DEP0036965DA - Process for removing fluorine from fluorine-containing phosphoric acid or from acidic phosphate liquors - Google Patents
Process for removing fluorine from fluorine-containing phosphoric acid or from acidic phosphate liquorsInfo
- Publication number
- DEP0036965DA DEP0036965DA DEP0036965DA DE P0036965D A DEP0036965D A DE P0036965DA DE P0036965D A DEP0036965D A DE P0036965DA
- Authority
- DE
- Germany
- Prior art keywords
- fluorine
- phosphoric acid
- containing phosphoric
- acidic phosphate
- liquors
- 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.)
- Expired
Links
- YCKRFDGAMUMZLT-UHFFFAOYSA-N Fluorine atom Chemical compound [F] YCKRFDGAMUMZLT-UHFFFAOYSA-N 0.000 title claims description 10
- 239000011737 fluorine Substances 0.000 title claims description 10
- 229910052731 fluorine Inorganic materials 0.000 title claims description 10
- 229910019142 PO4 Inorganic materials 0.000 title claims description 6
- 238000000034 method Methods 0.000 title claims description 4
- NBIIXXVUZAFLBC-UHFFFAOYSA-K phosphate Chemical compound [O-]P([O-])([O-])=O NBIIXXVUZAFLBC-UHFFFAOYSA-K 0.000 title claims description 4
- 239000010452 phosphate Substances 0.000 title claims description 4
- 230000002378 acidificating effect Effects 0.000 title claims 2
- NBIIXXVUZAFLBC-UHFFFAOYSA-N Phosphoric acid Chemical compound OP(O)(O)=O NBIIXXVUZAFLBC-UHFFFAOYSA-N 0.000 title description 18
- 229910000147 aluminium phosphate Inorganic materials 0.000 title description 9
- CDBYLPFSWZWCQE-UHFFFAOYSA-L Sodium Carbonate Chemical compound [Na+].[Na+].[O-]C([O-])=O CDBYLPFSWZWCQE-UHFFFAOYSA-L 0.000 claims description 5
- 239000002244 precipitate Substances 0.000 claims description 2
- 235000011007 phosphoric acid Nutrition 0.000 claims 1
- 150000003016 phosphoric acids Chemical class 0.000 claims 1
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 7
- HEMHJVSKTPXQMS-UHFFFAOYSA-M Sodium hydroxide Chemical compound [OH-].[Na+] HEMHJVSKTPXQMS-UHFFFAOYSA-M 0.000 description 5
- 235000021317 phosphate Nutrition 0.000 description 4
- QAOWNCQODCNURD-UHFFFAOYSA-L Sulfate Chemical compound [O-]S([O-])(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-L 0.000 description 3
- 229910052785 arsenic Inorganic materials 0.000 description 3
- RQNWIZPPADIBDY-UHFFFAOYSA-N arsenic atom Chemical compound [As] RQNWIZPPADIBDY-UHFFFAOYSA-N 0.000 description 3
- 229910052742 iron Inorganic materials 0.000 description 3
- 238000004519 manufacturing process Methods 0.000 description 3
- MBMLMWLHJBBADN-UHFFFAOYSA-N Ferrous sulfide Chemical compound [Fe]=S MBMLMWLHJBBADN-UHFFFAOYSA-N 0.000 description 2
- FYYHWMGAXLPEAU-UHFFFAOYSA-N Magnesium Chemical compound [Mg] FYYHWMGAXLPEAU-UHFFFAOYSA-N 0.000 description 2
- QAOWNCQODCNURD-UHFFFAOYSA-N Sulfuric acid Chemical compound OS(O)(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-N 0.000 description 2
- 229910052782 aluminium Inorganic materials 0.000 description 2
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 description 2
- OSGAYBCDTDRGGQ-UHFFFAOYSA-L calcium sulfate Chemical compound [Ca+2].[O-]S([O-])(=O)=O OSGAYBCDTDRGGQ-UHFFFAOYSA-L 0.000 description 2
- 238000002425 crystallisation Methods 0.000 description 2
- 230000008025 crystallization Effects 0.000 description 2
- 239000001177 diphosphate Substances 0.000 description 2
- XPPKVPWEQAFLFU-UHFFFAOYSA-J diphosphate(4-) Chemical compound [O-]P([O-])(=O)OP([O-])([O-])=O XPPKVPWEQAFLFU-UHFFFAOYSA-J 0.000 description 2
- 235000011180 diphosphates Nutrition 0.000 description 2
- 229910052749 magnesium Inorganic materials 0.000 description 2
- 239000011777 magnesium Substances 0.000 description 2
- 238000006386 neutralization reaction Methods 0.000 description 2
- 150000003013 phosphoric acid derivatives Chemical class 0.000 description 2
- 239000000047 product Substances 0.000 description 2
- 239000001488 sodium phosphate Substances 0.000 description 2
- 229910021653 sulphate ion Inorganic materials 0.000 description 2
- RYFMWSXOAZQYPI-UHFFFAOYSA-K trisodium phosphate Chemical compound [Na+].[Na+].[Na+].[O-]P([O-])([O-])=O RYFMWSXOAZQYPI-UHFFFAOYSA-K 0.000 description 2
- 229910000406 trisodium phosphate Inorganic materials 0.000 description 2
- 235000019801 trisodium phosphate Nutrition 0.000 description 2
- OYPRJOBELJOOCE-UHFFFAOYSA-N Calcium Chemical compound [Ca] OYPRJOBELJOOCE-UHFFFAOYSA-N 0.000 description 1
- KRHYYFGTRYWZRS-UHFFFAOYSA-M Fluoride anion Chemical compound [F-] KRHYYFGTRYWZRS-UHFFFAOYSA-M 0.000 description 1
- UCKMPCXJQFINFW-UHFFFAOYSA-N Sulphide Chemical compound [S-2] UCKMPCXJQFINFW-UHFFFAOYSA-N 0.000 description 1
- 229910000288 alkali metal carbonate Inorganic materials 0.000 description 1
- 150000008041 alkali metal carbonates Chemical class 0.000 description 1
- 229910052791 calcium Inorganic materials 0.000 description 1
- 239000011575 calcium Substances 0.000 description 1
- YYRMJZQKEFZXMX-UHFFFAOYSA-N calcium;phosphoric acid Chemical compound [Ca+2].OP(O)(O)=O.OP(O)(O)=O YYRMJZQKEFZXMX-UHFFFAOYSA-N 0.000 description 1
- 239000012459 cleaning agent Substances 0.000 description 1
- 150000001875 compounds Chemical class 0.000 description 1
- 239000003599 detergent Substances 0.000 description 1
- 159000000011 group IA salts Chemical class 0.000 description 1
- 229910000398 iron phosphate Inorganic materials 0.000 description 1
- WBJZTOZJJYAKHQ-UHFFFAOYSA-K iron(3+) phosphate Chemical compound [Fe+3].[O-]P([O-])([O-])=O WBJZTOZJJYAKHQ-UHFFFAOYSA-K 0.000 description 1
- 239000010446 mirabilite Substances 0.000 description 1
- 150000004712 monophosphates Chemical class 0.000 description 1
- 239000000843 powder Substances 0.000 description 1
- 238000001953 recrystallisation Methods 0.000 description 1
- 229920006395 saturated elastomer Polymers 0.000 description 1
- AJPJDKMHJJGVTQ-UHFFFAOYSA-M sodium dihydrogen phosphate Chemical compound [Na+].OP(O)([O-])=O AJPJDKMHJJGVTQ-UHFFFAOYSA-M 0.000 description 1
- RSIJVJUOQBWMIM-UHFFFAOYSA-L sodium sulfate decahydrate Chemical compound O.O.O.O.O.O.O.O.O.O.[Na+].[Na+].[O-]S([O-])(=O)=O RSIJVJUOQBWMIM-UHFFFAOYSA-L 0.000 description 1
- 239000002426 superphosphate Substances 0.000 description 1
- 239000000080 wetting agent Substances 0.000 description 1
Description
Beim Aufschluss von Rohphosphaten mittels Schwefelsäure in bekannter Art und Weise erhält man Phosphorsäure, die an Calciumsulfat gesättigt ist und außerdem noch Verbindungen des Fluors, Aluminiums, Eisens, Magnesiums, Arsens u.a. enthält.When raw phosphates are broken down by means of sulfuric acid in a known manner, phosphoric acid is obtained, which is saturated in calcium sulfate and also contains compounds of fluorine, aluminum, iron, magnesium, arsenic, etc.
Bei der üblichen Herstellung von Di- bzw. Trinatriumphosphat aus der rohen Phosphorsäure durch Neutralisation mittels Soda bzw. mittels Soda und Natronlauge werden Aluminium, Eisen, Magnesium und Calcium praktisch vollständig ausgefällt. Sulfat und Arsen verbleiben volständig, Fluor größtenteils in der Lauge. Arsen pflegt man durch Zugabe von Sulfid zur rohen Phosphorsäure zu entfernen.In the usual production of di- or trisodium phosphate from crude phosphoric acid by neutralization using soda or using soda and sodium hydroxide solution, aluminum, iron, magnesium and calcium are practically completely precipitated. Sulphate and arsenic remain completely, fluorine for the most part in the lye. Arsenic is usually removed by adding sulfide to the crude phosphoric acid.
Das Di- bzw. Trinatriumphosphat wird durch Kristallisation in Form der 12-Hydrate von Sulfat und Fluorid getrennt.The di- or trisodium phosphate is separated from sulfate and fluoride by crystallization in the form of the 12-hydrates.
Es wurde nun die überraschende Feststellung gemacht, dass die Entfernung des Fluors in sehr viel einfacherer Weise möglich ist, wenn man die Neutralisation der Phosphorsäure mittels Alkalien, vorzugsweise Soda, in zwei Stufen vollzieht, und zwar stellt man zunächst auf pH-Werte von 3,0-5,0, vorteilhaft 4,7, ein, filtriert ab und neutralisiert anschließend bis zur Diphosphatstufe. Das so erhaltene Produkt kann in üblicher Weise weiterverarbeitet werden. Der Fluorgehalt der so gereinigten Produkte ist nicht höher als der durch Umkristallisieren gewonnene.The surprising finding has now been made that the removal of the fluorine is possible in a much simpler way if the neutralization of the phosphoric acid by means of alkalis, preferably soda, is carried out in two stages. 0-5.0, advantageously 4.7, a, filtered off and then neutralized up to the diphosphate level. The product obtained in this way can be further processed in the usual way. The fluorine content of the products purified in this way is not higher than that obtained by recrystallization.
Das Verfahren ist nicht nur auf rohe Phosphorsäure beschränkt, sondern kann ebenso gut auf Laugen angewandt werden, wie man sie z.B. durch Umsetzung von Superphosphat mittels Glaubersalz erhält. Diese erhalten primäres Natriumphosphat neben freier Phosphorsäure. Es ist zwar schon vorgeschlagen worden, Phosphorsäure mehrstufig mit Alkalicarbonat zu neutralisieren, um Eisen nicht in Form von Eisenphosphat, sondern als Eisensulfid fällen zu können. Doch muss dazu soweit neutralisiert werden, dass etwas weniger als die Hälfte des gebildeten Mono- in Diphosphat überführt wird, d.h. auf einen pH-Wert von etwa 6,7. Indessen ist bei diesem pH-Wert eine genügende Entfernung des Fluors nicht mehr möglich. Es muss dazu viel mehr in einem pH-Bereich gearbeitet werden, in dem Eisensulfid noch löslich ist.The process is not limited to crude phosphoric acid, but can also be applied to alkalis, such as those obtained by converting superphosphate with Glauber's salt, for example. These contain primary sodium phosphate in addition to free phosphoric acid. It has already been proposed to neutralize phosphoric acid in several stages with alkali metal carbonate in order to be able to precipitate iron not in the form of iron phosphate but as iron sulfide. However, it must be neutralized to such an extent that a little less than half of the monophosphate formed is converted into diphosphate, i.e. to a pH value of around 6.7. However, sufficient removal of the fluorine is no longer possible at this pH value. To do this, you have to work much more in a pH range in which iron sulfide is still soluble.
Der Vorteil dieses Verfahrens besteht darin, dass die erhaltenen Phosphatlaugen, gegebenenfalls nach Zusatz von Netzmitteln, alkalischen Salzen u.dgl., in ihrer Gesamtheit in Pulverform überführt werden können, wie das z.B. bei der Herstellung von Wasch- und Reinigungsmitteln geschieht. Dadurch kann ein ganzer Fabrikationsgang, die Kristallisation der Phosphate, erspart werden. Die geringen, in den Rohlaugen enthaltenen Sulfatmengen stören dabei nicht.The advantage of this process is that the phosphate liquors obtained, if necessary after the addition of wetting agents, alkaline salts and the like, can be converted in their entirety into powder form, as is the case, for example, in the manufacture of detergents and cleaning agents. This saves a whole manufacturing process, the crystallization of the phosphates. The small amounts of sulphate contained in the raw liquor do not interfere with this.
Beispiel:Example:
Eine rohe Phosphorsäure mit 185 g P(sub)2O(sub)5, 7,9 g Fe(sub)2O(sub)3, 1,7 g Al(sub)2O(sub)3, 5,6 g CaO, 7,7 g SO(sub)3 und 8 g F im Liter wurde durch Zugabe von Soda auf verschiedene pH-Werte eingestellt. Die Niederschläge wurden abfiltriert. In den Phosphatlaugen wurden die folgenden Fluorgehalte gefunden:A crude phosphoric acid with 185 g P (sub) 2O (sub) 5, 7.9 g Fe (sub) 2O (sub) 3, 1.7 g Al (sub) 2O (sub) 3, 5.6 g CaO, 7.7 g SO (sub) 3 and 8 g F per liter were adjusted to different pH values by adding soda. The precipitates were filtered off. The following fluorine contents were found in the phosphate liquors:
Claims (1)
Family
ID=
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| DE2046295A1 (en) | Process for the separation of magnesium from wet process phosphoric acid | |
| DE2528895C3 (en) | ||
| DE3429921A1 (en) | METHOD FOR PRODUCING PHOSPHATES FROM ALKALINE-TREATED PHOSPHATE STONES | |
| DE646109C (en) | Manufacture of cryolite | |
| DEP0036965DA (en) | Process for removing fluorine from fluorine-containing phosphoric acid or from acidic phosphate liquors | |
| DE1567745B1 (en) | PROCESS FOR THE PRODUCTION OF SODIUM POTASSIUM POLYPHOSPHATE | |
| DE721410C (en) | Production of technically pure alkali phosphates | |
| DE1811829C3 (en) | Process for the production of sodium fluosilicate | |
| DE2629776A1 (en) | METHOD OF TREATMENT OF PHOSPHATING SLUDGE | |
| DE2820445A1 (en) | Potassium sulphate prodn. by double decomposition - via glaserite, with recirculation of chloride soln. after pptn. of sodium chloride in useful form | |
| DE567113C (en) | Production of fluoroaluminium-fluoroalkali double compounds | |
| DE648295C (en) | Purification of raw phosphoric acid | |
| DE427651C (en) | Process for the preparation of sodium silicofluoric acid | |
| DE1567619B2 (en) | Process for the preparation of low-vanadium alkali phosphates | |
| AT151948B (en) | Process for the production of commercially pure alkali phosphates. | |
| DE2538720C2 (en) | Process for purifying wet process phosphoric acid | |
| DE413723C (en) | Process for the production of pure lithium salts from technical lithium liquors | |
| DE1265726B (en) | Process for the preparation of hydrated potassium magnesium phosphate | |
| DE453118C (en) | Process for the production of solutions suitable for the manufacture of ammonium sulphate and alkali sulphate or their double salts | |
| DE460902C (en) | Production of double compounds of fluoroaluminum with fluoroalkali including fluoroammon | |
| DE862443C (en) | Process for removing sulphate from acidic phosphate liquors | |
| DE595235C (en) | Production of fluorine-containing sodium phosphate | |
| DE556321C (en) | Process for the production of pure zinc sulphate from alkalis containing zinc sulphate and sodium sulphate | |
| DE859005C (en) | Process for the production of alumina | |
| DE436280C (en) | Production of pure phosphoric acid from natural phosphates |