JPS5813499B2 - Method for producing hydrated titanium oxide - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for purifying hydrochloric titanium oxide obtained by heating and hydrolyzing an aqueous solution of titanium in hydrochloric acid.

Industrial production of hydrous titanium oxide has been carried out exclusively by heating and hydrolysis of titanium in an acidic aqueous solution of sulfuric acid, but in this case, the hydrolyzed titanium oxide produced is a cohesive precipitate, and it is difficult to purify it by washing with water using conventional methods. There is no difficulty.

On the other hand, a method of producing hydrated titanium oxide at °C by heating and hydrolyzing an aqueous solution of titanium in hydrochloric acid is well known, but when attempting to wash the resulting precipitate with water, fine colloidal particles are generated due to peptization, making it impossible to process It is difficult to implement this method industrially because it causes significant leakage.

Although it is possible to improve the permeability by adding a polymer flocculant, washing with water still causes peptization, and the above-mentioned disadvantage cannot be solved.

In fact, it has been found that by using a multifunctional substance capable of adsorbing titanium oxide for water use in combination with an organic polymer flocculant, the precipitate can be washed with water while still flocculating, and adhering impurities can be easily and sufficiently removed. .

The present invention provides a method for producing hydrated titanium oxide in which a hydrochloric acid acidic aqueous solution of titanium is heated and hydrolyzed and the resulting precipitate is washed with water. A method for producing water-reduced titanium oxide, which comprises treating with at least one type of organic acid or phenol having two or more or their salts, and at least one type of organic polymer flocculant, and then washing with water. be.

The hydrochloric acid acidic aqueous solution of titanium can be obtained by dissolving industrially produced titanium tetrachloride in water or by dissolving aqueous titanium oxide in hydrochloric acid.

As is well known, thermal hydrolysis is carried out by heating these liquids to a temperature at or near the boiling point, and the resulting water-containing titanium oxide precipitate is formed by agglomeration of several fine colloidal particles. It consists of aggregated particles.

Normally, seed crystals are used during hydrolysis, but when seed crystals are used, the colloid particles become finer than when they are not used, and when peptization occurs by washing with water, they become more difficult to handle.

Therefore, it can be said that the present invention is of great value when seed crystals are used for thermal hydrolysis.

By heating and hydrolysis, cohesive water-recovery titanium oxide precipitates in the mother liquor, producing a precipitated slurry.

Even if the treatment of the present invention is applied after this precipitate is separated from each other and washed with water to cause deflocculation, reaggregation cannot be expected to be significant.

Therefore, in the present invention, the above-mentioned slurry, its diluted product with water, the cake obtained by removing the offshore filtration mother liquor by diluting the above-mentioned slurry with water or not diluting it by 1 degree, etc. are used as water-use titanium oxide adsorbent polyfunctional group-containing substances. and an organic polymer flocculant are added and stirred to homogenize.

Polyfunctional group-bearing substances include polybasic mineral acids such as sulfuric acid, phosphoric acid, carboxyl groups, organic acids having two or more hydroxyl groups, or phenols such as citric acid, tartaric acid, maleic acid, phthalic acid, catechol, hytroquinone, and pyroganoic acid. tannic acid, and their salts such as sodium, potassium, and ammonium salts.

When at least one of these is used as a salt, it is added in an amount of 1 to 10 parts, preferably 2 to 5 parts, in terms of Ti02 of hydrated titanium oxide, in terms of acid or phenol.

This addition may be done at the same time as or after the addition of the organic polymer flocculant, but it is better to add the organic polymer flocculant at ℃ prior to it, mix it uniformly with the hydrated titanium oxide particles, and allow it to be well adsorbed. has a more pronounced effect.

The organic polymer flocculant used in combination is generally used as a flocculant, and anionic and cationic flocculants are widely used.

For example, Thiofloc W-0 (Allied Colloid product)
, Clifflock XK-77 and PA-341 (both Kurita Kogyo products), Sunpoly A-520 and A-530 (both Sankyo Kasei products), Sunflock AH-200P (Sanyo Kasei products), etc. Nonionic products cannot be expected to be effective.

At least one of these is added in an amount of 0.03 to 3 parts, preferably 0.05 to 1 part, based on Ti02 of water-containing titanium oxide, and stirred to homogenize.

Hydrated titanium oxide treated in this way does not deflocculate the precipitated particles even when washed with water by regular means, and washing can be continued without causing door cloth leakage or clogging of the furnace cloth. , highly purified water-containing titanium oxide is obtained.

When used for pigments, catalysts, adsorbents, and photosensitive materials, they usually go through a firing process, but most of the processing agent used in the present invention decomposes and vaporizes during that process. There is no danger of disturbing the nature.

Example 1 A commonly used seed crystal for promoting hydrolysis was added to a titanium tetrachloride solution with a concentration of 1.5 mol/l in terms of TiO2, and the mixture was heated at the boiling point for 2 hours to hydrolyze and precipitate water-reusing titanium oxide. I let it happen.

After diluting the generated slurry twice with water, 50g/1
Tannic acid in the form of an aqueous solution was added in an amount of 2% based on Ti02 in the slurry and stirred.

A cationic polymer flocculant Thiofloc W-0 in a 0.5 g/1 aqueous solution was added to the slurry containing the precipitate, which had become light yellowish brown due to the adsorption of tannic acid, based on the Tie2 standard in the slurry. did.

This slurry was filtered and washed with water, but no peptization of the precipitate occurred, and no problems due to leakage or clogging of the washcloth were observed.

For comparison, when the same operation was performed except that tannic acid was not added, overflow due to peptization occurred during water washing, and at the same time, the r overspeed decreased, making it impossible to perform sufficient water washing. .

Example 2 Hydrated titanium oxide, which had been thoroughly washed with water, was obtained in the same manner as in Example 1, except that three portions of tartaric acid were added instead of adding 2% of tannic acid.

Example 3 Hydrated titanium oxide which had been thoroughly washed with water was obtained in the same manner as in Example 1 except that citric acid 3 was used in place of tannic acid 2.

Example 4 Irrigated titanium oxide that had been thoroughly washed with water was obtained in the same manner as in Example 1, except that 9 parts of ammonium sulfate (amount equivalent to sulfuric acid) was used in place of 2 parts of tannic acid.

Claims (1)

[Claims] 1. In a method for producing water-use titanium oxide, which involves heating and hydrolyzing a hydrochloric acid acidic aqueous solution of titanium and washing the generated precipitate with water,
The precipitate produced by hydrolysis is mixed with at least one of polybasic mineral acids, organic acids or phenols having two or more carboxyl groups and/or hydroxyl groups, and their salts, and at least one organic polymer flocculant. A method for producing water-use titanium oxide, which comprises treating with seeds and washing with water.