JP6163326B2 - Method for recovering dissolved salts, device for recovering dissolved salts, and method for producing calcium chloride - Google Patents

Description

  The present invention relates to a method and a recovery device for recovering dissolved salts from water associated with resource mining.

The accompanying water generated by mining resources such as natural gas and crude oil such as CSG (Coal Seam Gas) contains NaCl and NaHCO ₃ at high concentrations, so it is desalted and released into the aqueous environment. There is a need. Conventionally, a large amount of removed salt is evaporated to dryness and disposed of as waste. On the other hand, attempts have been made to recover these salts as valuable materials.

For example, Patent Document 1 discloses a technique (Penrice method) for recovering salt in water as valuable salt Na ₂ CO ₃ for water associated with resource mining. This is a method in which C ₁₂ amine and CO ₂ dissolved in an oil phase are reacted with NaCl to convert them to NaHCO ₃ and then converted to Na ₂ CO ₃ by applying heat.

Non-Patent Document 1 and Patent Document 2 disclose a method for producing NaHCO ₃ from water containing NaCl using an ion exchange resin, as represented by Formula (1).
R ₃ N + CO ₂ + NaCl + H ₂ O → R ₃ N—HCl + NaHCO ₃ Formula (1)

To increase the reaction efficiency in the above methods, as represented by the formula (2) is blown with CO ₂ dissolved water to an ion exchange resin, type R _{3 N-H} the bicarbonate or carbonate on tree fat trapped _After being converted to ₂ CO ₃ (carbonic acid type), as shown by the formula (3), water to be treated containing NaCl is passed to produce NaHCO ₃ .
R ₃ N + CO ₂ + H ₂ O → R ₃ N—H ₂ CO ₃ formula (2)
R ₃ N—H ₂ CO ₃ + NaCl → R ₃ N—HCl + NaHCO ₃ Formula (3)

Patent Document 3 discloses a method using limestone (CaCO ₃ ) as a CO ₂ supply source. Further, in this method, CaCO ₃ is burned to obtain CO ₂ and, as represented by the formula (4), Ca (OH) _{2 as a} by-product is used as a regenerated alkali of the ion exchange resin.
2R ₃ N—HCl + Ca (OH) ₂ → 2R ₃ N + CaCl ₂ + 2H ₂ O Formula (4)

The method of Patent Document 3 uses CO ₂ gas generated during the production of Ca (OH) ₂ as a reaction raw material and is fixed as a carbonate, and as a system that emits almost no CO ₂ gas to the atmosphere, global warming This is an effective technique from the viewpoint of prevention. Moreover, since no oil is used, wastewater containing oil as a COD source is not generated. Furthermore, if the water flow conditions are appropriate, the reaction of formula (3) proceeds almost completely, so there is no loss of carbonate recovery and a very high recovery rate can be obtained.

Australian Patent No. 1053 South African Patent No. 785962 Japanese Patent No. 7337512

R. Kunin, Ion Exchange in Chemical Synthesis, Industrial & Engineering Chemistry, 1964, 56 (1), p35-39.

By the way, in the ion exchange resin method, CaCl ₂ is generated during the regeneration of the resin, but in order to completely regenerate the ion exchange resin (R ₃ N-HCl) combined with HCl (formula (4)). Theoretically, a half amount of Ca (OH) ₂ of HCl may be brought into contact with the ion-exchange resin, but in practice, a larger amount of Ca (OH) than half the amount of HCl. ₂ must be brought into contact with the ion exchange resin. Therefore, in the prior art, the number of Ca (OH) ₂ contained in the ion-exchange resin in the Ca (OH) ₂ treatment solution obtained by contacting, low even to obtain a CaCl ₂ from the treatment liquid Only pure CaCl ₂ is obtained, and the obtained CaCl ₂ becomes waste. In general, the cost for disposing of this large amount of waste is high at the site of resource mining. However, if this CaCl ₂ can be recovered with high purity, it can be used as an industrial raw material in the same way as carbonates, and thus can be a valuable resource. In addition, by doing so, this ion exchange method becomes extremely effective as a technique for recovering salts from the accompanying water generated by resource mining such as natural gas or crude oil such as CSG.

An object of the present invention is to recover the CaCl ₂ from resource mining produced water, in particular, to provide a recovery method and recovery apparatus of dissolution salts makes it possible to recover the CaCl ₂ that suppresses entry of impurities It is.

The method for recovering dissolved salts of the present invention includes a first recovery step of passing NaCl-containing resource mining accompanying water through an anion exchange resin and recovering NaHCO ₃ , and anion after the resource mining accompanying water passing A regeneration step of regenerating the anion exchange resin by passing a Ca (OH) ₂ solution through the exchange resin, and a second recovery step of recovering the regenerated treatment solution. In the process, the pH of the regenerated reprocessing solution is monitored, and the regenerated processing solution collected until the monitored pH value reaches a predetermined set value is concentrated and dried to recover CaCl ₂ .

The method for recovering dissolved salts of the present invention includes a first recovery step of passing NaCl-containing resource mining accompanying water through an anion exchange resin and recovering NaHCO ₃ , and anion after the resource mining accompanying water passing A regeneration step of regenerating the anion exchange resin by passing a Ca (OH) ₂ solution through the exchange resin, and a second recovery step of recovering the regenerated treatment solution. In the step, the Cl ⁻ ion concentration of the regenerated reprocessing solution is monitored, and the Cl ⁻ ion desorption amount of the anion exchange resin obtained based on the monitored Cl ⁻ ion concentration is set to a predetermined set value. The regenerated solution collected until reaching the concentration is concentrated and dried to recover CaCl ₂ .

  Further, in the method for recovering dissolved salts, in the second recovery step, the anion exchange resin is recovered from the regeneration processing solution recovered after the monitored pH value reaches a predetermined set value. It is preferable to store as a regenerant.

Further, in the method for recovering dissolved salts, in the second recovery step, the regenerated liquid recovered after the Cl ⁻ ion desorption amount of the anion exchange resin has reached a predetermined set value is used as the anion exchange. It is preferable to store the resin as a regenerant for regenerating the resin.

Further, in the method for recovering dissolved salts, the regeneration is recovered until the predetermined set value is the pH of the Ca (OH) ₂ solution and the monitored pH reaches the pH of the Ca (OH) ₂ solution. The treatment liquid is concentrated and dried to recover CaCl ₂ , and the regeneration treatment liquid collected after the monitored pH reaches the pH of the Ca (OH) ₂ solution is used to regenerate the anion exchange resin. It is preferable to store as a regenerating agent.

Further, in the method for recovering a dissolved salt, the pre-set set value is set between pH 10 and 12, and the regenerated process recovered until the monitored pH reaches the set value set between pH 10 and 12 The solution is concentrated and dried to recover CaCl _2, and the anion exchange resin is regenerated using the regenerated solution collected after the monitored pH reaches a set value set between pH 10-12. It is preferable to store as a regenerating agent.

Further, in the method of recovering the dissolved salts, the predetermined set value Cl of the anion-exchange resin in the first recovery step ^- as an ion adsorption amount, Cl of the anion exchange resin ^- ion elimination amount, The regenerated solution collected until reaching the Cl ⁻ ion adsorption amount of the anion exchange resin is concentrated and dried to recover CaCl _2, and the Cl ⁻ ion desorption amount of the anion exchange resin is determined by the anion exchange amount. It is preferable to store the regeneration treatment liquid recovered after reaching the Cl ⁻ ion adsorption amount of the resin as a regeneration agent for regenerating the anion exchange resin.

Further, in the method of recovering the dissolved salts, wherein the predetermined set value Cl of the anion exchange resin ^- set between 85 to 96 percent of the ion desorption amount, Cl of the anion exchange resin ^- ion removal The regenerated solution collected until the separation amount reached a set value set between 85 and 96% of the Cl ⁻ ion adsorption amount of the anion exchange resin was concentrated and dried to recover CaCl ₂ , and the anion exchange resin was recovered. The regenerated solution recovered after the Cl ⁻ ion desorption amount of the ion exchange resin reaches a set value set between 85 and 96% of the Cl ⁻ ion adsorption amount of the anion exchange resin is treated with the anion exchange. It is preferable to store the resin as a regenerant for regenerating the resin.

The dissolved salt recovery apparatus of the present invention includes a packed column filled with an anion exchange resin, first recovery means for recovering NaHCO ₃ by passing water associated with resource mining containing NaCl through the packed column. , Ca (OH) ₂ solution is passed through the packed tower to regenerate the anion exchange resin, a pH sensor for monitoring the pH of the regenerated regenerated liquid, and the monitored pH value. A second recovery means for recovering the reclaimed processing liquid until a predetermined set value is reached, a concentrating means for concentrating the recovered reclaimed liquid, and a drying means for drying the concentrated regenerated liquid. .
The dissolved salt recovery apparatus of the present invention includes a packed column filled with an anion exchange resin, first recovery means for recovering NaHCO ₃ by passing water associated with resource mining containing NaCl through the packed column. , A regeneration means for allowing the Ca (OH) ₂ solution to flow through the packed tower and regenerating the anion exchange resin, a Cl ⁻ ion sensor for monitoring the Cl ⁻ ion concentration of the regenerated treatment solution, A second recovery means for recovering a regeneration treatment solution until a Cl ⁻ ion desorption amount of the anion exchange resin determined based on the monitored Cl ⁻ ion concentration reaches a predetermined set value; and the recovered regeneration Concentrating means for concentrating the treatment liquid and drying means for drying the concentrated regeneration treatment liquid.

Method for producing a calcium chloride present invention, a resource extraction produced water containing NaCl was passed through an ion exchange resin, and recovering the NaHCO _3, after the resource extraction associated water through water, the ions associated with hydrochloric acid A first step of starting monitoring the calcium chloride purity of the treatment liquid while contacting the exchange resin with a calcium hydroxide solution to obtain a treatment liquid containing calcium chloride; It includes a second step of stopping the acquisition of the treatment liquid from a state higher than purity to a state lower than the purity, and a third step of obtaining the calcium chloride from the acquired treatment liquid. The manufacturing method includes setting a specified value corresponding to the reference purity before the second step, and stops obtaining the processing liquid based on the specified value in the second step. The specified value can be the pH of the treatment liquid when the calcium chloride purity is the reference purity, and in this case, the monitoring of the calcium chloride purity is to measure the pH of the treatment liquid. . Further, the specified value can be a chlorine ion desorption amount of the ion exchange resin when the calcium chloride purity is the reference purity. In this case, the calcium chloride purity is monitored by the treatment liquid. Measuring the chloride ion concentration, and calculating the chlorine ion desorption amount based on the measured chloride ion concentration.

According to the present invention, recovering the CaCl ₂ from resource mining produced water, in particular, it is possible to provide a recovery method and recovery apparatus of dissolution salts makes it possible to recover the CaCl ₂ that suppresses entry of impurities .

It is a schematic block diagram which shows an example of a structure of the dissolved salt collection | recovery apparatus which concerns on this embodiment. It is a schematic block diagram which shows an example of a structure of the dissolved salt collection | recovery apparatus which concerns on this embodiment. PH of the reproduction processing solution for Ca _{(OH) 2} supply amount and Cl ^- is a diagram showing the relationship between ion desorption amount. It is a schematic block diagram which shows an example of a structure of the dissolved salt collection | recovery apparatus concerning a reference example. It is a schematic block diagram which shows another example of a structure of the dissolved salt collection | recovery apparatus which concerns on a reference example. It is a schematic block diagram which shows an example of a structure of the dissolved salt collection | recovery apparatus at the time of performing a reproduction | regeneration process.

  Embodiments of the present invention will be described below. This embodiment is an example for carrying out the present invention, and the present invention is not limited to this embodiment.

FIG.1 and FIG.2 is a schematic block diagram which shows an example of a structure of the dissolved salt collection | recovery apparatus concerning this embodiment. As shown in FIG. 1, the dissolved salt recovery apparatus 1 includes a drainage storage tank 10, a drainage inflow line 12, a drainage pump 14, a packed tower 16 filled with an anion exchange resin, a treated water discharge line 18, a treated water tank 20, As shown in FIG. 2, the dissolved salt recovery device 1 includes a Ca (OH) ₂ storage tank 22, a Ca (OH) ₂ inflow line 24, a Ca (OH) ₂ pump 26, and a blower 32. The air inlet line 34, the regeneration processing liquid discharge lines 36a and 36b, and the regeneration processing liquid storage tanks 38a and 38b are further provided. As shown in FIG. 1, a Cl ⁻ ion sensor 31 is installed in the drainage inflow line 12. A Cl ⁻ ion sensor 21 is installed in the waste water treatment line 18. The Cl ⁻ ion sensor 21 may be installed in the treated water tank 20 . As shown in FIGS. 1 and 2, the packed column 16 is provided with a pH sensor 28 and a Cl ⁻ ion sensor 30. As the Cl ⁻ ion sensors 21, 30, and 31, it is desirable to use sensors using Cl ⁻ ion electrodes. Moreover, as shown in FIG.1 and FIG.2, the dissolved salt collection | recovery apparatus 1 is equipped with the control part 40, and is electrically connected with each sensor and the integrating | accumulating flow meter 19, and the measured value of each sensor and the integrating | accumulating flow meter 19 is shown. It is supposed to be sent. Further, the dissolved salt recovery apparatus 1 includes a concentrating device 42 and a drying device 44. It is desirable that a stirring device (not shown) is installed in the Ca (OH) ₂ storage tank 22. In the dissolved salt recovery apparatus 1 of the present embodiment, when recovering NaHCO ₃ described later, the components shown in FIG. 1 are installed in the packed tower 16, and when recovering CaCl ₂ described later, the packed tower 16 1 may be removed, and the components shown in FIG. 2 may be installed in the packed column 16, or the packed column 16 may be configured as shown in FIGS. 1 and 2 through the recovery of NaHCO _{3 and} the recovery of CaCl ₂ . Parts may be installed.

As shown in FIG. 1, one end of the drainage inflow line 12 is connected to the drainage storage tank 10, and the other end is connected to the upper part of the packed tower 16. In the drainage inflow line 12, a drainage pump 14, an integrating flow meter 19, and a Cl ⁻ ion sensor 31 are installed. One end of the treated water discharge line 18 is connected to the bottom of the packed tower 16, and the other end is connected to the treated water tank 20. As shown in FIG. 2, one end of the Ca (OH) ₂ inflow line 24 is connected to the Ca (OH) ₂ storage tank 22, and the other end is connected to the upper part of the packed tower 16. The Ca _{(OH) 2} inlet line 24 Ca _{(OH) 2} pump 26 is installed. One end of the air inflow line 34 is connected to the blower 32, and the other end is connected to the lower side surface of the packed tower 16. One end of the regeneration processing liquid discharge line 36a is connected to the lower side surface of the packed tower 16, the other end is connected to the regeneration processing liquid storage tank 38a, and one end of the regeneration processing liquid discharge line 36b is connected to the regeneration processing liquid discharge line 36a. The other end is connected to the regeneration processing liquid storage tank 38b.

The drainage storage tank 10, the drainage inflow line 12, the drainage pump 14, the treated water discharge line 18, and the treated water tank 20 pass the resource mining associated water containing NaCl to the packed tower 16 and collect the NaHCO _3. It functions as a device. However, the first recovery device, if a configuration of recovering NaHCO ₃ from resource mining produced water containing NaCl, but is not limited to the above structure.

The Ca (OH) ₂ storage tank 22, the Ca (OH) ₂ inflow line 24, and the Ca (OH) ₂ pump 26 function as a regeneration device that regenerates the anion exchange resin in the packed tower 16. However, the regenerating apparatus is not limited to the above structure as long as it has a structure for regenerating an anion exchange resin.

As will be described later, the regeneration treatment liquid discharge line 36a and the regeneration treatment liquid storage tank 38a have a Cl ⁻ ion desorption of the anion exchange resin determined based on the pH of the regeneration treatment liquid or the Cl ⁻ ion concentration of the regeneration treatment liquid. It functions as a second recovery device that recovers the regenerated processing liquid until the amount reaches a predetermined specified value. However, if the second recovery device has a configuration for recovering the regeneration treatment solution until the pH of the regeneration treatment solution or the Cl ⁻ ion desorption amount of the anion exchange resin reaches a predetermined specified value, However, the present invention is not limited to this configuration.

  The concentrating device 42 has a function of concentrating the regeneration processing liquid, and examples thereof include an evaporator and a liquid film descending evaporation concentrating device. The drying device 44 is for drying the concentrated regeneration treatment liquid, and examples thereof include an electric heating dryer and a vacuum drum dryer.

  Hereinafter, operation | movement of the dissolved salt collection | recovery apparatus 1 of this embodiment is demonstrated.

  The wastewater to be treated in this embodiment is resource mining associated water containing NaCl. The water associated with resource mining is water associated with resource mining such as natural gas such as CSG (Coal Seam Gas) or crude oil, and includes NaCl or the like.

  First, it is desirable that the resource extraction accompanying water containing NaCl is subjected to a pretreatment step and a concentration step before being supplied to the drainage storage tank 10. The pretreatment step is a step of removing suspended substances, oils, and the like contained in the water associated with resource mining by coagulation sedimentation, coagulation flotation separation, membrane filtration using an MF membrane / UF membrane, or the like. The concentration step is a step of concentrating water associated with resource mining with an RO membrane or the like to increase the NaCl concentration in the water. The concentration of NaCl in the concentrated resource extraction accompanying water is preferably 0.1 mol / L or more from the viewpoint of shortening the subsequent treatment time and performing efficient operation.

<First recovery step for recovering NaHCO ₃ >
In the present embodiment, water associated with resource mining containing NaCl is passed through a weakly basic acrylic ion exchange resin of the H ₂ CO ₃ type, NaCl is exchanged for NaHCO ₃ by the reaction of the above formula (3), and NaHCO ₃ The 1st collection process which collects is carried out. Preferably the anion exchange resin is a H ₂ CO ₃ type weakly basic ion-exchange resin, and more preferably H ₂ CO ₃ type weakly basic acrylic ion exchange resin. Hereinafter, an H ₂ CO ₃ type weakly basic acrylic ion exchange resin will be described as an example. The H ₂ CO ₃ type weakly basic acrylic ion exchange resin is a carbonate-dissolved water obtained by dissolving carbonic acid in pure water or the like in a packed tower 16 filled with a weakly basic acrylic ion exchange resin before the first recovery step. It is necessary to pass water and convert it into H ₂ CO ₃ type. Examples of the dissolution of carbonic acid include a method of dissolving CO ₂ gas in pure water or the like using a gas absorption tower or the like. As the CO ₂ gas, it is desirable to use CO ₂ gas produced as a by-product when methane gas is burned or Ca (OH) ₂ is produced from CaCO ₃ .

The first recovery process will be described in detail with reference to FIG. 1. The resource extraction accompanying water containing NaCl in the drainage storage tank 10 passes through the drainage inflow line 12 by the drainage pump 14, and is a weak base of H ₂ CO ₃ type. Is supplied to a packed tower 16 filled with a functional acrylic ion exchange resin. In the packed tower 16, Cl ⁻ is adsorbed by the H ₂ CO ₃ type weakly basic acrylic ion exchange resin, and treated water containing NaHCO ₃ is discharged from the treated water discharge line 18 and stored in the treated water tank 20. The The treated water containing NaHCO ₃ stored in the treated water tank 20 is then concentrated by a concentrating device 42 such as an evaporator and dried by a drying device 44 such as a dryer. In the first recovery step in the present embodiment, it is desirable to monitor the Cl ⁻ ion concentration in the treated water with the Cl ⁻ ion sensor 21 installed in the treated water discharge line 18 and to end immediately when the Cl ⁻ ion concentration increases. For example, even when the measurement data of the Cl ⁻ ion sensor 21 is sent to the control unit 40 and the Cl ⁻ ion concentration is increased, the control unit 40 is electronically controlled so as to stop the operation of the drain pump 14 and the like. Alternatively, the operator may check the measurement data of the Cl ⁻ ion sensor 21 and manually stop the operation of the drainage pump 14 or the like when the Cl ⁻ ion concentration increases.

Further, in the present embodiment, from the start to the end of the first recovery step, Cl H ₂ CO ₃ type weakly basic acrylic ion exchange resin is adsorbed ^- is that you calculate the ion adsorption amount desired. Specifically, the Cl ⁻ ion concentration of the resource mining accompanying water detected by the Cl ⁻ ion sensor 31 installed in the drainage inflow line 12 and the treatment detected by the Cl ⁻ sensor 21 installed in the treated water discharge line 18. It is obtained by multiplying the difference from the Cl ⁻ ion concentration of water by the flow rate (water flow rate) of the water associated with resource mining detected by the integrating flow meter. As for the Cl ⁻ ion adsorption amount adsorbed by the H ₂ CO ₃ type weakly basic acrylic ion exchange resin, for example, the measurement data of each Cl ⁻ sensor and the integrating flow meter 19 are transmitted to the control unit 40, and the control unit 40 It is calculated by.

The anion exchange resin used in this embodiment is a weakly basic anion exchange resin having an acrylic tertiary amine type functional group. For example, Amberlite (registered trademark) IRA-67 is used. Is preferred. It is preferable that the water passing SV of the resource mining associated water in the first recovery step is about 0.5 to 10 (1 / h).

<Regeneration process>
In the present embodiment, a Ca (OH) ₂ solution (hereinafter sometimes referred to as Ca (OH) ₂ slurry) is passed through the anion exchange resin to which HCl has been adsorbed in the first recovery step, and the above formula (4 In the reaction (1), a regeneration step is performed in which HCl is desorbed from the anion exchange resin to regenerate the anion exchange resin. Prior to the regeneration step, it is desirable to pass pure water through the packed tower 16 and wash away the water associated with resource mining that is retained in the gap between the anion exchange resins.

Specifically explaining a reproduction process with reference to FIG. 2, operate the Ca _{(OH) 2} pumps 26, Ca _{(OH) 2} Ca in the storage tank 22 _{(OH) 2} slurry Ca _{(OH) 2} inlet line 24 Is supplied to the packed tower 16, and the blower 32 is operated, and air is supplied to the packed tower 16 through the air inflow line 34. Within packed tower 16, the air, by anion exchange resin is contacted with Ca (OH) ₂ slurry with stirring, HCl is desorbed from the anion-exchange resin, CaCl ₂ is produced a valuable . Such a regeneration step is a batch type in which the Ca (OH) ₂ slurry is gradually added to a predetermined condition while stirring the resin in the packed tower 16 and the reaction solution is discharged from the packed tower 16 after a certain time of reaction. You can go. Alternatively, the Ca (OH) ₂ slurry may be passed through the packed tower 16 to continuously discharge the regeneration treatment liquid. From the viewpoint of more efficiently advancing the reaction of formula (4) on the anion exchange resin covered with the slurry, a batch of gradually adding the Ca (OH) ₂ slurry to a predetermined amount while stirring the anion exchange resin. The formula is preferred.

The concentration of the Ca (OH) ₂ slurry is preferably 5 to 10% when used in batch mode, and 0.05 to 0.5% is preferable when used in continuous mode.

  The fluid for supplying air to the packed column 16 and stirring the anion exchange resin in the packed column 16 is not limited to air, and any fluid that does not hinder the reaction of formula (4) may be used. For example, methane gas etc. are mentioned.

In the regeneration step, undissolved Ca _{(OH) 2} is ^{Ca 2+} and OH ^- from the dissolved, OH ^- because cause regeneration reaction with HCl on an anion exchange resin, the added Ca _{(OH) 2} is reproduced It may take several minutes to 10 minutes to be fully used in the process. Therefore, it is preferable to add the Ca (OH) ₂ slurry in a batch system intermittently in anticipation of the time.

<Second recovery process>
In this embodiment, to implement the second time yield recovering the reproduction process liquid discharged from the packed tower 16. At this time, the pH of the regeneration treatment solution is monitored, and the recovered regeneration solution is concentrated and dried until the monitored pH value reaches a predetermined value. Or reproduction processing liquid Cl ^- monitoring the ion concentration, monitoring the Cl ^- Cl anion exchange resin obtained based on the ion concentration ^- ion elimination amount recovered to reach a predetermined default reproduction processing solution Is concentrated and dried.

FIG. 3 is a graph showing the relationship between the pH of the regeneration treatment solution and the Cl ⁻ ion desorption amount with respect to the supply amount of Ca (OH) ₂ . As shown in FIG. 3, when monitoring the pH of the regeneration treatment solution, before complete regeneration, the Ca (OH) _{2 that} has passed through the packed column 16 is consumed by the anion exchange resin, while the anion exchange resin. Since HCl is desorbed from the ion exchange resin, the pH of the regeneration treatment solution is lower than the pH 12.2 of the Ca (OH) ₂ slurry (when the water temperature is 20 ° C.). The purity of CaCl ₂ is high. On the other hand, if it is after complete regeneration, desorption of HCl is completed, and the Ca (OH) ₂ slurry that has passed through the packed tower 16 is discharged from the packed tower 16 as a regenerated process liquid. The pH of the slurry reaches pH 12.2 (when the water temperature is 20 ° C.) of the Ca (OH) ₂ slurry, and the purity of CaCl ₂ in the regeneration treatment liquid is in a state of decreasing.

Therefore, in the present embodiment, the pH of the regeneration treatment liquid discharged from the packed tower 16 is monitored by a pH sensor, and the monitored pH value is transmitted to the control unit 40. Then, for example, the control unit 40 compares the pH value of the regeneration processing solution with a predetermined pH value set in advance, and while the pH value does not reach the preset specified value, CaCl ₂ in the regeneration processing solution. Therefore, the valve A provided in the regeneration processing liquid discharge line 36a is opened, and the valve B provided in the regeneration processing liquid discharge line 36b is closed. That is, while the pH value is less than the preset specified value, the regeneration processing liquid is supplied from the regeneration processing liquid discharge line 36a to the regeneration processing liquid storage tank 38a. The processing liquid stored in the regeneration processing liquid storage tank 38a is sent to a concentrating device 42 such as an evaporator and concentrated, and then sent to a drying device 44 such as a dryer and dried to recover high-purity CaCl _2. . In addition, when the pH value reaches a preset specified value by the control unit 40, the valve A is closed and the valve B is opened because the purity of the CaCl ₂ in the regenerating solution is lowered. To do. That is, after the pH value reaches a preset specified value, the regeneration processing liquid is supplied from the regeneration processing discharge line b to the regeneration processing storage tank b. In the present embodiment, the comparison between the pH value and the specified value, the opening / closing of the valve, and the like may be performed by electronic control by the control unit 40 or may be performed manually by an operator. When the packed tower 16 is a batch type, the pH value of the regeneration treatment liquid can be measured by the pH sensor 28 installed in the packed tower 16, but when it is a continuous type, the regeneration treatment liquid It is necessary to install a pH sensor in the discharge line 36a or the regeneration processing liquid storage tank 38a and measure the pH of the regeneration processing liquid.

The specified value to be set in advance is not particularly limited as long as it is a value capable of recovering high-purity CaCl ₂ , but in the case of pH monitoring, it should be set to the pH value of the Ca (OH) ₂ slurry. Is preferable, and it is more preferable to set between pH 10.0 and 12.0. By setting the specified value to pH 12.0 or less, it is possible to reliably transfer the regeneration treatment liquid containing high-purity CaCl ₂ to the concentration / drying step. In addition, by setting the specified value to pH 10.0 or more, it is possible to suppress an increase in the regeneration processing liquid stored for regeneration, and it is possible to use a storage facility with a small capacity. In this way, first, a prescribed value (for example, the pH of the regenerating solution) corresponding to a predetermined reference purity of calcium chloride is set, and then the calcium hydroxide solution is applied to the ion exchange resin combined with hydrochloric acid. The contact is made to obtain a regeneration treatment liquid containing calcium chloride, and monitoring of the calcium chloride purity of the regeneration treatment liquid is started. Then, based on the specified value, the acquisition of the regeneration treatment liquid is stopped until the calcium chloride purity is changed from a state higher than the reference purity to a state lower than the reference purity. Thus, the acquisition of the regeneration treatment liquid was stopped until the calcium chloride purity of the regeneration treatment liquid became lower than the reference purity (for example, the calcium chloride purity of the regeneration treatment liquid when the pH of the regeneration treatment liquid was 12.0). Thereafter, by obtaining calcium chloride from the regeneration treatment solution, calcium chloride can be obtained from the regeneration treatment solution having a relatively high calcium chloride purity, and high purity calcium chloride can be produced. In the above example, the specified value is the pH (for example, pH 12.0) of the regeneration treatment liquid when the calcium chloride purity of the regeneration treatment liquid is the reference purity, and when monitoring the calcium chloride purity, Measure the pH. The specified value can be the chlorine ion desorption amount of the ion exchange resin when the calcium chloride purity of the regeneration treatment solution is the reference purity, instead of the above example which is the pH of the regeneration treatment solution. In this case, when monitoring the purity of calcium chloride, the Cl ⁻ ion concentration of the regenerating solution is monitored.

As shown in FIG. 2, when monitoring the Cl ⁻ ion concentration of the regeneration treatment solution, the HCl that had been adsorbed on the anion exchange resin is at a stage of desorption before complete regeneration. The Cl ⁻ ion desorption amount of the anion exchange resin determined based on the Cl ⁻ ion concentration in the solution is lower than the Cl ⁻ ion adsorption amount of the anion exchange resin, and the purity of CaCl _{2 in} the regeneration treatment solution is high. is there. On the other hand, if it is after complete regeneration, desorption of HCl is completed, and the Ca (OH) ₂ slurry that has passed through the packed tower 16 is discharged from the packed tower 16 as a regeneration treatment liquid. The Cl ⁻ ion desorption amount of the resin reaches the Cl ⁻ ion adsorption amount of the anion exchange resin, and the purity of CaCl ₂ in the regeneration treatment liquid is in a state of decreasing.

Therefore, in another embodiment, the Cl ⁻ ion concentration of the regeneration treatment liquid discharged from the packed tower 16 is monitored by a Cl ⁻ ion sensor, and the monitored Cl ⁻ ion concentration value is transmitted to the control unit 40. . Here, the desorption amount of Cl ⁻ ions adsorbed on the anion exchange resin is determined by the product of the Cl ⁻ ion concentration of the regeneration treatment solution and the regeneration treatment solution amount. If the flow rate of the regeneration process liquid is constant, the control unit 40, the monitored Cl ^- obtained by multiplying the constant ion density values, if the reproduction processing solution constant, integrating the reproduction processing liquid discharge line 36a the flowmeter is installed, it transmits a flow rate value of the measured playback processing solution by integrating flowmeter to the control unit 40, the control unit 40, the monitored Cl ^- measured ion concentration value reproduction processing solution flow rate value It is calculated by multiplying. Then, the controller 40 compares, for example, the Cl ⁻ ion desorption amount adsorbed on the anion exchange resin with a preset specified value, and the Cl ⁻ ion desorption amount has reached the preset specified value. During the absence, since the purity of CaCl ₂ in the regeneration processing solution is high, the valve A is opened and the electromagnetic valve B is closed. That is, while the Cl ⁻ ion desorption amount is less than a preset specified value, the regeneration processing liquid is supplied from the regeneration processing liquid discharge line 36a to the regeneration processing liquid storage tank 38a. The processing liquid stored in the regeneration processing liquid storage tank 38a is sent to a concentrating device 42 such as an evaporator and concentrated, and then sent to a drying device 44 such as a dryer and dried to recover high-purity CaCl _2. . Further, when the amount of Cl ⁻ ion desorption reaches a predetermined value set in advance by the control unit 40, the purity of CaCl ₂ in the regeneration treatment liquid starts to decrease, so the valve A is closed, Open valve B. That is, after the Cl ⁻ ion desorption amount reaches a preset specified value, the regeneration processing liquid is supplied from the regeneration processing discharge line b to the regeneration processing storage tank b. In the present embodiment, the comparison between the Cl ⁻ ion desorption amount and the specified value, the opening / closing of the valve, and the like may be performed by electronic control by the control unit 40 or may be performed manually by an operator. When the packed tower 16 is a batch type, the Cl ⁻ ion concentration of the regeneration treatment liquid can be measured by a Cl ⁻ ion sensor 30 installed in the packed tower 16. It is necessary to install a Cl ⁻ ion sensor in the regeneration processing liquid discharge line 36a or the regeneration processing liquid storage tank 38a and measure the Cl ⁻ ion concentration of the regeneration processing liquid.

The specified value to be set in advance is not particularly limited as long as it is a value capable of recovering high-purity CaCl ₂ , but in the case of Cl ⁻ ion concentration monitoring, the Cl ⁻ ion adsorption amount of the anion exchange resin Is preferably set between 85 and 96% of the Cl ⁻ ion adsorption amount of the anion exchange resin. By setting the specified value to 96% or less of the Cl ⁻ ion adsorption amount of the anion exchange resin, it becomes possible to reliably transfer the regeneration treatment liquid containing high-purity CaCl ₂ to the concentration / drying step. . By making the specified value 85% or more of the value of the Cl ⁻ ion adsorption amount of the anion exchange resin, it is possible to suppress an increase in the amount of the regeneration treatment liquid stored for regeneration, and use a storage device with a small capacity. It becomes possible to do. The calculation of the Cl ⁻ ion adsorption amount of the anion exchange resin is as described above.

In the present embodiment, after the pH of the regeneration treatment solution or the Cl ⁻ ion desorption amount reaches a predetermined value, the Ca (OH) ₂ slurry is further introduced into the packed column 16 to completely regenerate the anion exchange resin. It is preferable. Complete regeneration after regeneration treatment liquid, i.e., reproduction processing liquid stored as reproduction processing liquid reservoir 38b playback processing liquid discharge line 36b as described above, Cl ^- somewhat containing ions, Cl ^- as compared with ion Since the content of Ca (OH) ₂ is large, it is desirable to store it for use as a regenerant for regenerating the anion exchange resin in the next cycle. Further, when there are a plurality of packed columns 16 filled with an anion exchange resin, they may be used for regeneration of other series. By doing so, the number of storage facilities can be reduced.

After completion of the second recovery step, it is desirable to wash the anion exchange resin by passing pure water through the packed tower 16. Since this washing waste water is a dilute Ca (OH) ₂ solution, it may be used as dissolved water for preparing a Ca (OH) ₂ slurry.

FIG. 4 is a schematic configuration diagram illustrating an example of a configuration of a dissolved salt recovery apparatus according to a reference example. As shown in FIG. 4, the dissolved salt recovery apparatus 2 includes a drainage storage tank 46, drainage inflow lines 48a and 48b, drainage pumps 50a and 50b, a pH adjusting tower 52, a blower 54, a gas inflow line 56, and an anion exchange resin. A packed tower 58, a treated water discharge line 60, and a treated water tank 62 are provided. As shown in FIG. 4, a Cl ⁻ ion sensor 64 and an alkalinity meter 68 are installed in the drainage inflow line 48 a, a pH sensor 70 is installed in the drainage inflow line 48 b, and a Cl ⁻ ion is installed in the treated water discharge line 60. A sensor 66 is installed. As the Cl ⁻ ion sensors 64 and 66, it is desirable to use a sensor using a Cl ⁻ ion electrode. As shown in FIG. 4, the dissolved salt recovery apparatus 2 includes a control unit 72 and is electrically connected to each sensor and the alkalinity meter 68, and the measurement values of each sensor and the alkalinity meter 68 are transmitted. It is like that. The dissolved salt recovery apparatus 2 includes a concentrating device 74 and a drying device 76.

  As shown in FIG. 4, one end of the drainage inflow line 48 a is connected to the drainage storage tank 46, and the other end is connected to the upper part of the pH adjustment tower 52. A drainage pump 50a is installed in the drainage inflow line 48a. One end of the gas inflow line 56 is connected to the blower 54, and the other end is connected to the side surface of the pH adjusting tower 52. One end of the drainage inflow line 48 b is connected to the lower side surface of the pH adjusting tower 52, and the other end is connected to the upper part of the packed tower 58. A drainage pump 50b is installed in the drainage inflow line 48b. One end of the treated water discharge line 60 is connected to the bottom of the packed tower 58, and the other end is connected to the treated water tank 62.

  The drainage inflow line 48a, the drainage pump 50a, the pH adjusting tower 52, the blower 54, and the gas inflow line 56 function as a pH adjusting device that adjusts the pH of the water associated with resource mining. The pH adjusting device is not limited to the above configuration as long as it has a configuration for adjusting the pH of the resource mining accompanying water. It is preferable to fill the pH adjusting tower 52 with a filler such as Raschig ring from the viewpoint of suppressing the amount of the gas for adjusting the pH of the resource extraction accompanying water.

  The concentrating device 74 has a function of concentrating the regeneration processing liquid, and examples thereof include an evaporator and a liquid film descending evaporation concentrating device. The drying device 76 is for drying the concentrated regeneration treatment liquid, and examples thereof include an electric heating dryer and a vacuum drum dryer.

  Hereinafter, the operation of the dissolved salt recovery apparatus 2 of the reference example will be described.

The wastewater to be treated in the reference example is resource mining accompanying water containing NaCl and a carbonate substance. The water associated with resource mining is water associated with resource mining such as natural gas such as CSG (Coal Seam Gas) or crude oil, and includes NaCl or the like. Here, the carbonate substance is bicarbonate ion (HCO ₃ ⁻ ), carbonate ion (CO ₃ ²⁻ ), free carbonic acid (soluble CO ₂ ) and the like.

  First, it is desirable that the resource mining accompanying water containing NaCl and the carbonate substance is subjected to a pretreatment process and a concentration process before being supplied to the drainage storage tank 46. The pretreatment step is a step of removing suspended substances, oils, and the like contained in the water associated with resource mining by coagulation sedimentation, coagulation flotation separation, membrane filtration using an MF membrane / UF membrane, or the like. The concentration step is a step of concentrating water associated with resource mining with an RO membrane or the like to increase the NaCl concentration in the water. The concentration of NaCl in the concentrated resource extraction accompanying water is preferably 0.1 mol / L or more from the viewpoint of shortening the subsequent treatment time and performing efficient operation.

<PH adjustment step>
In the reference example, the amount of Cl ⁻ ions (moles) relative to the amount (moles) of all carbonated substances (HCO ₃ ⁻ , CO ₃ ²⁻ ) excluding free carbonic acid in the water associated with resource mining (after the pretreatment and concentration step). ) Is adjusted according to the ratio (molar ratio) of the source mining accompanying water. In order to recover high-purity NaHCO ₃ , it is necessary to lower the pH of the resources associated with resource mining as the ratio of the amount of Cl ⁻ ions to the amount of all carbonates excluding free carbonic acid in the resources associated with resource mining is smaller. There is.

Normally, regardless of the molar ratio, when processing is performed by passing water associated with resource mining at a pH of 8.5 or more through the packed column 58 at the subsequent stage, the treated water discharged from the packed column 58 includes NaHCO ₃ in addition to NaHCO ₃ . Since Na ₂ CO ₃ is contained, there is no problem with the purity of the dissolved salts, but the purity of NaHCO ₃ alone is lowered. Further, when the water associated with resource mining with a pH of 9.5 or more is passed through the packed tower 58 at the subsequent stage, the regeneration reaction of the ion exchange resin by OH ⁻ ions occurs simultaneously with the reaction of the above formula (3). Since Cl ⁻ ions are mixed in the treated water discharged from the column 58, the purity of NaHCO ₃ in the treated water discharged from the packed column 58 is further lowered. However, when the ratio of the mass (mol) of Cl ⁻ ions to the mass (mol) of all carbonic substances excluding free carbonic acid is 2 or more, the pH of the water associated with resource mining is set to 6.5 to 8.5. Then, the reaction of the above formula (3) proceeds sufficiently, and most of the total carbonic acid contained in the resource extraction accompanying water is HCO ₃ ⁻ , so that the amount of water from the treated water discharged from the packed tower 58 in the subsequent stage is high. Purity NaHCO ₃ can be recovered. When the ratio of the mass amount (mol) of Cl ⁻ ions to the mass amount (mol) of all carbonic substances excluding free carbonic acid is 2 or more, the pH of the water associated with resource mining is set at 7.0 to 8.0 in particular. By adjusting, since most of the total carbonic acid contained in the water associated with resource mining is HCO ₃ ⁻ , high-purity and more NaHCO ₃ is obtained from the treated water discharged from the packed tower 58 at the subsequent stage. It can be recovered. On the other hand, as the ratio of the mass (mol) of Cl ⁻ ions to the mass (mol) of the total carbon dioxide excluding free carbonic acid becomes smaller than 2, the pH of the water associated with resource mining is 6.5 to 8.5. It is adjusted to the range to become difficult to proceed the reaction of the above formula (3), Cl to treated water discharged from the packed tower 58 ^- incorporation of ions becomes large. However, since the amount of HCO ₃ ⁻ with respect to Cl ⁻ ions can be reduced by lowering the pH of the water associated with resource mining from the above range and converting the carbon dioxide in the resource mining associated water to free carbonate, The reaction of the above formula (3) is likely to proceed. In addition, by setting the pH of the water associated with resource mining within the above range, the reaction of the above formula (3) can be promoted by the nature of the anion exchange resin that performs ion exchange at low pH. For this reason, mixing of Cl ^- ions into the treated water is reduced, and high-purity NaHCO ₃ can be recovered from the treated water.

In the reference example, in order to recover high-purity NaHCO ₃ , the lower the ratio of the substance amount of Cl ⁻ ions to the substance amount of the total carbonate substance excluding free carbonic acid in the resource extraction associated water, the lower the pH of the resource extraction associated water. However, it is preferable to adjust the pH based on the following criteria. If the ratio of the substance amount of Cl ⁻ ions to the substance amount of the total carbonic substance excluding free carbonic acid in the resource extraction associated water is 2 or more, the pH of the resource extraction associated water in the pH adjustment tower 52 is 6.5 to 8 It is preferable to adjust the amount of Cl ⁻ ions to 7.0 or less, more preferably to 7.0 to 8.0, and the amount of Cl ⁻ ion relative to the amount of all carbonates excluding free carbonic acid in the resource extraction accompanying water. If the ratio is less than 2, the pH adjustment tower 52 preferably adjusts the pH of the water associated with resource mining to a range of 5.6 or more and less than 6.5. Further, if the ratio of the amount of Cl ⁻ ions to the amount of all carbonates excluding free carbonic acid in the resource extraction associated water is less than 2 to 1 or more, the pH adjustment tower 52 sets the pH of the resource extraction associated water to 6 It is preferable to adjust to a range of 0.0 or more to less than 6.5, and if the ratio of the substance amount of Cl ⁻ ions to the substance amount of the total carbonate substance excluding free carbonic acid in the resource extraction accompanying water is less than 1, pH adjustment It is preferable that the tower 52 adjusts the pH of the water associated with resource mining to a range of 5.6 or more and less than 6.0.

The pH adjustment process will be described in detail with reference to FIG. 4. The resource mining accompanying water containing NaCl and carbonated material in the drainage storage tank 46 is sent to the drainage inflow line 48a by the drainage pump 50a. Cl of resource extraction associated water through the drainage inlet line 48a ^- substance amount of ions (mol) of Cl ^- is measured by the ion sensor 64, the alkalinity of the resource extraction associated water is measured by the alkalinity meter 68. The measured substance amount and alkalinity of Cl ⁻ ions are transmitted to the controller 72. Based on the alkalinity and pH, the control unit 72 calculates the amount (mol / L) of the total carbonic acid material excluding free carbonic acid (= M alkalinity / 100,000-10 ^(pH-14) ). Then, the ratio of the substance amount of Cl ⁻ ion to the substance amount of the total carbonic acid substance excluding free carbonic acid (Cl ⁻ ion / total carbonic acid substance excluding free carbonic acid) is obtained. Then, CO ₂ gas or air supplied from the blower 54 to the pH adjusting tower 52 through the gas inflow line 56 is brought into contact with the resource mining accompanying water supplied to the pH adjusting tower 52 to adjust the pH of the resource mining accompanying water. The In the reference example, the pH of the resource extraction accompanying water discharged from the pH adjustment tower 52 is measured by the pH sensor 70 installed in the drainage inflow line 48 b, and the measured value is transmitted to the control unit 72. Then, the pH of the water associated with resource mining discharged from the pH adjusting tower 52 is Cl ⁻ ion with respect to the amount (mole) of the total carbonic substances (HCO ₃ ⁻ , CO ₃ ²⁻ ) excluding free carbonic acid in the water associated with resource mining. When the pH adjusted according to the ratio of the amount of substance (mol) is not satisfied, the output of the blower 54 and the like is controlled by the control unit 72 so as to satisfy the pH range, and the CO ₂ gas or air The supply amount is adjusted. In the reference example, when lowering the pH of the water associated with resource mining, CO ₂ gas is supplied (or added with HCl or the like described later), and when increasing the pH of the water associated with resource mining, air is supplied (or later described). NaOH to be added). In the case of using a CO ₂ gas, a CO ₂ that by-product produced when burning the lime to be used for regeneration of the ion exchange resin described later (Ca _{(OH) 2)} and limestone (CaCO ₃₎ It may be used, or CO ₂ gas obtained by burning methane gas obtained locally.

<Recovery process for recovering NaHCO ₃ >
In the reference example, as described above, pH-adjusted NaCl and carbonated water containing resource mining accompanying water is passed through an anion exchange resin, NaCl is exchanged for NaHCO ₃ by the reaction of the above formula (3), and NaHCO ₃ A recovery process is performed to recover the. Preferably the anion exchange resin is a H ₂ CO ₃ type weakly basic ion-exchange resin, and more preferably H ₂ CO ₃ type weakly basic acrylic ion exchange resin. Hereinafter, an H ₂ CO ₃ type weakly basic acrylic ion exchange resin will be described as an example. The H ₂ CO ₃ type weakly basic ion exchange resin is passed through a packed tower 58 filled with a weakly basic ion exchange resin before the recovery step, by passing carbonate-dissolved water in which carbonic acid is dissolved in pure water or the like. Obtained by conversion to ₂ CO ₃ type. Examples of the dissolution of carbonic acid include a method of dissolving CO ₂ gas in pure water or the like using a gas absorption tower or the like. As the CO ₂ gas, it is desirable to use CO ₂ gas produced as a by-product when methane gas is burned or Ca (OH) ₂ is produced from CaCO ₃ .

The recovery process will be described in detail with reference to FIG. 4. The resource extraction accompanying water containing NaCl and carbonated material flowing through the drainage inflow line 48 b and adjusted in pH is filled with anion exchange resin by the drainage pump 50 b. Feeded to column 58. In the packed tower 58, Cl ⁻ is adsorbed by the anion exchange resin, and treated water containing NaHCO ₃ is discharged from the treated water discharge line 60 and stored in the treated water tank 62. The treated water containing NaHCO ₃ stored in the treated water tank 62 is then concentrated by a concentrating device 74 such as an evaporator and dried by a drying device 76 such as a dryer. In the recovery process in the reference example, it is desirable that the Cl ⁻ ion concentration in the treated water is monitored by the Cl ⁻ ion sensor 66 installed in the treated water discharge line 60 or the treated water tank 62, and is immediately terminated when the Cl ⁻ ion concentration increases. . For example, the measurement data of the Cl ⁻ ion sensor 66 may be sent to the control unit 72, and electronic control may be performed by the control unit 72 to stop the operation of the drainage pump 50 b and the like when the Cl ⁻ ion concentration increases. Then, the operator may check the measurement data of the Cl ⁻ ion sensor 66 and manually stop the operation of the drainage pump 50b and the like when the Cl ⁻ ion concentration increases.

The anion exchange resin used in the reference examples is preferably an anion exchange resin having an acrylic tertiary amine type functional group, and for example, Amberlite (registered trademark) IRA-67 is preferably used. It is. It is preferable that the water SV associated with resource mining in the recovery process is about 0.5 to 10 (1 / h).

In the reference example, the pH of the water associated with resource mining supplied to the packed tower 58 is adjusted according to the ratio of the amount of Cl ⁻ ions to the amount of the total carbonic acid material excluding free carbonic acid in the water associated with resource mining. In the packed column 58, Cl ⁻ is efficiently adsorbed by the anion exchange resin, and it becomes possible to recover NaHCO ₃ with high purity.

  FIG. 5 is a schematic configuration diagram illustrating another example of the configuration of the dissolved salt recovery apparatus according to the reference example. In the dissolved salt recovery apparatus 3 shown in FIG. 5, the same components as those of the dissolved salt recovery apparatus 2 shown in FIG. As shown in FIG. 5, the dissolved salt recovery apparatus 3 includes an HCl storage tank 78, an HCl addition line 80, an HCl pump 82, and a pH adjustment tank 84. As shown in FIG. 5, a pH sensor 70 is installed in the pH adjustment tank 84. In addition, it is desirable that a stirring device (not shown) is installed in the pH adjustment tank 84.

  As shown in FIG. 5, one end of the drainage inflow line 48 a is connected to the drainage storage tank 46, and the other end is connected to the pH adjustment tank 84. One end of the HCl addition line 80 is connected to the HCl storage tank 78, and the other end is connected to the pH adjustment tank 84. One end of the drainage inflow line 48 b is connected to the pH adjustment tank 84, and the other end is connected to the upper part of the packed tower 58. A drainage pump 50b is installed in the drainage inflow line 48b. One end of the treated water discharge line 60 is connected to the bottom of the packed tower 58, and the other end is connected to the treated water tank 62.

  The drainage inflow line 48a, the pH adjustment tank 84, the HCl storage tank 78, the HCl addition line 80, and the HCl pump 82 function as a pH adjustment device that adjusts the pH of the water associated with resource mining. The pH adjusting device is not limited to the above configuration as long as it has a configuration for adjusting the pH of the resource mining accompanying water.

  Hereinafter, the operation of the dissolved salt recovery apparatus 3 of the reference example will be described.

As described above, it is desirable to perform the pretreatment process and the concentration process on the resource extraction accompanying water containing NaCl and the carbonate substance before being supplied to the drainage storage tank 46. Then, resource extraction produced water containing NaCl and carbonate material in the waste water storage tank 46, it passes through the drainage inlet line 48a, Cl of resource extraction accompanying water ^- the amount of substance of ions (mol) of Cl ^- by ion sensor 64 The alkalinity in the water associated with resource mining is measured by an alkalinometer 68. The measured substance amount and alkalinity of Cl ⁻ ions are transmitted to the controller 72. Based on the alkalinity and pH, the control unit 72 calculates the amount (mol / L) of the total carbonic acid material excluding free carbonic acid (= M alkalinity / 100,000-10 ^(pH-14) ). Then, the ratio of the substance amount of Cl ⁻ ion to the substance amount of the total carbonic acid substance excluding free carbonic acid (Cl ⁻ ion / total carbonic acid substance excluding free carbonic acid) is obtained. Then, the resource mining accompanying water is supplied to the pH adjusting tank 84, and the HCl solution in the HCl storage tank 78 is supplied from the HCl addition line 80 to the pH adjusting tank 84 by the HCl pump 82, and the pH of the resource mining accompanying water is set. Adjusted. In the reference example, the pH sensor 70 installed in the pH adjusting tank 84 measures the pH of the water associated with resource mining and transmits the measured value to the control unit 72. The pH of the water associated with resource mining in the pH adjustment tank 84 is such that the amount of Cl ⁻ ions relative to the total amount (moles) of carbonic acid substances (HCO ₃ ⁻ , CO ₃ ²⁻ ) excluding free carbonic acid in the resource mining accompanying water ( When the pH adjusted according to the ratio of (mol) is not satisfied, the output of the HCl pump 82 and the like are controlled by the controller 72 so as to satisfy the pH range, and the supply amount of HCl is adjusted. Resource mining associated water adjusted according to the ratio of the mass (mol) of Cl ⁻ ions to the mass (mole) of all carbonates (HCO ₃ ⁻ , CO ₃ ²⁻ ) excluding free carbonic acid in the resource mining associated water The pH is as described above.

  In the reference example, HCl is used for pH adjustment, but it is not limited to this as long as it adjusts the pH of water associated with resource mining. For example, an acid agent such as carbonated water can be used. is there. The acid agent such as HCl is used for lowering the pH of the water associated with resource mining, and it is necessary to use an alkaline agent such as NaOH when the pH of the water associated with resource mining is increased.

The resource extraction accompanying water whose pH is adjusted in the pH adjusting tank 84 is supplied to the packed tower 58 filled with the anion exchange resin by the drain pump 50b. In the packed tower 58, Cl ⁻ is adsorbed by the anion exchange resin, and treated water containing NaHCO ₃ is discharged from the treated water discharge line 60 and stored in the treated water tank 62. The treated water containing NaHCO ₃ stored in the treated water tank 62 is then concentrated by a concentrating device 74 such as an evaporator and dried by a drying device 76 such as a dryer. In the recovery process in the reference example, it is desirable that the Cl ⁻ ion concentration in the treated water is monitored by the Cl ⁻ ion sensor 66 installed in the treated water discharge line 60 or the treated water tank 62, and the process is immediately terminated when the Cl ⁻ ion concentration increases. . For example, even if the measurement data of the Cl ⁻ ion sensor 66 is sent to the control unit 72 and the Cl ⁻ ion concentration is increased, the control unit 72 is electronically controlled to stop the operation of the drain pump 50b and the like. Alternatively, the operator may check the measurement data of the Cl ⁻ ion sensor 66 and manually stop the operation of the drainage pump 50b and the like when the Cl ⁻ ion concentration increases.

Next, the anion exchange resin regeneration process after the recovery of NaHCO ₃ will be described.

FIG. 6 is a schematic configuration diagram illustrating an example of a configuration of a dissolved salt recovery apparatus when performing a regeneration process. As shown in FIG. 6, the dissolved salt recovery device (2, 3) includes a Ca (OH) ₂ storage tank 86, a Ca (OH) ₂ inflow line 88, a Ca (OH) ₂ pump 90, a blower 92, and an air inflow line. 94, a regeneration processing liquid discharge line 98, and a regeneration processing liquid storage tank 38a. It is desirable that a stirring device (not shown) is installed in the Ca (OH) ₂ storage tank 86. In the reference example, in practicing the regeneration process described below, remove the components shown in FIG. 4 or 5 from the packed tower 58, may be equipped with components shown in FIG. 6 in the packed column 58, NaHCO ₃ The components shown in FIG. 4 or 5 and FIG. 6 may be installed in the packed tower 58 through the recovery and regeneration process.

As shown in FIG. 6, one end of the Ca (OH) ₂ inflow line 88 is connected to the Ca (OH) ₂ storage tank 86, and the other end is connected to the upper portion of the packed tower 58. The Ca _{(OH) 2} inlet line 88 Ca _{(OH) 2} pump 90 is installed. One end of the air inflow line 94 is connected to the blower 92, and the other end is connected to the lower side surface of the packed tower 58. One end of the regeneration processing liquid discharge line 98 is connected to the lower side surface of the packed tower 58, and the other end is connected to the regeneration processing liquid storage tank 38a.

  The operation of the dissolved salt recovery apparatus (2, 3) when performing the regeneration process shown in FIG. 6 will be described.

<Regeneration process>
In the reference example, a Ca (OH) ₂ solution (hereinafter sometimes referred to as Ca (OH) ₂ slurry) is passed through the anion exchange resin to which HCl has been adsorbed in the recovery step, and the above formula (4) In the reaction, a regeneration step is performed in which HCl is desorbed from the anion exchange resin to regenerate the anion exchange resin. Prior to the regeneration step, it is desirable to pass pure water through the packed tower 58 and wash away the water associated with resource mining that is retained in the gap between the anion exchange resins.

Specifically explaining a reproduction process with reference to FIG. 6, Ca _(OH) operate the _second pump 90, Ca _{(OH) 2} Ca in the storage tank 86 _{(OH) 2} slurry Ca _{(OH) 2} inlet line 88 Is supplied to the packed tower 58 and the blower 92 is operated, and the air is supplied to the packed tower 58 through the air inflow line 94. In the packed tower 58, HCl is desorbed from the anion exchange resin and CaCl ₂ is generated by contacting the Ca (OH) ₂ slurry with air while stirring the anion exchange resin. Then, the regeneration processing liquid is supplied from the regeneration processing liquid discharge line 98 to the regeneration processing liquid storage tank 38a. The regeneration treatment liquid contains CaCl ₂ , Ca (OH) _2, etc., and is sent to the concentrating device 74 and the drying device 76 as necessary.

Such a regeneration step is a batch type in which the Ca (OH) ₂ slurry is gradually added to a predetermined condition while stirring the resin in the packed column 58 and the reaction solution is discharged from the packed column 58 after a predetermined time of reaction. You can go. Alternatively, the Ca (OH) ₂ slurry may be passed through the packed tower 58 to continuously discharge the regeneration treatment liquid. From the viewpoint of more efficiently advancing the reaction of formula (4) on the anion exchange resin covered with the slurry, a batch of gradually adding the Ca (OH) ₂ slurry to a predetermined amount while stirring the anion exchange resin. The formula is preferred.

The concentration of the Ca (OH) ₂ slurry is preferably 5 to 10% when used in batch mode, and 0.05 to 0.5% is preferable when used in continuous mode.

  The fluid for stirring the anion exchange resin in the packed tower 58 is not limited to air, and may be any fluid that does not inhibit the reaction of the formula (4), and examples thereof include methane gas.

In the regeneration step, undissolved Ca _{(OH) 2} is ^{Ca 2+} and OH ^- from the dissolved, OH ^- because cause regeneration reaction with HCl on an anion exchange resin, the added Ca _{(OH) 2} is reproduced It may take several minutes to 10 minutes to be fully used in the process. Therefore, it is preferable to add the Ca (OH) ₂ slurry in a batch system intermittently in anticipation of the time.

  EXAMPLES Hereinafter, although an Example is given and this invention is demonstrated in detail more concretely, this invention is not limited to a following example.

(Example 1 and comparative example)
CSG resources mining accompanying simulated water is subjected to coagulation pressure flotation separation for the purpose of SS removal and membrane filtration using a UF membrane as a pretreatment step, and further concentration using a reverse osmosis membrane (concentration by 10 times) Went. Table 1 summarizes the water quality of the simulated water accompanying CGS resource mining (hereinafter referred to as treated water) after the pretreatment step and the concentration step.

Weakly basic acrylic anion exchange resin (manufactured by Organo, Amberlite (registered trademark) IRA-67) in a packed column filled 0.2 L, the CO ₂ dissolved water prepared with CO ₂ gas aeration tower and passed through The weakly basic anion exchange resin was converted to H ₂ CO ₃ type (see reaction of formula (2) above). Here, the inorganic carbon concentration of the CO ₂ -dissolved water before flowing into the packed tower and the inorganic carbon concentration of the effluent discharged from the packed tower are measured, and the inorganic carbon concentration of the effluent water is the inorganic concentration of CO ₂ -dissolved water before flowing in. Until the carbon concentration becomes equal, the flow of CO ₂ dissolved water is continued, and the total exchange capacity of 0.32 mol of 0.2 L of IRA-67 is H ₂ CO ₃ type (R ₃ N—H ₂ CO ₃ ). Converted to. Six packed towers (hereinafter referred to as 6 series) packed with the weakly basic anion exchange resin converted into H ₂ CO ₃ type were prepared.

Start the water flow of the water to be treated (21 ° C.) to a packed column of each series, the water to be treated passing water, Cl of the treated water discharged from the packed tower ^- ion concentration was measured. Cl from passing water early in the treated water ^- ion the concentration was less than 180mg / L (0.005mol / L) , the treated water at the time of passing water 360 mL Cl ^- ion concentration of 200mg / L (0.006mol / L The water flow stopped at that time. At this time, the Cl ⁻ ion adsorption amount was estimated to be 0.140 mol. This treated water was concentrated under reduced pressure using an evaporator and evaporated to dryness using a hot plate (70 ° C.) to precipitate dissolved salts containing NaHCO ₃ . Here, the precipitate was dissolved again in pure water, the Cl ⁻ ion concentration was measured, and the Cl ⁻ ion content in the precipitate was confirmed to be less than 0.1% by weight. It was confirmed that NaHCO ₃ was recovered.

Pure water of 5 times the amount of weakly basic anion exchange resin in the packed tower of each series was passed through the packed tower to wash the packed tower. After washing, aeration of air into the resin tower and in a state where the weakly basic anion exchange resin is flowed, 5 w / v% Ca (OH) ₂ slurry is intermittently added to the packed tower. The pH and Cl ⁻ ion concentration of the regeneration treatment solution were measured with the installed pH sensor and Cl ⁻ ion sensor.

Six series packed towers were used, and the pH of the regenerated solution was 9.8 (Example 1-1: First series), 10.0 (Example 1-2: Second series), 10.5 (Example) 1-3: 3rd series), 11.7 (Example 1-4: 4th series), 12.0 (Example 1-5: 5th series), and 12.2 Then, 0.018 mol of Ca (OH) ₂ was added (comparative example: 6th series), and the regenerated waste liquid was taken out (hereinafter referred to as “first stage regenerated solution”), vacuum concentrated by an evaporator, and hot plate ( (70 ° C.) was evaporated to dryness, and dissolved salts containing CaCl ₂ were precipitated. A small amount of the precipitate was dissolved again in pure water, and the Ca ²⁺ and Cl ⁻ concentrations were measured to confirm the molar ratio of both elements in the precipitate. The results are summarized in Table 2. Note that the comparative example is already completely reproduced at this point.

After that, in Examples 1-1 to 1-5, an amount of pure water (130 mL) sufficiently immersed in the weakly basic anion exchange resin in the packed column was introduced, and Ca (OH) was allowed to flow while the resin was flowing by air aeration. ₂ Slurries were added. The addition of Ca (OH) ₂ slurry from the start of regeneration was continued until the same amount as in the comparative example. Moreover, it confirmed that pH at this time was set to 12.2.

In Examples 1-1 to 1-5, a regeneration treatment liquid (hereinafter referred to as “second-stage regeneration treatment liquid”) after additional addition of the Ca (OH) ₂ slurry is taken out, concentrated by distillation under reduced pressure using an evaporator, and Evaporation to dryness by a hot plate was performed to precipitate dissolved salts containing Ca (OH) ₂ . A small amount of the precipitate was dissolved again in pure water, and the Ca ²⁺ and Cl ⁻ concentrations were measured to confirm the molar ratio of both elements in the precipitate. The results are summarized in Table 2.

Since the molar ratio of Ca ²⁺ to Cl ^{− in} CaCl ₂ is 1: 2, the closer the Cl / Camol ratio of the precipitates of Examples 1-1 to 1-5 and the comparative example is to 2, the CaCl in the regeneration treatment liquid _The higher the purity of _{2 and} the lower the value, the lower the purity of CaCl ₂ . Therefore, looking at the results in Table 2, in the comparative example, the Cl / Camol ratio of the precipitate was as low as 1.46, whereas the addition of Ca (OH) ₂ was temporarily stopped before the complete regeneration. In Examples 1-1 to 1-5 in which the regeneration treatment liquid was taken out as the regeneration treatment liquid, the Cl / Camol ratio was 1.86 or more. This Cl / Camol ratio of 1.86 has a CaCl ₂ purity of 95.2% in terms of weight, and contains only 4.2% of Ca (OH) ₂ as an impurity. In Examples 1-1 to 1-4 having a pH of 11.7 or less (Cl desorption rate of 95%), the Cl / Camol ratio is 1.95 or more. This Cl / Camol ratio, when converted to weight, has a CaCl ₂ purity of 98.3%, and contains only 1.7% of Ca (OH) ₂ as an impurity. That is, the lower the pH of the first stage regeneration treatment solution or the lower the Cl desorption rate, the higher the purity of CaCl ₂ recovered from the regeneration treatment solution. However, the lower the pH of the first stage regeneration treatment liquid or the lower the Cl desorption rate, the more the amount of the second stage regeneration treatment liquid tends to increase when the second stage regeneration treatment liquid is recovered. Therefore, it is predicted that the storage facility will become large.

From the above results, it was confirmed that CaCl ₂ can be obtained with high purity from water associated with resource mining containing NaCl. In order to recover CaCl ₂ with high purity, the pH of the regeneration treatment solution is measured, or the Cl ^- ion concentration is measured to determine the amount of Cl desorption, and the regeneration recovered until they reach a predetermined set value. It has been found that it is necessary to concentrate and dry the treatment liquid, that is, to obtain CaCl ₂ from a regeneration treatment liquid having a relatively high CaCl ₂ purity. The range of the set value is set between pH 10.0 and 12.0 in the case of pH measurement, and is set between 85 and 96% of the Cl ⁻ ion adsorption amount in the case of Cl ⁻ ion concentration measurement. It is preferable.

(Example 2)
In Example 2, the same operation as in Example 1 was performed until CSG resource mining accompanying water simulated water was passed through the resin tower, NaHCO ₃ was collected, and washed with pure water. Thereafter, the packed column, pH and Cl regeneration treatment solution ^- while measuring the ion concentration, and the second stage regeneration process liquid obtained in Example 1-4 (purity CaCl ₂ is low) intermittently added . After using all of the second stage regeneration solution, 5 w / v% Ca (OH) ₂ slurry was added intermittently. Then, when the pH of the regeneration treatment solution reached 11.7, the regeneration treatment solution in the packed tower was taken out. The reclaimed reprocessing solution (first stage regenerating solution) was concentrated by vacuum distillation with an evaporator and evaporated to dryness with a hot plate to precipitate dissolved salts containing CaCl ₂ . A small amount of the precipitate was dissolved again in pure water, and the Ca ²⁺ and Cl ⁻ concentrations were measured to confirm the molar ratio of both elements in the precipitate.

Next, pure water is introduced into the packed tower, Ca (OH) ₂ slurry is added intermittently, the pH of the regenerated solution is measured, and even if Ca (OH) ₂ slurry is added, the pH is 12.2. It was set as the state which does not go up more. The regeneration treatment liquid at this stage (second stage regeneration treatment liquid) was taken out from the packed tower, and Cl ⁻ ions in the second stage regeneration treatment liquid were measured. Then, the total Cl desorption rate combined with the Cl ⁻ ion desorption amount of the first stage regeneration treatment liquid was calculated, and it was confirmed that the regeneration was complete.

As a result of Example 2, the Cl / Camol ratio of the precipitate obtained by concentrating and evaporating and drying the first stage regenerating solution taken out when the pH reached 11.7 was 1.96, and CaCl It was confirmed that ₂ could be recovered with high purity. After the first stage regeneration, until complete regeneration (until the pH of the regeneration treatment solution reaches 12.2), new Ca (OH) ₂ was further added, including Ca (OH) ₂ added in the first stage regeneration. The amount of new Ca (OH) ₂ added until complete regeneration is 0.071 mol (0.142 eq), which is almost equal to the amount of Cl ⁻ ion (0.140 mol = 0.140 eq) adsorbed by passing water to be treated. It was equivalent. The complete regeneration, as required _Ca (OH) 2 0.100 mol in Comparative Example in Table 2, originally Cl ^- but must often Ca _{(OH) 2} than ion adsorption amount, regeneration of the previous cycle By using the second stage regeneration treatment solution in as a regenerant, it can be confirmed that the amount of new Ca (OH) ₂ used per regeneration is almost equal to the adsorption amount of Cl ⁻ ions. It was.

Further, it was confirmed that CaCl ₂ can be recovered with high purity even when the second stage regeneration treatment liquid is used as a regenerant together with Ca (OH) ₂ . As a result, it is possible to regenerate weakly basic anion exchange resin with the minimum amount of Ca (OH) ₂ added, and there is almost no loss or disposal of Ca (OH) ₂ , reducing the running cost related to regeneration. It was shown that it can be done.

(Simulated drainage of Reference Examples 1-5)
In Reference Examples 1 to 5, simulated waste water having the composition shown in Table 3 was prepared. The Cl ⁻ concentration and each carbonic acid concentration in the simulated waste water were values within the range assumed as the concentration after the pretreatment / concentration step was performed on the actual resource extraction accompanying water.

(Reference Example 1)
by blowing CO ₂ gas into the simulated wastewater pH 9.5, adjusted simulated wastewater PH6.7～9, and not blown CO ₂ gas for comparison, the simulated wastewater pH 9.5, weakly basic acrylic ion Water was passed through a packed tower packed with 200 mL of an exchange resin (manufactured by Organo Corporation, Amberlite (registered trademark) IRA-67, exchange capacity 1.6 eq / LR). The weakly acidic acrylic ion exchange resin in the packed tower is preliminarily supplied with CO ₂ -dissolved water so that the entire amount of the weak basic ion exchange resin is converted into HCO ₃ type, and then the simulated waste water is converted into SV1. Water was passed at 0.0 / h. The concentration of HCO ₃ ⁻ , CO ₃ ²⁻ , and Cl ⁻ in the treated water discharged from the packed tower was measured, and when the total amount of these total anions reached 0.2 equivalent, the simulated waste water flow was stopped. did. The Na ⁺ ion concentration and the pH of the treated water were confirmed. Based on the NaHCO ₃ , Na ₂ CO ₃ , NaCl, and NaOH concentrations of the obtained treated water, the concentration of NaHCO ₃ when precipitated as a solid by concentration and drying. Purity and recovery were determined. The results are summarized in Table 4. Here, NaHCO ₃ concentration contained in the treated water HCO ₃ ^- were determined from the concentration (mol / L). HCO ₃ ^- concentration was determined by measuring the M alkalinity and P alkalinity.
[NaHCO ₃ ] (g / L) = [HCO ₃ ⁻ ] (mol / L) × (84/61)
[HCO ₃ ] (mol / L) = M alkalinity−P alkalinity (mol / L)
The NaHCO ₃ concentration _is determined from the ^{CO 3 2-} concentrations, _CO ^{3 2-} concentrations were determined from the M alkalinity and pH.
[Na ₂ CO ₃ ] (g / L) = [CO ₃ ²⁻ ] (mol / L) × (106/60)
[CO ₃ ²⁻ ] = 2 × (M alkalinity−10 (pH−14)) (mol / L)
Moreover, the amount of NaHCO ₃ recovered per liter of simulated waste water (g / L) was calculated by the amount of precipitate after concentration and drying × purity (%).

Table 3 and as can be seen from Table 4, Cl to substances of total carbonate material except free carbon dioxide ^- in the simulated wastewater in the ratio of the amount of substance of ions 6.0, a pH in the CO ₂ gas from 6.7 to 8. By adjusting in the range of 5, high-purity NaHCO ₃ could be recovered in high yield. In particular, at pH 6.7 to 8.0, the purity was higher, and NaHCO ₃ could be recovered with a higher yield.

(Reference Example 2)
Reference Example 1 except that simulated drainage having a pH of 6.0 to 8.4 was adjusted by blowing air into simulated drainage having a pH of 6.0, and that simulated drainage having a pH of 6.0 was used without comparison. As well as. The results of Reference Example 2 are summarized in Table 5.

As can be seen from Table 3 and Table 5, in the simulated drainage in which the ratio of the amount of Cl ⁻ ions to the amount of all carbonates excluding free carbonic acid is 6.0, the pH is 6.5 to 8.4 with air. By adjusting within the range, NaHCO ₃ with high purity could be recovered in high yield. In particular, at a pH of 6.5 to 8.0, the purity was higher and NaHCO ₃ could be recovered with a higher yield.

(Reference Example 3)
Except that the simulated drainage of pH 9.5 was blown with CO ₂ gas and adjusted to pH 6.4 to 8.0, and for comparison, CO ₂ gas was not blown, and simulated drainage of pH 9.5 was used. This was carried out in the same manner as in Reference Example 1. The results of Reference Example 3 are summarized in Table 6.

Table 3 and as can be seen from Table 6, Cl to substances of total carbonate material except free carbon dioxide ^- in the simulated wastewater in the ratio of ions of a substance amount of 2.0, a pH in the CO ₂ gas 6.4 to 8 By adjusting within the range of 0.0, high-purity NaHCO ₃ could be recovered in a high yield. In particular, it was possible in PH6.7～8.0, recovering NaHCO ₃ at a higher yield.

(Reference Example 4)
by blowing CO ₂ gas into the simulated wastewater pH9.5, adjusted simulated wastewater PH6.1～8.0, and not blown CO ₂ gas for comparison, except for using simulated waste water pH9.5 This was carried out in the same manner as in Reference Example 1. The results of Reference Example 4 are summarized in Table 7.

As can be seen from Tables 3 and 7, in the simulated waste water in which the ratio of the amount of Cl ⁻ ions to the amount of all carbonates excluding free carbonic acid is 1.5, the pH is adjusted to 6.1 to 6. with CO ₂ gas. By adjusting within the range of 7, high purity NaHCO ₃ could be recovered in high yield. In particular, NaHCO ₃ with higher purity could be recovered at pH 6.1.

(Reference Example 5)
by blowing CO ₂ gas into the simulated wastewater pH9.5, adjusted simulated wastewater PH5.8～6.5, and not blown CO ₂ gas for comparison, except for using simulated waste water pH9.5 This was carried out in the same manner as in Reference Example 1. The results of Reference Example 5 are summarized in Table 8.

As can be seen from Tables 3 and 8, in the simulated waste water in which the ratio of the amount of Cl ⁻ ions to the amount of all carbonates excluding free carbonic acid is 0.9, the pH is adjusted to 5.8 to 6.5 with CO ₂ gas. By adjusting in the range of 5, high-purity NaHCO ₃ could be recovered in high yield. In particular, NaHCO ₃ with higher purity could be recovered at pH 5.8.

As described above, from the results of Reference Examples 1 to 5, NaCl and carbonate ions / bicarbonate ions coexist in the water associated with resource mining, and even if the content / abundance ratio changes variously, Cl to a substance quantity ^- in accordance with the ratio of the ionic material quantity, by adjusting the pH of the resource extraction produced water, it was confirmed that retrieve high purity NaHCO ₃ stably.

1 to 3 Dissolved salt recovery device 10, 46 Drainage storage tank, 12, 48a, 48b Drain inflow line, 14, 50a, 50b Drain pump, 16, 58 Packing tower, 18, 60 Treated water discharge line, 19 Integrated flow meter 20, 62 Treated water tank, 21, 30, 31, 64, 66 Cl ^- ion sensor, 22, 86 Ca (OH) ₂ storage tank, 24, 88 Ca (OH) ₂ inflow line, 26, 90 Ca (OH) ₂ pump, 28, 70 pH sensor, 32, 54, 92 blower, 34, 94 air inflow line, 36a, 36b, 98 regeneration processing liquid discharge line, 38a, 38b, regeneration processing liquid storage tank, 40, 72 control unit, 42,74 Concentrator, 44,76 Dryer, 52 pH adjustment tower, 56 Gas inflow line, 68 Alkali meter, 78 HCl reservoir, 80 HCl addition line, 8 HCl pump, 84 pH adjustment tank.

Claims (14)

A first recovery step of passing water associated with resource mining containing NaCl through an anion exchange resin and recovering NaHCO ₃ ;
A regeneration step of passing the Ca (OH) ₂ solution through the anion exchange resin after passing water through the resource mining and regenerating the anion exchange resin;
A second recovery step of recovering the regenerated reprocessing solution,
In the second recovery step, the pH of the regenerated reprocessing solution is monitored, and the regenerated processing solution recovered until the monitored pH value reaches a preset value is concentrated and dried to recover CaCl ₂ . A method for recovering dissolved salts. A first recovery step of passing water associated with resource mining containing NaCl through an anion exchange resin and recovering NaHCO ₃ ;
A regeneration step of passing the Ca (OH) ₂ solution through the anion exchange resin after passing water through the resource mining and regenerating the anion exchange resin;
A second recovery step of recovering the regenerated reprocessing solution,
In the second recovery step, the Cl ⁻ ion concentration of the regenerated reprocessing solution is monitored, and the Cl ⁻ ion desorption amount of the anion exchange resin determined based on the monitored Cl ⁻ ion concentration is determined in advance. A method for recovering dissolved salts, comprising recovering CaCl ₂ by concentrating and drying the regenerated solution recovered until the set value is reached.   In the second recovery step, the regenerated liquid collected after the monitored pH value reaches a predetermined set value is stored as a regenerant for regenerating the anion exchange resin. The method for recovering dissolved salts according to claim 1. In the second recovery step, the reprocessing solution recovered after the Cl ⁻ ion desorption amount of the anion exchange resin reaches a predetermined set value is used as a regenerant for regenerating the anion exchange resin. The method for recovering dissolved salts according to claim 2, wherein the method is stored. The predetermined set value as the pH of the Ca _{(OH) 2} solution, pH was the monitoring, the Ca _{(OH) 2} concentration of the regeneration process liquid collected to reach the pH of the solution and dried CaCl ₂ The reprocessing solution collected after the monitored pH reaches the pH of the Ca (OH) ₂ solution is stored as a regenerant for regenerating the anion exchange resin. Method for recovering dissolved salts. The predetermined set value is set between pH 10 and 12, and the regenerated solution collected until the monitored pH reaches the set value set between pH 10 and 12 is concentrated and dried to obtain CaCl ₂ . The regenerated solution collected after the collected and monitored pH reaches a set value set between pH 10 and 12 is stored as a regenerant for regenerating the anion exchange resin. Method for recovering dissolved salts. The predetermined set value is defined as the Cl ⁻ ion adsorption amount of the anion exchange resin in the first recovery step, and the Cl ⁻ ion desorption amount of the anion exchange resin is the Cl ⁻ ion adsorption amount of the anion exchange resin. The regenerated solution collected until reaching the amount was concentrated and dried to recover CaCl _2, and the Cl ⁻ ion desorption amount of the anion exchange resin reached the Cl ⁻ ion adsorption amount of the anion exchange resin. The method for recovering a dissolved salt according to claim 4, wherein a reprocessing solution recovered later is stored as a regenerating agent for regenerating the anion exchange resin. The predetermined set value is set between 85 and 96% of the Cl ⁻ ion desorption amount of the anion exchange resin, and the Cl ⁻ ion desorption amount of the anion exchange resin is The regenerated solution collected until reaching a set value set between 85 and 96% of the Cl ⁻ ion adsorption amount is concentrated and dried to recover CaCl _2, and the Cl ⁻ ion desorption amount of the anion exchange resin is recovered. Is used as a regenerant for regenerating the anion exchange resin, using the regenerated liquid recovered after reaching a set value set between 85 and 96% of the Cl ⁻ ion adsorption amount of the anion exchange resin. The method for recovering a dissolved salt according to claim 4 to be stored. A packed tower filled with an anion exchange resin;
A first recovery means for recovering NaHCO ₃ by passing water associated with resource mining containing NaCl through the packed tower;
A regeneration means for passing the Ca (OH) ₂ solution through the packed tower and regenerating the anion exchange resin;
A pH sensor for monitoring the pH of the regenerated reprocessing solution;
A second recovery means for recovering the regeneration treatment liquid until the monitored pH value reaches a predetermined set value;
A concentration means for concentrating the recovered regeneration treatment solution;
And a drying means for drying the concentrated reclaimed processing solution. A packed tower filled with an anion exchange resin;
A first recovery means for recovering NaHCO ₃ by passing water associated with resource mining containing NaCl through the packed tower;
A regeneration means for passing the Ca (OH) ₂ solution through the packed tower and regenerating the anion exchange resin;
A Cl ⁻ ion sensor for monitoring the Cl ⁻ ion concentration of the regenerated reprocessing solution;
A second recovery means for recovering a regeneration treatment solution until a Cl ⁻ ion desorption amount of the anion exchange resin determined based on the monitored Cl ⁻ ion concentration reaches a predetermined set value;
A concentration means for concentrating the recovered regeneration treatment solution;
And a drying means for drying the concentrated reclaimed processing solution. The resource extraction produced water containing NaCl was passed through an ion exchange resin, and recovering the NaHCO _3, after the resource extraction associated water through water, is contacted with calcium hydroxide solution to the ion exchange resin combined with hydrochloric acid A first step of starting monitoring the calcium chloride purity of the treatment liquid while obtaining a treatment liquid containing calcium chloride;
A second step of stopping the acquisition of the treatment liquid until the calcium chloride purity is lowered from a state higher than a predetermined reference purity;
And a third step of obtaining the calcium chloride from the obtained treatment liquid. Setting a specified value corresponding to the reference purity before the second step,
The method for producing calcium chloride according to claim 11, wherein acquisition of the treatment liquid is stopped based on the specified value in the second step. The specified value is the pH of the treatment liquid when the calcium chloride purity is the reference purity,
The method for producing calcium chloride according to claim 12, wherein the calcium chloride purity is monitored by measuring a pH of the treatment liquid. The specified value is a chlorine ion desorption amount of the ion exchange resin when the calcium chloride purity is the reference purity,
The calcium chloride purity monitoring according to claim 12, wherein the monitoring of the calcium chloride purity includes measuring a chlorine ion concentration of the treatment liquid and calculating the chlorine ion desorption amount based on the measured chlorine ion concentration. Manufacturing method.

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