DE2030956A1 - Process for obtaining highly pure manganese compounds from liquids containing manganese (II) salts - Google Patents

Description

Kodak Limited of Kodak House, Kingsway, London, W.C. 2.

Process for the extraction of high-purity manganese compounds Liquids containing manganese (II) salts

The invention relates to a method for obtaining at least a high-purity manganese compound from at least one Manganese (II) salt-containing liquid.

It is known that in industrial oxidation processes as Liquids containing manganese (II) salts are formed. One such process is the process for producing p-benzoquinone by oxidizing aniline as a precursor for the production of hydroquinone using manganese of a relatively high oxidation level as an oxidizing agent. The manganese-containing liquids resulting from this and other such processes contain several Impurities that should be removed as far as possible so that one or more manganese compounds are in a highly pure state can be won. However, it has been shown that the Impurities can only be removed with difficulty with the methods known up to now, since the precipitates formed in the process are gel-like masses that are poorly filtered and washed can be

009017/1811

The object of the invention was therefore to provide a method in which the disadvantages described above do not occur and in which the production of high-purity manganese compounds from manganese =, Liquids containing salts made possible.

It has now been found, surprisingly, that this object can be achieved by using the manganese salt containing Liquid at a certain pH value of an aqueous solution containing ammonium ions is added, with a precipitate arises that settles quickly.

The invention relates to a method for obtaining at least a highly pure manganese compound from a with. at least one manganese (II) salt-containing liquid, which thereby is characterized in that the liquid containing the manganese salt of an aqueous solution of ammonia or one substituted ammonium hydroxide with a pH value of at least 10 is added until its pH value falls to an I '/ ert between 9.0 and 9.5 has fallen and the manganese hydroxide which precipitates is separated off.

It was now extraordinarily surprising that with the help of this convenient and simple method is possible to separate the manganese from the impurities that remain in solution. Surprisingly is the precipitate formed in contrast to the previously known method is not in the form of a gel-like mass before, but it settles out quickly, so that the above liquid can easily be decanted or the precipitate can be easily filtered off and processed further.

If the liquid containing manganese salts contains solid impurities, such as B. Tars contains, so these wjoerden filtered off or otherwise removed before the liquid is added to the ammonia-containing solution.

009887/1819

BATH ORIGINAL

The further treatment of the. Method of the invention precipitate depends on which manganese compound is desirable. When the precipitate washed and is dried, a high-purity trimanganese tetroxide is formed (Mn-O.), Which can be used to make ferrites. When the precipitate is dissolved in acetic acid, it forms a highly pure manganese (II) acetate that can be used as a polymerization catalyst. It is also possible that precipitated manganese hydroxide with a dilute ammonium hydroxide / ammonium chloride solution wash to the change in its physical properties caused by prolonged washing can be caused by water, and thus contamination by alkaline earth metal present in the tap water to prevent ions and to further reduce the amount of impurities present. ·

The precipitated manganese hydroxide can also at elevated temperatures and printing while passing compressed air or compressed oxygen in distilled water will. This procedure is for working on a large scale Scale more suitable than the above-described washing with a dilute ammonium hydroxide / ammonium chloride solution.

The manganese hydroxide is precipitated in the process of the invention preferably at a constant temperature, preferably at a temperature between 25 and 35, especially at 30 ^° C., so that the course of the reaction can be more easily controlled and more reproducible process conditions can be achieved. The precipitation is preferably carried out in the absence of air in order to prevent the oxidation of the manganese hydroxide, in particular when the product is to be converted into a manganese (II) compound, for example manganese (II) acetate.

009887/1819. bath

In carrying out the method of the invention, the manganese-containing liquid before it is added to the ammoniacal solution, preferably diluted. If the liquid containing manganese contains manganese sulfate, the concentration will be of manganese sulfate, preferably to a value of about 5 Gew.-V set.

The ammoniacal solution used in the method of the invention should, as indicated above, a pH having from idndestens 10, for which a 3.5 wt -.% Ammonium hydroxide solution containing sufficient. Instead of ammonium hydroxide, substituted ammonium hydroxides with pKa values of more than 9, e.g. B. aqueous solutions of mono-, di- or trialkyl (or -aryl) amines or nitrogen-containing heterocyclic bases, e.g. B. triethylamine can be used.

The manganese salt is preferred to the ammoniacal solution added with stirring until the pll-Vvert of the ammoniacal Solution dropped to a value between 9.2 and 9.3 is. In certain cases, for example when the purity of the If the end product is to be increased even further, it is particularly preferred to lower the pH to a value of only 9.5 allow.

The following examples are intended to clarify the invention in a minor way. Example 1 . - ■.

A liquid containing manganese sulfate became the following Composition used:

MnSO ₄ 200-250 g / l

(NH ₄ ) ₂ SO ₄ 44-50 g / l

pH at 20 ⁰ C 6.5-6.7

009887/1819

203Q956

This liquid was diluted with water about 4 times until the solution was about 5.0% manganese (II) sulfate xvar. The temperature of the solution was set to a value between 25 and 35 ^° C

and the solution was added from the solution at a rate of about 100 ml per minute to 4 liters of 3.5 w / v 1.-4 ammonia from the solution until the pH dropped to a fourth between 9.2 and 9.3 was. The temperature of the ammoniacal solution was, that is kept in "the same Tenperatarbereich between 25 and 35 ⁰ C, and stirred without introduction of air.

After the desired ρH value has been reached; was stirred for a further 15 minutes and the precipitated manganese hydroxide was allowed to settle for about 30 minutes. The supernatant liquid was decanted and the precipitate was washed at a temperature between 25 and 35 ⁰ C with 5 1 of a 0.07 Gei \ r./Vol ..% of ammonia and 0.2 wt .- / vol.% Ammonium chloride solution containing again taking care that no air could enter. Washing was repeated or continued until the wash waters were sulfate-free. (If tap water containing sulphate is used to replenish the wax liquid, the final wash should be done with distilled water).

The precipitate formed was finally filtered from the final washing liquid and dried at 110 ⁰ C. In this way, trimanganese tetroxide was obtained in the form of a free-flowing bismarck-brown powder which was suitable for the production of ferrites.

After this procedure, about 851 of the in the original Liquid obtained manganese. The product obtained had the following analytical composition:

ORIGINAL

009887/1819 ^AL

Manganese as Mn 68.5-70.0%

Hydrogen as H-O 2.5 - 2.7%

Sulfur as sulfate $ 0.3-0.5

Manganese dioxide 36.0 - 38.0%

Ammonia <0.1 %

other metals traces

It should be noted that after this procedure a 0.3 to 0.5% sulfate-containing product was obtained, though this was washed until the wash water was free of sulfate ions. One containing less than 0.2% sulfate Product was obtained by the following modified procedure.

The precipitated manganese hydroxide was washed twice with only the ammonia / ammonium chloride solution, then filtered off, washed in a small amount of water and ^{dried at 110 °} C. to form a free-flowing bismarck-brown powder which contained about 1.2% sulfate. After drying, the powder was washed three more times with the ammonia / ammonium chloride solution. The product was washed with a small amount of water and dried at 110 ⁰ C to form Trimangantetroxyd containing only 0.21 sulfate. It is believed that residual sulfate trapped in the precipitate is released during the intermediate drying stages, which can then be removed in the subsequent washing stages. Otherwise the composition of the product was unchanged.

In some cases it is desirable to have those present in the product To reduce amounts of other metals and silicon even further. For example, manganese hydroxide, which is contained in trimanganese tetroxide transferred and used for the production of ferrites, only very small amounts of cobalt and silicon dioxide contain. It has now been found that the cobalt in a

009887/1819

Pre-treatment stage can be removed by removing the manganese-containing Liquid with sulfide ions, for example with a Metal sulfide, e.g. B. sodium sulfide, treated, the pH V / ert the liquid must be adjusted so that it is acidic, Cobalt is precipitated as sulphide and it is believed that some nickel and molybdenum are not precipitated either.

The amount of existing silicon dioxide can be decreased in one-.zweiten Vorbehandiunfsstufe or in a single pretreatment stage \ -er the by fluoride ions, for example od.er of sodium fluoride Natriumlaydrogendifluorid added to the FiItrat from the Kob al th tfernungs stage or unbehandelteri liquid. This has the effect that the silicon dioxide, possibly as silicon fluoride, remains in solution.

In the following example 2 the pre-treatment stages are for Reduction in cobalt and silicon dioxide content as well as a further procedure for the distribution of tri-manganese tetroxide Manganese hydroxide explained.

Example 2 ■

2.052 kg of sodium sulfide heptahydrate became 110.5 1 (24.3 gallons) a liquid containing manganese sulphate in the same concentration was added in the same amount as in Example 1 and the mixture was stirred for 15 to 45 minutes. There were 5.64 1 of a 10 vol / vol aqueous acetic acid solution give, the mixture was stirred for at least 45 minutes, allowed to settle for at least 2 hours and then the insoluble KobaMsulfid together with some nickel and molybdenum sulfide filtered off. ■

The filtrate from this pretreatment step to remove the Cobalt was treated with a hot aqueous solution of 180 g of sodium hydrogen difluoride treated in 7.2 1, then for 30 minutes both

009887/1819 ^BAD

side put. This second pre-treatment stage had the effect that the silica was kept in solution.

The treated as described above solution was diluted with 2 1 503j (110.7 gallons) tap water, heated to 30 ⁰ C and (40.9 gallons 1 £ 9) of a 368 under stirring over a period of 1 prior to an aqueous ammonia solution , 2 1 (81 gallons) tap water diluted 0.88% ammonia solution having a pH value of a temperature of 3O ⁰ C) was added over 10 and. After all of the liquid had been added and the pH had dropped to 9.5, the reaction mixture was stirred for a further 15 minutes, allowed to settle for 30 minutes and then filtered. The filter cake consisting of manganese hydroxide was washed with 245.5 liters (54 gallons) of distilled water.

The moist filter cake was placed in a pressure vessel filled with 454.6 l (100 gallons) and the mixture was ^{stirred vigorously for 2 hours at 110 to 14O 0} C, during which time compressed air was introduced into the suspension in order to within the Boiler a pressure vi
70 psi) to get open.

7 half of the boiler a pressure of 2.11 to 4 _S 92 kg / cm (30 to.

The resulting slurry was cooled and then filtered under pressure, and the recovered product was washed on the filter with 227.3 liters (50 gallons) of distilled water. The Trimangantetroxyd thus obtained was then dried at SO ⁰ C overnight and it had the following composition on

Manganese (as MnO) 89.7%

Sulphate (as SO ₃ ) $ 0.43

Silicon dioxide 0.06%

Magnesium (as MgO) 156 ppm Calcium (as Ca0) 31 ppm

Cobalt (as CoO) 34 ppm

Iron (as FeO) 346 ppm Nickel (as NiO) 6 2 ppm

009887/1819. bath

Chromium (as Cr ₂ O ₃ ) <25 ppm

Copper (as CuO) 68 ppm

Zinc (as ZnO) 83 ppm

Water (H ₂ O) 2%

The procedure described above was repeated, WO bei this time instead of washing the product on the filter of distilled water, a 0.03 volume / volume solution of acetic acid used in distilled water. This resulted in the following reduction in the amounts of alkaline earth metals and sulfate:

ppm MgO ppm CaO % SO *

Before washing 1640 430 1.5-2, .5

After washing 53 78 0.45

Washing with a 0.5 vol / vol Hgen solution of ammonia in the presence of the heated water also produced a lower sulphate content than when using distilled water alone. The trimanganese tetroxide obtained by the process described in Example 2, in which, however, the distilled water used for washing had been replaced by a 0.5% by volume aqueous ammonia solution, contained 0.2% SO, compared to that normally obtained SO ₃ -Ge ¹ AaIt of 0.431.

Both the content of alkaline earth metals and sulfate can be reduced by using a wax liquid, which contains both acid and ammonia. For example, the trimanganese tetroxide prepared according to Example 2 contained In which, however, the washing instead of with distilled water with a solution of $ 0.09 acetic acid and $ 0.251 ammonia in distilled Water was brought in:

009887 / 18U

- ίο -

SO ₃ 0.20 *

MgO 800 ppm

CaO 254 "

Example .3 '■

In this example, the extraction of manganese acetate from a Solution containing manganese compounds explained.

A liquid containing manganese sulphate in the same concentration as in Example 1 was treated in the manner described in Example 1 to precipitate manganese hydroxide, but this time ir.an only allowed the pH to drop to 9.5. After removing the supernatant liquid, the precipitate at a temperature of from 25 to '35 ⁰ C with 5 1 solution of ammonia was 0.07 wt a. ~ L / vol-% washed, taking care that no air ingress consisted. Washing was repeated twice under the same conditions. The precipitate was then washed with 5 liters of water under the same conditions. The precipitate was then treated with 200 ml of glacial acetic acid which had been diluted to 650 ml with distilled water. The dissolution was supported by adding small amounts of 100% hydrogen peroxide.

The solution was diluted to 1000 ml with water and its sulfate content was determined. Barium acetate was added to the solution at its boiling point in a slight s toichiome excess of the amount required to precipitate all of the sulfate, and the whole was allowed to stand for at least 4 hours, preferably overnight, in order to precipitate the barium sulfate. This was done by filtering removed and the filtrate was evaporated until its density was between 1.29 and 1.30 g / ml. ^{It was cooled to 2O 0} C with constant stirring and the

009887/1819

fallen manganese acetate tetrahydrate was filtered off. This was washed twice in 100 ml portions of acetone containing 15% by weight / volume of water. The product was dried at 50 to 60 ^° C. and a free-flowing crystalline powder (yield about 55%) of the following composition was obtained

Manganese x 22.65;

Carbon 19.41

Hydrogen 5.7%

Water 29.0%

In the following example 4 are a pretreatment stage for Reduction of the silicon content and another process for the production of manganese acetate is illustrated. ν

Example 4

18.4 1 (4.05 gallons) of a liquid containing manganese sulfate in the concentration specified in Example 1 were treated with a hot aqueous solution of 30 g of Niriumhydrogendi fluoride in 1200 ml of water and, after standing for 30 minutes, with 85.2 1 ( 18.75 gallons) of tap water diluted heated at 3O ⁰ C and with stirring over a period of 1 hour, an aqueous ammonia solution of 30 ⁰ C (6.8 1 (1.5 gallons) of 0.88% ammonia, diluted with 61.4 liters (13.5 gallons) of tap water was added. The mixture was stirred for an additional 15 minutes, allowed to settle for 30 minutes, and the above liquid was decanted off. The remaining solid was washed twice by stirring for 30 minutes at 90.9 liters ( 20 gallons) of distilled water, allowing the above liquid to settle for 30 minutes and decanting off.

009887/1819 ^BA ° ^{0R (QINAL}

2030356

The moist filter cake was in 15 l of a 30 vol / vol% Dissolve acetic acid in distilled water. and nan let the solution stand overnight. The solution was ow! SO C and the calculated amount of bariureacetate (105% of the

2- "

GO, sample) was added with stirring. The mixture was then heated and stirred for an additional hour, then left the
Mix overnight, stand. After carefully filtering off the precipitated Bari uras ul fats, the liquid was transferred to a ¹ . Spray dryer Kit ar not smelled an inlet temperature of 280 to 300 ⁰ C dried white-pink to form a fine solid which is only weakly or r * by acetic acid.

That after this. Process obtained anhydrous manganese (II)
acetate had the following composition:

Manganese (Mn) V / assers to ff 31, 5% 0.
Ό more organic Kohlens to ff 3, 57 more organic 27 4% p Chloride (Cl) <25 P. Il Sulphate (CO ₄ ) 67 It Iron (Fe) 77 M. Lead (Pb) <25

If a sample of the manganese (II) acetate obtained in this example was dissolved in wet, the solution had a pale yellow color in contrast to the normally pink color of manganese acetate. It has been found that this coloration can be removed by treating the solution with activated charcoal.

The procedure described in this example was repeated, but this time before the treatment with barium acetate 10.0 g (0.504) activated carbon (A2 / 10/50) from Forestal Chemicals Ltd) was added to 2 liters of the solution and stirred for 1 hour 7O ⁰ C were heated. Then, as described above, the sulfate

009887/1819

precipitated with uarium acetate and the filtrate was spray dried. The final dried manganese acetate product contained 15 ppm Sulfate ions and gave a pale when dissolved in water pink solution.

The dry manganese acetate treated as above, the one more too high sulfate content, could again by dissolving in a 100% by weight solution of acetic acid in distilled water Water, then filtering and drying to give a product with a low Sulfate content. This further treatment reduced the sulphate content of a sample from 64 to 34 ppm.

BATH ORIGINAL

009887/1818

Claims (22)

Claims . Process for obtaining n-at least one highly pure manganese = compound from a liquid containing at least one manganese (II) salt, characterized in that the liquid containing the iiangane salt is an aqueous solution of ammonia or a substituted ammonium hydroxide with a: pll-tfert of at least 10 is added until its pH value has fallen to between 9.0 and 9 ₈ 5 and the manganese hydroxide which precipitates is separated off. 2. Procedure according to. Claim 1, characterized in that the Precipitation of the. Manganese hydroxide is carried out at constant temperature. 3. The method according to claim 2, characterized in that the precipitation of Manganhydroxyds is carried out at a constant temperature between 25 and 35 ⁰ C. 4. The method according to claims 1 to 3, characterized in that diej / Uis precipitation of the manganese hydroxide to the exclusion is carried out by air. 5 »Process according to claims 1 to 4" characterized in that that a liquid containing manganese sulfate is used, the content of manganese sulfate before the addition to the aqueous solution has been adjusted to 5 wt .-%. 6. The method according to claims 1 to 5, characterized in that that as an aqueous solution, a 3.5% strength by weight ammonium hydroxide solution is used. 009887/1819 BATH ORIGINAL 7. The method according to claims 1 to 6, characterized in that that the liquid containing the manganese compound the aqueous solution is added until its plied to a 17ert between 9.2 and 9.3 is, 8. The method according to any one of claims 1 to 6, characterized in that the liquid containing the manganese compound is added to the aqueous solution until whose pii-V.ert has dropped to a '. \' ert of 9.5. 9. Method according to claims 1 to 8, characterized in that that the precipitated manganese hydroxide, after separation, is a solution of ammonia and ammonium chloride and, if appropriate is cleaned with distilled water until the wash water is free of sulfate. 10. The method according to claims 1 to 9, characterized in that the precipitated manganese hydroxide for conversion into Trimänfantetroxyd in the presence of air and / or oxygen is heated. 11. The method according to claims 1 to 8, characterized in that that the precipitate to convert the manganese hydroxide in trinangantetroxide in distilled water in the case of increased Temperature and elevated pressure while passing through compressed Air or oxygen is stirred. 12. Verfaiiren according to one of claims 1 to 11, characterized in that a liquid containing manga is used, the substance that provides sulfide ions has been added before addition to the aqueous solution, and that after Acidify by filtering deir. precipitated cobalt sulfide has been released. 009887/1819 BATH ORIGINAL 13. The method according to claim 12, characterized in that a r.anganhaltige liquid is used, which before adding sodium sulfide to the aqueous solution as Salfidion-producing substance has been added. 14. The method according to any one of claims 1 to 13, characterized in, that. a liquid containing piangaa is used, which before the addition to the aqueous solution with a fluoride ion-donating substance has been treated. 15. The method according to claim 14, characterized in that a nangan-containing liquid is used, which is before the Addition to the aqueous solution of sodium fluoride or sodium hydrogen difluoride has been added as a substance providing fluoride ions. 16. The method according to any one of claims 1 to 3, characterized in, da.'j the precipitated I-langanhydroxyd to the exclusion washed by air ir. with a solution of ammonia will. 17. The method according to any one of claims 1 to 15, characterized in that da. "the precipitated hangan hydroxide distilled ,. "ater is washed. 15. Vcrfaarcn according to claim 16 or 17, characterized in that dail treated the precipitate with acetic acid and a bariuir.ionen-delivering substance is added and that the from [each fallen barium sulfate is then filtered off. 19. The method as claimed in claim 18, characterized in that barium acetate is added as the substance which supplies iJariur.iionen will. 009887/1819 BATH ORIGINAL 2030958 20. The method according to claim 1S or 19, characterized in that that for the precipitation of manganese acetate tetrahydrate the filtrate is evaporated. 21. The method according to claim 18 or 19, characterized in that that for the formation of anhydrous Hangan acetate the filtrate is spray dried. 22. The method according to claim 20 or 21, characterized in that that the solid product thus formed m dissolved in acetic acid and is filtered and that the filtrate is dried. 009887/1 * 1