Apparatus and method for producing layered zirconium phosphate

Abstract

An apparatus for producing lamellar zirconium phosphate through a wet synthesis method, comprising: a mixing device for mixing at least a zirconium compound, phosphoric acid and / or a phosphate, an organic acid, an inorganic acid having an acid dissociation exponent (pKa) not higher than 0, and a solvent; and an aging device for aging the liquid mixture obtained by mixing, in the mixing device, at least the zirconium compound, the phosphoric acid and / or the phosphate, the organic acid, the inorganic acid, and the solvent.

Description

[Technical field]

[0001] The present invention relates to an apparatus and method for producing layered zirconium phosphate, which is an ion exchanger that has excellent heat resistance and chemical resistance and can be used as an impurity ion trapping agent for electronic materials, an antibacterial agent raw material, a deodorant, a discoloration inhibitor, a rust inhibitor, an intercalation support, etc. [Background technology]

[0002] Zirconium phosphate, an inorganic ion exchanger, is used for a variety of purposes, taking advantage of its characteristics. Zirconium phosphates include amorphous ones and crystalline ones with two-dimensional layered structure and three-dimensional mesh structure. Among these, layered zirconium phosphate Zr2(HPO4)2·nH2O with two-dimensional layered structure has excellent ion exchange performance, heat resistance, chemical resistance and radiation resistance, and is used as impurity ion trapping agent for electronic materials, immobilization agent for radioactive waste, solid electrolyte, gas adsorbent, gas separator, rust inhibitor, catalyst, intercalation support and antibacterial raw material.

[0003] Since layered zirconium phosphate is easy to synthesize and has excellent performance, various methods for producing it have been disclosed. Examples include a hydrothermal method in which raw materials are mixed in water or in a state containing water, and then pressurized and heated to synthesize, and a wet synthesis method in which raw materials are mixed in water, and then heated under normal pressure to synthesize.

[0004] WO 2008 / 053694 discloses that layered zirconium phosphate which may contain Hf (hafnium) exhibits excellent performance, particularly in the field of electronic materials, and discloses a so-called wet synthesis method as a production method thereof, in which an aqueous solution containing a zirconium compound is mixed with an aqueous solution containing phosphoric acid and / or a salt thereof to produce a precipitate, which is then aged to synthesize the layered zirconium phosphate, and discloses that the addition of oxalic acid during synthesis reduces waste of raw materials and improves their utilization efficiency.

[0005] Japanese Patent Application Laid-Open No. 2012-224517 discloses that, when synthesizing layered zirconium phosphate by a wet synthesis method, a recovered filtrate obtained after separating a layered zirconium phosphate precipitate is used as at least a part of a reaction liquid in the wet synthesis method, and at least one of phosphoric acid and a zirconium compound is added in the presence of an organic acid such as oxalic acid, thereby further obtaining a layered zirconium phosphate precipitate and increasing the utilization rate of raw material components remaining in the mother liquor.

[0006] Japanese Patent Application Laid-Open No. 2012-224518 discloses that when layered zirconium phosphate is synthesized by a wet synthesis method, the use of an inorganic acid having a pKa (acid dissociation exponent) of 0 or less in combination increases the yield of layered zirconium phosphate obtained as a precipitate, thereby improving the utilization efficiency of the raw material. Summary of the Invention [Problem to be solved by the invention]

[0007] However, in the methods for producing layered zirconium phosphate disclosed in International Publication No. 2008 / 053694, Japanese Patent Application Publication No. 2012-224517, and Japanese Patent Application Publication No. 2012-224518, the efficiency of raw material utilization, i.e., the yield of the product layered zirconium phosphate, is improved, but it is difficult to increase the concentration of layered zirconium phosphate in the synthesis solution. For example, in the method described in Japanese Patent Application Publication No. 2012-224518, layered zirconium phosphate could only be produced at a low concentration of 5.6% by weight in the synthesis solution, and the product yield per synthesis batch was low. Furthermore, these manufacturing methods require synthesis for each batch, which is time-consuming and inefficient, and further improvement in productivity is required. In addition, these manufacturing methods require synthesis for each batch, which tends to cause variation in particle size of the obtained product.

[0008] According to one embodiment of the present invention, in a wet synthesis method for layered zirconium phosphate, it is possible to provide an apparatus for producing layered zirconium phosphate that can improve the zirconium phosphate concentration in a synthesis solution, and further, can perform a synthesis reaction continuously, and is highly productive, and has a high quality with small variation in particle size, and a production method using the same. [Means for solving the problem]

[0009] The present invention includes the following aspects [1] to

[10] . [1] An apparatus for producing layered zirconium phosphate by a wet synthesis method, A mixing device for mixing at least a zirconium compound, phosphoric acid and / or a phosphate, an organic acid, an inorganic acid having an acid dissociation constant (pKa) of 0 or less, and a solvent; an aging device for aging a mixed liquid obtained by mixing at least the zirconium compound, the phosphoric acid and / or the phosphate, the organic acid, the inorganic acid, and the solvent in the mixing device; An apparatus for producing layered zirconium phosphate comprising: [2] The apparatus for producing layered zirconium phosphate according to [1], wherein the mixing apparatus is a tank type having a stirring device, and includes a supply mechanism for supplying at least the zirconium compound, the phosphoric acid and / or the phosphate, the organic acid, the inorganic acid, and the solvent, and an extraction mechanism for extracting the mixed liquid from the mixing apparatus. [3] The apparatus for producing layered zirconium phosphate according to [1] or [2], wherein the aging device is a tank type equipped with a heating device. [4] The apparatus for producing layered zirconium phosphate according to [1] or [2], wherein the aging device is a tubular type equipped with a heating device. [5] The apparatus for producing layered zirconium phosphate according to any one of [2] to [4], wherein the supply mechanism has a mechanism capable of continuous supply, and the withdrawal mechanism has a mechanism capable of continuous withdrawal. [6] The apparatus for producing layered zirconium phosphate according to [5], wherein the supply mechanisms are a plurality of independent supply mechanisms, and the apparatus has a mechanism for continuously supplying the aqueous solution containing the zirconium compound, the aqueous solution containing the phosphate and / or the aqueous solution containing the phosphate, and the aqueous solution containing the organic acid and the inorganic acid from each of the plurality of independent supply mechanisms to the mixing device. [7] A method for producing layered zirconium phosphate using the production apparatus according to any one of [1] to [5], a mixing step of mixing at least the zirconium compound, the phosphoric acid and / or the phosphate, the organic acid, the inorganic acid, and the solvent; an aging step of aging a mixed liquid obtained by mixing at least the zirconium compound, the phosphoric acid and / or the phosphate, the organic acid, the inorganic acid, and the solvent in the mixing step; A method for producing layered zirconium phosphate comprising the steps of: [8] A method for producing layered zirconium phosphate using the production apparatus according to [6], a mixing step of mixing at least the zirconium compound, the phosphoric acid and / or the phosphate, the organic acid, the inorganic acid, and the solvent; an aging step of aging a mixed liquid obtained by mixing at least the zirconium compound, the phosphoric acid and / or the phosphate, the organic acid, the inorganic acid, and the solvent in the mixing step; Including, The method for producing layered zirconium phosphate, wherein the zirconium compound and the phosphate and / or the phosphate are continuously supplied to the mixer from each of the plurality of independent supply mechanisms. [9] The method for producing layered zirconium phosphate according to [8], wherein the aqueous solution containing the zirconium compound, the aqueous solution containing the phosphate and / or the aqueous solution containing the phosphate, and the aqueous solution containing the organic acid and the inorganic acid are continuously supplied to the mixing device from each of the multiple independent supply mechanisms.

[10] The method for producing layered zirconium phosphate according to any one of [7] to [9], wherein the amount of the inorganic acid added is in the range of 0.1 to 5.0 mol per 1 mol of the zirconium compound, the organic acid is at least one of oxalic acid and an oxalate, and the amount of the organic acid added is in the range of 0.01 to 0.8 mol per 1 mol of the inorganic acid. Effect of the Invention

[0010] According to one embodiment of the present invention, the variation in the median size of the layered zirconium phosphate particles produced can be suppressed, and the thickening of the synthesis solution caused by the swelling of the produced gel containing the zirconium phosphate particles can be suppressed, making it easier to stir. Therefore, the concentration of zirconium phosphate in the synthesis reaction solution can be increased, and the product yield can be improved. Furthermore, since raw materials, etc. can be continuously fed into the production equipment, it is possible to reduce the troublesome work of feeding a series of raw materials, etc., which was previously required for each batch. Furthermore, while conventionally the mixing equipment (i.e., the reaction equipment) for the raw materials, etc. and the maturation tank for the synthetic liquid slurry were used in the same tank, i.e., for the same batch, by separating the mixing equipment and the maturation equipment, it becomes easy to install multiple simple and inexpensive maturation equipment and / or to increase the size of the equipment, and therefore it is possible to improve productivity while suppressing equipment costs. [Brief description of the drawings]

[0011] [Figure 1] FIG. 1 is a schematic diagram showing a production apparatus for layered zirconium phosphate, which is used in Examples 1 to 5 and is equipped with a tank-type mixer and a tank-type aging device. [Diagram 2] FIG. 2 is a diagram showing the analysis results of X-ray diffraction measurement of the layered zirconium phosphate produced in Example 1. [Diagram 3] FIG. 1 is a schematic diagram showing a production apparatus for layered zirconium phosphate, which is used in Example 6 and is equipped with a tank-type mixer and a tubular aging device. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] The present disclosure relates to a highly productive apparatus and method for producing layered zirconium phosphate. Layered zirconium phosphate refers to zirconium phosphate having a two-dimensional layered structure, and examples thereof include α-zirconium phosphate, β-zirconium phosphate, and γ-zirconium phosphate. The present disclosure will be described below. In addition, unless otherwise specified, "%" means "% by weight" and "parts" means "parts by weight." In addition, in this disclosure, the description "lower limit to upper limit" indicating a numerical range means "not less than the lower limit, not more than the upper limit," and the description "upper limit to lower limit" indicates "not more than the upper limit, not less than the lower limit." In other words, it represents a numerical range including the upper limit and the lower limit. Furthermore, in this disclosure, a combination of two or more of the preferred embodiments described below is also a preferred embodiment. In the present disclosure, the term "process" refers not only to an independent process, but also to a process that cannot be clearly distinguished from other processes, as long as the intended purpose of the process is achieved.

[0013] 1.Layered zirconium phosphate manufacturing equipment The manufacturing apparatus of the layered zirconium phosphate of the present disclosure includes a mixing device and an aging device. The raw materials can be mixed by the mixing device, and the mixed liquid obtained thereby (hereinafter also referred to as a synthetic liquid slurry) can be aged by the aging device. The mixing device and the aging device are separate devices. The manufacturing equipment may be equipped, as necessary, with a supply device for supplying raw materials and the like to the mixing equipment, an extractor for extracting the mixed liquid from the mixing equipment and sending it to the maturing equipment, a washing device for washing the synthetic liquid slurry, a drying device for drying the slurry after washing, a grinding device for grinding the layered zirconium phosphate obtained by drying, and an extracting device for extracting the product.

[0014] In the present disclosure, "mixing" refers to mixing raw materials and the like, and the mixed liquid refers to a liquid obtained by mixing raw materials and the like in a mixing device, and may be a reaction product in which an initial sol-gel reaction has progressed, as appropriate, and is preferably a slurry liquid in which initial layered zirconium phosphate particles have precipitated.

[0015] In the present disclosure, aging refers to a process in which a mixed solution is left at an appropriate temperature with and / or without stirring for an appropriate time to allow a target reaction to proceed, thereby producing layered zirconium phosphate particles having a desired particle size with good yield and little variation in particle size.

[0016] 1-1.Mixing device The mixing device according to the present disclosure is a device for mixing at least a zirconium compound, phosphoric acid and / or a salt thereof (hereinafter also referred to as "phosphoric acid (salt)"), an organic acid, an inorganic acid, and a solvent. Details of the zirconium compound, phosphoric acid (salt), organic acid, inorganic acid, and solvent will be described later in the section on the production method.

[0017] As the mixing device, it is preferable to use a tank type device. The tank-type mixing device is preferably equipped with a mechanism, structure, or method (hereinafter, these are collectively referred to as a "heating mechanism") capable of heating or warming the mixed liquid, and there are no particular limitations on the mechanism. Examples of heating mechanisms include a mechanism for immersing a tank in a heating medium such as a water bath or an oil bath, a mechanism for selecting a jacketed tank and controlling the temperature using hot water, steam, or the like, and a mechanism for controlling the temperature by attaching a heat exchanger to the outside of the tank-type apparatus. The mixer may be equipped, as required, with a supply device for supplying raw materials and the like to the mixer, and with a withdrawal device for withdrawing the mixed liquid from the mixer and sending it to an aging device.

[0018] There are no particular limitations on the material of the mixer, but it is preferable to use a corrosion-resistant material to prevent corrosion by the acid. Examples of corrosion-resistant materials include stainless steel (hereinafter referred to as "SUS") and other materials with the inner surface coated with a glass material or a fluorine-containing resin for corrosion resistance, as well as highly durable materials such as nickel alloys (commercially available products include Hastelloy (registered trademark) and titanium). Specifically, examples of corrosion-resistant processed products include stainless steel equipment with a glass lining inside the tank and stainless steel equipment with a fluororesin coating inside the tank, and an example of a highly durable material is equipment made of Hastelloy. As the fluororesin, known ones can be used, for example, PTFE: Polytetrafluoroethylene (tetrafluoride), PFA: Tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer, FEP: Tetrafluoroethylene-hexafluoropropylene copolymer (4,6 fluorine), ETFE: Tetrafluoroethylene-ethylene copolymer, PVDF: Polyvinylidene fluoride (difluoride), PCTFE: Polychlorotrifluoroethylene (trifluoride), Examples include: Among these, PTFE (polytetrafluoroethylene (tetrafluoride)) is preferable, and Teflon (registered trademark) is more preferable.

[0019] The mixing device is preferably one having a device for mixing the raw materials, etc., and examples thereof include a tank-type device equipped with an agitating blade, and a tank-type device equipped with an external liquid-transfer pump having a stirring capacity. An example of a tank-type apparatus equipped with an external liquid-sending pump having stirring capability is an apparatus in which a static mixer or a line mixer is combined with a liquid-sending pump.

[0020] In the case of a tank-type device equipped with an agitator, examples of the agitator include a three-blade swept-back impeller, a turbine impeller, a propeller impeller, a paddle impeller, an anchor impeller, a full zone impeller, a max blend impeller, and a super mix impeller. Baffles can also be installed as necessary. There are no particular limitations on the material of the stirring blade, but it is preferable to use a corrosion-resistant material to prevent corrosion by the acid. Examples of the corrosion-resistant material include the materials exemplified for the mixing device. Specifically, examples of corrosion-resistant processed blades include stainless steel blades with a glass-lined surface and stainless steel blades with a fluororesin coating on the surface, while examples of blades made of highly durable materials include blades made of Hastelloy.

[0021] As the tank-type apparatus, one having a device for controlling the liquid temperature in the tank is preferable, and an example of such an apparatus is one having a mechanism for circulating the liquid, which is composed of a jacketed tank and a heat exchanger attached to its exterior.

[0022] Examples of tank-type apparatus equipped with an external liquid-feeding pump having stirring capability include an apparatus combining a static mixer with a liquid-feeding pump, an apparatus combining an in-line mixer with a liquid-feeding pump, and an apparatus combining an emulsifier or homogenizer capable of continuous processing with a liquid-feeding pump. In an apparatus that combines a static mixer or a line mixer with a liquid feed pump, a mixing device can be assembled by connecting multiple mixers in parallel or series so that the four raw materials, i.e., zirconium compound, phosphoric acid (salt), organic acid, and inorganic acid, can be mixed in any order.

[0023] 1-2.Aging device The maturation device according to the present disclosure is a device for maturing the mixed liquid (i.e., the synthetic liquid slurry) obtained in the mixing device. For example, the maturation device is a device that receives the mixed liquid intermittently or continuously, and heats it as necessary to maintain the temperature for a long period of time.

[0024] The aging apparatus is not particularly limited, but a tank type, a tube type, or the like is preferred. In both the tank type and tubular type devices, it is preferable that a heating mechanism is provided, and there are no particular limitations on the mechanism. Examples of heating mechanisms include a mechanism for immersing the tank and tube in a heating medium such as a water bath or oil bath, a mechanism for selecting a jacketed tank and tube and controlling the temperature using hot water, steam, or the like, and a mechanism for controlling the temperature by attaching a heat exchanger to the outside of the tank-type or tubular apparatus. In addition to the above, the heating mechanism of the tubular aging apparatus may be a mechanism in which the tube has a double tube structure, the synthetic liquid slurry flows inside, and hot water or steam is introduced outside to heat the synthetic liquid slurry in the inner tube.

[0025] The heating temperature is not particularly limited and can be set arbitrarily, but a higher temperature is preferable since it can shorten the aging time, and is, for example, 40°C or higher, preferably 60°C or higher, and more preferably 80°C or higher.

[0026] There is no particular limitation on the material of the tank-type aging device, but it is preferable to use a corrosion-resistant material to prevent corrosion by the acid. Examples of the corrosion-resistant material include the materials exemplified for the mixing device, etc. Specific examples of the use of the corrosion-resistant material include the devices exemplified for the mixing device, etc. In the case of a tank-type device equipped with an agitator, the agitator blades that can be used include three-blade swept-back blades, turbine blades, propeller blades, paddle blades, anchor blades, full zone blades, max blend blades, and super mix blades. There are no particular limitations on the material of the stirring blade, but it is preferable to use a corrosion-resistant material to prevent corrosion by the acid. Examples of the corrosion-resistant material include the materials exemplified for the mixing device. Specific examples of the stirring blade using a corrosion-resistant material include the stirring blades exemplified in the mixing device described above.

[0027] In the case of a tubular maturation apparatus, a structure in which the synthesis liquid slurry inside the tube is pushed out by laminar flow is preferable. Laminar flow is a dimensionless number called the Reynolds number (hereafter referred to as the Re number), and is expressed as the inner diameter of the pipe D [m], the average velocity of the fluid U [m / s], and the density of the fluid ρ [kg / m 3 ] and the fluid viscosity is μ [Pa s], it is expressed as "Re = DUρ / μ", and a value of 2500 or less is generally expressed as laminar flow. Specifically, a long tubular structure with a small diameter is suitable for pushing out the synthetic liquid slurry in a pipe by laminar flow, and what is generally called a pipe or tube is used. There is no particular limitation on the material of the tubular maturation apparatus, but it is preferable to use a corrosion-resistant material to prevent corrosion by the acid. Examples of the corrosion-resistant material include the materials exemplified for the mixing device. Specifically, examples of corrosion-resistant treated products include SUS pipes with a glass lining on the inside, SUS pipes with a fluororesin coating on the inside, and fluororesin tubes (for example, PTFE (polytetrafluoroethylene (tetrafluoride)) tubes and PFA (tetrafluoroethylene-perfluoroalkylvinylether copolymer) tubes), and examples of highly durable materials include titanium pipes processed into a long, tubular shape, and Hastelloy pipes processed into a long, tubular shape.

[0028] The maturation apparatus may be, for example, one apparatus for one mixing apparatus, or a combination of multiple apparatuses. When a combination of multiple apparatuses is used, they may all be tank type, or all be tubular type, or a combination of tank type and tubular type, or a combination of types other than tank type and tubular type may be used. As the maturation apparatus, a tubular maturation apparatus is preferable since it can continuously carry out the steps of feeding the raw materials, generating the mixed liquid and feeding it to the maturation apparatus, maturing the liquid, and withdrawing the generated product, thereby enabling higher productivity.

[0029] 1-3. Raw material supply equipment The mixing device is preferably provided with a supply device for supplying raw materials and the like. When a supplying device is provided, for example, a suitable material may be selected, and a raw material tank placed on a scale, a supplying device, and a mixing device may be connected by piping. In this case, raw materials can be supplied by adjusting the operation of the supplying device while measuring the weight change of the raw material tank. An example of the supply device is a liquid delivery pump. Examples of liquid delivery pumps include centrifugal pumps, mixed flow pumps, and axial flow pumps, which are classified as non-positive displacement pumps, as well as reciprocating pumps such as plunge pumps and diaphragm pumps, which are classified as positive displacement pumps, and rotary pumps such as gear pumps and vane pumps.

[0030] In addition to the method of directly measuring the weight of the raw material supply, a flow meter can also be used. Examples of flow meters include electromagnetic flow meters, Karman vortex flow meters, impeller flow meters, diaphragm flow meters, ultrasonic flow meters, and Coriolis flow meters, and an appropriate type is selected depending on the properties of the raw materials, etc. Among these, a combination of a positive displacement pump such as a diaphragm pump or a gear pump with a flow meter is preferred for stabilizing the supply amount. Also, in a relatively small scale for the purpose of research and testing, a combination of a scale for measuring the weight change of raw materials and a tube pump or a hose pump is preferably used because it is easy to operate the liquid transfer.

[0031] 1-4. Liquid delivery device from the mixer to the maturation device The production apparatus is preferably equipped with an extractor for extracting the mixed liquid from the mixing apparatus. The withdrawal device is not particularly limited, and examples thereof include a device that withdraws the liquid from the bottom of the mixer, a device that installs a pipe on the top or side of the mixer and withdraws the liquid through the pipe, and in either case, a means for sending the liquid, such as a liquid sending pipe, can be used as necessary. There is no limitation on the driving force for sending the liquid, and gravity, a liquid sending pump, etc. can be used, or they can be combined, and are selected arbitrarily. There are no particular limitations on the material of the liquid delivery pipe, but it is preferable to use a corrosion-resistant material to prevent corrosion by acid. Examples of corrosion-resistant materials include the materials exemplified for the mixing device, etc. Specifically, examples of corrosion-resistant processed materials include SUS liquid-transfer pipes with the inner surface of the pipes lined with glass and SUS liquid-transfer pipes with the inner surface of the pipes coated with fluororesin, and an example of a material with high durability is a liquid-transfer pipe made of Hastelloy.

[0032] A manufacturing apparatus for layered zirconium phosphate equipped with a tank-type mixer and a tank-type aging apparatus is shown in Fig. 1. The manufacturing apparatus shown in Fig. 1 includes a raw material supply pump 1, a raw material supply pump 2, a raw material supply pump 3, a liquid A tank 4, a liquid B tank 5, a liquid C1 to C4 tank 6, a mixing motor 7, a mixing impeller 8, a mixing tank 9, a mixing jacket 10, an extraction pipe 11, a aging motor 12, a aging impeller 13, an aging tank 14, and an aging jacket 15. A manufacturing apparatus for layered zirconium phosphate equipped with a tank-type mixer and a tubular aging apparatus is shown in Fig. 3. The manufacturing apparatus shown in Fig. 3 includes a raw material supply pump 1, a raw material supply pump 2, a raw material supply pump 3, a liquid A tank 4, a liquid B tank 5, a C1 to C4 liquid tank 6, a mixing apparatus stirring motor 7, a mixing apparatus stirring blade 8, a mixing tank 9, a mixing apparatus jacket 10, an extraction pipe 16, a mixed liquid delivery pump 17, an aging pipe 18, an oil bath 19, and a synthetic liquid slurry tank 20.

[0033] 2. Manufacturing method of layered zirconium phosphate The method for producing layered zirconium phosphate of the present disclosure is a method for producing layered zirconium phosphate using a production apparatus, and includes a mixing step of mixing at least the zirconium compound, the phosphoric acid and / or the phosphate, the organic acid, the inorganic acid, and the solvent, and an aging step of aging a mixed liquid obtained by mixing at least the zirconium compound, the phosphoric acid and / or the phosphate, the organic acid, the inorganic acid, and the solvent in the mixing step. According to the method for producing layered zirconium phosphate of the present disclosure, raw materials and the like are continuously or alternately supplied to a mixer and mixed, and the obtained mixed liquid (i.e., synthetic liquid slurry) can be sent to an aging apparatus and aged in the aging apparatus. The method for producing layered zirconium phosphate of the present disclosure may further include other steps other than the mixing step and the aging step, as necessary. Examples of the other steps include a supply step of supplying raw materials to a mixing device, a withdrawal step of withdrawing the mixed liquid from the mixing device and sending it to an aging device, a washing step of washing the synthetic liquid slurry, a drying step of drying the washed slurry, a grinding step of grinding the layered zirconium phosphate obtained by drying, and a removal step of removing the product.

[0034] 2-1. Raw materials etc. In the present disclosure, at least a zirconium compound, phosphoric acid (salt), inorganic acid, organic acid, and solvent are used as raw materials and the like.

[0035] Examples of the zirconium compound include zirconium nitrate, zirconium acetate, zirconium sulfate, zirconium carbonate, basic zirconium carbonate, basic zirconium sulfate, zirconium oxysulfate, and zirconium oxychloride. Zirconium nitrate, zirconium acetate, zirconium sulfate, zirconium carbonate, basic zirconium sulfate, zirconium oxysulfate, and zirconium oxychloride are preferred, and in consideration of reactivity, economy, and the like, zirconium oxychloride is more preferred. These zirconium compounds may be mixed with water to prepare an aqueous solution of the zirconium compound, which may then be used in the production of layered zirconium phosphate. Alternatively, a commercially available aqueous solution, such as an aqueous solution of Zircosol (manufactured by Daiichi Kigenso Kagaku Kogyo Co., Ltd.), may be used.

[0036] Examples of phosphoric acid (salt) include phosphoric acid, sodium phosphate, potassium phosphate, and ammonium phosphate, with phosphoric acid being preferred. The phosphoric acid (salt) is preferably used as an aqueous solution, more preferably a high-concentration aqueous phosphoric acid (salt) solution, still more preferably a 75 to 85 wt % aqueous phosphoric acid (salt) solution, and particularly preferably a 75 to 85 wt % aqueous phosphoric acid solution. The reaction ratio of the phosphoric acid (salt), in terms of the molar ratio of the charge to the zirconium compound, is 2 or more, preferably 2.05 or more, and more preferably 2.1 or more. The reaction ratio of phosphoric acid (salt) may be in large excess relative to the zirconium compound, but in consideration of the conductivity of the supernatant during washing with water after synthesis, and from the viewpoint of improving the efficiency of the washing step, the molar ratio is 3 or less, preferably 2.9 or less, and more preferably 2.6 or less.

[0037] The inorganic acid is an inorganic acid having an acid dissociation constant (pKa) of 0 or less. Specific examples of the inorganic acid include hydrochloric acid, sulfuric acid, nitric acid, hydroiodic acid, hydrobromic acid, chloric acid, bromic acid, iodic acid, permanganic acid, thiocyanic acid, perchloric acid, perbromic acid, tetrafluoroboric acid, and hexafluorophosphoric acid, etc. Among these, hydrochloric acid, sulfuric acid, and nitric acid, which are easily obtained industrially, are preferred, and hydrochloric acid is particularly preferred because it is safe in that it is not oxidizing and does not easily produce sparingly soluble salts. The reaction ratio of the inorganic acid, in terms of a molar ratio to the zirconium compound, is 0.1 to 8.0, more preferably 0.5 to 5.0, and even more preferably 1.0 to 3.0. In the present disclosure, this ratio is preferable because it facilitates the production of layered zirconium phosphate.

[0038] In the production method of the present disclosure, an organic acid is used in combination. The organic acid is preferably an aliphatic carboxylic acid, more preferably an aliphatic dibasic carboxylic acid. Specific examples of the aliphatic dibasic carboxylic acid include oxalic acid, maleic acid, malonic acid, and succinic acid, and more preferably oxalic acid. These organic acids may be salts, and the counter ions in the salts are not particularly limited, but are preferably selected from ammonium ions, sodium ions, and potassium ions.Specific examples of preferred counter ions include oxalic acid dihydrate, ammonium oxalate, and ammonium hydrogen oxalate, and oxalic acid dihydrate is particularly preferred. The organic acid is believed to have the effect of increasing the solubility of the zirconium compound by forming a coordinate bond with the zirconium compound, and is therefore preferably mixed in advance with the aqueous solution of the zirconium compound. The reaction ratio of the organic acid, in terms of a molar ratio to the zirconium compound, is 1.0 to 3.5, more preferably 1.5 to 3.2, and even more preferably 2.0 to 3.0. In the present disclosure, this ratio is preferable because it facilitates the production of layered zirconium phosphate.

[0039] In the present disclosure, a solvent is used as a raw material, etc. The solvent in the present disclosure refers to a liquid used to dissolve raw materials or by-products or to disperse products to form a liquid slurry. The solvent is not particularly limited, but examples thereof include water. In the present disclosure, raw materials such as a zirconium compound, phosphoric acid (salt), an organic acid, and an inorganic acid are mixed in a solvent. The raw materials, such as the zirconium compound, phosphoric acid (salt), organic acid, inorganic acid, and solvent, can be separately charged into a mixing device to prepare a mixed liquid, or the raw materials, such as the zirconium compound, phosphoric acid (salt), organic acid, and inorganic acid, can be dissolved and / or dispersed in a solvent in advance, or can be appropriately combined, and then charged into a mixing device to prepare a mixed liquid. The zirconium compound, phosphoric acid (salt), organic acid, and inorganic acid are preferably used as an aqueous solution containing each compound using water as a solvent. An aqueous solution containing two or more of the zirconium compound, phosphoric acid (salt), organic acid, and inorganic acid may be used in combination, and an aqueous solution containing an organic acid and an inorganic acid is exemplified. The solvent can be pre-added to the mixing device or added separately at a later time.

[0040] The amount of solvent used in the mixed liquid, i.e., the synthesis liquid slurry, is not particularly limited, but from the viewpoint of high productivity of the target layered zirconium phosphate, the amount of solvent is preferably such that the concentration of zirconium phosphate in the synthesis liquid slurry is 5 wt % or more, more preferably 8 wt % or more, and even more preferably 10 wt % or more.

[0041] The total proportion of the zirconium compound and phosphoric acid (salt) to the total amount of raw materials, etc. is preferably 4.0 to 25.0% by weight, more preferably 6.0 to 18.0% by weight, from the viewpoints of improving the yield of layered zirconium phosphate and providing excellent stirrability of the mixed liquid.

[0042] As a preferred combination of raw materials, etc., it is preferable to use water as a solvent, and to supply an aqueous solution containing a zirconium compound, an aqueous solution containing a phosphate (salt), and an aqueous solution containing an organic acid and an inorganic acid from each of a plurality of independent supply mechanisms to the mixer. In this case, the concentration of the aqueous solution containing the zirconium compound is appropriately set depending on the solubility. A dispersion system may be used, but an aqueous solution is preferable. The concentration of the zirconium compound in the aqueous solution is, for example, preferably 10 to 50% by weight, more preferably 20 to 40% by weight. From the viewpoint of stability, 25 to 38% by weight is even more preferable. When preparing an aqueous solution containing phosphoric acid (salt), the concentration of phosphoric acid (salt) in the aqueous solution is preferably 10 to 100% by weight, more preferably 30 to 98% by weight, and even more preferably 35 to 90% by weight from the viewpoints of the storage tank volume and the viscosity of the aqueous solution. When the aqueous solution contains an organic acid and an inorganic acid, the total concentration of the organic acid and the inorganic acid in the aqueous solution is preferably 2.0 to 40% by weight, more preferably 4.0 to 35% by weight, and further preferably 5.0 to 15.0% by weight from the viewpoint of the solubility of the compounds.

[0043] The raw materials and the like in the present disclosure are a zirconium compound, phosphoric acid (salt), inorganic acid, organic acid, and solvent, but compounds and additives other than these can also be used as necessary. For example, polymer compounds called flocculants, dispersants or scale control agents, specifically: Examples of the copolymer include a copolymer obtained by polymerizing at least two of acrylic acid and / or a neutralized salt thereof, acrylamide, and 2-(acryloyloxy)ethyl-N,N,N-trimethylammonium chloride; and a copolymer obtained by polymerizing at least two of acrylic acid and / or a neutralized salt thereof, 2-acrylamido-2-methylpropane-1-sulfonic acid and / or a neutralized salt thereof, and tertiary butylacrylamide.

[0044] 2-2. Manufacturing conditions (1) Mixing conditions In the present disclosure, as described above, a production apparatus is used that is equipped with a mixer and, if necessary, with a supply mechanism, an extraction mechanism, etc. The mixing conditions for using the mixing device will be described below with specific examples, but are not limited thereto.

[0045] When a supply mechanism is provided, there is no particular limitation on the method of supplying the raw materials, but it is preferable that the raw materials containing a zirconium compound and the raw materials containing phosphoric acid (salt) are each supplied to the mixer from separate supply devices. In this case, it is preferable that the raw materials containing the zirconium compound and the raw materials containing phosphoric acid (salt) are continuously supplied to the mixer, respectively, which reduces the bias and variation in the concentration and molar ratio of each raw material in the mixer, reduces the variation in particle size of the obtained layered zirconium phosphate, and increases the zirconium phosphate concentration in the mixed solution, thereby enabling continuous mass production of high-quality layered zirconium phosphate with high productivity.

[0046] In the case of a mixing device that continuously supplies raw materials and extracts / sends mixed liquid, the manufacturing conditions are set appropriately by combining the residence time of the mixed liquid, the temperature of the mixed liquid, and the stirring strength. The supply rate of the raw materials, etc. is set accordingly. The residence time of the mixed liquid in the mixer can be calculated by dividing the amount of liquid held in the mixer by the amount of raw materials supplied or the amount of the mixed liquid withdrawn. There is no particular limit to the residence time, but it is preferably 1 to 60 minutes, more preferably 5 to 40 minutes, and even more preferably 10 to 30 minutes. The temperature of the mixture is not particularly limited, but is preferably 10 to 80° C., and more preferably 25 to 60° C. The temperature of the mixture can be selected arbitrarily in combination with the residence time. For example, when a relatively long residence time is selected, it is preferable to set the temperature of the mixture to a low level. The stirring strength is not particularly limited, and can be finely adjusted by using a stirring blade selected from the above-mentioned stirring blades. In this case, the speed of the tip of each blade, so-called tip speed, can be used as an index. In terms of the stirring strength of the mixed liquid in the mixer, the tip speed is preferably 0.2 to 6.0 m / s, more preferably 0.6 to 3.0 m / s. Since the stirring strength is related to the control of the median diameter of the layered zirconium phosphate particles, for example, when the median diameter is to be increased, it is advisable to take measures to lower the tip speed.

[0047] (2) Aging conditions In the present disclosure, as described above, the maturation device is a device that receives the mixed liquid extracted from the mixing device, heats it as necessary, and maintains the temperature for a long period of time. After receiving the mixed liquid, production is carried out under the aging temperature, aging time and stirring conditions described below. The aging temperature is not particularly limited, but is preferably 60 to 130° C., more preferably 80 to 130° C., and further preferably 90 to 100° C. By setting the temperature at 100° C. or less, a pressure-resistant device becomes unnecessary, and the equipment cost can be reduced. There is no particular restriction on the maturation time, but it is preferably 1 to 24 hours, more preferably 3 to 18 hours, and even more preferably 6 to 12 hours. When a tank-type maturation device is used, the synthetic liquid slurry can be matured in the tank for the above-mentioned specified time and then cooled in the maturation device (maturation tank), or the synthetic liquid slurry can be extracted to another tank or the like and cooled there. When a tubular maturation apparatus is used, the flow rate of the synthetic liquid slurry can be arbitrarily set in consideration of the diameter and length of the pipe and the supply rate of the raw materials and the like to the mixing apparatus so that the synthetic liquid slurry is retained in the pipe for the above-mentioned specified time.

[0048] In the case of a tank-type maturation apparatus, the above-mentioned stirring blades can be selected for stirring, and the rotation speed can be arbitrarily selected depending on the blade shape. Although layered zirconium phosphate can be produced using an aging apparatus not equipped with stirring blades, it is preferable to use stirring blades in consideration of making the temperature of the synthesis liquid slurry as uniform as possible and of withdrawing the synthesis liquid slurry after aging. The synthetic liquid slurry obtained by heating for the required time in a tank-type maturation device is cooled to below 60°C by running cold water through the tank jacket. Alternatively, it can be cooled using an external heat exchanger. Alternatively, the heat exchange capacity of the heat exchanger can be increased to cool the synthetic liquid slurry in one pass while sending it to the next process.

[0049] In the case of a tubular aging apparatus, it is preferable that the relationship between the tube diameter and the flow rate is such that a laminar flow state with a Reynolds number of 2500 or less is maintained. In addition, in order to ensure an arbitrarily set residence time, an appropriate tube length is selected according to the purpose. The synthesis liquid slurry obtained by heating for an appropriate time in the tubular maturation device is cooled to 60°C or less through a heat exchanger and sent to the next process. Alternatively, the synthesis liquid slurry discharged from the maturation device can be temporarily received in a tank and cooled in a jacket, or circulated and cooled by an external heat exchanger.

[0050] (3) Purification method The synthesis liquid slurry after aging is purified by removing unreacted raw materials such as zirconium compounds and phosphoric acid (salts), additives such as oxalic acid and hydrochloric acid, and by-products in the synthesis liquid slurry. Methods for purifying the synthetic liquid slurry include a method of performing displacement washing in a slurry state, a method of combining solid-liquid separation and cake washing, and a method of combining both. The end points of the displacement washing and cake washing can be determined, for example, by measuring the electrical conductivity of the liquid discharged after washing. The smaller the electrical conductivity number, the more the washing has progressed. The electrical conductivity at the end point of washing can be arbitrarily set depending on the application of the layered zirconium phosphate to be produced, and is, for example, preferably 0.01 to 10 mS / cm, more preferably 0.01 to 1.0 mS / cm.

[0051] As a method for displacement washing of a synthetic liquid slurry, for example, there is a method using an organic or inorganic membrane in a cross-flow system in which the continuous phase (liquid phase excluding solids, also called mobile phase) is replaced with deionized water. Examples of the displacement washing device include a tubular type ceramic filter device (commercially available devices include those manufactured by NGK Insulators, Ltd. and Noritake Company Limited. Hereinafter, the names in parentheses similarly refer to examples of commercially available products), a disk type ceramic filter device (manufactured by Mitsubishi Kakoki Kaisha, Ltd. and Eurotech Co., Ltd., etc.), and a rotary filter device equipped with a filter cloth (manufactured by Hiroshima Metal & Machinery Chemtech Company, Ltd. and Tsukishima Kikai Co., Ltd., etc.).

[0052] Examples of methods that combine solid-liquid separation and cake washing include methods that use a filter press apparatus (manufactured by Hitachi Zosen Corporation, Kurita Machinery Works, etc.), a horizontal belt filter apparatus (manufactured by Hitachi Zosen Corporation and Tsukishima Kikai Co., Ltd., etc.), a pressure filtration apparatus (manufactured by Tanabe Willtec Corporation and Kobelco Eco-Solutions, etc.), a leaf filter apparatus (manufactured by IHI Corporation), and a FUNDABAC filter apparatus (manufactured by IHI Corporation).

[0053] (4) Drying conditions The synthesis liquid slurry after purification can be dried in any manner, for example, by directly drying the liquid to a powder, or by subjecting the synthesis liquid slurry to solid-liquid separation and drying the resulting cake. A multi-stage drying process can also be carried out by combining a plurality of drying devices. Methods for directly drying the slurry include, for example, a jet turbo dryer (manufactured by Hiraiwa Iron Works, Ltd.), a fluidized bed dryer with balls (manufactured by Nara Machinery Works, Ltd. and Okawara Manufacturing Co., Ltd., etc.), a drum dryer (manufactured by Katsuragi Kogyo Co., Ltd. and Chuo Kakoki Co., Ltd., etc.), and a CD dryer (manufactured by Nishimura Iron Works, Ltd.). As a method for drying the cake obtained by solid-liquid separation after displacement washing, and the cake obtained by combining solid-liquid separation and cake washing, for example, the above-mentioned solid-liquid separation device with a drying function can be applied. In addition, a fluidized bed dryer (manufactured by Nara Machinery Works, Ltd.), a paddle dryer (manufactured by Nara Machinery Works, Ltd.), a vibration dryer (manufactured by Chuo Kakoki Co., Ltd., etc.), and a double cone dryer (manufactured by Chuo Kakoki Co., Ltd., Kobelco Eco-Solutions Co., Ltd., Katsuragi Kogyo Co., Ltd., etc.) can be applied.

[0054] (5) Grinding conditions The layered zirconium phosphate obtained by drying is usually crushed and then sieved to produce a product. Since the layered zirconium phosphate obtained by drying is hygroscopic, it is preferable to perform the crushing and sieving processes under dry air, nitrogen atmosphere, or an atmosphere equivalent thereto. It is preferable to control the dry air and nitrogen used so that the dew point temperature is −10° C. or lower. As the pulverizer, devices classified as fine pulverizers such as a hammer mill, a pin mill, and a jet mill are preferable. The screening method includes vibration type, ultrasonic vibration type, and air flow classification type, and any combination with a pulverizer can be selected. EXAMPLES

[0055] Hereinafter, the present disclosure will be described with reference to examples and comparative examples, but the present disclosure is not limited thereto. In addition, unless otherwise specified, % is % by weight and parts is parts by weight.

[0056] <Median diameter measurement> The particle size of the obtained layered zirconium phosphate was measured using a laser diffraction particle size distribution analyzer "LA-950" manufactured by Horiba, and the results were analyzed on a volume basis. The measurement conditions were as follows: a dispersion liquid in which 1.0% of the obtained powder was added to 100% deionized water was dispersed using ultrasonic waves, and the measurement was performed at a refractive index of 2.4.

[0057] <Powder X-ray diffraction> X-ray diffraction patterns were obtained by measuring with a Rigaku Denki RINT2400V type X-ray diffractometer using CuKα radiation at 40 kV / 150 mA.

[0058] <Sodium ion exchange test> 1.0 g of the obtained layered zirconium phosphate was added to 50 mL of 0.1 mol / L aqueous sodium hydroxide solution, and the mixture was stirred at 40° C. for 20 hours. The Na concentration (A, mol / L) in the filtrate was then measured to determine the ion exchange capacity of the layered zirconium phosphate. As a blank experiment, the same operation as above was performed without adding layered zirconium phosphate, and the Na concentration (B, mol / L) of the filtrate (i.e., aqueous sodium hydroxide solution) was measured. The sodium ion exchange capacity (C) of the layered zirconium phosphate was calculated by the following formula (1). C(meq / g)=(BA)×1000 (1)

[0059] <Ammonia gas adsorption test> 0.2 g of the layered zirconium phosphate obtained was added to a gas test bag containing 3 L of air containing 200 ppm ammonia gas, and left at room temperature for 2 hours. The ammonia gas concentration (D, ppm) in the bag was measured with a detector tube. As a blank experiment, the ammonia gas concentration (E, ppm) was measured after leaving the bag at room temperature for 2 hours without adding the layered zirconium phosphate. The ammonia gas removal rate (F) was calculated using the following formula (2). F(%) = {(ED) / E} × 100 (2)

[0060] <Example 1> [The concentration of layered zirconium phosphate in the mixed liquid (synthetic liquid slurry) is 5.6% by weight, and the mixture is continuously mixed and operated in a tank-type aging device for 7 batches] Zirconium oxychloride octahydrate (523 g) manufactured by Daiichi Kigenso Kagaku Kogyo Co., Ltd. was dissolved in ion-exchanged water (477 g) to prepare an aqueous solution of zirconium oxychloride (hereinafter referred to as Liquid A). The 75% phosphoric acid aqueous solution (hereinafter referred to as solution B) used was a 75% phosphoric acid aqueous solution manufactured by Rasa Kogyo Co., Ltd. Oxalic acid dihydrate (186.6 g) manufactured by Ube Industries, Ltd. and 35% hydrochloric acid (185.3 g) manufactured by Toagosei Co., Ltd. were mixed and dissolved in deionized water (1628.1 g) to prepare an oxalic acid / hydrochloric acid mixed aqueous solution (hereinafter referred to as liquid C1). The A, B and C1 solutions were prepared in separate containers, and the operation was continued while replenishing the tanks in FIG. 1 with the necessary amounts to obtain the desired product.

[0061] The production apparatus used was the one shown diagrammatically in FIG. The mixing device used was a tank-type glass container (volume: 0.8 L) (hereafter referred to as the mixing tank) equipped with an agitator and jacket. The agitator consisted of three swept-back blades and a stirring motor that rotated them. The jacket was designed to adjust the liquid temperature in the tank by circulating temperature-adjusted liquid from a separate thermostatic device. Liquids A, B, and C1, which are the raw materials, were supplied to the mixing device from each tank via a metering pump. The maturation equipment was a tank-type glass container (volume: 2L) equipped with a stirrer and jacket. The stirrer consisted of three swept-back blades and a stirrer motor to rotate it. The jacket was designed to adjust the liquid temperature in the tank by circulating temperature-controlled liquid from a separate thermostatic device. The mixer and the aging device were connected using an extraction pipe as shown in Figure 1, and the mixed liquid that overflowed from the mixer was received in the aging device. In FIG. 1, for convenience, only one maturation apparatus is shown, but after the maturation apparatus was filled with a predetermined amount, the withdrawal pipe of the mixing apparatus was connected to another maturation apparatus, and the withdrawal of the mixed liquid was repeated.

[0062] Liquid C1 (aqueous mixture of oxalic acid and hydrochloric acid, 100 g) was initially added to the mixing device, and stirring was started at a rotation speed of 200 rpm. In addition, warm water was passed through the jacket so that the liquid temperature in the mixing tank was 50°C. Liquid A (a solution of zirconium oxychloride octahydrate, feed rate: 7 g / min), liquid B (aqueous solution of 75% phosphoric acid, feed rate: 3.1 g / min), and liquid C1 (feed rate: 31.8 g / min) were continuously added. After about 5 minutes, the stirring blade was completely immersed in the mixed liquid and the liquid no longer splashed, at which point the rotation speed was increased to 395 rpm. After about 10 minutes, the tank was filled with liquid, and the mixed liquid began to flow out from the overflow port. The mixed liquid was received from the withdrawal pipe in a 2 L maturation device (maturation tank No. 1), and 20 minutes after the mixed liquid was received, stirring was started at 220 rpm. Approximately 40 minutes after the start of continuous feeding, when 1.5 kg of mixed liquid had accumulated in the maturation tank, the reception of the mixed liquid from the withdrawal pipe was switched to another maturation device (maturation tank No. 2). The same operation was used to sequentially switch the maturation devices from No. 3 to No. 6. Aging tank No. 7 was a 10 L glass container, and 7.5 kg of mixed liquid was stored therein. The zirconium phosphate concentration in the mixed liquids (synthetic liquid slurry) of No. 1 to No. 7 was 5.6 wt%. In maturation tank No. 1, in which the mixed liquid had accumulated, the heating device was operated to raise the temperature of the mixed liquid to 98°C over a period of approximately 90 minutes, and this temperature was maintained for 12 hours. After that, the heating device was stopped and the synthetic liquid slurry in the tank was allowed to cool naturally to below 40°C. The synthesis liquid was filtered through a membrane filter with a pore size of 0.47 μm. The resulting precipitate was poured with deionized water and washed thoroughly with water until the conductivity of the washing filtrate measured with a conductivity meter was 30 μS / cm or less. The precipitate was then dried in an electric dryer at 110°C for 16 hours to obtain a powdered product. This was then crushed with a rotor speed mill (Fritsch Japan, 16,000 rpm, sieve opening 80 μm).

[0063] The obtained zirconium phosphate was measured for powder X-ray diffraction, median diameter, and ammonia gas removal rate. Powder X-ray diffraction analysis confirmed that the obtained zirconium phosphate was layered α-zirconium phosphate. The powder X-ray diffraction pattern is shown in Figure 2. The median diameter was 0.90 μm, the sodium ion exchange capacity was 6.5 meq / g, and the ammonia gas removal rate was >99%.

[0064] The heating devices of aging tanks No. 2 to No. 6, each of which had 1.5 kg of mixed liquid stored therein, and No. 7, which had 7.5 kg of mixed liquid stored therein, were operated in sequence, and the mixture was treated in the same manner as in aging tank No. 1, to obtain α-zirconium phosphate. Table 1 shows the yield (based on elemental zirconium) and median diameter of the α-zirconium phosphate obtained in each of aging tanks No. 1 to No. 7.

[0065] <Comparative Example 1> [The concentration of zirconium phosphate in the mixed liquid (synthetic liquid slurry) was 5.6% by weight, and seven batches were operated separately and discontinuously] In a 2L reactor equipped with a reflux condenser, zirconium oxychloride octahydrate (70.8g) was dissolved in 850mL of deionized water, 35% hydrochloric acid (48.0g) was added, and then powdered oxalic acid dihydrate (78.1g) was added and dissolved. The liquid temperature was 25°C. While stirring this solution, 75% phosphoric acid aqueous solution (90.1g) was added thereto over 30 minutes. Next, the reactor was heated while continuing to stir, and the reaction liquid reached 98°C after 90 minutes. Heating and stirring were continued for 12 hours while maintaining the internal temperature of the reactor at 98°C. The zirconium phosphate concentration in this mixed liquid (synthetic liquid slurry) was 5.6% by weight. Thereafter, the heating device was stopped, and the synthesis liquid slurry was allowed to cool naturally to a temperature of 40° C. or less, and the synthesis liquid slurry was filtered through a membrane filter with a pore size of 0.47 μm. Deionized water was poured into the obtained precipitate, which was thoroughly washed with water until the electrical conductivity of the washing water filtrate measured with a conductivity meter was 30 μS / cm or less. The precipitate was then dried in an electric dryer at 110° C. for 16 hours to obtain α-zirconium phosphate particles (referred to as Reaction No. 1). The yield of the obtained α-zirconium phosphate was calculated to be 82% based on the zirconium element relative to the zirconium oxychloride octahydrate charged, and the median diameter of the α-zirconium phosphate was 0.92 μm. This series of manufacturing operations was repeated six more times (referred to as reaction numbers No. 2 to No. 7, respectively). The yield and median diameter of the α-zirconium phosphate obtained from each of reaction numbers No. 1 to No. 7 were determined. The results are shown in Table 1.

[0066] [Table 1]

[0067] Comparing Example 1, in which the mixing of raw materials is performed continuously, with Comparative Example 1, in which the mixing of raw materials and aging are repeated for each batch, it is found that the former has a higher product yield and a smaller variation in median size. In addition, aging tank No. 7 in Example 1 is the result of aging in a 10 L tank, and it is also found that there is no effect of scale in the aging tank.

[0068] <Example 2> [The concentration of zirconium phosphate in the mixed liquid (synthetic liquid slurry) is 8.3% by weight, and the mixture is continuously mixed in a tank-type maturation device for one batch operation] Oxalic acid dihydrate (211.5 g) and 35% hydrochloric acid (210.1 g) were mixed and dissolved in deionized water (1615.4 g) to prepare an oxalic acid / hydrochloric acid mixed solution (hereinafter referred to as liquid C2). Using the same equipment as in Example 1, 100 g of C2 liquid was initially added to the mixer, and stirring was started at a rotation speed of 200 rpm. In addition, warm water was passed through the jacket so that the liquid temperature in the mixer tank was 50°C. Here, continuous feeding of A liquid (feed rate: 6.8 g / min), B liquid (feed rate: 3.1 g / min) and C2 liquid (feed rate: 30.1 g / min) was started. Thereafter, in the same manner as in Example 1, aging was started when 1.5 kg of the mixed liquid was accumulated in the aging device. The zirconium phosphate concentration in this mixed liquid (synthetic liquid slurry) was 8.3% by weight. Thereafter, cooling, filtration through a membrane filter, cake washing, drying and pulverization were carried out in the same manner as in Example 1, to obtain α-zirconium phosphate in a yield of 90%. The median diameter of the obtained α-zirconium phosphate was 0.91 μm. The sodium ion exchange capacity was 6.5 meq / g, and the ammonia gas removal rate was >99%.

[0069] <Example 3> [The zirconium phosphate concentration in the mixed liquid (synthetic liquid slurry) is 11.2% by weight, and the mixture is continuously mixed in a tank-type aging device for one batch operation] Oxalic acid dihydrate (285.4 g) and 35% hydrochloric acid (283.5 g) were mixed and dissolved in deionized water (1131.7 g) to prepare an oxalic acid / hydrochloric acid mixed solution (hereinafter referred to as solution C3). Using the same equipment as in Example 1, 100 g of C3 liquid was initially added to the mixer, and stirring was started at a rotation speed of 200 rpm. In addition, warm water was passed through the jacket so that the liquid temperature in the mixer tank was 50°C. Here, continuous feeding of A liquid (feed rate: 9.2 g / min), B liquid (feed rate: 4.1 g / min) and C3 liquid (feed rate: 26.7 g / min) was started. Thereafter, in the same manner as in Example 1, aging was started when 1.5 kg of the mixed liquid was accumulated in the aging device. The zirconium phosphate concentration in this mixed liquid (synthetic liquid slurry) was 11.2 wt%. Thereafter, cooling, filtration through a membrane filter, cake washing, drying and pulverization were carried out in the same manner as in Example 1, to obtain α-zirconium phosphate in a yield of 92%. The median diameter of the obtained α-zirconium phosphate was 0.92 μm. The sodium ion exchange capacity was 6.5 meq / g, and the ammonia gas removal rate was >99%.

[0070] <Comparative Example 2> [The concentration of zirconium phosphate in the mixed liquid (synthetic liquid slurry) is 8.3% by weight, and one batch operation is performed by discontinuous mixing] In a 2L reactor equipped with a reflux condenser, zirconium oxychloride octahydrate (106.3 g) was dissolved in 844 mL of deionized water, 35% hydrochloric acid (72.0 g) was added, and then powdered oxalic acid dihydrate (117.2 g) was added and dissolved. The liquid temperature was 25°C. While stirring this solution, 75% phosphoric acid aqueous solution (89.9 g) was added thereto over 30 minutes. Next, when the reactor was heated while continuing to stir, the mixed liquid became viscous with the rise in temperature and lost its fluidity. After about 90 minutes, the synthesis liquid slurry reached 98°C, but it lost its fluidity and started to bump, and the reflux condenser was soiled by the liquid splashing, so heating was stopped midway through production. As a result, the target α-zirconium phosphate could not be produced. The concentration of zirconium phosphate in this mixed liquid (synthetic liquid slurry) was 8.3% by weight.

[0071] <Example 4> [The zirconium phosphate concentration in the mixed liquid (synthetic liquid slurry) is 8.3% by weight, and the mixture is continuously mixed in a tank-type aging device, and operated in one batch without stirring.] The mixer was operated in the same manner as in Example 2, and the mixed liquid flowing out of the overflow port was received in an aging tank without a stirrer. After about 40 minutes, when 1.5 kg had accumulated, the receiver of the mixed liquid was switched to another aging tank. The heating device attached to the aging tank in which the previous 1.5 kg of mixed liquid had accumulated was operated, and the mixed liquid temperature was raised to 98°C in about 90 minutes and maintained at this temperature for 12 hours. Thereafter, the heating device was stopped, and the synthesis liquid slurry in the tank was allowed to cool naturally to 40°C or less. The same treatment as in Example 2 was performed, and 109.6 g of α-zirconium phosphate was obtained in a yield of 88%. The median diameter of the obtained α-zirconium phosphate was 0.92 μm. The sodium ion exchange capacity was 6.5 meq / g, and the ammonia gas removal rate was >99%. This shows that the yield, median diameter and sodium ion exchange capacity are not particularly affected by the presence or absence of stirring during the aging stage.

[0072] <Example 5> [The zirconium phosphate concentration in the mixed liquid (synthetic liquid slurry) is 14.0% by weight, one batch operation in a tank-type aging device with continuous mixing, aging time: 6 hours] Oxalic acid dihydrate (212.5 g) and 35% hydrochloric acid (315.1 g) were mixed and dissolved in deionized water (2527.8 g) to prepare an oxalic acid / hydrochloric acid mixed solution (hereinafter referred to as C4 solution). Using the same apparatus as in Example 1, 100 g of C4 liquid was initially added to the mixer, and stirring was started at a rotation speed of 200 rpm. In addition, warm water was passed through the jacket so that the liquid temperature in the mixer tank was 60°C. Here, continuous feeding of A liquid (feed rate: 9.33 g / min), B liquid (feed rate: 4.16 g / min) and C4 liquid (feed rate: 18.67 g / min) was started. Thereafter, in the same manner as in Example 1, maturation was started when 1.5 kg of the mixed liquid was accumulated in the maturation device. The zirconium phosphate concentration in this mixed liquid (synthetic liquid slurry) was 14.0% by weight. After 6 hours, the heating was stopped and the synthesis liquid slurry in the tank was allowed to cool naturally to below 40° C. The same treatment as in Example 2 was carried out to obtain α-zirconium phosphate in a yield of 90%. The median diameter of the obtained α-zirconium phosphate was 0.88 μm. The sodium ion exchange capacity was 6.5 meq / g, and the ammonia gas removal rate was >99%.

[0073] <Example 6> [The concentration of zirconium phosphate in the mixed liquid (synthetic liquid slurry) is 8.3% by weight, and the entire process from mixing to maturation is carried out continuously using a continuous mixer and tubular maturation device] The production apparatus used was the one shown diagrammatically in FIG. The mixing device used was a tank-type glass container (volume: 0.3 L) equipped with an agitator and jacket. The agitator consisted of three swept-back blades and a stirring motor that rotated it. The jacket was designed to adjust the liquid temperature in the tank by circulating temperature-controlled liquid from a separate thermostatic device. The raw materials A, B, and C2 liquids were supplied to the mixing device via a metering pump. The maturation device consisted of a PTFE (polytetrafluoroethylene (tetrafluoride)) tube (inner diameter 6mmφ, outer diameter 8mmφ, length 100m) (hereafter referred to as maturation tube) placed in an oil bath. One end of the PTFE tube was connected to the discharge port of the liquid delivery pump, and the pump suction port was connected to the mixing device. The other end was connected to a tank for receiving the synthetic liquid slurry. The synthetic liquid slurry tank was pressure-resistant and capable of being pressurized up to 0.4MPa with pressurized air. The liquid delivery pump was capable of increasing the discharge pressure up to 0.3MPa. The oil bath was equipped with a heater and mixing function. The mixer and aging device were connected from the bottom of the mixer using an extraction pipe as shown in Figure 3, and the flow rate of the liquid delivery pump was adjusted so as to keep the liquid level of the mixed liquid in the mixer constant.

[0074] 50 g of C2 liquid was initially added to the mixer, and stirring was started at a rotation speed of 200 rpm. Warm water was passed through the jacket so that the liquid temperature in the tank was 50°C. Then, continuous feeding of A liquid (feed rate: 2.7 g / min), B liquid (feed rate: 1.2 g / min), and C2 liquid (feed rate: 12.1 g / min) was started. After about 5 minutes, when the stirring blades were completely immersed in the liquid and the liquid no longer splashed, the rotation speed was increased to 650 rpm. After about 10 minutes, the liquid level in the tank reached 80%, so the liquid pump was operated to start drawing out the mixed liquid and sending it to the tube. The zirconium phosphate concentration in this mixed liquid (synthetic liquid slurry) was 8.3% by weight. The oil bath temperature was set to 110°C, and oil was circulated to keep the temperature uniform. The flow rate of the liquid pump that kept the liquid level in the mixer constant was 16g / min, and the mixed liquid was heated in the tubular maturation device for 3 hours. The mixing device was operated and the liquid was sent to the maturation device continuously for 12 hours. The synthetic liquid slurry discharged from the tube was received in a 1 L tank, and the container was switched every hour to obtain nine synthetic liquid slurries (synthetic liquid No. 1 to synthetic liquid No. 9). After the synthesis liquid was allowed to cool naturally to 40°C or less, the synthesis liquid slurries of Synthesis Liquid No. 1 to Synthesis Liquid No. 9 were each filtered through a membrane filter with a pore size of 0.47 μm. Deionized water was poured into each of the obtained precipitates, and the precipitates were thoroughly washed with water until the electrical conductivity of the washing water filtrate measured with a conductivity meter was 30 μS / cm or less. Each precipitate was then dried in an electric dryer at 110°C for 16 hours to obtain a powdered product. Each of these was crushed with a rotor speed mill (16000 rpm, sieve opening 80 μm). The median diameter of the α-zirconium phosphate obtained from synthesis solution No. 1 was 0.91 μm. The sodium ion exchange capacity was 6.5 meq / g, and the ammonia gas removal rate was >99%. The results of similar measurements for each of Synthetic Solutions No. 2 to No. 9 are shown in Table 2.

[0075] [Table 2]

[0076] From this, by using a tubular aging device, the target layered zirconium phosphate can be continuously obtained with almost no variation in median diameter and at a high yield. Since the aging device is a tubular type rather than a tank type, the device is simpler than tank type aging and the equipment cost can be reduced, and the operation is simpler and the productivity is further improved compared to tank type aging.

[0077] As described above, the production apparatus and method for layered zirconium phosphate disclosed herein, which includes a mixing apparatus for mixing raw materials and an aging apparatus for aging the mixed liquid, can reduce the workload of preparing raw materials for each batch, stabilize the median diameter of the product, and increase the concentration of the synthetic liquid slurry, thereby improving the quality and productivity of layered zirconium phosphate production. [Industrial Applicability]

[0078] The manufacturing apparatus and method of layered zirconium phosphate disclosed herein can reduce the workload, suppress the variation in the median diameter of the product, and further increase the zirconium phosphate concentration in the synthetic liquid slurry to increase the product yield, thereby providing a highly productive and high-quality manufacturing method of layered zirconium phosphate.

[0079] The disclosure of Japanese Patent Application No. 2020-082457, filed on May 8, 2020, is incorporated herein by reference in its entirety. All publications, patent applications, and standards mentioned in this specification are herein incorporated by reference to the same extent as if each individual publication, patent application, or standard was specifically and individually indicated to be incorporated by reference.

Claims

1. An apparatus for producing layered zirconium phosphate by a wet synthesis method, comprising: a mixing device for mixing at least a zirconium compound, phosphoric acid and / or a phosphate, an organic acid, an inorganic acid having an acid dissociation constant (pKa) of 0 or less, and a solvent; an aging device for aging a mixed liquid obtained by mixing at least the zirconium compound, the phosphoric acid and / or the phosphate, the organic acid, the inorganic acid, and the solvent in the mixing device; Equipped with The mixing device and the aging device are separate devices, the mixing apparatus is a tank type having a stirring device, the tank being provided with a supply mechanism for supplying at least the zirconium compound, the phosphoric acid and / or the phosphate, the organic acid, the inorganic acid, and the solvent, and a discharge mechanism for discharging the mixed liquid from the mixing apparatus; The supply mechanism has a mechanism capable of continuously supplying, and the extraction mechanism has a mechanism capable of continuously extracting. Equipment for manufacturing layered zirconium phosphate.

2. 2. The apparatus for producing layered zirconium phosphate according to claim 1, wherein the aging device is a tank type equipped with a heating device.

3. 2. The apparatus for producing layered zirconium phosphate according to claim 1, wherein the aging device is a tubular device equipped with a heating device.

4. 4. The apparatus for producing layered zirconium phosphate according to claim 1, wherein the supply mechanisms are a plurality of independent supply mechanisms, and the apparatus has a mechanism for continuously supplying the aqueous solution containing the zirconium compound, the aqueous solution containing phosphoric acid and / or a phosphate, and the aqueous solution containing the organic acid and the inorganic acid from each of the plurality of independent supply mechanisms to the mixing device.

5. A method for producing layered zirconium phosphate using the production apparatus according to any one of claims 1 to 4, a mixing step of mixing at least the zirconium compound, the phosphoric acid and / or the phosphate, the organic acid, the inorganic acid, and the solvent; an aging step of aging a mixed liquid obtained by mixing at least the zirconium compound, the phosphoric acid and / or the phosphate, the organic acid, the inorganic acid, and the solvent in the mixing step; A method for producing layered zirconium phosphate comprising the steps of:

6. A method for producing layered zirconium phosphate using the production apparatus according to claim 4, a mixing step of mixing at least the zirconium compound, the phosphoric acid and / or the phosphate, the organic acid, the inorganic acid, and the solvent; an aging step of aging a mixed liquid obtained by mixing at least the zirconium compound, the phosphoric acid and / or the phosphate, the organic acid, the inorganic acid, and the solvent in the mixing step; Including, The method for producing layered zirconium phosphate, wherein the zirconium compound and the phosphoric acid and / or the phosphate are continuously supplied to the mixer from each of the plurality of independent supply mechanisms.

7. 7. The method for producing layered zirconium phosphate according to claim 6, wherein the aqueous solution containing the zirconium compound, the aqueous solution containing phosphoric acid and / or a phosphate, and the aqueous solution containing the organic acid and the inorganic acid are continuously supplied to the mixing device from each of the multiple independent supply mechanisms.

8. The method for producing layered zirconium phosphate according to any one of claims 5 to 7, wherein the amount of the inorganic acid added is in the range of 0.1 to 5.0 moles per mole of the zirconium compound, the organic acid is at least one of oxalic acid and an oxalate, and the amount of the organic acid added is in the range of 0.01 to 0.8 moles per mole of the inorganic acid.

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