JPS5835933B2 - Method for producing basic aluminum salt - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a process for producing basic aluminum salts, particularly basic aluminum salts useful as water treatment agents.

Basic aluminum chloride has become widely used as a water treatment agent, and numerous production methods are being investigated.

One of the major reasons for this is that even basic aluminum chloride having the same composition has different performance as a water treatment agent due to differences in manufacturing methods, as well as from an economic standpoint.

Methods for producing basic aluminum salts include: (1) A method in which metallic aluminum is reacted with a monovalent acid having an amount equal to or less than its equivalent.

■ A method of removing monovalent acid ions from an aluminum salt of a monovalent acid through an ion-exchange resin membrane O A method of calcining aluminum chloride hexahydrate crystals and volatilizing Ct ions as HCl.

@ A method in which aluminum hydroxide is mixed with a monovalent acid less than its equivalent and reacted under pressure and high temperature.

■ A method in which an aqueous alkaline aluminate solution is neutralized with an acid to produce an active aluminum hydroxide gel, and this is reacted with an equivalent amount or less of a monovalent acid.

(2) A method in which a basic aluminum sulfate precipitate obtained by reacting aluminum sulfate with an alkali or an alkali metal aluminate is reacted with a monovalent acid or an aluminum salt of a monovalent acid.

■ A method in which a calcium compound is added to an aqueous solution of a mixture of aluminum chloride and aluminum sulfate to remove sulfate ions as gypsum.

etc.

Among these methods, methods (1) to (2) are laboratory methods and are not suitable as industrial methods from the economic point of view.

In addition, method (2) requires an expensive alkaline agent, mainly caustic soda, as a raw material, and method (2) has the disadvantage of producing a large amount of gypsum as a by-product.

In view of the current situation, the present inventors conducted research on a method for producing basic aluminum salts, and as a result, they discovered a method for producing basic aluminum salts that is inexpensive and has excellent water treatment performance, and have completed the present invention.

That is, the aluminate of the divalent metal of the present invention and the monovalent or divalent metal
The present invention relates to a method for producing a basic aluminum salt, which comprises reacting a basic aluminum salt with an aluminum salt of a basic acid.

As the divalent metal aluminate used in the present invention, calcium aluminate and barium aluminate are suitable.

Therefore, regarding these manufacturing methods, aluminum sources include aluminum hydroxide, bauxite, kaolin, etc. with an aluminum content of 35% (as At203).
The above-mentioned inorganic chemicals or minerals can be cited as good examples, and the calcium or barium source that reacts with them can be exemplified by calcium or barium oxides, hydroxides, or carbide slag.

Calcium aluminate or barium aluminate can be produced by stirring and mixing the above aluminum source and calcium or barium source through water, forming a slurry, and reacting the mixture under normal pressure or increased pressure.

Sarariko, to describe these manufacturing methods in detail, the ratio of aluminum source to calcium source and the ratio of aluminum source to barium source are respectively Ca0At203
(molar ratio), B a O/Az2o a (molar ratio)
As 1. The range of υ~6.0 and 1.0~3.0 (preferably.

That is, CaO/lAt203 (molar ratio), Ba0A
If t203 (molar ratio) significantly exceeds the above upper limit, the aluminum source will be insufficient, and unreacted calcium and barium sources will remain.

On the other hand, if the above lower limit is significantly exceeded, an excessive amount of aluminum source will be present, which is economically disadvantageous in either case.

By the way, when producing the above aluminate, alkali metal hydroxide, chloride such as caustic soda, caustic potassium, sodium chloride, potassium chloride, sodium sulfate, sodium nitrate, etc. are added to produce calcium aluminate. , can promote the production reaction of barium aluminate.

The amount of this accelerator added is 70% of At203 in the raw material.
The following is desirable.

If more than this is added, a portion of the aluminum source will be eluted into the hydroxide solution in the form of alkali aluminate when calcium aluminate, etc. is produced, resulting in a loss of the aluminum source, which will only lead to an increase in raw material costs. be.

In addition, if the amount of the accelerator mentioned above is large and may have a negative effect on the production and stability of the basic aluminum source salt (in this case, the accelerator cannot be easily removed by rinsing the mouth). It is possible.

In addition, the cake at this time had good mouthfeel and had little moisture in the cake.

The composition of calcium aluminate obtained as described above varies depending on the type of raw materials, the ratio of raw materials, the reaction temperature, the type and amount of accelerator, etc., but can be exemplified as follows.

That is, CaO”A42034H20,4CaO”3
At203”3H20,2CaO”A42034H20
,3CaO-At203・6H20,4CaO-A12
03・H2O, 4CaO-A1203・13H20 etc.m
1) t>3Ca O” At2o produced by accelerator
3' Ca 804 ' 12H20-3CaO-At
203・CaCt2・10H20,3CaO・At20
3.Ca(No3)2.10H20 etc., when using SiO2-containing material as an aluminum source, 2CaO.At
203"S iO□"8H20,3CaO' At
,,03''X5i02YH20 etc. are also generated.

On the other hand, the composition of barium aluminate is B a O-
At2032 H20* B a O・A403・H2
O etc.

What is important in this reaction is the reaction temperature.

Therefore, the relationship between the reaction temperature and the production rate of divalent metal aluminate 4 will be specifically described as follows.

Specific example l Aluminum hydroxide 76.47r and calcium hydroxide 1
08.8: Ill and water 8151 with cooling pipe installed.
The mixture was placed in a 3-bottle flask and the reaction was carried out with stirring at the reaction temperature shown in Table 1. The production rate at each reaction time was measured (the calcium aluminate produced was examined by X-ray diffraction).

The results are shown in Table 1.

As is clear from the above table, when the reaction temperature becomes 80'C or higher, the production rate increases rapidly.

Furthermore, when calcium aluminate produced at temperatures above 80°C is used as a raw material, the stability and water treatment ability of the basic aluminum salt are superior to those produced at temperatures below this range. .

The method for producing the multilayered calcium aluminate and barium aluminate includes: (1) A method of mixing and igniting an aluminum source and a calcium source or barium source.

■ A method in which an alkali hydroxide aluminate solution and an aqueous solution of calcium salt or barium salt are mixed and precipitated.

etc.

However, these methods are practically unsuitable for application as raw materials for producing basic aluminum salts.

That is, calcium aluminate or barium aluminate obtained by the method (2) is in the form of a composite oxide, has poor reactivity with aluminum salt solutions such as aluminum chloride and aluminum sulfate, and requires a long reaction time. However, calcium aluminate and barium aluminate obtained by method (2) have the disadvantage that they do not react completely and leave a large amount of unreacted substances, and the calcium aluminate and barium aluminate obtained by method (2) contain polyhydric water in the cake, resulting in the possibility of it becoming an impurity. A large amount of salt is mixed in,
When basic aluminum salts are produced using this method, the product has the disadvantage of poor stability.

The present invention produces an aluminate of a divalent metal as described above, and after separating the mother liquor in the form of a slurry or by filtration etc., the suspension in the slurry or the cake after separation is converted into a monovalent metal aluminate. Alternatively, a basic aluminum salt is produced by dissolving it in an aluminum salt of a divalent acid.

Examples of aluminum salts of monovalent or divalent acids used in the present invention include aluminum chloride, aluminum nitrate, and aluminum sulfate.

The detailed description of the method for producing the basic aluminum salt of the present invention is as follows.

The reaction between the aluminate of a divalent metal and the aluminum salt aqueous solution of a monovalent or divalent acid is preferably carried out under stirring, so that the aluminate slurry or cake is uniformly dispersed in the aluminum salt aqueous solution by stirring. This prevents unreacted substances from forming into lumps and significantly accelerates the reaction.

The reaction temperature is not particularly limited as long as it is above room temperature, and the reaction time depends on the reaction temperature, but since the aluminate obtained as described above easily reacts with an aluminum salt aqueous solution, 20 to 40 minutes is sufficient. That's enough.

By the way, when only the aluminum salt of a monovalent acid is used, calcium or barium derived from aluminate titanium is present in the basic aluminum salt solution, but even in this case, the conventional method (aluminium chloride and calcium carbonate) In other words, the conventional method has a basicity of 50.
% change is the upper limit [On the other hand, it is possible to produce basic aluminum salts with high basicity such as 80φ, and even when the basicity is the same, it is still less expensive than those produced by conventional methods. However, the storage capacity is large and the water treatment capacity is excellent.

In addition, in situations where the presence of calcium or barium in the basic aluminum salt solution is avoided, 'tel- or aluminum sulfate etc. can be used simultaneously or separately with the aluminum salt of a monovalent acid to form a base. A basic aluminum salt can also be produced by precipitating and removing calcium or barium in a basic aluminum salt solution as calcium sulfate or barium sulfate. Examples of the present invention will be described below.

Example 1 Calcium hydroxide 2961, aluminum hydroxide 1561, sodium hydroxide 2 (H') and water 548 V were put into a three-bottle flask with a capacity of 1, equipped with a cooling tube, and the liquid temperature was 60
The reaction was carried out for 24 hours at 0.degree. C. with stirring, and the product was filtered, washed with water, and dried to obtain 533 tons of white powder.

This white powder has a composition of 4CaO. At203・13H20
The production rate of calcium aluminate was 75% in the mixture of calcium aluminate, unreacted aluminum hydroxide, and unreacted calcium hydroxide.

Next, add 5 to a container with a volume of At2038 concentration aluminum sulfate hydroxide g2264f, aluminum chloride 6 water ja79
The mixture was heated to 60° C., and the above mixture 5332 was gradually added over 20 minutes, and after aging for 1 hour, it was filtered to obtain a basic aluminum salt solution.

Its composition is At2039.96, So, 2.98φ
, C78.09%, basicity 50.5 or better.

Example 2 500m/l with cooling pipe installed! In a three-bottle flask, 366 ml of water, 55.55 ml of calcium hydroxide, and 46.8 ml of aluminum hydroxide were put, and the reaction was carried out for 2 hours with stirring at a liquid temperature of 90°C, resulting in a composition of 3 CaO・Al2O3.
- A slurry containing 6H20 calcium aluminate and a small amount of unreacted hydroxyl f-hyaluminum was obtained.

Next, 446 f of an aqueous aluminum sulfate solution having a concentration of At2 o a s %, 50 f of water, and 193 f of 6 water bottles of aluminum chloride were added to a beaker having a volume of 1 to 20 ml, and the mixture was heated to 70° C. to dissolve the aluminum chloride.

While keeping this solution at 70°C and stirring, the above slurry was gradually added over 20 minutes, and further aged for 30 minutes.
After 1 filtration, a transparent basic aluminum salt aqueous solution was obtained.

Its composition is At20, 9.98%, 5O42, 82 articles,
It had an excellent C18.34 and a basicity of 49.9%.

Example 3 Reaction vessel of Example 1 [calcium hydroxide 218v1 aluminum hydroxide 153? , 502 sodium chloride and 579 f of water were added, the temperature of the liquid was set to 100°C, the reaction was carried out for 1 hour with stirring, and the product was filtered, washed with water and dried to form a white powder 3.
I got 95f.

This white powder consists of 3CaO-At203, 6H20 and 3C
It was a calcium aluminate mixture having the composition aO-At203-CaC12.1OH20.

Next, put 5 into an enamel container with a capacity of A7. ．． 038 concentration aluminum sulfate aqueous solution 1709S', aluminum oxide 6 water t1572s' and water 1265f,
The mixture was heated to 0°C, 395 g of the above mixture was added, kept at 60°C, stirred, reacted for 1.5 hours, and filtered once to obtain a transparent basic aluminum salt solution.

Its composition is At, 0310.00, 5O43,01
%, CL 8.21%, and basicity 50.0%.

Example 4 The reaction vessel of Example 1 [42v of aluminum hydroxide, 8 barium hydroxide, 1232f of water, and 2261ml of water were charged, the liquid temperature was set to 100°C, the reaction was carried out for 2 hours with stirring, and the product was filtered once, washed with water, and then dried. Barium aluminate 1701 was obtained.

Next, in a flask with a volume of 1 O3 s% aluminum sulfate hydroxide solution 168 P, aluminum nitrate nonahydrate 137 S' and water 520 P? The mixture was heated to 60° C., 100 s' of the above barium aluminate was added, kept at 60° C., stirred, reacted for 4 hours, filtered, and a transparent basic aluminum salt aqueous solution was obtained.

Its composition is A! It was 2037.82%, 8040.07 yen, No. 38.15 yen, and basicity 71.1.

Example 5 In a three-necked flask with a capacity of 5, equipped with a cooling tube, 100s' of sodium hydroxide, 797S' of aluminum hydroxide,
1134s' of calcium hydroxide and 296'l of water were added, the temperature was brought to 100°C, the reaction was carried out for 2 hours with stirring, the product was filtered, washed with water and dried, composition 3Ca0/At2
Calcium aluminate 1920 mainly composed of 03/6H20
I got /.

Next, a predetermined amount of water was added to an aqueous aluminum chloride solution with an At203 concentration of lOφ, heated to 90°C, and the above calcium aluminate was gradually added at the rate shown in the table below over a period of 30 minutes. A basic aluminum salt having the composition shown below was produced.

For comparison, basic aluminum salts having the compositions shown in Table 2 were produced under the same conditions using calcium carbonate instead of calcium aluminate.

This basic aluminum salt was allowed to stand at room temperature and the formation of a precipitate was observed.

The results are shown in Table 2. Example 6 A water treatment test was conducted using Examples 1, 2.3 and a basic aluminum brine solution prepared by the following method as a comparative amount.

Test method: River surface water (water temperature 18℃, turbidity 2)
0p pm, pH 7.20, M alkalinity 75ppm
, COD 21 ppm) was placed in a jar tester, a predetermined amount of a basic aluminum salt aqueous solution was added, and the mixture was rapidly stirred for 2 minutes, slowly stirred for io minutes, and left to stand for 10 minutes, and the turbidity of the supernatant water was examined.

The results are shown in Table 3.

Comparative Amount Production Method and Composition 765 f of an aqueous aluminum sulfate solution with an At2038% concentration and 193 g of aluminum chloride were placed in a three-bottle flask equipped with a cooling tube and heated to 70°C, followed by CtL ECC.
a Calcium carbonate slurry IJ-32 with a C03 concentration of 47 tons
0S' was gradually added over 20 minutes, and after stirring for 30 minutes, the mixture was filtered to obtain a basic aluminum salt.

Its composition is A720310.02, SO, 2, 84.

The Ct was 8.37% and the basicity was 49.9.

Claims (1)

[Scope of Claims] A method for producing a basic aluminum salt, which comprises reacting an aluminate of a dodecvalent metal with an aluminum salt of a monovalent or divalent acid. 2. Divalent metal aluminate obtained by reacting an aluminum-containing substance with a divalent metal oxide, hydroxide, or its salt in a solution at 80°C or higher, and a monovalent or divalent acid. A method for producing a basic aluminum salt, which comprises reacting a basic aluminum salt with an aluminum salt.