JPS60137823A - Production of precipitated barium sulfate containing little sulfide - Google Patents

Abstract

PURPOSE:To produce economically the titled barium sulfate in high yield, by forming adding hydrochloric acid to a solution containing barium sulfide to form an aqueous solution of barium chloride, adding sulfuric acid thereto to precipitate barium sulfate, and reusing the hydrochloric acid formed as a by-product. CONSTITUTION:(1) Hydrochloric acid of relatively high concentration is added to a solution containing barium sulfide and reacted to prepare an aqueous solution in >=0.8mol barium chloride concentration (formula I ). (2) Sulfuric acid in about 10mol concentration is then added to the above-mentioned aqueous solution of barium chloride and reacted at about 5-60 deg.C to collect the formed and precipitated barium sulfate (formula II). (3) The hydrochloric acid formed as a by- product is returned to the step (1) and reused for the reaction with the barium sulfide.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing precipitated barium 1) acid with a high yield and in a simple and flexible process with less sulfur and sulfate.

Precipitated barium sulfate is a white pigment widely used as a raw material for producing printing inks and colored pigments.

In addition, in recent years, a large amount of filler for handle fat has been used. To outline the conventional industrial manufacturing method for precipitated barium sulfate, barite (the main component is barium sulfate) is usually mixed with coke, and this is roasted in a rotary kiln to reduce the barium oxide and sulfide. A black roasted product whose main component is barium (generally called black ash)
is obtained. This is leached with hot water to make an aqueous solution of barium sulfide, which is then mixed with an aqueous sulfate solution and reacted with an aqueous sodium phosphate solution or an aqueous sulfuric acid solution. Barium sulfate obtained by an acid solution reaction is filtered and washed. A common method is to dry and crush powdered barium sulfate.The above-mentioned barium #L acid is reduced and roasted to produce barium sulfide. If the method (2) is to carry out a complete reaction to obtain barium tC acid, and the method (3) is to react barium sulfide aqueous solution and sulfuric acid aqueous solution (to obtain barium uf acid),
Their chemical reaction formulas are shown below.

(1) BaSO4+2C-BaS+2C02(21'
BaS+Na So →BaSO4+Na2S4 (31BaS+H2So4-+BaSO4 edition (2SHowever, it is biased; 11. Because it is mixed in barium acid, there is a precipitate of barium sulfate.
J Cleaning from the surface alone is not enough, and excess μ! (After 1, sulfides are removed by repulping in reciprocal water and washing, or by using a multi-stage thickener and washing with a large amount of water sound, etc.), which is a time-consuming process. Sono (In method 31, most of the sulfide is discharged out of the yarn as hydrogen sulfide gas during the reaction, so the amount of sulfide in barium sulfate is much lower than in method 2).
Although this has been considerably improved, not all of the H2S produced as a result of the reaction leaves the liquid as a gas.
4++ Since it remains in the solution when bathed in water, to remove it, add Na0J-1 Seigane 7711 to the solution to form a stable form of jiit compound and add it to the outside of the yarn.

Therefore, even when following formula (6) of the above (3), sufficient washing is required to obtain a product with a low sulfide content.

In the production method of the present invention, in the first step, barium sulfide is reacted with relatively high concentration hydrochloric acid to produce a barium chloride water bath solution. The reaction is carried out according to the reaction formula (4) below.

IJ BaS+2HC1-BaC12+H2S As the barium sulfide used in this reaction, the roasted carcasses can be used as they are, but either an aqueous dispersion mixed with water to form a slurry or a leached barium sulfide aqueous solution can be used. (11) is preferable because it facilitates the reaction. When separating the residue for the purpose of manufacturing, this residue VH contains a considerable amount of acid-soluble barium sulfide, which can also be used as a raw material1. Acid-soluble barium sulfide refers to barium sulfide produced when a mixture of barite and coke is completely roasted.
Although it is insoluble in water, it easily forms a barium chloride solution in hydrochloric acid.

Most of the hydrochloric acid used in the first step of the method of the present invention is used repeatedly as a by-product in the second step described below. Therefore, one major feature of the process of the present invention is that it can be carried out economically and advantageously, despite the extra intermediate step of forming barium chloride. In order for such repeated use to be possible, the hydrochloric acid produced and recovered in the second step must have a certain level of high humidity.

The reaction in the second step is achieved according to the reaction formula (5) below.

(5) B a C1+ FISO-+Ha S 04
+ 2 I (CI2 2 4) Therefore, in order for the concentration of the generated hydrochloric acid to be high, it is necessary to increase the humidity of the barium chloride water bath solution to a level corresponding to that of the barium monochloride. In the method of the invention, the need for major components in the bath solution for the anti-L1, - system as a whole is eliminated at a fairly high level.As a result, in the first step The number of rice cakes and hydrogen oxides generated due to the high number of six companies and branches is kept high, and in this process t5
, most of the sulfuric acid is removed from the system. This is one of the lli mountains that significantly reduces the inclusion of sulfides into products.

In addition, in the second step, the hydrochloric acid produced according to the reaction of formula (F)) is obtained in a high concentration, so it can be easily recovered, and the recovered hydrochloric acid can be used in the first step without disturbing the high concentration equilibrium state of the entire reaction system. You can make a return flight 111.

In addition, since the acid concentration of the solution is maintained at a high level in the second step, even if a small amount of sulfide remains, it will not adhere to the barium sulfate precipitation and remain as a sulfide encapsulant. Very few precipitated barium sulfate products with 111 are easily produced! I get caught. In addition, since the entire reaction system is maintained at a straw-rich level, the amount of liquid in the entire system can be small, which is extremely advantageous in terms of actual operation.

In order to maintain the above-mentioned balance and conveniently carry out the method of this invention, the concentration of barium sulfide due to the raw material to be extracted and the concentration of hydrochloric acid to be added must be adjusted so that the barium chloride concentration in the water bath solution to be produced is 12+++ It is necessary to set the concentration so that the concentration of melon is 0.8 molar or more.

Most of the hydrochloric acid used in the production method of the present invention is by-produced in the second step, and can be used up to a minimum concentration of 4.4 molar. 'I=, become I? δ “j of the 11i acid; once, barium chloride (As r
Although it varies depending on the production rate of the sulfuric acid to be added, in order to economically obtain the by-product hydrochloric acid, a higher JL degree of sulfuric acid i is required.
It is preferable to use f history.

In any case, take into account the concentration of hydrochloric acid to be used, and make sure to obtain a bathing material with the necessary barium sulfide humidity, so that the barium chloride concentration is 0.8 mol 9'' or more. .

The barium chloride aqueous solution prepared in this way contains almost no sulfide and is suitable for the purpose. Next, this barium chloride water soluble g! 1. The second step is to react with concentrated sulfuric acid to produce precipitated barium sulfate, but it is necessary to carry out the reaction under the reaction conditions shown in this subtraction method. That is, the sulfuric acid used in this step needs to be a concentrated sulfuric acid with a molar strength of 10 or more. The reaction force of the reaction between barium chloride water bath solution and threshold acid is as follows:
If the molar ratio of H2SO4 in the 1'k 7m5 acid is the same, but one of them may be slightly higher than the other, if the concentrations of barium chloride and sulfuric acid are "; When the barium sulfate particles are low, the particles of barium sulfate formed become Japanese dogs, and the average particle diameter suitable for the purpose of the present invention is [J, 3 ~
1.6 micron ones are not possible. It is necessary that the reaction temperature in the second step of this process is 5 to 60°C,
When the temperature is higher than this, the generated particles tend to grow quickly, the average particle diameter tends to increase, and the particle size tends to vary.

After the reaction in the second step is completed, if necessary for separation, leave it for several hours to 10-odd hours, then separate solid and liquid by a conventional method such as filtration, centrifugation, or sedimentation, wash with water, dry, and crush. to obtain precipitated barium sulfate. I need more,
! Precipitated barium sulfate having a more preferable particle structure can be obtained by carrying out the treatment in an acidic or alkaline water bath.

These products not only contain less sulfide, but also have high reflectance and excellent whiteness.

After the hydrochloric acid produced as a by-product in the second step is separated from barium sulfate, it can be returned to the first step and used repeatedly.
It is a hot theory that 1.1 stool can be made by mixing 1 m of commercially available hydrochloric acid.

In the conventional method, the production of barium sulfate using barium chloride as a starting material was only carried out for the production of special products; It was considered necessary to use a diluted version of li2. One example is the production of what is commonly referred to as pharmaceutical barium sulfate for use in X-ray examinations. In order to pass the regulations of this ('IH hydropharmacopoeia), barium chloride was made to a much greater extent, and at the same time, thorium chloride was also sufficiently purified.
Each of the purified solutions is prepared as a relatively dilute solution and subjected to anti-L-+S, and the resulting precipitate is thoroughly washed to obtain a product. 1. This reaction +a is carried out according to the following formula (6).

(61BaCl2 + Na2SO4-+ Ba5O4
+ 2NaCl In this method, all of the by-product sodium chloride is drained, making it very expensive.
This is unavoidable because the product is for medical use.

Another example is a method for producing a special pigment disclosed in JP-A-48-14598, in which barium sulfate is produced from barium chloride and sulfuric acid. It is a reaction between a solution and sulfuric acid with a concentration of 9 molar or less, and 'P1. The entire requirement is to maintain the temperature above 70°C. The barium sulfate obtained by this method has coarse particles and is clearly different from the object of the present invention. Furthermore, in this prior art method, although the hydrochloric acid solution produced at the same time has the effect of enlarging the particles, it is a dilute solution and is therefore unsuitable for the purpose of recovering and using -C. Therefore, this is a method for producing barium sulfate for special purposes, and is a costly method that does not meet the purpose of the present invention.

Examples of the present invention are listed below, but the present invention is not limited to these Examples.

Example 1 630 g of black ash and 1 Lff of water were placed in an IS container and reacted by adding an equivalent amount of 9 molar hydrochloric acid to barium sulfide while stirring. The entire dissolved residue was separated overnight, and 1.3 tons of barium chloride solution with a 1.2 molar concentration was collected. It was confirmed that this chloride) (sulfide was not contained in the lithium dispersion. This solution was kept at 45°C, and 18 molar sulfuric acid 9!M' was added, followed by stirring for 4 hours. The suspension was filtered and 1.4 t of a 2.1 molar hydrochloric acid solution was added.
I got it.

Further, the water-containing cake was washed with water and dried to obtain 4007 barium monoate. - Add 12 molar hydrochloric acid to the 2.1 molar hydrochloric acid solution obtained here, react with Black Ash 3602, and proceed in the same manner as above: T! The barium sulfate obtained by repeating I4r contained no sulfide and had a particle size of 0.7 to 1.1 microns.

Implementation 9Il12 10 tons of barium sulfide solution with a 1.18 molar concentration was placed in a reaction vessel, and 10 molar IM 1& of hydrochloric acid f was added to it while stirring.
1.05 equivalents of K were added and reacted, and aeration was carried out with stirring in diluted 100 ml. It was confirmed that this barium chloride bath liquid did not contain sulfide. Next, the internal volume is 10100O! In a reaction vessel, barium chloride solution f 100 tnl/min and 18 molar sulfuric acid 5.6
The reactor was fed continuously at a rate of 17 m to 17 min, keeping the inside of the reaction system at 35°C. The suspension was filtered once, and 1.9 mol δ゛1', 11' of hydrochloric acid was added.
3 L was obtained. Also, wash the water and dry it.2.
5 kg of barium sulfate.

Hydrochloric acid of 12 molar concentration was added to the jΔA 7'112 solution of 1.9 molar concentration obtained here, and the same treatment as above was carried out.
1. f, the barium nitrate obtained by repeating the process nine times contained no llf oxide and had a particle size of 08 to 16 microns.

Example 6 Water-insoluble residue 3 containing 14.7% barium sulfide
Put kr into the reaction vessel and add to it for 10 minutes while stirring PI'L.
Add 1.02 molar concentration of hydrochloric acid to barium sulfide and let it warp, then aerate while stirring, and there will be no residual Δ! 2.2 t"k of barium chloride with 1.1 molar density was obtained by separating the barium chloride. It was confirmed that this barium chloride did not contain sulfide. It was kept at 45°C and added to 143 m7! of 18 molar sulfuric acid, followed by stirring for 4 hours, the resulting suspension was filtered once, and 2.1 t of a 2.1 molar hydrochloric acid solution was added.
I got it. The water-containing cake was washed with water and dried to obtain 6002 barium sulfate.

To the obtained 2.1 molar hydrochloric acid solution, 12 molar hydrochloric acid was added once, and the same treatment as above was repeated by reacting with the aqueous residue, and the obtained barium sulfate was converted into sulfide. is not contained at all, and the particle size is 0.4-10
It was micron in size.

Patent applicant: Barite Industries Co., Ltd. Agent Chi [Buried Earth] Kyozo Yuasa (4 other people)

Claims (1)

[Scope of Claims] 1. A step of adding highly aggressive hydrochloric acid to a solid material containing barium sulfide or its aqueous dispersion or solution to prepare a barium chloride aqueous solution; The second step is to add high sulfuric acid to cause a reaction to produce a precipitate of barium Tsukuda C acid; in the second step, the chloride produced simultaneously with barium sulfate is separated from the barium sulfate for 1 minute, and then the separated salt [7 , the 3rd process is returned to the 1st process for reuse in the reaction with barium sulphide in the 1st process.
F! Sulfide II with f sign! A method for producing precipitated barium sulfate with less /j. Table 2, Water-bath chloride produced in the first step] (The amount of raw material solids or the barium sulfide solubility of its aqueous dispersion or solution so that the lithium acidity is 0.8 mol or more,
The method according to claim 1, characterized in that the turbidity and turbidity of hydrochloric acid used for subaxe is determined. 3. The sulfuric acid used in the second step is at least 1
The method according to claim 1 or 2, characterized in that the sulfuric acid has a concentration of 0 mol. 4. The method described in any one of claims 1 to 6, characterized in that the reaction temperature in the second step is maintained in the range of 5°C to 60°C. 5. Any one of parts 1 to 4 of the patent claim, characterized in that the barium acid produced is barium i+ii acid with an average particle size ranging from 0.3 to 1.6 microns. The method described in.