit includes a bag filter;

[0037] The second mixed liquid obtaining unit includes a reaction tank;

[0038] The filter pressing unit includes a filter press;

[0039] The evaporative drying unit includes an evaporator;

[0040] The absorption tower, bag filter, reaction tank, filter press and evaporator are connected in sequence.

[0041] Furthermore, the gas phase inlet at the top of the absorption tower is connected to the gas phase outlet at the top of the stripping tower through a pipeline, and the gas phase outlet at the bottom of the absorption tower is connected to the Roots blower and the gas phase inlet at the bottom of the stripping tower in sequence through a pipeline.

[0042] The technical effects and advantages of this application are:

[0043] This application addresses the problems of serious waste of bromine resources in existing gas field water treatment processes, the use and production of hazardous chemicals involved in traditional chlorine oxidation bromine extraction processes, and high safety and environmental risks. Through the "electro-oxidation-stripping absorption-evaporation crystallization" process, electro-oxidation is used to achieve oxidative extraction of bromide ions in gas field water, avoiding the use of hazardous chemical chlorine in the traditional bromine extraction process. At the same time, iron powder suspension is used as the absorption liquid to prepare lithium bromide, avoiding the problem of the product being hazardous chemical bromine and the by-product lithium bromate in the traditional lithium bromide production process. The application can safely and environmentally friendly realize the recovery and utilization of bromide ions in gas field water, which is expected to alleviate the depletion of underground brine bromine resources and ensure the supply of bromine resources.

[0044] Other features and advantages of the present application will be described in the following description, and in part will become apparent from the description, or will be understood by practicing the present application. The purpose and other advantages of the present application can be realized and obtained by the structures indicated in the description, claims and drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] Figure 1 Flow chart of the method for producing lithium bromide using bromine-containing gas in this application

[0046] Figure 2 A flow chart of the method for preparing bromine-containing gas for this application;

[0047] Figure 3 This is a schematic diagram of the structure of an apparatus for producing lithium bromide using bromine-containing gas in this application;

[0048] Figure 4 This is a schematic structural diagram of the bromine molecule extraction unit of the present application. DETAILED DESCRIPTION

[0049] The following will be combined with the drawings in the embodiments of this application to clearly and completely describe the technical solutions in the embodiments of this application. Obviously, the embodiments described are only part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0050] On the one hand, if Figure 2 As shown, the present application provides a method for producing lithium bromide, comprising:

[0051] Passing bromine-containing gas into the iron powder suspension to obtain a first mixed solution;

[0052] filtering the first mixed liquid to obtain a ferric bromide solution and iron powder;

[0053] adding lithium carbonate to the ferric bromide solution to obtain a second mixed solution;

[0054] The second mixed liquid is filter-pressed to obtain a lithium bromide solution and ferric hydroxide solid;

[0055] The lithium bromide solution is evaporated to dryness to obtain a lithium bromide solid product.

[0056] The chemical reaction equation for the reaction between bromine-containing gas and iron powder suspension is:

[0057] 2Fe+3Br2=2Fe2Br3

[0058] The iron powder obtained by filtering the first mixed liquid can be used to prepare an iron powder suspension.

[0059] The reaction formula of ferric bromide solution and lithium carbonate is:

[0060] 2FeBr3+3Li2CO3+3H2O=6LiBr+3CO2+2Fe(OH)3

[0061] In some embodiments of the present application, Figure 1 As shown, the method for preparing bromine-containing gas includes:

[0062] Using hydrochloric acid, the pH value of the gas field water is adjusted to 1-4, for example, the pH value is adjusted to 1, 1.5, 2.0, 2.5, 3.0, 3.5 or 4 to obtain an acidified solution;

[0063] The acidified solution is electrolyzed to obtain an oxidized solution at the anode;

[0064] The oxidizing liquid is stripped with air. According to the gas-liquid equilibrium relationship between the gas and liquid phase concentrations of bromine, the bromine is blown out of the oxidizing liquid by the air to obtain bromine-containing gas.

[0065] When the acid solution is electrolyzed, bromide ions undergo an oxidation reaction at the interface between the anode plate and the bromine-containing solution under the action of current, oxidizing the bromide ions into elemental bromine. The chemical reaction equation is:

[0066] 2Br - -2e - =Br2

[0067] Under the action of current, hydrogen ions undergo a reduction reaction at the interface between the cathode plate and the bromine-containing solution, reducing the hydrogen ions to hydrogen gas. The chemical reaction equation is:

[0068] 2H - +2e - =H2

[0069] In some embodiments of the present application, the gas-liquid flow ratio of air to oxidizing liquid is 130-260:1, for example, 130:1, 150:1, 170:1, 190:1, 210:1, 230:1, 250:1 or 260:1, so as to ensure that bromine is blown out of the oxidizing liquid.

[0070] In some embodiments of the present application, the concentration of ferric bromide in the first mixed solution is 20-30 wt %.

[0071] In some embodiments of the present application, the flow ratio of the bromine-containing gas to the iron powder suspension is 40-100:1, for example, 40:1, 50:1, 60:1, 70:1, 80:1, 90:1 or 100:1.

[0072] In some embodiments of the present application, the mass ratio of lithium carbonate to ferric bromide solution is 1.5-2.7:1, for example, 1.5:1, 1.6:1, 1.7:1, 1.8:1, 1.9:1, 2.0:1, 2.1:1, 2.2:1, 2.3:1, 2.4:1, 2.5:1, 2.6:1 or 2.7:1.

[0073] On the other hand, Figure 3 As shown, the present application also discloses a device for producing lithium bromide, comprising:

[0074] a first mixed liquid obtaining unit, for passing bromine-containing gas into the iron powder suspension;

[0075] a filtration unit, configured to filter the first mixed liquid to obtain a ferric bromide solution and iron powder;

[0076] a second mixed liquid obtaining unit, configured to add lithium carbonate to the ferric bromide solution to obtain a second mixed liquid;

[0077] A filter press unit, used for filter pressing the second mixed liquid to obtain a lithium bromide solution and ferric hydroxide solid;

[0078] The evaporation and drying unit is used to evaporate and dry the lithium bromide solution to obtain a lithium bromide solid product.

[0079] In some embodiments of the present application, the device further comprises a bromine molecule extraction unit for preparing bromine-containing gas using gas field water, such as Figure 3 As shown, the bromine molecule extraction unit includes an acid regulating tank, an electrolytic cell and a stripping tower connected in sequence. The acid regulating tank is used to adjust the pH value of the gas field water to 1-4 using hydrochloric acid to obtain acidizing liquid; the electrolytic cell is used to electrolyze the acidizing liquid, and the anode obtains the oxidizing liquid; the stripping tower is used to use air to strip the sprayed oxidizing liquid to obtain bromine-containing gas.

[0080] Specifically, electrolyzing the acidified liquid using an electrolytic cell includes: passing the acidified liquid into an anode chamber of the electrolytic cell; applying power to the electrolytic cell, causing bromide ions in the acidified liquid to undergo an oxidation reaction at the anode to produce bromine molecules, thereby converting the acidified liquid in the anode chamber into an oxidizing liquid; and passing dilute hydrochloric acid into the cathode chamber of the electrolytic cell to maintain acidic conditions in the cathode chamber. The oxidation rate of the bromine molecules in the oxidizing liquid is 90-99%, which is the ratio of the actual amount of bromine molecules converted from bromide ions in the oxidizing liquid to the theoretical yield of bromine molecules converted from bromide ions in the oxidizing liquid. The electrolytic cell is preferably a DF002 electrolytic cell.

[0081] In some embodiments of the present application, Figure 4 As shown, the first mixed liquid obtaining unit includes an absorption tower; the filtration unit includes a bag filter; the second mixed liquid obtaining unit includes a reaction tank; the filter pressing unit includes a filter press; the evaporation and drying unit includes an evaporator; the absorption tower, bag filter, reaction tank, filter press, and evaporator are connected in sequence.

[0082] In some embodiments of the present application, the gas phase inlet at the top of the absorption tower is connected to the gas phase outlet of the stripping tower through a pipeline. After entering the absorption tower, the bromine-containing gas flows from top to bottom and is absorbed by the iron powder suspension circulated and sprayed at the top of the absorption tower.

[0083] In order to better explain the present invention, the following examples are provided.

[0084] Example 1

[0085] S1: Gas field water containing bromide ions (300 mg / L) is continuously pumped into an acid adjustment tank using a centrifugal pump, and the pH is adjusted to 4 using 30% hydrochloric acid to obtain an acidified solution.

[0086] S2: The acidified liquid is pumped into the electrolytic cell for oxidation using a centrifugal pump. The electrolytic cell is energized with a current density of 300A / m 2The acidified liquid undergoes an oxidation reaction in the electrolytic cell to generate elemental bromine, which becomes an oxidizing liquid. After the equipment is running stably, the oxidation rate of bromide ions reaches 99%. The oxidation rate is the ratio between the actual content of bromine molecules converted from bromide ions in the oxidizing liquid and the theoretical yield of bromine molecules converted from bromide ions in the oxidizing liquid.

[0087] S3: The oxidizing liquid is transported to the stripping tower through a pipeline. The oxidizing liquid is sprayed down from the top of the stripping tower. The bromine molecules in the oxidizing liquid are pushed by the Roots blower in the stripping tower and blown out by the air flowing from bottom to top to turn into bromine-containing gas. The gas-liquid flow ratio of the air entering the stripping tower to the oxidizing liquid in the stripping tower is 130:1.

[0088] S4: The top gas phase outlet of the stripping tower is connected to the top gas phase inlet of the absorption tower through a pipeline, and the bottom gas phase outlet of the absorption tower is connected to the gas phase inlet at the bottom of the stripping tower through a Roots blower, that is, the Roots blower serves as the power source for both the stripping tower and the absorption tower. 30% of the iron powder suspension in the absorption tower is circulated and sprayed from the top through a centrifugal pump providing power source. The gas-liquid flow ratio of the flow rate of the bromine-containing gas entering the absorption tower to the self-circulating spray flow rate of the absorption tower is 40:1. After the iron powder suspension reaches the absorption end point, a first mixed liquid is obtained, and the concentration of ferric bromide in the first mixed liquid is 20%.

[0089] S5: The first mixed liquid is pumped into a bag filter through a centrifugal pump to obtain the ferric bromide solution and iron powder, and the iron powder is recovered to prepare an iron powder suspension.

[0090] S6: Passing the ferric bromide solution into the reaction tank, adding lithium carbonate solid powder into the reaction tank, with the mass ratio of the added lithium carbonate to the ferric bromide solution being 1.5:1. After the reaction is complete, a second mixed solution is obtained.

[0091] S7: The second mixed liquid is pumped into a filter press to filter and obtain a lithium bromide solution and ferric hydroxide solid.

[0092] S8: Evaporating, crystallizing and drying the lithium bromide solution to obtain solid lithium bromide.

[0093] Example 2

[0094] S1: Gas field water containing bromide ions (600 mg / L) is continuously pumped into an acid adjustment tank using a centrifugal pump, and the pH is adjusted to 3.5 using 30% hydrochloric acid to obtain an acidified solution.

[0095] S2: The acidified liquid is pumped into the electrolytic cell for oxidation using a centrifugal pump. The electrolytic cell is energized with a current density of 600A / m 2The acidified liquid undergoes an oxidation reaction in the electrolytic cell to generate bromine elemental substance and turn into oxidizing liquid. After the equipment runs stably, the oxidation rate of bromide ions reaches 98%. The oxidation rate is the ratio between the actual content of bromine molecules converted from bromide ions in the oxidizing liquid and the theoretical yield of bromine molecules converted from bromide ions in the oxidizing liquid.

[0096] S3: The oxidizing liquid is transported to the stripping tower through a pipeline. The oxidizing liquid is sprayed down from the top of the stripping tower. The bromine molecules in the oxidizing liquid are pushed by the Roots blower in the stripping tower and blown out by the air flowing from bottom to top to become bromine-containing gas. The gas-liquid flow ratio of the air entering the stripping tower to the oxidizing liquid in the stripping tower is 200:1.

[0097] S4: The top gas phase outlet of the stripping tower is connected to the top gas phase inlet of the absorption tower through a pipeline, and the bottom gas phase outlet of the absorption tower is connected to the gas phase inlet at the bottom of the stripping tower through a Roots blower, that is, the Roots blower serves as the power source for both the stripping tower and the absorption tower. 35% of the iron powder suspension in the absorption tower is circulated and sprayed from the top through a centrifugal pump providing power source. The gas-liquid flow ratio of the flow rate of the bromine-containing gas entering the absorption tower to the self-circulating spray flow rate of the absorption tower is 60:1. After the iron powder suspension reaches the absorption end point, a first mixed liquid is obtained, and the concentration of ferric bromide in the first mixed liquid is 25%.

[0098] S5: The first mixed liquid is pumped into a bag filter through a centrifugal pump to obtain the ferric bromide solution and iron powder, and the iron powder is recovered to prepare an iron powder suspension.

[0099] S6: Passing the ferric bromide solution into the reaction tank, adding lithium carbonate solid powder into the reaction tank, with the mass ratio of the added lithium carbonate to the ferric bromide solution being 1.7:1. After the reaction is complete, a second mixed solution is obtained.

[0100] S7: The second mixed liquid is pumped into a filter press to filter and obtain a lithium bromide solution and ferric hydroxide solid.

[0101] S8: Evaporating, crystallizing and drying the lithium bromide solution to obtain solid lithium bromide.

[0102] Example 3

[0103] S1: Gas field water containing bromide ions (1000 mg / L) is continuously pumped into an acid adjustment tank using a centrifugal pump, and the pH is adjusted to 3.3 using 30% hydrochloric acid to obtain an acidified solution.

[0104] S2: The acidified liquid is pumped into the electrolytic cell for oxidation using a centrifugal pump. The electrolytic cell is energized with a current density of 1000A / m 2The acidified liquid undergoes an oxidation reaction in the electrolytic cell to generate elemental bromine, which becomes an oxidizing liquid. After the equipment is running stably, the oxidation rate of bromide ions is 97%. The oxidation rate is the ratio between the actual content of bromine molecules converted from bromide ions in the oxidizing liquid and the theoretical yield of bromine molecules converted from bromide ions in the oxidizing liquid.

[0105] S3: The oxidizing liquid is transported to the stripping tower through a pipeline. The oxidizing liquid is sprayed down from the top of the stripping tower. The bromine molecules in the oxidizing liquid are pushed by the Roots blower in the stripping tower and blown out by the air flowing from bottom to top to turn into bromine-containing gas. The gas-liquid flow ratio of the air entering the stripping tower to the oxidizing liquid in the stripping tower is 260:1.

[0106] S4: The top gas phase outlet of the stripping tower is connected to the top gas phase inlet of the absorption tower through a pipeline, and the bottom gas phase outlet of the absorption tower is connected to the bottom gas phase inlet of the stripping tower through a Roots blower, that is, the Roots blower serves as the power source of the stripping tower and the absorption tower at the same time. 40% of the iron powder suspension in the absorption tower is circulated and sprayed from the top through a centrifugal pump providing power source. The gas-liquid flow ratio of the flow rate of the bromine-containing gas entering the absorption tower to the self-circulating spray flow rate of the absorption tower is 100:1. After the iron powder suspension reaches the absorption end point, a first mixed liquid is obtained, and the concentration of ferric bromide in the first mixed liquid is 35%.

[0107] S5: The first mixed liquid is pumped into a bag filter through a centrifugal pump to obtain the ferric bromide solution and iron powder, and the iron powder is recovered to prepare an iron powder suspension.

[0108] S6: Passing the ferric bromide solution into the reaction tank, adding lithium carbonate solid powder into the reaction tank, with the mass ratio of the added lithium carbonate to the ferric bromide solution being 2:1, and obtaining a second mixed solution after the reaction is complete.

[0109] S7: The second mixed liquid is pumped into a filter press to filter and obtain a lithium bromide solution and ferric hydroxide solid.

[0110] S8: Evaporating, crystallizing and drying the lithium bromide solution to obtain solid lithium bromide.

[0111] The process effects of the above examples were recorded. The results are shown in Table 1. The oxidation rate of bromine molecules in the oxidizing solution was 97-99%, the lithium bromide rate was about 90%, the power consumption was 773-782 KW / t, and the quality of the lithium bromide produced met product requirements.

[0112] In summary, the present application realizes the oxidative extraction of bromide ions in gas field water by utilizing electro-oxidation through the process of "electro-oxidation-stripping absorption-evaporation crystallization", thereby avoiding the use of hazardous chemical chlorine in the traditional bromine extraction process. At the same time, the use of iron powder suspension as the absorption liquid to prepare lithium bromide avoids the problem of hazardous chemical bromine as the product and lithium bromate as a by-product in the traditional lithium bromide production process. The invention can realize the safe and environmentally friendly recovery and utilization of bromide ions in gas field water, and is expected to alleviate the problem of depletion of underground brine bromine resources and ensure the supply of bromine resources.

[0113] Table 1 Experimental effect data

[0114]

[0115] Finally, it should be noted that the above is only a preferred embodiment of the present application and is not intended to limit the present application. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art can still modify the technical solutions described in the aforementioned embodiments or make equivalent replacements for some of the technical features therein. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present application should be included in the scope of protection of the present application.

Claims

1. A method for producing lithium bromide, characterized in that: include: Passing bromine-containing gas into the iron powder suspension to obtain a first mixed solution; filtering the first mixed solution to obtain a ferric bromide solution and iron powder; adding lithium carbonate to the ferric bromide solution to obtain a second mixed solution; The second mixed liquid is subjected to filter pressing to obtain a lithium bromide solution and ferric hydroxide solid; the lithium bromide solution is evaporated and dried to obtain a lithium bromide solid product.

2. A method for producing lithium bromide according to claim 1, characterized in that, The preparation method of the bromine-containing gas comprises: Using hydrochloric acid to adjust the pH value of gas field water to 1-4 to obtain acidified fluid; electrolyzing the acidified solution to obtain an oxidized solution at the anode; The oxidizing liquid is stripped by air to obtain bromine-containing gas.

3. A method for producing lithium bromide according to claim 2, characterized in that, The gas-liquid flow ratio of the air to the oxidizing liquid is 130-260:

1.

4. A method for producing lithium bromide according to claim 1, characterized in that, The concentration of ferric bromide in the first mixed solution is 20-30 wt %.

5. A method for producing lithium bromide according to claim 1, characterized in that, The flow ratio of the bromine-containing gas to the iron powder suspension is 40-100:

1.

6. A method for producing lithium bromide according to claim 1, characterized in that, The mass ratio of the lithium carbonate to the ferric bromide solution is 1.5-2.7:

1.

7. A device for producing lithium bromide, characterized in that: include: a first mixed liquid obtaining unit, for passing bromine-containing gas into the iron powder suspension; a filtration unit, configured to filter the first mixed solution to obtain a ferric bromide solution and iron powder; a second mixed liquid obtaining unit, configured to add lithium carbonate to the ferric bromide solution to obtain a second mixed liquid; a filter press unit, configured to filter the second mixed liquid to obtain a lithium bromide solution and ferric hydroxide solid; The evaporation and drying unit is used to evaporate and dry the lithium bromide solution to obtain a lithium bromide solid product.

8. The device for producing lithium bromide according to claim 7, characterized in that: The device also includes a bromine molecule extraction unit for preparing bromine-containing gas using gas field water; The bromine molecule extraction unit includes an acid conditioning tank, an electrolytic cell and a stripping tower connected in sequence. The acid adjustment tank is used to adjust the pH value of the gas field water to 1-4 using hydrochloric acid to obtain acidified liquid; The electrolytic cell is used to electrolyze the acidified solution, and the anode obtains the oxidized solution; The stripping tower is used to strip the oxidizing liquid with air to obtain bromine-containing gas.

9. The device for producing lithium bromide according to claim 8, characterized in that: The first mixed liquid obtaining unit includes an absorption tower; The filtration unit includes a bag filter; The second mixed liquid obtaining unit includes a reaction tank; The filter press unit includes a filter press; The evaporative drying unit includes an evaporator; The absorption tower, bag filter, reaction tank, filter press and evaporator are connected in sequence.

10. The device for producing lithium bromide according to claim 9, characterized in that: The gas phase inlet at the top of the absorption tower is connected to the gas phase outlet at the top of the stripping tower through a pipeline, and the gas phase outlet at the bottom of the absorption tower is sequentially connected to a Roots blower and the gas phase inlet at the bottom of the stripping tower through a pipeline.

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