DE1206872B - Process for the production of barium hydroxide of high purity through ion exchange - Google Patents

Description

FEDERAL REPUBLIC OF GERMANY

JR. Jl a. GERMAN MM PATENT OFFICE

EDITORIAL

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German class: 12 m - 11/10

L 40283 IV a / 12 m October 23, 1961 1.6. December 1965

So far it has given rise to certain difficulties with the aqueous barium sulfide solutions which are usually obtained to a barium hydroxide of a high degree of purity, which is 99.5% and more to work up. Such aqueous solutions are obtained when clinker is leached by reducing Barytes with coke or the like. Be made.

This technical problem can be solved according to the invention in a very simple and expedient manner using the technique of ion exchange dissolve by using a strongly basic anion exchange resin is treated in the hydroxyl form with an aqueous BaS solution in such an amount that The resin is not yet exhausted, whereupon the resulting solution is separated from the exchanger resin and is crystallized, or that a strongly acidic sodium or potassium cation exchange resin in the charged in the same way and after separating the draining alkali sulfide solution the resin with simultaneous Isolation of the barium hydroxide solution formed with NaOH or KOH solution, preferably in countercurrent, is regenerated.

In the case of the anion exchange resin in the hydroxyl form, the sulfide ions are bound, and the desired Ba (OH) ₂ -containing solution flows off immediately, from which barium hydroxide crystals with an almost 100% degree of purity are obtained after concentration. After regeneration with z. B. a solution of NaOH, the exchanger can be used again immediately, while _{very pure sodium sulfide can be obtained from the runoff of the Na 2} S solution formed, which is also a valuable commercial product.

In the case of the cation exchange resin, the treatment with the raw barium sulfide solution takes place first Obtain a sodium sulfide solution, which in turn turns into solid sodium sulfide of a high degree of purity can work up, while in the regeneration treatment with z. B. NaOH solution from the drain the desired solution containing barium hydroxide, from which a very pure end product crystallized out.

A particular advantage of the new method is that a multiple cycle management for the purpose of enrichment of barium hydroxide is not required.

It is known from water softening that _{a large amount of exchangeable barium ions is present in the sodium permutite-BaCl 2} system and that this exchange takes place very easily when treated with an n / 2-KCL solution. However, the structure of the exchanger is different from the method of the present invention.

Process for the production of barium hydroxide with a high degree of purity by means of ion exchange

Applicant:

Laporte Chemicals Limited, Luton, Bedfordshire (Great Britain)

Representative:

Dr. E. Jung, patent attorney,

Munich 23, Siegesstr. 26th

Named as inventor:

John Geoffrey Marshall,

Bletchley, Buckinghamshire;

Anthony Macdonald Hildon,

Dunstable, Bedfordshire;

Alfred Edward Oates, Luton, Bedfordshire (Great Britain)

Claimed priority:

Great Britain October 26, 1960 (36 791)

It is also known that strongly basic exchangers with quaternary ammonium groups are theirs Exchange the OH group for other anions, but it has never been considered before these properties for a treatment of barium sulfide solutions for the purpose of obtaining barium hydroxide to make high purity usable.

It has also been recommended to use anion exchange resins to be used in their neutral or salt form. When treating with the aqueous solution of a Alkaline earth hydroxide is then bound to the hydroxyl ions in the exchange resin and one flows aqueous solution of the corresponding alkaline earth salt, but this is no longer used. if after careful washing with water, a more concentrated solution of an alkali halide is obtained Sends through the exchange column, falls in the middle part of the outlet, enriched in alkali hydroxide Fraction, but it requires multiple recirculation of the latter in order to be worthy of processing To obtain proportions with an alkali hydroxide content of about 17 percent by weight. One Such a procedure would not be suitable for the pure preparation of barium hydroxide from barium sulfide solutions suitable.

509 758/377

3. 4th

There is also a multi-stage process for flowing through, with the drain being collected. Position of MgCl _{2 has been} described according to The resin releases hydroxyl ions to the solution, which releases the magnesium ions from a salt solution and thereby displaces the sulfur-containing ions adsorbed on the exchanger and then by means of water (e.g. S-, SH-); As a result, the drain contains an aqueous hydrochloric acid from the resin 5 substance ions barium hydroxide. When concentrating and crystallizing out, they are displaced. After the completion of this process, a magnesium salt solution containing barium hydroxide is obtained, followed by a regenerated octahydrate with a purity of more than 99.5%.

ration treatment. It was found that the above

Preferably, the operations of the er amount of barium sulfide solution are the exchangeability

treatment according to the invention in the manner before the resin is practically exhausted. In the run

suppose that the barium sulfide solution would be replaced by a further amount of barium sulfide solution

certain amount of the ion exchange resin outflow also contain sulfur-containing ions,

runs through and collects the drain. An equivalent of n-sodium hydroxide solution is then left on

If using a cation exchanger, flow upwards through the bed. In this treatment resin, it is advantageous to pass the aqueous 15 treatment, about 60% of the resin is converted back into the solution of barium sulfide by a column or hydroxyl form, so that one bed of sodium exchange resin, during the next barium sulfide treatment, about 400 ml of the treatment with the alkaline regeneration solution can be used before the resin is exhausted in countercurrent. The same procedure can is. The effluent from the bed contains sodium sulfide, even in the case of anion exchange resins, and results in the product being concentrated and crystallized out. In all cases, the exchangers Na ₂ S · 9 H ₂ O with a purity of 97% · The mother resins - if required - can be washed with water before the rain solution contains 29% sodium hydroxide and about 5%. Very desirable Na ₂ S. If this mother liquor with fresh sodium is it, if the barium sulfide solution of hydroxide used is added in the required proportion, then an aqueous extract of the clinker consists, which can be reintroduced into the process in the reduction of barytes Coke or the like and used for further resin regeneration processes. The barium sulfide solution can be at one temperature. With this subsequent Regeneriervorgänperatur of 50 to 70 ⁰ C are used. gen with one equivalent η-sodium hydroxide solution is the

According to a preferred embodiment, the exchangeability of the resin is restored, and

Invention one leaves the barium sulfide solution from above 30 to practically the value it had after the first

had down through a column or bed of a regeneration. With all the first step

strongly acidic sodium exchange resin flow. The following operations or exchanges

The solution that runs off is collected and amounts of from the barium sulfide solution are therefore crystallized out

siert, whereby crystals of Na ₂ S · 9H ₂ O are obtained. about 400 ml used.

Then through the exchange column or the 35

Bed caustic soda pumped up from the bottom and example 2

the draining solution is collected and removed. The bed described in Example 1 was replaced

crystallizes, whereby crystals of Ba (OH) ₂ · 8 H ₂ O are replaced by a strongly acidic sodium cation exchanger

receives. Preferably, the solutions of resin, of the type crosslinked polystyrene with SO ₂ OH-

Sodium sulfide or of barium hydroxide before the 40 groups (Permutit Zeokarb 225).

Crystallize concentrated. Advantageously, 800 ml of the im is left at room temperature

the resulting barium hydroxide octahydrate with about Example 1 mentioned barium sulfide solution by the

washed a volume of cold water, causing bed to flow. The resin exchanges its sodium ions

the contamination with alkali up to about 0.1% against the barium ions of the solution. The sequence

is reduced. 45 is a solution containing sodium sulfide which

The mother liquor from the crystallization of the barium can be concentrated and when the hydroxyd octahydrate crystallizes out it still contains noticeable amounts of crystals of Na ₂ S -9H ₂ O. One has solid of sodium hydroxide. This mother liquor can be such that the above amount of solution is added to the outside with fresh sodium hydroxide and practically exhausted if the resin is exchangeable,
a further regeneration of the exchange resin 50 _ The resin is then used as in Example 1 with a. Treated equivalent η-sodium hydroxide solution. At this

Also the mother liquor from the crystallization of the action will be about 30% of the resin back into the

Sodium sulfide can be converted back into the sodium form, so that at the next

be introduced, namely to the barium sulfide-barium sulfide treatment about 250 ml of solution

leaching clinker. 55 can be turned before the resin is exhausted.

In this way it is possible to stop the process from the treatment with caustic soda

Production of barium hydroxide from the aqueous is a solution which contains barium hydroxide and

Carry out barium sulfide extracts in the circuit. contains excess sodium hydroxide. From this

The following examples serve to illustrate the solution crystallizes after concentrating barium

of the present invention. 60 hydroxyd octahydrate with a content of 1.3%

_R. -Ii sodium hydroxide from. When washing with about one

Example 1 volume of cold water, however, the sodium

700 ml of a 3% aqueous barium hydroxide content is reduced to less than 0.1%,

room temperature sulfide solution obtained by the only other impurities are tiny

Leaching of the clinker from the reduction of 65 quantities of metal compounds, which are obviously

Barytes with coke by means of water, by a bed of borrowed already in the original barium sulphide

100 g of a fresh, strongly basic anion were withstand. So the octahydrate has a purity

exchanger resin with a volume of about 140 cm ^a of about 99.9%

The exchangeability of the acidic resin is repeated in subsequent regeneration processes renewed, practically to the value it had after the first regeneration. One can therefore allow 250 ml of the barium sulfide solution to run through each time during the subsequent exchanges.

Example 3

Through a bed of sodium cation exchange resin "Permutit Zeokarb 225" was allowed (200 g / l) run a concentrated barium sulfide of 70 ⁰ C temperature. The resin absorbed barium ions in the amount of 40% of its exchangeability before barium ions could be detected in the process.

The resin was then washed with water and then with an eight-fold excess (to the Barium in the resin) regenerated by 4N sodium hydroxide solution. In this way, 80% of the barium ions became displaced in the resin. The resulting solution in sodium hydroxide solution was cooled to Barium hydroxide octahydrate crystallizes out at room temperature. Since the mother liquor is now only 0.3% Contained barium hydroxide, the same after enrichment with fresh sodium hydroxide was for them Reintroduction into the process for the purpose of further regeneration of the resin is suitable.

The barium hydroxide octahydrate was washed with a volume of cold water and then had a purity of 99.5%.

It must be pointed out here that both acidic and basic exchange resins are used the exchangeability of the resin can be restored to a higher degree, than Examples 1 and 2 above show, namely by using more than one equivalent of the regenerating solution used.

As previously mentioned and shown in Examples 1 and 2, a suitable starting product for barium sulfide is an aqueous extract of clinker from the reduction of barytes by coke od Subject to a number of operations including the formation of barium carbonate and its decomposition by heating into the oxide. This extract usually has a temperature of 7O ⁰ C. In practice, it will be convenient to let the solution run through the ion exchanger. For this reason, cation exchange resins are preferred, since they are considerably more stable than the anion exchange resins, especially at higher operating temperatures.

In fact, the resistance of the cation exchange resins is surprising when using concentrated Bariumsulfidlösungen of about 70 ⁰ C temperature and unexpectedly high, given the strong alkalinity of such solutions. Example, it has been found that such resin had lost only 14% of its exchange capacity, after being used are 6 months on end with 20% ⁿ Bariumsulfidlösungen of 7O ⁰ C temperature.

It is easy to see from this that the process according to the invention provides a simple means of obtaining a barium hydroxide of high purity from the above-mentioned aqueous extract. In addition, the yield achieved in the process is high and often amounts to practically 100%, since practically all of the Ba ⁺⁺ ions added to the ion exchange resin are recovered as the hydroxide. Furthermore, the only by-product of the process is Na ₂ S · 9H ₂ O, which is a marketable product.

It should be emphasized here that the resin must be strongly cationic or anionic. Weakly cationic or anionic exchange resins are not suitable for the process according to the invention. Even though that would probably be expected, as far as weakly anionic exchange resins are concerned, is that Unsuitability of the weakly acidic exchange resins really surprising. However, it has been found that even when the regenerant was used in excess, no noticeable regeneration occurred.

Claims (3)

Patent claims: 1. Process for the production of barium hydroxide of high purity by ion exchange, characterized in that a strongly basic anion exchange resin in the hydroxyl form is treated with an aqueous BaS solution in such an amount that still no exhaustion of the resin occurs, whereupon the resulting solution is separated from the exchange resin and is crystallized, or that a strongly acidic sodium or potassium cation exchange resin charged in the same way and after separating the draining alkali sulfide solution the resin with simultaneous isolation of the barium hydroxide solution formed with NaOH or KOH solution, preferably in countercurrent, is regenerated. 2. The method according to claim 1, characterized in that aqueous solutions of barium sulfide, in the reduction of barytes with z. B. coke are used as a starting material. 3. The method according to claim 1 and 2, characterized in that the aqueous barium sulfide having a temperature of 50 to 70 ⁰ C. Considered publications:
British Patent No. 662,314;
U.S. Patent No. 2,409,861;
"U11 ma η η", 3rd edition, 8th vol. (1957) pp. 788 and 807. 509 758/377 12.65 © Bundesdruckerei Berlin