JPH01278593A - Strongly basic solution and solid strong base - Google Patents

Abstract

PURPOSE:To obtain the subject solution and solid substitutable to sodium hydroxide in a low cost and large amount by acidifying sea water and adding strongly alkaline agent to generate precipitate, then concentrating supernatant liquid of the resultant water, cooling and separating resultant precipitate. CONSTITUTION:3-5% concentrated sulfuric acid is added to an aqueous solution of activated calcium phosphate and generated precipitate is removed to obtain an aqueous solution of strong acid. Sea water is adjusted to pH<=2 preferably using said aqueous solution of strong acid, then adjusted to, for instance, ph>=13 with addition of strongly alkaline agent such as sodium hydroxide, thus a precipitate is generated. Supernatant liquid of said solution is heated and concentrated, then cooled to respectively obtain solid strong base from the precipitate and strongly basic solution from the supernatant liquid. Said strongly basic substance is used as cleaning fluid, neutralizing agent, sewage treatment agent, catalyst, solvent for coating material or modifier of gasoline, etc.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a strong basic substance that replaces conventional alkalis for hydroxides I to R-8, and is suitable for use in various cleaning solutions, neutralizing agents, sewage treatment agents, The present invention relates to an extremely basic substance that can be used as a catalyst, a paint solvent, and a modifier for gasoline, etc.

[Prior Art and Problems to be Solved by the Invention] Conventionally, sodium hydroxide and its aqueous solution have been mainly used as cleaning liquids, neutralizing agents, etc. in various industries.

However, sodium hydroxide is difficult to handle because of its large deliquescent property, and its aqueous solution is viscous, so it cannot be used as a solvent for paints or other applications.

Incidentally, in recent years, it has been reported that certain metal oxides such as alkaline earth oxides to which Na metal is added exhibit extremely strong basicity and exhibit interesting behavior in terms of catalysis and the like. Substances that exhibit extremely strong basicity are called superstrong bases (although the definition is unclear), and currently there are three types: Na-MgO, which is MgO with Na added, AQ, and 03 with Na metal added. Those obtained by firing Na-A, Q, 03, and CaO in a vacuum are known.

These substances are particularly important in terms of organic synthesis chemistry, but their physicochemical properties are still under research, and they must be fired under specific conditions other than in air (for example, in argon or vacuum). , Manufacture that requires Na metal, etc.
Due to the second difficulty, it has not yet been put into practical use industrially, and it is not suitable for fields where a large amount of alkaline agents are used.

The object of the present invention is to provide a strong base that is inexpensive, can be easily mass-produced, and can be used for various purposes.

A further object of the present invention is to provide a strong basic solution and solid strong base that can replace sodium hydroxide produced using seawater.

[Means for Solving the Problems] One of the strong bases of the present invention that achieves this purpose is to make seawater acidic, then add a strong alkaline agent to make it have a high p I-1, and remove the precipitate generated at that time. Solution obtained by removing (,)
Solution (b) is obtained by concentrating, cooling, and removing the precipitate generated during cooling, and the other is a solid obtained by removing water from solution (b).

The present inventor has already proposed a method for separating salts from seawater (Japanese Patent Application No. 62-201578), in which the pH of seawater is adjusted to low with a strong acid containing sulfate ions, and then a strong alkaline agent is added to raise the pH to high. Precipitate and solution (a)
It was shown that ions such as various metal ions contained in seawater can be separated and scaled by separating them. The strong bases of the invention are prepared on the basis of this solution (a).

Seawater separation will be briefly explained below. First, a few percent dilute sulfuric acid can be used as a strong acid containing sulfate ions to lower the pH of seawater, but 3 to 5 percent concentrated acid can be used in an aqueous solution in which activated phosphoric acid is dissolved. An aqueous solution (hereinafter abbreviated as P-8 acid) obtained by adding sulfuric acid and removing a precipitate can be used. This P-8 acid has a pI (0
It exhibits a strong acidity of about .2, but unlike harmful substances such as sulfuric acid, it can be used as a highly safe acid that is easy to handle and does not cause any abnormality when it comes in contact with the skin. Add a few percent of dilute sulfuric acid or P-S acid to seawater and leave it for 2 to 3 hours to adjust the pH of the seawater to 2.
It is possible to adjust to the following low p and H values.

At this time, almost no precipitates are formed, but some precipitates are removed together with the original suspended matter in the seawater by means such as filtration.

Next, the strong alkaline agent is used to neutralize seawater that has been adjusted to a low pH and raise the pH further.
Hydrogen precipitates alkali metals whose solubility decreases and salts such as sulfates of other metals. As such a strong alkaline agent, sodium hydroxide as it is, or a solution obtained by adding sodium hydroxide to an aqueous solution of calcium oxide (hereinafter abbreviated as Ca--Na aqueous solution) is used.

The amount of strong alkaline agent should be at least the amount that can achieve the above purpose, and usually 3% of thorium hydroxide (solid) is added to seawater, and about 5% of Ca-Na aqueous solution is added to 10% of the seawater. Leave it for more than an hour.

As a result, the seawater exhibits a basicity of p, H13 or more, and a precipitate is formed.

After removing this precipitate, solution (a) contains about the same amount of alkali metal ions as seawater, but contains less alkali metal ions such as Ca and Mg, and contains mainly hydroxide ions and chloride ions as anions. It is a basic aqueous solution containing

Next, the solution obtained by separating seawater in this way (a
) to produce the strong base of the present invention [3] will be explained.

First, solution (a) is appropriately concentrated by heating to evaporate water. When this concentrated product is cooled, a precipitate is deposited, and by removing this precipitate, a very strongly basic solution (b) is obtained.

The degree of concentration here varies depending on the purpose for which solution (b) is applied, but by concentrating it to about 10% to 1.50% of the original solution (a), an extremely strong basic solution with a pH exceeding 14 can be obtained. I can do it. Table 1 shows the results of elemental analysis of solutions (a) and (b) obtained by first separating seawater and the seawater.

This 7-volume solution (b) is obtained by removing salts with a lower degree of dissociation as precipitates from the solution (a) obtained by first separating seawater, so it contains Na+, K+, Ca+ as cations.
It mainly contains Li+ ions, and contains more Li+ ions than seawater.

Such basic solutions can be effectively used as cleaning solutions and neutralizers as substitutes for aqueous solutions of sodium to lithium hydroxide; It exhibits excellent effects as a separating agent for separating seawater and oil, and as a treatment liquid for acidic waste liquid discharged from paper mills, etc.

Furthermore, it can also be applied as a solvent for epoxy paints and acrylic paints, which conventionally had to use toluene, lacquer thinner, etc. as solvents. These paints can also be dissolved in an aqueous solution of sodium trihydroxide, but in the case of an aqueous solution of sodium trihydroxide, the viscosity of the paint increases, making it unsuitable as a solvent. However, in the case of the strongly basic solution of the present invention, there is no increase in viscosity, and both the mixing state and the coating properties are good.

Margin Table 1 Below: The solid strong base, which is the second invention of the present application, can be obtained by heating this strong basic solution (b) to evaporate water. Since the strongly basic solution (b) has extremely strong basicity, when removing moisture from it under heating, a container with corrosion resistance is required.

Moisture removal can also be carried out under reduced pressure and at relatively low temperatures.

The solid strong base thus obtained was a sandy white solid without deliquescent properties. Mainly Na, C
Salts, oxides and hydroxides of a, when dissolved in water,
Since it exhibits extremely strong basicity, it is estimated that it also contains compounds called super strong bases such as Na-Ca○.

By dissolving this solid strong base in water, it can be used as a strong basic solution according to the first invention, and has the advantage that unlike a liquid, it is easy to transport and can be adjusted appropriately at the site of use.

Further, the solid strong base of the present invention can utilize its catalytic action, and can be used as a combustion reaction catalyst, for example, as a reforming agent for gasoline etc. by kneading it with alcohol.

[Example] An example of the method for producing a strong basic solution and solid strong base of the present invention will be described.

1. Preparation of P-8 acid Dissolve 50 g of powder mainly composed of calcium phosphate made from calcined animal bones in fresh water IQ to obtain an aqueous solution with p I (13 or more). Add 5% concentrated sulfuric acid to the aqueous solution. addition, pH
0.2 P-8 acid was prepared.

2゜Separated seawater Add 10Q of the above p-s acid to 500Q of seawater,
After standing for 3 hours, impurities were removed by filtration. As a result, the pH of the seawater became 1.6. Then low p,
Add 25% 3% Na-〇■1 aqueous solution to 500Q of hydrogenated seawater.
11 was added and left to stand for 10 hours. At this time, the p and H values of solution (a) after filtering off the generated precipitate were 13.5.

3. Preparation of strongly basic solution Solution (a) 10Q after separating the seawater was heated to remove water to obtain a concentrated solution of 1.5Q. By rapidly cooling this concentrated solution, the precipitate deposited was removed to obtain the desired strong basic solution. The amount of precipitate removed was 200 g.

4. Production of solid strong base The strong basic solution (30 kg) produced in step 3 was heated in a quartz crucible to evaporate water to obtain the target solid strong base (approximately 5 kg).

[Effects of the Invention] As is clear from the above explanation, the strong base of the present invention has superior properties to sodium hydroxide, which can replace sodium hydroxide, and can be widely used in industry. is possible.

Furthermore, since the strong base of the present invention is produced using seawater, it can be produced at low cost and in large quantities, and the method for producing it is also easy.

Agent Patent Attorney Moriya - Yu

Claims (1)

[Claims] 1. Solution (a) obtained by making seawater acidic and then adding a strong alkaline agent to increase the pH and removing the precipitate generated at that time.
A strongly basic solution consisting of solution (b) obtained by concentrating, cooling, and removing the precipitate formed during cooling. 2. A solid strong base obtained by removing water from the solution (b) which is the super strong base described in item 1.