JPS593929B2 - Manufacturing method of fine powder aluminosilicate - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing aluminosilicic acid, and more specifically, the present invention relates to a method for producing aluminosilicic acid from various silicic acid raw materials without using soda and without producing a large amount of waste acid as a by-product. The present invention relates to a method for producing fine powder aluminosilicate.

Aluminosilicic acid is widely used as a reinforcing agent or filler for rubbers, plastics, etc., as a matting agent for paints and other coating compositions, and as a raw material for the synthesis of various silicates. .

This aluminosilicate is obtained by pouring an acid such as sulfuric acid, hydrochloric acid, or nitric acid into a mixed solution of sodium aluminate and sodium silicate to remove soda and produce a coprecipitated gel of aluminum and silicic acid. ing.

However, when this coprecipitated gel is subjected to a heat history such as drying, the aluminosilicate coagulates due to its gelatinous nature, resulting in an extremely low powderability.
The drawback is that it is difficult to obtain powder with excellent pigment properties.

In addition, silicic acid hydrogel and highly oil-absorbing silicic acid gel such as white carbon are impregnated with an aluminum nitrate solution, and then thermally decomposed at a temperature higher than the thermal decomposition temperature of the nitrate (200°C) to form an amorphous material. A process for the production of aluminosilicate is known, which consists in preparing an aluminosilicate gel; however, in this process, the impregnating salt melts just before the pyrolysis temperature and becomes uniformly cementitious throughout. Therefore, it is impossible to expect to obtain salminosilicic acid with excellent chemical properties.

That is, an object of the present invention is to provide a method for producing fine powder aluminosilicic acid from various silicic acid raw materials without using expensive soda and without producing a large amount of waste acid as a by-product. .

Another object of the present invention is to use a vitreous polyvalent metal aluminosilicate as a raw material and treat this raw material with a monobasic acid such as nitric acid, thereby preventing the aluminosilicate from becoming a sol or gel. The object of the present invention is to provide a method by which a fine powder can be directly recovered in a form that is easily purified.

Still another object of the present invention is to provide a method for producing fine powder aluminosilicate which has a low content of impurities, excellent whiteness, and a small particle size distribution controlled within a narrow range.

Still another object of the present invention is that the use of nitric acid in the treatment of aluminosilicate facilitates the removal of basic metal components in the aluminosilicate and allows the acid used for treatment to be reused. The object of the present invention is to provide a method for producing and distributing fine powder aluminosilicate that can be easily recovered and recycled in a form that is possible.

According to the present invention, an aqueous slurry of a glassy polyvalent metal aluminosilicate formed by melting and a monobasic acid in an amount equal to or more than the equivalent amount per polyvalent metal component of the aluminosilicate are mixed together. The solution containing the water-soluble polyvalent metal salt and the insoluble finely powdered aluminosilicate are reacted under conditions such that the ratio of the mixed system is 1.3 to 5 for most of the time from the time until the end of the mixing. Provided is a method for producing aluminosilicic acid, which is characterized by producing aluminosilicic acid, then separating insoluble fine powder, and washing if necessary.

An important feature of the present invention is that a glassy polyvalent metal aluminosilicate (hereinafter sometimes simply referred to as a silicic acid raw material) is selected as the silicic acid raw material, and various mineral acids are selected as the acid to be treated. Among them, a monobasic acid such as nitric acid is selected and reacted under the specific conditions described below to remove the mineral metal components in the aluminosilicate without causing the aluminosilicate to become a sol or gel. This is based on the new findings that the aluminosilicate can be eluted, and that the aluminosilicate obtained after eluting the polyvalent metal component is extremely fine powder, but has outstandingly excellent washability.

First, when the silicic acid raw material used is a monovalent metal salt of soda salt, as shown in Comparative Example 1 described later, aluminosilicic acid produced by reaction with nitric acid easily becomes hydrosil or hydrogel, and becomes an insoluble It is extremely difficult to recover fine powder, especially in the form of fine powder that is easily washed away.

Further, when the aluminosilicate is a crystalline substance, such as clay or other mineral, it will be shown in Comparative Example 2, which will be described later.

As such, it is difficult to quickly dissolve polyvalent metal components in the form of nitrates, and the aluminosilicic acid produced is more like coarse particles than fine powder.

Furthermore, when using an acid other than a monobasic acid, such as sulfuric acid, polyvalent metal salts such as lead and calcium in the aluminosilicate become insoluble, making it difficult to separate them from the aluminosilicate. In addition, the aluminosilicate content may be in the form of hydrosil or hydrogel, making it similarly difficult to recover it in the form of a fine powder that is easy to filter.

On the other hand, according to the present invention, when a monobasic acid such as nitric acid is applied to a vitreous polyvalent metal aluminosilicate, the aluminosilicate component is not turned into a sol or gel. It becomes possible to elute the polyvalent metal component in the salt, and by selecting such reaction conditions, it becomes possible to produce fine aluminosilicate in a pure and easily filterable form.

The present invention will be explained in detail below.

In this specification, parts and percentages are based on weight unless otherwise specified.

Aluminosilicate Raw Material In the present invention, any polyvalent metal aluminosilicate can be used as long as it is vitreous.

Polyvalent metals include metals from group II of the periodic table such as calcium, magnesium, strontium, barium, and zinc;
Examples include Group Ⅰ metals, Group Ⅰ metals such as lead, titanium, and zirconium, Group Ⅰ metals such as iron, cobalt, and nickel, chromium, manganese, and the like.

The chemical composition of these aluminosilicates can vary widely within the range of being glassy, but expressed on an oxide basis, they have the following general formula: 8102·nMOk/2·mA l 203...
................................................... (1) In the formula, M represents a polyvalent metal, especially the one mentioned above, k is the valence of the metal M, and n is 0,3 Preferably, the chemical composition is a number of 5 to 5, particularly 0.5 to 3, and m is a positive number of 3 or less, particularly 2 or less.

Such aluminosilicic acid may be obtained synthetically, naturally, or by-product in ceramics, metal smelting, or other industries.

For example, silica sand, quartz sand, cristobalite, feldspar, synthetic silicic acid, aluminosilicate raw materials obtained by acid treatment such as clay minerals, and the aforementioned polyvalent metal oxides, hydroxides, carbonates, and nitrates. A vitreous aluminosilicate can be obtained by mixing and melting.

Through such a melting reaction, silicic acid reacts with a polyvalent metal component that also acts as a flux, and the strong chain or network bonds of aluminosilicate are broken, creating a glass-like structure in which polyvalent metal ions exist between them. It is thought that fine aluminosilicate is produced by the formation of an amorphous structure and the subsequent elution of polyvalent metal ions with nitric acid.

Therefore, according to this aspect of the present invention, an inexpensive lime raw material such as calcium oxide, calcium hydroxide, or calcium carbonate can be used instead of using an expensive soda raw material such as soda carbonate. This makes it possible to produce powdered aluminosilicate, and it is significantly superior in terms of economy compared to known methods.

Instead of using synthetic aluminosilicates, naturally occurring glassy silicates, such as glassy minerals such as shirasu, can be used.

Furthermore, the present invention can also be applied to vitreous aluminosilicate produced as a by-product during ceramics or metal smelting.

For example, blast furnace slag can be cited as an example of such a raw material. Although the composition of blast furnace slag differs depending on each steel mill, the main components are calcia (CaO), silica, and alumina, with a small amount of manganese. , magnesium, titanium,
Contains metal components such as iron and sulfur.

An example of the composition of typical blast furnace slag is as follows:
It will be as follows.

When directly mixing blast furnace slag powder with nitric acid, the sulfur contained in the blast furnace slag will volatilize in the form of hydrogen sulfide.
Prior to mixing the blast furnace slag powder and nitric acid, it is preferable to remove the sulfur content contained in the blast furnace slag in advance.

The present inventors have proposed a step (5) of pulverizing the blast furnace slag and a step (B) of bringing the blast furnace slag fine particles into contact with an alkaline aqueous medium.
When performing these simultaneously or in this order, the sulfur content contained in the blast furnace slag is eluted into the aqueous medium, and the sulfur extract and the blast furnace slag from which the sulfur content has been substantially removed are effectively separated. As previously discovered, this treatment method can be advantageously applied to the removal of sulfur from blast furnace slag.

In the present invention, from the standpoint of homogeneous and uniform reactivity with nitric acid, it is first important to finely grind the siliceous raw material.

Generally speaking, it is desirable that the degree of pulverization of the siliceous raw material is such that the maximum particle size is 80 microns (μ) or less, preferably 50 μ or less, and most preferably 20 μ or less.

Grinding can be done using ball mills, ring roll mills, rod mills,
Impact crusher, disc crusher, jet crusher, Hikius,
This can be carried out in a wet or dry manner using a known pulverizer such as a colloid mill or a scale mill.

Of course, if the diameter of the raw material used is large, before pulverizing it, use a coarse crusher such as a show crusher or gyratory crusher, or an intermediate crusher such as a hammer mill or roll crusher. The powder should have a particle size suitable for use.

Reaction with nitric acid According to the present invention, the above-mentioned silicic acid raw material and a monobasic acid equivalent to or more per polyvalent metal component in the silicic raw material are reacted under conditions in which the aluminosilicate content does not become a sol or gel. to produce a solution of polyvalent metal nitrate and insoluble finely powdered aluminosilicate.

The monobasic acid may be any acid whose salt with a polyvalent metal is water-soluble, such as inorganic acids such as nitric acid, hydrochloric acid, and hydrobromic acid, and organic acids such as formic acid and acetic acid. used.

However, in the present invention, nitric acid is most suitable, and by using nitric acid, it is possible to recycle the acid.

Therefore, although the use of nitric acid will be discussed below, it should be noted that the use of other monobasic acids, such as hydrochloric acid, is also possible in the production of finely powdered aluminosilicic acid.

In order to produce pure and fine aluminosilicic acid, it is first necessary to use an amount of nitric acid equivalent to or more per polyvalent metal component (excluding aluminum component) of the silicic acid raw material, and generally 0. .3 to 1.5 equivalents, especially 0
It is necessary to use between 4 and 1.4 equivalents of nitric acid.

If more nitric acid is used than necessary, the aluminum component will form water-soluble aluminum nitrate, so care must be taken.

In the present invention, in order to cause the aluminosilicate component to react without turning into a sol or gel, first, the mixing system is It is extremely important to carry out both reactions under conditions such that ... is 1.3 to 5.

If the pH is higher than this range, insoluble polyvalent metal hydroxides will be produced, and if the pH is lower than this range, the following problems will occur.

In order to maintain the pH of the reaction system under the above-mentioned conditions, it is generally necessary to carry out the reaction by gradually (continuously or intermittently) mixing nitric acid into the aqueous slurry of the siliceous raw material.

For example, as shown in Comparative Example 3 below, when an aqueous slurry of siliceous raw materials is mixed in nitric acid or a nitric acid aqueous solution, the mixing system (reaction system) is heated for a considerable period of time from the start of the mixing. ... is lower than 1.3, and under such reaction conditions gelled aluminosilicic acid is produced, and such aluminosilicic acid has extremely poor filterability and is difficult to use in products as fillers and reinforcing agents. The quality is also unsatisfactory.

In addition, as shown in Comparative Example 4, which will be described later, when simultaneously separating the aqueous slurry of the silicic raw material and nitric acid or its diluted aqueous solution, the base of the silicic raw material is mixed with the nitric acid. Because there is a time lag between the reaction of the chemical components and nitric acid, the pH of the mixed system (reaction system) is still 1.3.
When the concentration of the siliceous raw material in the mixed system is low, a sol containing aluminosilicate is produced, and when the concentration of siliceous raw material is high, a gel containing aluminosilicate is produced. Become.

In this way, when reacting a silicic acid raw material with an acid, if free acid exists in the reaction system at a certain concentration or more, such free acid acts to solize the aluminosilicate component. However, this sol-formed aluminosilicate is further easily gelled depending on conditions such as acid concentration, silicic acid raw material concentration, and temperature.

On the other hand, when nitric acid is added to an aqueous slurry of siliceous raw materials, the nitric acid is gradually removed into the system where a large excess of basic components is present, so that the free nitric acid remains below a certain concentration. (pH 1.3 or higher), making it possible to produce fine powder aluminosilicate that is easy to filter while preventing sol or gelation of aluminosilicate.

Another factor for maintaining the pH of the mixed system (reaction system) at 1.3 or higher is the Ebetsu rate of nitric acid.

The total amount of nitric acid added depends on the content of basic components contained in the siliceous raw material, but the amount of free nitric acid (g) present in the mixed system can be calculated using the following formula % formula % (2) In the formula, 〇 is the amount of nitric acid to be removed, and [ is the amount of nitric acid consumed by the basic components in the siliceous raw material.

It is expressed as

Therefore, if the siliceous raw material used is relatively hard in its reactivity with nitric acid, the rate of nitric acid production can be increased, and the reactivity of the silicic raw material used with nitric acid is relatively low. In some cases, the nitric acid flow rate can be set low.

No matter which siliceous raw material is used, it is preferable to determine the rate of nitric acid so that - of the mixing system (reaction system) is 1.3 to 5.

However, if the reaction between the two is too slow and it takes a long time to react with nitric acid, silicic acid tends to form a sol, so in order to prevent the reaction time from becoming too long, the temperature should be raised to allow the reaction between the two to occur. The speed should be increased.

Generally, the time period for nitric acid is preferably selected from 10 minutes to 20 hours, particularly 10 to 12 hours, depending on the reactivity of the siliceous raw material.

Furthermore, during the mixing reaction between the silicic acid raw material and nitric acid, it is necessary to avoid even temporary contact between the silicic acid raw material and concentrated nitric acid. Consideration must be given to reacting to

From this point of view, the aqueous slurry of siliceous raw material should generally have a concentration of less than 50%, and preferably a concentration of 40 to 1%.

Furthermore, as the nitric acid, it is generally desirable to use 67% or less nitric acid, particularly 65 to 10% nitric acid.

In the present invention, the basic component in the silicic acid raw material is reacted with nitric acid without causing the aluminosilicate content to become a sol or gel, but it is possible to separate the nitric acid within the above-mentioned time. Therefore, it is advisable to select an appropriate reaction temperature depending on the degree of reactivity of the siliceous raw material.

The reaction temperature may be room temperature, but is generally 20 to 130°C.
In particular, it is desirable to set the temperature in the range of 40 to 120° C. in order to react the basic component with nitric acid and solubilize it while preventing the silicic acid component from becoming a sol or gel.

For this purpose, it is generally desirable to heat the mixed system (reaction system), but the heat of reaction with nitric acid can also be used to maintain the reaction system at the above-mentioned temperature.

When using nitric acid in an amount greater than the equivalent amount to the basic component in the siliceous raw material, the pH of the reaction system may become lower than the above-mentioned 1 and 3 at the final stage of the nitric acid process. ,
Furthermore, it may be desirable to age the reaction system after the nitric acid extraction at the above-mentioned temperature in order to complete the reaction between the basic component in the silicic acid raw material and nitric acid.

In the present invention, even in these cases, -
If the mixing or aging time from the time when the aluminosilicic acid content becomes lower than 1.3 is within 40 minutes, especially within 30 minutes, aluminosilicic acid can be produced while preventing the aluminosilicic acid component from becoming a sol or gelling. be able to.

Separation of aluminosilicic acid Thus, according to the present invention, aluminosilicic acid is produced in the form of a fine powder that is extremely easy to filter.
Separate by liquid separation operation.

In the reaction under conditions where the aluminosilicate component becomes a sol or gel, the filtration rate of the aluminosilicate component is 0.05 m/h.
However, according to the present invention, although the aluminosilicate content has an extremely fine particle size such as a primary particle size of 1 μ or less, it has a very low speed of 0 ．．
Aluminosilicate components can be separated at extremely high offshore overspeeds of 1 m/hr or more.

The reason for this is that in the glassy polyvalent metal aluminosilicate used in the present invention, the network or chain bonds of the aluminosilicate are cut into narrowly distributed sizes by the polyvalent metal, and this aluminosilicate remains as it is. This is probably because the fine powder aluminosilicate has a fine particle size and a narrow (sharp) distribution.

The separated aluminosilicate is washed, dried, and optionally crushed or crushed to produce a product.

The products according to the invention have a very fine primary particle size and have no significant tendency to agglomerate or agglomerate even in the dry state.

Of course, this aluminosilicate fine powder can be subjected to post-treatments that are well known per se. For example, in order to neutralize this fine powder, its surface can be treated with quicklime, slaked lime, magnesium hydroxide, etc. Moreover, in order to improve dispersibility, the surface can be coated with higher fatty acids, resin acids, naphthenic acids or metal salts thereof, various surfactants, etc.

Recovery of metal components and acids from mother liquor In the present invention, the mother liquor separated from the silicate contains polyvalent metal components in the form of nitrates, and furthermore contains trace amounts or small amounts of free nitric acid. .

All of the nitric acid contained in free or salt form in these mother liquors can be recovered in recyclable form.

For example, free nitric acid contained in the mother liquor can be recovered as nitric acid since it is distilled out in the form of nitric acid vapor when distilled.

The residue or concentrated solution of polyvalent metal nitrate is thermally decomposed into polyvalent metal oxides and NOx gas at a relatively low temperature, for example, 100 to 600°C. After passing it through an oxidation catalyst known per se, it is recovered in water as nitric acid.

The recovered nitric acid can be used repeatedly in the Ebetsu reaction to the siliceous feedstock described above, and thus, according to the present invention, nitric acid can be recovered from the silicate without producing waste acid or without substantial loss of acid. It becomes possible to produce fine powder aluminosilicate.

In addition, the polyvalent metal oxides obtained by thermal decomposition of nitrates are extremely pure and have high chemical activity, and can not only be reused in the production of glassy aluminosilicates, but can also be used as a well-known compound. It can be supplied for a variety of applications.

When multiple types of polyvalent metal salts are contained in the separated mother liquor, these polyvalent metal salts can also be separated and recovered.

For example, when the solution contains aluminum and alkaline earth metal, the alkaline earth metal is added to the solution to increase the concentration of the liquid from 4.5 to 6.0.
In particular, by setting the ratio to 5 to 5.5, the aluminum component can be separated as a precipitate.

As explained above, according to the present invention, it is useful as a reinforcing agent or filler for rubber, plastics, etc., as a matting agent for paints or other coating materials, and as a raw material for synthesizing various silicates. There is an advantage that finely powdered aluminosilicate can be provided at low cost without using soda raw materials and without producing waste acids.

The effects of the present invention will be explained with the following example.

Example 1 The pretreated blast furnace slag powder is treated with nitric acid to produce CaO.

k1203. A method for separating and recovering Fe2O3, MnO, MgO, etc. and simultaneously producing pure, finely powdered water-use aluminosilicate will be described.

As the blast furnace slag, we chose water slag, which is a by-product during iron manufacturing.

Its main components are as follows.

8102 35.39 (wt%) Ca0 40.26 A120314.36 Fe203 0.85 Mn0 1.25 Mg0 5.28 TiO20,42 S O,82 Loss on ignition 1.04 As a pretreatment for blast furnace slag, coarse crushing 1 piece of blast furnace slag 2 pieces of water
The mixture was charged into a ball mill with an internal volume of 7e and ground for 10 hours to obtain a slurry of 200 mesh.

The recovery rate at this time was 95% by weight.

This slurry was transferred to a 5e container equipped with a stirrer, and 5% by weight of lime was added as CaO to the anhydrous blast furnace slag.
The mixture was heated and aged at 90° C. for 1 hour while stirring.

Next, this heat-aged slurry was filtered under reduced pressure and further washed with 0.5e of lime-saturated water to recover about 24 g of blast furnace slag cake and lachrymal fluid (5).

In order to separate and recover the sulfur content eluted into the lachrymal fluid (5) collected in this step, add 1 ml of hydrogen peroxide (30% concentration) to the fluid.
After heating at 85° C. for 10 minutes, the precipitated sulfide was collected from house to house.

The resulting lachrymal fluid and blast furnace slag cake, which contain almost no sulfur content, were transferred again to a container equipped with a stirrer and heated at 85 to 90°C for 3 hours while stirring.
After heating and aging for 0 minutes, it was filtered under reduced pressure, and further washed with 0.5 g of lime-saturated water to form a blast furnace slag cake (B) and tear fluid (B) of about 2.
5g was collected.

This lacrimal fluid (B) was also treated in the same manner as the fluid F, and the sulfur content was separated and recovered.

Through this pretreatment, 95% of the sulfur content in the blast furnace slag could be removed.

To the thus obtained blast furnace slag cake (B) 11V (water content 44.5%), 2.71 parts of water was added to obtain a uniform slurry with a concentration of 15% by weight in a container equipped with a high-speed stirrer. Ta.

This slurry was transferred to a container equipped with a stirrer, heated at 85 to 90°C with stirring, and 0.7 equivalents of nitric acid (HNO3) was added at a concentration of 65% by weight based on the total basic components in the blast furnace slag used as the raw material. Using nitric acid, add 2 nitric acid equivalent to the desired equivalent of each
Slowly aging for 0 minutes, taking care not to make the - of the mixed reaction system less than 1.3, aging with nitric acid for another 10 minutes with stirring at a temperature of 90°C. When using .7 equivalents of nitric acid, the reaction is completed under the reaction conditions in which the aluminosilicate produced does not pass through the state of sol or gel, resulting in good filterability and, therefore, calcium nitrate, etc. produced by the reaction with nitric acid. The mother liquor containing nitrate and silicic acid were separated using a Nutsche filter.

The filtration rate at this time was 2.05 m/hr.

Next, it was washed with water and dried at 110°C to produce a fine white powder of hydrated aluminosilicate with a very soft texture (1-1).
was recovered and manufactured.

Various properties of the aluminosilicate powder (1-1) obtained here were determined and are shown in Table 1.

Next, lime was added to the separated and recovered mother liquor containing each calcium nitrate as a main component and neutralized, whereby each component contained in the mother liquor was separated and recovered by the following method.

That is, first, lime powder is added to the recovered mother liquor, and the p of the solution is
When H was adjusted to 5, a solution was obtained in which manganese, calcium, a small amount of magnesium, etc. were dissolved as nitrates.

Furthermore, when lime was added to this solution to adjust the pH of the solution to 10, manganese was also completely precipitated as a brown hydroxide.

When this was subjected to Oki separation, a colorless and transparent solution containing calcium and a small amount of magnesium as nitrate and basic nitrate was obtained.

Nitric acid and calcium components were separated and recovered from the nitrate or basic nitrate obtained here by a conventional method, and the recovered nitric acid and calcium components were reused in the process of the present invention.

As a result of the above, by using blast furnace slag as a raw material and paying attention to the mixed reaction system with nitric acid so that the ratio is 1.3 to 5, the silicic acid content can be processed without passing through the sol or gel. It is understood that as a result of effective removal of impurities, fine powder of white hydrated aluminosilicate was suitably produced.

Comparative Example 1 A case will be described in which natural mortenite zeolite is used as the soda salt of crystalline aluminosilicate and treated with nitric acid.

The raw materials used were Na2O・Al2O3・9Si02
This crystallized material is crushed with a composition of 100
The powder was made to be able to pass through a mesh sieve, and water was added to one tube of this powder to prepare slurries having concentrations of 15% by weight and 3% by weight.

About 90% of each diluted sodium aluminosilicate 2e was mixed with stirring.
65° C. in the same manner as used in Example 1.
Using % nitric acid (HNO3), an amount of nitric acid equivalent to 1.2 chemical reaction equivalents was slowly added to the soda content (Na2O) in sodium aluminosilicate over a period of 20 minutes, during which time Continue stirring while heating at °C.
In the case of a sodium aluminosilicate solution with a concentration of 15% by weight,
After dispensing about half the amount of nitric acid required, gelation started to occur, and the whole product gradually became jelly-like, making it difficult to stir, making it impossible to dispense the predetermined amount of nitric acid into a homogeneous system. .

In the case of a sodium aluminosilicate solution with a concentration of 5% by weight, the whole solution did not become jelly-like as in the case of high concentration, but flocs of silicic acid gel were observed as well as nitric acid.

After pouring a predetermined amount of nitric acid into the mixture and aging under the same heating and stirring conditions for 10 minutes, a Nutsche filter was used to separate and recover the mother liquor containing the sodium nitrate produced by the reaction with the aluminosilicate gel. Filtration speed is 0.002 m/h
The filtration rate was small, and was hardly an industrially possible filtration rate.

Since the aluminosilicate gel recovered here is not easy to filter, the nitrates contained in the recovered aluminosilicate gel are removed using a salting-out method, and then dehydrated and dried at 110°C to form a gritty current (glass debris). Aluminosilicate gel is recovered.

Regarding the aluminosilicate gel (H-1) recovered here, various properties were determined in the same manner as in Example 1, and the results are also shown in Table 1.

As is clear from the above results, when sodium aluminosilicate is used as a raw material and treated with nitric acid, the aluminosilicate content gels regardless of the slurry concentration, and the nitrate and aluminosilicate components produced at this time are separated. Moreover, the obtained aluminosilicate was in the form of a gel and could only be obtained in the form of a current, and powdered silicic acid could not be obtained as it was.

Comparative Example 2 Using kaolin as a crystalline polyvalent metal silicate,
The case of treatment with nitric acid will be explained.

As the kaolin, sericite kaolinite produced in Itaya, Yamagata Prefecture and having the following composition was selected.

SiO□ 46.59 (wt%) A'20338.71 Fe203 0. cy 2 Mn0 0.17 Ca0 0.72 Mg0 0.62 After pulverizing the above kaolinite until it passes through at least a 100 mesh sieve, water is added to 1 kg of this kaolin powder,
A slurry with a concentration of 15% by weight was prepared, heated to about 90°C, and mixed with 65% nitric acid (HNO3) while stirring to remove 1.4% of the chemical reaction equivalent of the basic components contained in the raw kaolinite.
An equivalent amount of nitric acid was diluted over a period of 20 minutes, and then stirred under heating at 90° C. for 10 minutes to perform ripening.

When the reaction slurry thus obtained was separated into solid and liquid using a Nutsche type filter, filtration was possible at a flow rate of 0.7 m/hr.

When the transfer rate of alumina (A1203) was determined for the mother liquor containing nitrates separated and recovered, it was found that the transfer rate of alumina (A1203) was only 4% of the raw material, which was essentially crystalline kaolinite. The decomposition reaction of was not progressing, and aluminosilicate could not be recovered.

Comparative Example 3 A case where a silicate slurry of a polyvalent metal is dissolved in nitric acid will be explained.

As the nitric acid, the same 65% nitric acid (HNO3) selected in Example 1 was used.

The slurry of polyvalent metal silicate was the same as described in Example 1, and the blast furnace slag cake (B) prepared in Example 1 1
A slurry having a slurry concentration of ky plus 2e of water was selected.

The reaction conditions for nitric acid and silicate include heating 220ml of 65% nitric acid solution to 90°C and stirring, using an amount of nitric acid equivalent to 0.7 equivalent to the polyvalent metal content in aluminosilicate. During this time, the aluminosilicate slurry was slowly stirred for about 20 minutes.

After about 10 minutes, the reaction mixture started to gel, and when the entire predetermined amount of aluminosilicate slurry was mixed, the whole gelled into a soft jelly, and was passed through a Nutsche vacuum filter. It was impossible to separate the produced polyvalent metal nitrate mother liquor from aluminosilicate by filtration.

This is because the reaction took place in the presence of a large amount of free nitric acid, with the reaction mixture always having a pH of 1.3 or less, which was the condition when the two were mixed, so the aluminosilicate produced by the reaction was It is thought that due to the large amount of free nitric acid present in the sample, it first eluted into a sol and then changed into a jelly-like gel that could not be flowed.

Industrial separation and recovery was completely impossible.

Comparative Example 4 A case will be described in which a nitric acid solution and a polyvalent metal silicate slurry are simultaneously added to the reaction system and one reaction is carried out.

As the nitric acid, the same 65% nitric acid (HNO3) selected in Example 1 was used.

As the slurry of polyvalent metal silicate, a slurry having a slurry concentration obtained by adding 2 e of water to 1 kg of blast furnace slag cake (B) used in Comparative Example 3 was selected.

The reaction conditions were as follows: First, 500 m' of water was filled into a stainless steel cylindrical reaction tank with an internal volume of 5e, and the temperature was heated to 90°C.
The nitric acid and the aluminosilicate slurry are heated to and stirred in the predetermined reaction equivalents (
0.7 equivalent), the amount of nitric acid is 220ml! /20
At an Ebetsu speed of 3 to 9 minutes, the aluminosilicate slurry
At the Ebetsu speed of /20 minutes, sex was simultaneously carried out in the same cylinder reaction tank.

At this time, the value of the reaction mixture system was always 0.5 or less.

Note that the reaction system was heated so as to be maintained at 90° at all times.

After 15 minutes have elapsed from the start of the reaction, the reaction mixture partially gels and becomes a non-uniform system, and as time passes, the gelation becomes more intense, and after a predetermined amount of reaction is completed, the entire reaction mixture becomes a non-uniform system. It became a very soft jelly.

Attempts were made to separate and recover this material into a solution of aluminosilicate and nitrate using a Nutsche type vacuum filter, but the flow separation could not be completed within the specified time, and the separation was essentially carried out by filtration. was impossible.

Claims (1)

[Scope of Claims] 1. An aqueous slurry of a glassy polyvalent metal aluminosilicate formed by melting and a monobasic acid in an amount equal to or more than the equivalent amount per polyvalent metal component of the aluminosilicate, and a mixture of the two. Starting point! J) are reacted under conditions such that the pH of the mixed system is 1.3 to 5 for most of the opening until the end of mixing, and the solution containing the water-soluble polyvalent metal salt and the insoluble fine powder aluminosilica are reacted. A method for producing aluminosilicic acid, which comprises generating an acid, then separating an insoluble fine powder, and washing if necessary. 2 Glassy polyvalent metal aluminosilicate has the following formula, S io 2 ・n MOk /2 ・rnA l 2
In the formula 03, M is a metal of Group Ⅰ, a metal of Group Ⅰ, or a metal of Group ① of the periodic table.
group metal or manganese, k is the valence of the metal M,
The method according to claim 1, having a composition as follows: n is a number from 0.3 to 5, and m is a positive number of 3 or less. 3. The method according to claim 1, wherein the aluminosilicate is blast furnace slag. 4. The method according to claim 1, wherein the basic acid is nitric acid.