JPS5857222B2 - Zirconium zirconium - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The use of hydrated oxide ion exchangers to separate inorganic ions from aqueous solutions has been investigated and the results are published in U.S. Pat. It is reported in the specification of No.

In the terminology of this patent, zirconium aqueous oxide ion exchangers include zirconium or zirconium plus other oxides or hydroxides and varying amounts of water, and vary depending on the material and its processing. Defined as an amorphous or microcrystalline solid that has exchangeable ions.

Although such substances may be represented by specific formulas or names, they do not have a simple or stoichiometric composition, and no crystal structure will be detected when analyzed by X-ray diffraction. should be understood.

Zirconium phosphate ion exchangers have been prepared by mixing together a solution of a zirconium compound and a solution of a phosphate salt.

The resulting precipitated material is either a very fine powder or a gelatinous insoluble material suspended in an aqueous solution.

These products are very difficult to filter and dehydrate, and considerable equipment is required to remove trace amounts of zirconium phosphate.

When a gelatinous substance is obtained, it is dried after passing through a p-filter, resulting in large, hard particles.

"When finely divided zirconium phosphate is produced by the reaction of an aqueous solution of a zirconium salt with an aqueous solution of a phosphate salt, the resulting product is a non-stoichiometric mixed phosphoric acid containing cations from the soluble phosphoric acid. It might be salt.

Aqueous solutions are used because homogeneous reactions are easier to complete and occur faster.

The fine powder obtained after over-drying has too much resistance to flow through the ion exchange column, and is therefore too fine to be used in the ion exchange column.

Large amounts of crystalline zirconium phosphate are produced by Stein and Clearfield 5tynes and C1earfi.
It can be made as described in U.S. Pat. No. 3,416,884 to Eld.

Boiling the solution for several days gradually transforms the microscopic or amorphous material into macroscopic crystalline zirconium phosphate.

However, the long time required for this heating method
This makes the product expensive.

Due to the difficulties of making granular zirconium phosphate by this method, this product is not widely used.

Hydrated zirconium oxide ion exchangers can be made in the same manner, and the resulting product is also a very finely powdered material suitable for use as poison ivy ointments, dermatitis creams, and antiperspirants. There is.

However, the resulting fine powder cannot be used in ion exchange columns because it is difficult to pass water and causes a high pressure drop within the column.

Due to the particle size required for columns, conventional methods for producing zirconium hydrated oxide ion exchangers are not commercially viable.

The present invention relates to a method for producing zirconium aqueous phase oxide ion exchangers within a desired mesh size range.

This method is particularly useful for producing granular products within a mesh size range suitable for use in ion exchange columns to separate inorganic ions from liquids.

The need for such ion exchangers lies in dialysis processes for artificial kidney systems to remove ammonia obtained from the conversion of urea by urease.

Such a process is described in US Pat. No. 3,669,880.

In this system, ammonium ions obtained from the conversion of urea are removed by a zirconium phosphate ion exchanger in the column, and phosphate in the dialysis solution returning from the artificial kidney is removed by a hydrated zirconium oxide ion exchanger.

This dialysis process provides a circular flow process in which the dialysis fluid returning from the kidneys passes successively through one or several columns containing particulate zirconium phosphate and hydrated zirconium oxide.

Zirconium phosphate particles and hydrated zirconium oxide particles in the 12-325 mesh distribution band can be used in the column provided there is not a substantial amount of 325 mesh particles and no excessive amount of 12 mesh particles.

Fine mesh materials provide better contact with the liquid, but tend to inhibit liquid flow and clog within the column.

Larger particles, on the other hand, facilitate flow within the column, but do not leave enough surface area of the zirconium compound exposed to the liquid to pick up ions.

The present invention provides an industrially viable method for producing zirconium hydrated oxide ion exchangers, such as zirconium phosphate and zirconium oxide, in the mesh range suitable for use in exchange columns.

The method consists of adding solid particles of a water-soluble zirconium compound to a reactant solution.

The mesh of the initial zirconium compound particles defines the mesh distribution band of the final ion exchanger particles.

To obtain zirconium sulfate, particulate zirconium compounds are added to a phosphate solution, and to obtain hydrated zirconium oxide, particulate zirconium compounds are added to a basic solution such as sodium hydroxide.

The shape of the zirconium particles is determined by the reagent and is converted into ion exchanger particles without being dissolved in the insolubilizing reagent.

Thus, the present invention provides an inexpensive method for producing zirconium hydrated oxide ion exchangers, such as zirconium phosphate and hydrated zirconium oxide, in particulate form suitable for use in ion exchange columns. A manufacturing method that can be implemented industrially is provided.

Since the resulting granular product is formed rapidly, there is no need for costly and lengthy filtration, which facilitates the production of large quantities of the product.

All particle mesh sizes discussed herein are those of Tyler's standard sieves, and the particle sizes of the zirconium phosphate and hydrated zirconium oxide are for the ion exchanger form.

Since the size of the final particles of the zirconium compound depends on the size of its initial particles, the method is also useful for producing large particles that can be later ground to a suitable size if desired, and for other applications. It can be understood that this method can also be applied to the production of very fine particles.

In the production of zirconium phosphate particles, a zirconium compound in the form of particles having a desired mesh distribution band is added to an aqueous solution of phosphoric acid.

The zirconium compound must be water-soluble zirconium oxychloride, zirconium nitrate, silcol nitrate, zirconium sulfate, or zirconium acetate;
On the other hand, the phosphate solution can consist of a solution of phosphoric acid, sodium phosphate or a mixture of sodium hydrogen phosphate.

The concentration of the phosphate solution is preferably on the order of 2.5 molar and the reaction temperature is anywhere from room temperature to 100°C to obtain suitable products.

The solution to which the zirconium compound particles are added is stirred for 5 to 30 minutes to ensure that the phosphate permeates into the zirconium compound particles and converts all of the zirconium compound to insoluble zirconium phosphate.

The solution is then filtered to remove the reaction mixture and washed with water until all soluble phosphate is removed.

Afterwards, the granules are tested to determine whether any free zirconium compounds remain within them to ensure that there has been sufficient phosphate penetration under the given conditions. be able to.

Sufficient time must be allowed to incorporate the phosphate into the solid zirconium compound so that the resulting product is substantially all insoluble zirconium phosphate.

For many phosphate materials, the molar concentration of phosphate in the initial aqueous solution can be brought up to the solubility limit.

However, in the case of phosphoric acid, the initial molar concentration is
．． Higher than 5 moles results in undesirable gelling products.

Also, at any point during the process, the molar concentration of phosphate is 0.5.
Submolar amounts will produce brittle particulate materials that break down too easily into fine powders.

The zirconium compound must be soluble.

Insoluble zirconium compounds do not allow phosphate to penetrate into their interior, so the desired product is not obtained.

However, particles of such zirconium compounds do not dissolve during conversion to zirconium phosphate.

Phosphate converts zirconium into insoluble zirconium phosphate, fixing the particle shape and acting as an insolubilizing agent.

The size of the final particles of the zirconium phosphate product is governed by the size of the initial particles of the zirconium compound;
For example, if zirconium oxychloride is used as the starting compound, the final particles of zirconium phosphate will be 1
It will be slightly larger than mm.

Generally, some finer particles are introduced to treat the particles, although the size of the final particles increases slightly.

It has been found that raw material particles larger than 12 meshes become physically very weak particles and may easily break during subsequent operations.

It has also been found that raw material particles smaller than 325 mesh produce particles that are too fine to pass through, no matter what amount they are present.

Generally speaking, the size should fall within a distribution band of 12 to 325 meshes, with the majority of the particles falling in the intermediate size range.

The general reaction in which a zirconium compound is converted to zirconium phosphate is as follows: where X is the anion of the soluble zirconium compound and N is the cation of the soluble phosphate.

The phosphate must be a highly soluble phosphate, as semi-soluble compounds such as calcium phosphate are of no use.

Since the concentration of phosphate in the solution must not fall below 0.5 molar during the reaction, the phosphate compound must be soluble in more than 0.5 molar.

The reaction mechanism is that the phosphate ions in the soluble phosphate solution are exchanged with the anions of the soluble zirconium compound.

When insoluble zirconium phosphate comes into contact with phosphoric acid,
Zirconium is fixed within the particle shape.

A preferred reaction to produce zirconium phosphate is the reaction of zirconium oxychloride with phosphoric acid, as exemplified by the following reaction: (wherein X is typically 0-8).

The final zirconium phosphate product form is a mixed compound in which zirconium phosphate is only a portion of the product.

This product does not have a fixed chemical formula, but It has a skeleton.

As shown in the reaction above, phosphate ions are replacing chloride ions.

A typical example of a process for producing zirconium phosphate is as follows: Example 1 495 g of zirconium oxychloride, sieved to 28-48 meshes, are mixed with 100 ml of concentrated phosphoric acid in 900 ml of water.
It was slowly added to the fLl solution while stirring.

The granular product was filtered, washed and air dried.

The molar concentration of phosphate was 1.4 molar and the final mesh was 20-80.

Example 2 Zirconium oxychloride, sieved to 20-150 meshes, was added slowly with stirring to a solution of 691 sodium dihydrogen phosphate hydrate in 500 rrlls of water.

The product was filtered, washed and air dried.

The initial molar concentration of phosphate was 1.0 molar and the final mesh was 16-200.

Example 3 10 i of zirconyl nitrate (glass), sieved to 14 meshes and above, was added slowly with stirring to a solution of 20 cc of concentrated phosphoric acid in 180 cc of water.

The product was filtered, washed and air dried.

The initial molar concentration is 1.4 molar and the final mesh is 1
2 or more dogs.

Example 4 171 zirconium oxychloride, sieved to 28-48 mesh, was dissolved in 35 rrL of concentrated phosphoric acid in 965 ml of water.
1 was added slowly to the solution while stirring.

The granular product was filtered, washed and air dried.

The initial molar concentration of phosphate was 0.5 molar and the final mesh was 10-325.

The final molar concentration of phosphate was less than 0.5 molar, and the product was unsatisfactory for use in exchange columns, as large particles were easily crushed into particles smaller than 325 mesh. Met.

Example 5 120 i of zirconium oxychloride, sieved to 28-48 mesh, was added to 100 i of concentrated phosphoric acid in 900 ml of water.
It was slowly added to the rLl solution while stirring.

The granular product was filtered, washed and air dried.

The initial phosphate molar concentration was 1.4 molar and the final mesh was 12-80.

Example 6 49.5 f of zirconium oxychloride, sieved to 28-48 mesh, was slowly added to a solution of 170 TLl of concentrated phosphoric acid in 830 rfLl of water with stirring.

The granular product was filtered, washed and air dried.

The initial molar concentration of phosphate was 2.5 molar and the final mesh was 28-60.

Example 7 Thirty-two pounds of zirconium oxychloride, sieved to 14 mesh and larger, is added to 14.5 lbs. of water.
75% phosphoric acid 12.11 (24 gallons) in 0.81 (24 gallons)
3.2 gallons) was slowly added to the solution while stirring.

The final product was filtered, washed and air dried.

The initial molar concentration of phosphate was 1.5 molar and the final mesh was 12 and above.

In all of the above examples, the molar concentration exceeded 0.5 molar except for example 4, where an unsatisfactory product was obtained.

In the case of Example 6, the initial molar concentration of phosphate was 2.5, which was found to be a suitable upper limit for this particular phosphate.

Example 7 is an example of a typical industrial operation that produces about 40 pounds of product.

In the production of hydrated zirconium oxide, this method is essentially the addition of particulate zirconium compounds to a basic solution, and the size of the particles obtained is the same as the size of the original granules of zirconium compounds.

Addition of a soluble zirconium compound in particulate form to a stirred basic solution, such as a sodium hydroxide solution, produces granules of hydrated zirconium oxide.

At this time, the anion of the soluble zirconium compound is replaced by the hydroxyl group of the base.

In one particular example, a soluble zirconium compound, such as zirconium nitrate (zirconium oxynitrate), is added in particulate form to a sodium hydroxide solution to produce granules of hydrated zirconium oxide by the following reaction: The molar concentration of the basic solution is not critical, since at its minimum it may be 10-5.

Zirconium compounds include zirconium nitrate, zirconyl nitrate, and zirconium acetate.

This basic solution converts the zirconium into insoluble hydrated zirconium oxide and thereby determines the shape of the particles, thus acting as an insolubilizing agent.

A representative example of the production of hydrated zirconium oxide is as follows: Example 8 Zirconium Nitrate 502 with 60 Meshes and Higher
was added to a solution of 81 cc of sodium hydroxide in 25 cc of water with stirring.

This mixture was stirred for 10 minutes.

The product was filtered, washed and air dried.

The initial hydroxide molar concentration was 0.8 and the final mesh was 48 and above.

From the above it is clear that an insolubilizing agent such as a phosphate solution or a basic solution can fix the zirconium in a substantially insoluble form in the intact particle form when it comes into contact with the reagent.

That is, the size of the particles is substantially in the same range as the size of the initial particles, indicating that the mesh distribution band of the final product is determined by the initial mesh band.

Additionally, the final product can be manufactured industrially within the size range of particles that can be used in typical ion exchange columns.

In the case of zirconium phosphate, the insoluble phosphate fixes the zirconium, and in the case of basic solutions the resulting product is an insoluble hydrated oxide.

Zirconium phosphate in the appropriate size range can also be utilized in water softening, industrial water treatment and the separation of heavy metals from nuclear wastewater.

The particulates can be used in a slurry to remove ammonia and metal ions from solutions in wastewater treatment plants.

Aqueous zirconium oxide can also be used to remove phosphates from wastewater and fluoride from water, and its microparticles can be used in ointments, skin creams and antiperspirants.

Claims (1)

[Claims] 1. A method for producing a ruconium hydrated oxide ion exchanger having a predetermined particle size distribution and a skeleton (where R is a method for producing a ruconium hydrated oxide ion exchanger; A step of preparing an aqueous solution of a base to be supplied; reacting a drug in the aqueous solution with a particulate zirconium compound to form a particulate zirconium hydrated oxide ion exchanger having a particle size distribution determined by the particle size distribution of the particulate zirconium compound in the aqueous solution. When produced, a water-soluble zirconium compound selected from the group consisting of zirconium oxychloride, zirconium nitrate, zirconyl nitrate, ruconium sulfate and zirconium arsenate, and when R in the product is -OH. adds a water-soluble zirconium compound selected from the group consisting of zirconium nitrate, zirconyl nitrate, and zirconium acetate to the aqueous solution in particulate form to substantially transform the zirconium compound into the particulate ion exchanger product in the aqueous solution. a reaction step of accomplishing the reaction by reacting the zirconium compound with the agent for at least sufficient time to convert the ion exchanger product to manufacturing method.