DE3725583A1 - Phosphorous acid solns. of low iron and arsenic content - prepd. by converting sec. calcium phosphite to prim. calcium phosphite solns., removing iron and arsenic by pptn. etc - Google Patents
Phosphorous acid solns. of low iron and arsenic content - prepd. by converting sec. calcium phosphite to prim. calcium phosphite solns., removing iron and arsenic by pptn. etcInfo
- Publication number
- DE3725583A1 DE3725583A1 DE19873725583 DE3725583A DE3725583A1 DE 3725583 A1 DE3725583 A1 DE 3725583A1 DE 19873725583 DE19873725583 DE 19873725583 DE 3725583 A DE3725583 A DE 3725583A DE 3725583 A1 DE3725583 A1 DE 3725583A1
- Authority
- DE
- Germany
- Prior art keywords
- arsenic
- calcium phosphite
- iron
- solns
- calcium
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Ceased
Links
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 title claims abstract description 34
- XWKBMOUUGHARTI-UHFFFAOYSA-N tricalcium;diphosphite Chemical compound [Ca+2].[Ca+2].[Ca+2].[O-]P([O-])[O-].[O-]P([O-])[O-] XWKBMOUUGHARTI-UHFFFAOYSA-N 0.000 title claims abstract description 24
- 229910052742 iron Inorganic materials 0.000 title claims abstract description 20
- 229910052785 arsenic Inorganic materials 0.000 title claims abstract description 17
- RQNWIZPPADIBDY-UHFFFAOYSA-N arsenic atom Chemical compound [As] RQNWIZPPADIBDY-UHFFFAOYSA-N 0.000 title claims abstract description 17
- ISIJQEHRDSCQIU-UHFFFAOYSA-N tert-butyl 2,7-diazaspiro[4.5]decane-7-carboxylate Chemical compound C1N(C(=O)OC(C)(C)C)CCCC11CNCC1 ISIJQEHRDSCQIU-UHFFFAOYSA-N 0.000 title claims abstract description 10
- NBIIXXVUZAFLBC-UHFFFAOYSA-N Phosphoric acid Chemical compound OP(O)(O)=O NBIIXXVUZAFLBC-UHFFFAOYSA-N 0.000 claims abstract description 18
- QAOWNCQODCNURD-UHFFFAOYSA-N Sulfuric acid Chemical compound OS(O)(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-N 0.000 claims abstract description 18
- OSGAYBCDTDRGGQ-UHFFFAOYSA-L calcium sulfate Chemical compound [Ca+2].[O-]S([O-])(=O)=O OSGAYBCDTDRGGQ-UHFFFAOYSA-L 0.000 claims abstract description 11
- 238000000034 method Methods 0.000 claims abstract description 11
- 229910000147 aluminium phosphate Inorganic materials 0.000 claims abstract description 9
- AKHNMLFCWUSKQB-UHFFFAOYSA-L sodium thiosulfate Chemical compound [Na+].[Na+].[O-]S([O-])(=O)=S AKHNMLFCWUSKQB-UHFFFAOYSA-L 0.000 claims abstract description 5
- 235000019345 sodium thiosulphate Nutrition 0.000 claims abstract description 5
- -1 iron ions Chemical class 0.000 claims abstract description 4
- AWDBHOZBRXWRKS-UHFFFAOYSA-N tetrapotassium;iron(6+);hexacyanide Chemical compound [K+].[K+].[K+].[K+].[Fe+6].N#[C-].N#[C-].N#[C-].N#[C-].N#[C-].N#[C-] AWDBHOZBRXWRKS-UHFFFAOYSA-N 0.000 claims abstract description 4
- 239000003513 alkali Substances 0.000 claims abstract 2
- PBSJABOJCQOSCL-UHFFFAOYSA-N [As].P(O)(O)(O)=O Chemical compound [As].P(O)(O)(O)=O PBSJABOJCQOSCL-UHFFFAOYSA-N 0.000 claims description 2
- 238000000926 separation method Methods 0.000 claims description 2
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 2
- ZLMJMSJWJFRBEC-UHFFFAOYSA-N Potassium Chemical compound [K] ZLMJMSJWJFRBEC-UHFFFAOYSA-N 0.000 claims 1
- JXRVKYBCWUJJBP-UHFFFAOYSA-L calcium;hydrogen sulfate Chemical compound [Ca+2].OS([O-])(=O)=O.OS([O-])(=O)=O JXRVKYBCWUJJBP-UHFFFAOYSA-L 0.000 claims 1
- 239000000356 contaminant Substances 0.000 claims 1
- 239000011591 potassium Substances 0.000 claims 1
- 229910052700 potassium Inorganic materials 0.000 claims 1
- ABLZXFCXXLZCGV-UHFFFAOYSA-N Phosphorous acid Chemical class OP(O)=O ABLZXFCXXLZCGV-UHFFFAOYSA-N 0.000 abstract description 8
- 239000012535 impurity Substances 0.000 abstract description 2
- 239000001175 calcium sulphate Substances 0.000 abstract 2
- 235000011132 calcium sulphate Nutrition 0.000 abstract 2
- 239000001117 sulphuric acid Substances 0.000 abstract 2
- 235000011149 sulphuric acid Nutrition 0.000 abstract 2
- 239000004133 Sodium thiosulphate Substances 0.000 abstract 1
- 230000000536 complexating effect Effects 0.000 abstract 1
- TVZISJTYELEYPI-UHFFFAOYSA-N hypodiphosphoric acid Chemical compound OP(O)(=O)P(O)(O)=O TVZISJTYELEYPI-UHFFFAOYSA-N 0.000 abstract 1
- UMPKMCDVBZFQOK-UHFFFAOYSA-N potassium;iron(3+);oxygen(2-) Chemical compound [O-2].[O-2].[K+].[Fe+3] UMPKMCDVBZFQOK-UHFFFAOYSA-N 0.000 abstract 1
- 238000003756 stirring Methods 0.000 description 6
- OAICVXFJPJFONN-UHFFFAOYSA-N Phosphorus Chemical compound [P] OAICVXFJPJFONN-UHFFFAOYSA-N 0.000 description 5
- HEMHJVSKTPXQMS-UHFFFAOYSA-M sodium hydroxide Inorganic materials [OH-].[Na+] HEMHJVSKTPXQMS-UHFFFAOYSA-M 0.000 description 5
- ACVYVLVWPXVTIT-UHFFFAOYSA-M phosphinate Chemical compound [O-][PH2]=O ACVYVLVWPXVTIT-UHFFFAOYSA-M 0.000 description 4
- 239000011574 phosphorus Substances 0.000 description 4
- 229910052698 phosphorus Inorganic materials 0.000 description 4
- 239000010802 sludge Substances 0.000 description 4
- 235000008733 Citrus aurantifolia Nutrition 0.000 description 3
- 235000011941 Tilia x europaea Nutrition 0.000 description 3
- 239000004571 lime Substances 0.000 description 3
- 238000004519 manufacturing process Methods 0.000 description 3
- 238000001556 precipitation Methods 0.000 description 3
- XYFCBTPGUUZFHI-UHFFFAOYSA-N Phosphine Chemical compound P XYFCBTPGUUZFHI-UHFFFAOYSA-N 0.000 description 2
- 239000006227 byproduct Substances 0.000 description 2
- 229910001861 calcium hydroxide Inorganic materials 0.000 description 2
- 229940095672 calcium sulfate Drugs 0.000 description 2
- 239000012065 filter cake Substances 0.000 description 2
- 239000010440 gypsum Substances 0.000 description 2
- 229910052602 gypsum Inorganic materials 0.000 description 2
- 239000007788 liquid Substances 0.000 description 2
- 239000008267 milk Substances 0.000 description 2
- 210000004080 milk Anatomy 0.000 description 2
- 235000013336 milk Nutrition 0.000 description 2
- 239000002244 precipitate Substances 0.000 description 2
- UKUVVAMSXXBMRX-UHFFFAOYSA-N 2,4,5-trithia-1,3-diarsabicyclo[1.1.1]pentane Chemical compound S1[As]2S[As]1S2 UKUVVAMSXXBMRX-UHFFFAOYSA-N 0.000 description 1
- OYPRJOBELJOOCE-UHFFFAOYSA-N Calcium Chemical compound [Ca] OYPRJOBELJOOCE-UHFFFAOYSA-N 0.000 description 1
- ODINCKMPIJJUCX-UHFFFAOYSA-N Calcium oxide Chemical compound [Ca]=O ODINCKMPIJJUCX-UHFFFAOYSA-N 0.000 description 1
- RWSOTUBLDIXVET-UHFFFAOYSA-N Dihydrogen sulfide Chemical compound S RWSOTUBLDIXVET-UHFFFAOYSA-N 0.000 description 1
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical compound [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 description 1
- DGAQECJNVWCQMB-PUAWFVPOSA-M Ilexoside XXIX Chemical compound C[C@@H]1CC[C@@]2(CC[C@@]3(C(=CC[C@H]4[C@]3(CC[C@@H]5[C@@]4(CC[C@@H](C5(C)C)OS(=O)(=O)[O-])C)C)[C@@H]2[C@]1(C)O)C)C(=O)O[C@H]6[C@@H]([C@H]([C@@H]([C@H](O6)CO)O)O)O.[Na+] DGAQECJNVWCQMB-PUAWFVPOSA-M 0.000 description 1
- KWYUFKZDYYNOTN-UHFFFAOYSA-M Potassium hydroxide Chemical compound [OH-].[K+] KWYUFKZDYYNOTN-UHFFFAOYSA-M 0.000 description 1
- NINIDFKCEFEMDL-UHFFFAOYSA-N Sulfur Chemical compound [S] NINIDFKCEFEMDL-UHFFFAOYSA-N 0.000 description 1
- 239000002253 acid Substances 0.000 description 1
- 238000010306 acid treatment Methods 0.000 description 1
- 229940095564 anhydrous calcium sulfate Drugs 0.000 description 1
- 229940052288 arsenic trisulfide Drugs 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- 239000011575 calcium Substances 0.000 description 1
- 229910052791 calcium Inorganic materials 0.000 description 1
- AXCZMVOFGPJBDE-UHFFFAOYSA-L calcium dihydroxide Chemical compound [OH-].[OH-].[Ca+2] AXCZMVOFGPJBDE-UHFFFAOYSA-L 0.000 description 1
- 239000000920 calcium hydroxide Substances 0.000 description 1
- 239000001506 calcium phosphate Substances 0.000 description 1
- 229910000389 calcium phosphate Inorganic materials 0.000 description 1
- 235000011010 calcium phosphates Nutrition 0.000 description 1
- 238000005119 centrifugation Methods 0.000 description 1
- 238000001816 cooling Methods 0.000 description 1
- 239000013078 crystal Substances 0.000 description 1
- 150000004683 dihydrates Chemical class 0.000 description 1
- IIRVGTWONXBBAW-UHFFFAOYSA-M disodium;dioxido(oxo)phosphanium Chemical compound [Na+].[Na+].[O-][P+]([O-])=O IIRVGTWONXBBAW-UHFFFAOYSA-M 0.000 description 1
- ZRRLFMPOAYZELW-UHFFFAOYSA-N disodium;hydrogen phosphite Chemical class [Na+].[Na+].OP([O-])[O-] ZRRLFMPOAYZELW-UHFFFAOYSA-N 0.000 description 1
- 238000007323 disproportionation reaction Methods 0.000 description 1
- 238000000605 extraction Methods 0.000 description 1
- 239000000706 filtrate Substances 0.000 description 1
- 229910052739 hydrogen Inorganic materials 0.000 description 1
- 239000001257 hydrogen Substances 0.000 description 1
- 229910000037 hydrogen sulfide Inorganic materials 0.000 description 1
- 230000007062 hydrolysis Effects 0.000 description 1
- 238000006460 hydrolysis reaction Methods 0.000 description 1
- UETZVSHORCDDTH-UHFFFAOYSA-N iron(2+);hexacyanide Chemical compound [Fe+2].N#[C-].N#[C-].N#[C-].N#[C-].N#[C-].N#[C-] UETZVSHORCDDTH-UHFFFAOYSA-N 0.000 description 1
- 239000000203 mixture Substances 0.000 description 1
- 229910000073 phosphorus hydride Inorganic materials 0.000 description 1
- FAIAAWCVCHQXDN-UHFFFAOYSA-N phosphorus trichloride Chemical compound ClP(Cl)Cl FAIAAWCVCHQXDN-UHFFFAOYSA-N 0.000 description 1
- 239000011505 plaster Substances 0.000 description 1
- 239000002994 raw material Substances 0.000 description 1
- WBHQBSYUUJJSRZ-UHFFFAOYSA-M sodium bisulfate Chemical compound [Na+].OS([O-])(=O)=O WBHQBSYUUJJSRZ-UHFFFAOYSA-M 0.000 description 1
- 229910000342 sodium bisulfate Inorganic materials 0.000 description 1
- 235000011121 sodium hydroxide Nutrition 0.000 description 1
- RSIJVJUOQBWMIM-UHFFFAOYSA-L sodium sulfate decahydrate Chemical class O.O.O.O.O.O.O.O.O.O.[Na+].[Na+].[O-]S([O-])(=O)=O RSIJVJUOQBWMIM-UHFFFAOYSA-L 0.000 description 1
- 229910052979 sodium sulfide Inorganic materials 0.000 description 1
- GRVFOGOEDUUMBP-UHFFFAOYSA-N sodium sulfide (anhydrous) Chemical compound [Na+].[Na+].[S-2] GRVFOGOEDUUMBP-UHFFFAOYSA-N 0.000 description 1
- 239000011593 sulfur Substances 0.000 description 1
- 229910052717 sulfur Inorganic materials 0.000 description 1
- 150000003467 sulfuric acid derivatives Chemical class 0.000 description 1
- 238000003786 synthesis reaction Methods 0.000 description 1
- QORWJWZARLRLPR-UHFFFAOYSA-H tricalcium bis(phosphate) Chemical compound [Ca+2].[Ca+2].[Ca+2].[O-]P([O-])([O-])=O.[O-]P([O-])([O-])=O QORWJWZARLRLPR-UHFFFAOYSA-H 0.000 description 1
- 238000005406 washing Methods 0.000 description 1
Classifications
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
- C01B25/00—Phosphorus; Compounds thereof
- C01B25/16—Oxyacids of phosphorus; Salts thereof
- C01B25/163—Phosphorous acid; Salts thereof
Abstract
Description
Die vorliegende Erfindung betrifft ein Verfahren zur Gewinnung einer eisen- und arsenarmen Phosphorigsäure- Lösung aus sekundärem Calciumphosphit von der Hypophosphit herstellung.The present invention relates to a method for Obtaining a low-iron and arsenic phosphoric acid Solution of secondary calcium phosphite from the hypophosphite manufacturing.
Phosphorigsäure ist ein zur Synthese kom plexierender Phosphonate erforderlicher Rohstoff, den man in technischem Maßstab hauptsächlich durch Hydrolyse von Phosphortrichlorid erhält (DBP 22 00 653).Phosphoric acid is a synthesis plexing phosphonates required raw material, the on an industrial scale mainly by hydrolysis of phosphorus trichloride (DBP 22 00 653).
Aus gesättigter Dinatriumphosphit-Lösung läßt sich durch Behandeln mit Natriumhydrogensulfat oder Schwefelsäure und Abtrennen des ausgeschiedenen Natriumsulfat-Deka hydrates ebenfalls eine geeignete Phosphorigsäure- Lösung gewinnen (USP 28 43 457).From saturated disodium phosphite solution Treat with sodium hydrogen sulfate or sulfuric acid and separating the excreted sodium sulfate deca hydrates also a suitable phosphoric acid Win solution (USP 28 43 457).
Nutzt man die Disproportionierung von weißem Phosphor in Gegenwart von Basen wie z. B. Natron- oder Kalilauge oder Kalkmilch, so werden nur rund 50% des eingesetzten Phosphors zu Hypophosphit umgewandelt. Aus dem Rest des Phosphors bilden sich in schwankenden Mengen Phosphan und Phosphit (DRP 4 42 210). Bei Verwendung von Calcium hydroxid oder Mischungen von Natronlauge und Kalkmilch als Basen läßt sich auf Grund der Schwerlöslichkeit des sekundären Calciumphosphits in Wasser das unerwünschte Phosphit vom löslichen Hypophosphit abtrennen (CH 3 22 980 und 3 22 981). Hierbei fallen beträchtliche Mengen sekun dären Calciumphosphits als Nebenprodukt an, die 20-30% des ursprünglich eingesetzten Phosphors enthalten. If one uses the disproportionation of white phosphorus in Presence of bases such as e.g. B. sodium or potassium hydroxide solution or Lime milk, only about 50% of the used Phosphorus converted to hypophosphite. From the rest of the Phosphors form in fluctuating amounts of phosphine and phosphite (DRP 4 42 210). When using calcium hydroxide or mixtures of caustic soda and lime milk as bases can be due to the poor solubility of the secondary calcium phosphite in water the undesirable Separate phosphite from soluble hypophosphite (CH 3 22 980 and 3 22 981). Considerable amounts fall here in seconds calcium phosphite as a by-product, which is 20-30% contain the phosphorus originally used.
In ähnlicher Weise wie aus Dinatriumphosphit sollte es möglich sein, dieses Nebenprodukt zur Phosphorigsäure- Gewinnung zu verwenden.In a similar way as made from disodium phosphite it should be possible to convert this by-product to phosphorous acid Extraction.
Für einen späteren Einsatz dieser Phosphorigsäure zur Phosphonsäureerzeugung sind jedoch der hohe Eisen- und Arsengehalt, herrührend von Verunreinigungen des ein gesetzten Phosphors und Kalkes, äußerst störend. Die an sich bekannte Entfernung von Eisenionen durch Fällen mittels Hexacyanoferraten gelingt weder durch Einzel fällung noch bei der Simultanfällung bei Behandeln des Calciumphosphitschlammes mit Schwefelsäure in befriedi gender Weise. Arsen läßt sich dagegen aus der Phosphorig säure-Lösung durch Natriumsulfid recht leicht als Arsen trisulfid entfernen, wobei allerdings eine gewisse Schwefel wasserstoff-Belästigung in Kauf genommen werden muß. Ein direktes Entfernen von Eisen und Arsen aus dem ein gesetzten sekundären Calciumphosphit gelingt nicht wegen der Schwerlöslichkeit des sekundären Calciumphosphites, das sowohl Eisen als auch Arsen in eingeschlossener Form enthält.For later use of this phosphorous acid However, phosphonic acid production is the high iron and Arsenic content, resulting from impurities in the put phosphorus and lime, extremely annoying. The on known removal of iron ions by precipitation by means of hexacyanoferrates neither succeeds by individuals precipitation during simultaneous precipitation when treating the Calcium phosphite sludge with sulfuric acid in befriedi gender wise. Arsenic, however, can be made from the Phosphorous acid solution due to sodium sulfide quite easily as arsenic Remove trisulfide, although with a certain sulfur hydrogen nuisance must be accepted. A direct removal of iron and arsenic from the one secondary calcium phosphite does not succeed because of the poor solubility of the secondary calcium phosphite, both iron and arsenic in an enclosed form contains.
Dagegen wurde nun gefunden, daß sich Lösungen von pri märem Calciumphosphit mittels Hexacyanoferraten nahezu vollständig von Eisenionen befreien lassen. Die Verwendung von primären Calciumphosphitlösungen bietet einen weiteren Vorteil, indem der Einsatz von Natriumthiosulfat zur Ent arsenierung ermöglicht wird, so daß die Schwefelwasserstoff- Belästigung auf ein Minimum herabgesetzt wird. In contrast, it has now been found that solutions from pri near calcium phosphate using hexacyanoferrates Get completely free of iron ions. The usage of primary calcium phosphite solutions offers another Advantage by using sodium thiosulfate for ent arsenation is enabled so that the hydrogen sulfide Harassment is reduced to a minimum.
Primäre Calciumphosphitlösung läßt sich leicht herstellen durch Auflösung des bei der Hypophosphitproduktion an fallenden Calciumphosphit-Schlammes in der berechneten Menge Schwefelsäure und Abtrennen des gebildeten Calcium sulfates oder durch Auflösen in Phosphorigsäure aus einem vorhergehenden Ansatz.Primary calcium phosphite solution is easy to prepare by dissolving the hypophosphite production falling calcium phosphite sludge in the calculated Amount of sulfuric acid and separation of the calcium formed sulfates or by dissolving in phosphorous acid from a previous approach.
Ein beachtlicher Anteil der zum Auflösen benötigten Phosphorigsäure-Menge läßt sich auch aus der Wasch flüssigkeit des Gipsfilterkuchens decken. Um eine nicht zu geringe Phosphorigsäure-Konzentration zu erhalten, ist es hierbei allerdings erforderlich, die Waschflüssig keit für mehrere Gipsfilterkuchen zu verwenden, um eine entsprechende Anreicherung an Phosphorigsäure zu erzielen. Der Vorzug dieses Verfahrens besteht darin, daß die er haltene Phosphorigsäure-Lösung ohne weiteres Aufkonzen trieren zur Phosphonsäureerzeugung benutzt werden kann.A considerable proportion of those needed to resolve The amount of phosphoric acid can also be obtained from the wash Cover the liquid of the plaster filter cake. Not one to get too low phosphoric acid concentration, however, it is necessary to use the washing liquid can be used for several gypsum filter cakes to make one to achieve appropriate enrichment in phosphorous acid. The advantage of this method is that it holding phosphoric acid solution without further concentration trieren can be used to generate phosphonic acid.
Die Schwefelsäurebehandlung erfolgt innerhalb eines breiten Temperaturbereiches, wobei bei Temperaturen unterhalb von 65°C das Calciumsulfat als Dihydrat an fällt, während oberhalb dieser Temperatur kristall wasserfreies Calciumsulfat erhalten wird.The sulfuric acid treatment takes place within one wide temperature range, at temperatures below 65 ° C the calcium sulfate as a dihydrate falls while above this temperature crystal anhydrous calcium sulfate is obtained.
4000 g eines 60%igen Calciumphosphitschlammes mit einem Gehalt von 220 ppm Eisen und 28 ppm Arsen werden portionsweise unter Rühren in 2445 g 40%ige Schwefelsäure eingetragen, wobei durch leichtes Kühlen die Temperatur bei 50-60°C gehalten wird. Nach 30 min. Rühren wird vom entstandenen Gipshydrat abzentrifugiert.4000 g of a 60% calcium phosphite sludge with a content of 220 ppm iron and 28 ppm arsenic in portions with stirring in 2445 g of 40% sulfuric acid entered, the temperature by slight cooling is kept at 50-60 ° C. After 30 min. Will stir centrifuged off from the resulting gypsum hydrate.
Das Filtrat wird unter Rühren zunächst mit 8,5 ml einer 20%igen Kaliumhexacyanoferrat-II-Lösung und nach 30 min. mit 1,5 ml einer 10%igen Natriumthiosulfatlösung versetzt. Nach einstündigem Stehen wird der Niederschlag aus Eisen hexacyanoferrat und Arsentrisulfid abgetrennt und die erhaltene Lösung unter Rühren allmählich mit 1020 g 96%iger Schwefelsäure versetzt. Nach Abzentrifugieren des ausgeschiedenen Calciumsulfates erhält man eine rund 40%ige Phosphorigsäure-Lösung, die rund 15 ppm Eisen und rund 1 ppm Arsen enthält. The filtrate is first stirred with 8.5 ml of a 20% potassium hexacyanoferrate II solution and after 30 min. treated with 1.5 ml of a 10% sodium thiosulfate solution. After standing for one hour, the precipitate becomes iron separated hexacyanoferrate and arsenic trisulfide and the obtained solution with stirring gradually with 1020 g 96% sulfuric acid added. After centrifugation of the excreted calcium sulfate is obtained around 40% phosphoric acid solution, which around 15 ppm Contains iron and around 1 ppm arsenic.
2000 g 60%iger Calciumphosphitschlamm, verunreinigt mit 220 ppm Eisen und 42 ppm Arsen, werden unter Rühren in 2050 g 40%iger Phosphorigsäure gelöst und die Lösung nacheinander mit 30 min. Abstand unter Rühren mit 4,5 ml 20%iger Kaliumhexacyanoferrat-Lösung und 1,5 ml einer 10%igen Natriumthiosulfatlösung versetzt.2000 g 60% calcium phosphite sludge, contaminated with 220 ppm iron and 42 ppm arsenic are stirred in 2050 g of 40% phosphoric acid dissolved and the solution successively with 30 min. Distance with stirring with 4.5 ml 20% potassium hexacyanoferrate solution and 1.5 ml of one 10% sodium thiosulfate solution added.
Nach 45 min. Rühren wird der entstandene Niederschlag ab getrennt und zur Calciumphosphitlösung unter Rühren und Kühlen allmählich 1020 g 96%ige Schwefelsäure zulaufen lassen.After 45 min. The resulting precipitate is stirred off separated and to the calcium phosphite solution with stirring and Cool gradually add 1020 g of 96% sulfuric acid to let.
Nach einstündigem Rühren trennt man auskristallisiertes Calciumsulfat-Dihydrat ab. Die rund 40%ige Phosphorig säure enthält weniger als 20 ppm Eisen und unter 1 ppm Arsen.After stirring for one hour, it is separated out Calcium sulfate dihydrate. The approximately 40% phosphorus Acid contains less than 20 ppm iron and less than 1 ppm Arsenic.
Claims (5)
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DE19873725583 DE3725583A1 (en) | 1987-08-01 | 1987-08-01 | Phosphorous acid solns. of low iron and arsenic content - prepd. by converting sec. calcium phosphite to prim. calcium phosphite solns., removing iron and arsenic by pptn. etc |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DE19873725583 DE3725583A1 (en) | 1987-08-01 | 1987-08-01 | Phosphorous acid solns. of low iron and arsenic content - prepd. by converting sec. calcium phosphite to prim. calcium phosphite solns., removing iron and arsenic by pptn. etc |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| DE3725583A1 true DE3725583A1 (en) | 1989-02-09 |
Family
ID=6332887
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| DE19873725583 Ceased DE3725583A1 (en) | 1987-08-01 | 1987-08-01 | Phosphorous acid solns. of low iron and arsenic content - prepd. by converting sec. calcium phosphite to prim. calcium phosphite solns., removing iron and arsenic by pptn. etc |
Country Status (1)
| Country | Link |
|---|---|
| DE (1) | DE3725583A1 (en) |
Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE442210C (en) * | 1924-05-17 | 1927-03-24 | Merck Ag E | Production of hypophosphites with simultaneous production of phosphites and phosphoric acid |
| US2843457A (en) * | 1954-11-17 | 1958-07-15 | Hooker Electrochemical Co | Production of oxy acids of phosphorus |
| DE2028075A1 (en) * | 1969-08-25 | 1971-04-22 | Piesteritz Stickstoff | Process for the continuous Her position of pure concentrated phosphorous acid |
| DE2235425A1 (en) * | 1971-07-20 | 1973-02-15 | Albright & Wilson | PROCESS FOR THE PRODUCTION OF PHOSPHORUS ACIDS |
| DE2200653C3 (en) * | 1972-01-07 | 1978-01-26 | Hoechst Ag, 6000 Frankfurt | Process and apparatus for the production of phosphorous acid |
| DE2833380A1 (en) * | 1978-07-29 | 1980-02-14 | Hoechst Ag | METHOD FOR PRODUCING PHOSPHORIC ACID |
-
1987
- 1987-08-01 DE DE19873725583 patent/DE3725583A1/en not_active Ceased
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE442210C (en) * | 1924-05-17 | 1927-03-24 | Merck Ag E | Production of hypophosphites with simultaneous production of phosphites and phosphoric acid |
| US2843457A (en) * | 1954-11-17 | 1958-07-15 | Hooker Electrochemical Co | Production of oxy acids of phosphorus |
| DE2028075A1 (en) * | 1969-08-25 | 1971-04-22 | Piesteritz Stickstoff | Process for the continuous Her position of pure concentrated phosphorous acid |
| DE2235425A1 (en) * | 1971-07-20 | 1973-02-15 | Albright & Wilson | PROCESS FOR THE PRODUCTION OF PHOSPHORUS ACIDS |
| DE2200653C3 (en) * | 1972-01-07 | 1978-01-26 | Hoechst Ag, 6000 Frankfurt | Process and apparatus for the production of phosphorous acid |
| DE2833380A1 (en) * | 1978-07-29 | 1980-02-14 | Hoechst Ag | METHOD FOR PRODUCING PHOSPHORIC ACID |
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