DE2121152A1 - Activated silicon dioxide and cryolite - produced in integrated process from fluosilicic acid and sodium aluminate - Google Patents

Activated silicon dioxide and cryolite - produced in integrated process from fluosilicic acid and sodium aluminate

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Publication number
DE2121152A1
DE2121152A1 DE19712121152 DE2121152A DE2121152A1 DE 2121152 A1 DE2121152 A1 DE 2121152A1 DE 19712121152 DE19712121152 DE 19712121152 DE 2121152 A DE2121152 A DE 2121152A DE 2121152 A1 DE2121152 A1 DE 2121152A1
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suspension
concentration
nh4f
cryolite
sodium aluminate
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DE19712121152
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German (de)
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DE2121152B2 (en
Inventor
Antal Negotin Borsos (Jugoslawien). P
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Rudarsko - Topionicarski Basen Bor, Industrija Hemijskih Proizvoda Prahovo, Prahovo (Jugoslawien)
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Priority to DE19712121152 priority Critical patent/DE2121152B2/en
Publication of DE2121152A1 publication Critical patent/DE2121152A1/en
Publication of DE2121152B2 publication Critical patent/DE2121152B2/en
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    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B82—NANOTECHNOLOGY
    • B82Y—SPECIFIC USES OR APPLICATIONS OF NANOSTRUCTURES; MEASUREMENT OR ANALYSIS OF NANOSTRUCTURES; MANUFACTURE OR TREATMENT OF NANOSTRUCTURES
    • B82Y30/00—Nanotechnology for materials or surface science, e.g. nanocomposites
    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
    • C01B33/00—Silicon; Compounds thereof
    • C01B33/113—Silicon oxides; Hydrates thereof
    • C01B33/12—Silica; Hydrates thereof, e.g. lepidoic silicic acid
    • C01B33/18—Preparation of finely divided silica neither in sol nor in gel form; After-treatment thereof
    • C01B33/186—Preparation of finely divided silica neither in sol nor in gel form; After-treatment thereof from or via fluosilicic acid or salts thereof by a wet process
    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01F—COMPOUNDS OF THE METALS BERYLLIUM, MAGNESIUM, ALUMINIUM, CALCIUM, STRONTIUM, BARIUM, RADIUM, THORIUM, OR OF THE RARE-EARTH METALS
    • C01F7/00—Compounds of aluminium
    • C01F7/48—Halides, with or without other cations besides aluminium
    • C01F7/50—Fluorides
    • C01F7/54—Double compounds containing both aluminium and alkali metals or alkaline-earth metals
    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
    • C01P2004/00—Particle morphology
    • C01P2004/60—Particles characterised by their size
    • C01P2004/64—Nanometer sized, i.e. from 1-100 nanometer
    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
    • C01P2006/00—Physical properties of inorganic compounds
    • C01P2006/10—Solid density
    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
    • C01P2006/00—Physical properties of inorganic compounds
    • C01P2006/11—Powder tap density
    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
    • C01P2006/00—Physical properties of inorganic compounds
    • C01P2006/12—Surface area
    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
    • C01P2006/00—Physical properties of inorganic compounds
    • C01P2006/80—Compositional purity
    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
    • C01P2006/00—Physical properties of inorganic compounds
    • C01P2006/80—Compositional purity
    • C01P2006/82—Compositional purity water content
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
    • Y02P20/00—Technologies relating to chemical industry
    • Y02P20/10—Process efficiency

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  • Chemical & Material Sciences (AREA)
  • Organic Chemistry (AREA)
  • Engineering & Computer Science (AREA)
  • Inorganic Chemistry (AREA)
  • Nanotechnology (AREA)
  • Condensed Matter Physics & Semiconductors (AREA)
  • Composite Materials (AREA)
  • General Physics & Mathematics (AREA)
  • Materials Engineering (AREA)
  • Crystallography & Structural Chemistry (AREA)
  • Physics & Mathematics (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Geology (AREA)
  • Silicon Compounds (AREA)
  • Silicates, Zeolites, And Molecular Sieves (AREA)

Abstract

Aq. H2SiF6 (10-30%) is neutralised to pH 8-10 by steady addn., over 10-120 min., with vigorous agitation, of NH3 aq. (13-30 g/100 ml), at 10-70 degrees C, giving a SiO2 suspension of 2-7%. The suspension is filtered under 380 mm Hg vacuum, giving a cake 3-4 cm thick contg. 85% NH4F. The cake is washed with an equivalent amt. of aq. NH4F (4-8g/100 ml), then with softened water, and is dried at 80 degrees C; the filtrates are combined and reacted with sodium aluminate to yield a cryolite suspension contg. 8-14% solids, which are filtered and calcined. NH3 is recovered from the last stage and recycled.

Description

Verfahren zur Gewinnung von Na3AlF6 und aktivem Sir2. Process for obtaining Na3AlF6 and active Sir2.

Die Erfindung bezieht sich auf ein Verfahren zur Gewinnung von Na3AlF6 und aktivem SiO2 aus Siliziumfluorwasserstoffsäure, bei Verwendung von Ammoniakwasser.The invention relates to a method for obtaining Na3AlF6 and active SiO2 from hydrofluoric acid, when using ammonia water.

Nach bisherigen bekannten Verfahren bestand die Möglichkeit zur Gewinnung nur eines von diesen beiden Produkten und zwar auf der Basis verschiedener Verfahren. So stellt, zum Beispiel, die Firma Bayer durch Zerlegung von Silikaten mit Mineralsäuren einen aktiven Füllstoff her.According to previously known methods, there was the possibility of extraction only one of these two products based on different processes. For example, the Bayer company produces by breaking down silicates with mineral acids an active filler.

In der UdSSR wird dagegen das aktive SiO2 aus H2SiFe und A1(OH)3 gewonnen.In the USSR, on the other hand, the active SiO2 is obtained from H2SiFe and A1 (OH) 3.

Die Erfindung hat sich die Aufgabe gestellt, eine parallele Gewinnung von Na3AlF6 und SiO2 zu ermöglichen.The invention has set itself the task of a parallel extraction of Na3AlF6 and SiO2.

Zur Lösung dieser Aufgabe besteht das Verfahren nach der Erfindung im wesentlichen in der Neutralisierung von Siliziumfluorwasserstoffsäure durch Ammoniakwasser, wobei es - zwecks qualitätsmässiger Ausscheidung des SiO2 x H20 - erforderlich ist, daß als Reaktionsende der Augenblick des Auftretens. eines Uberschußes von freiem Ammoniak in der Lösung von NH4F betrachtet wird.The method according to the invention is used to achieve this object essentially in the neutralization of hydrofluoric acid by ammonia water, where it is necessary - for the purpose of quality separation of the SiO2 x H20, that the moment of occurrence is the end of the reaction. an excess of free Ammonia is considered in the solution of NH4F.

Die Reaktion wickelt sich nach der Gleichung ab: H2SiF6 + 6NH4OH ---- 6NH4F + SiO2 x N20 + yH20.The reaction proceeds according to the equation: H2SiF6 + 6NH4OH ---- 6NH4F + SiO2 x N20 + yH20.

Das Verhältnis des freien Ammoniaks zum Ammoniumfluorid kommt durch folgende Beziehung zum Ausdruck: NH/gr/100 mlj: NH4F /gr/100 ml/ # 0,07 gekennzeichnet, während der Ammoniaküberschuß in dieser Beziehung als Menge von min. 0,8/g NH3/100 ml/, bis maximal 5,0/g NH3/iOO ml, betrachtet wird.The ratio of free ammonia to ammonium fluoride comes through the following relation to the expression: NH / gr / 100 mlj: NH4F / gr / 100 ml / # 0.07 marked, while the excess of ammonia in this respect is an amount of at least 0.8 / g NH3 / 100 ml /, up to a maximum of 5.0 / g NH3 / 100 ml.

Diese derart erhaltene Suspension wird in der Folge, zwecks Abscheidung von SiO2 und NH4F, unter Anwendung von Vakuum filtriert.This suspension obtained in this way is subsequently used for the purpose of separation of SiO2 and NH4F, filtered using vacuum.

Der mittels Filtrieren erhaltene Kuchen wird weiter mit Ammoniumfluorid und erweichtem Wasser ausgewaschen und getrocknet. Das amorphe SiO2 x H20 wird als Gummifüllstoff ausgenutzt, während das ursprünglich gewonnene Filtrat des Ammoniumfluorids unddas durch Auswaschung erhaltene Filtrat vermischt und zur Gewinnung des Nà3AlF6 nach folgender Reaktion: 6NH4F + Na3AlO3 = NaAlF6 + 6 NH3 + 3H2O genutzt wird.The cake obtained by filtration is further treated with ammonium fluoride and softened water washed out and dried. The amorphous SiO2 x H20 is called Rubber filler exploited while the originally obtained filtrate of ammonium fluoride andthe filtrate obtained by washing is mixed and used to recover the Na3AlF6 after the following reaction: 6NH4F + Na3AlO3 = NaAlF6 + 6 NH3 + 3H2O is used.

Das frei werdende Ammoniak kehrt mit Hilfe von Wasserdampf und der im Wasser erfolgten Absorption in den Destillationsprozeß zurück, wobei das gewonnene Ammoniakwasser mit frischem Ammoniak angereichert und zur Neutralisierung der Silikofluorwasserstoffsäure benützt wird.The released ammonia returns with the help of water vapor and the absorption in the water took place back in the distillation process, with the recovered Ammonia water enriched with fresh ammonia and used to neutralize hydrofluoric acid is used.

Die SilikoSluorwasserstoffsäure wird als 10 O/o bis 30 5'o-ige Lösung genützt, in der P205 bis 9 g/l enthalten ist, während es von anderen Beimengungen Mn, Cu, Fe in Spuren enthält. Mechanische Verunreinigungen jedoch bestehen überhaupt nicht.The hydrofluoric acid is available as a 10% to 30% solution used, in the P205 up to 9 g / l is contained, while it is of other admixtures Contains traces of Mn, Cu, Fe. However, mechanical impurities exist at all not.

Beispiel 1 - minimale Konzentration Silikofluorwasserstoffsäure (Minimalmenge) 10 %-ig wird mit streng gleichmässig dosiertem Ammoniakwasser von 15 g NH3/ 100 ml ..., bei einer Temperatur von 100 und im Verlauf von 10 Min. intensiv neutralisiert, bis zur Erreichung einer Suspensionskonzentration von ca. 2 %. Die auf diese Weise erhaltene Suspension wird in der Folge durch einen Filter, unter Vakuum von 380 mm Hg filtriert, monat der so erhaltene Kuchen von etwa 3 cm Stärke und einem Feuchtigkeitsgehalt bzw. NH4F von ca. 85 % mit einer äquivalenten Lösungsmenge Ammoniumfluorid schwächerer Konzentration von 4-g NH4F/100 ml mit erweichtem Wasser ausgespült und nachgespült wird. Das Ende der Auswaschung wird durch Analyse auf NH4F, dessen Konzentration O,1 g/100 ml unterschreiten soll, bestimmt.Example 1 - minimum concentration of hydrofluoric acid (minimum amount) 10% is achieved with strictly evenly dosed ammonia water of 15 g NH3 / 100 ml ..., intensely neutralized at a temperature of 100 and in the course of 10 minutes, until a suspension concentration of approx. 2% is reached. That way The suspension obtained is then passed through a filter, under vacuum of 380 Filtered mm Hg, month the cake obtained in this way of about 3 cm thick and a moisture content or NH4F of approx. 85% with an equivalent amount of ammonium fluoride solution is weaker Concentration of 4-g NH4F / 100 ml rinsed out with softened water and rinsed will. The end of the washout is indicated by analyzing for NH4F, its concentration Should be less than 0.1 g / 100 ml.

Zur Sicherstellung der erwünschten Qualität des Si02 x H20 ist es erforderlich, daß das Verhältnis des Trockenstoffes und des verwendeten Wassers 1 : 25 beträgt. di Das ausgespülte Silizium/oxyd wird bei einer Temperatur von 800 C getrocknet. Die trockene amorphe Maße wird in Mühlen bis zu einer Teilchengröße von 30 Millimikron zerkleinert.To ensure the desired quality of the Si02 x H20 it is required the ratio of dry matter and water used Is 1:25. di The rinsed silicon / oxide is at a temperature of 800 C dried. The dry amorphous mass is milled down to a particle size crushed by 30 millimicrons.

Es wird ein Produkt folgender Qualität erhalten: "P R A S I L"-DK Spezifisches Gewicht .......................... 1,95 g/cm3 pH auf 5 % Suspension ........................ 7,2 - 7,5 Schüttgewicht ................................. 110 g/1 Absinken in Toluol ............................ 35 ml Glühverlust ................................... 5 % Feuchtigkeit bis ......................... 5 56 SiO2 . . . . 0 0 0 0 . 0 0 0 0 . . 0 0 0 0 84 - 86 56 R2O3 .......................................... 1 % CaO ........................................... 2 % SO4 . e . . . . . . . 0 0 . ... 0,05 % F .............................................. 0,07 % Mn ............................................ 0,001 % Cu ............................................ 0,001 % Fe ............................................ 0,03 % BET-Werte 50 - 180 m2/g Teilchengröße: 30 Millimikron Die durch Abscheidung und Ausspülung entstandenen Filtrate des SiO2 verbinden sich und werden zur Gewinnung von Kriolit ausgenützt.A product of the following quality is obtained: "P R A S I L "-DK Specific weight .......................... 1.95 g / cm3 pH 5% suspension ........................ 7.2 - 7.5 bulk weight ............... .................. 110 g / 1 sinking in toluene ............................ 35 ml loss on ignition ............ ....................... 5% moisture up to ......................... 5 56 SiO2. . . . 0 0 0 0. 0 0 0 0. . 0 0 0 0 84 - 86 56 R2O3 ......................................... 1% CaO ........................................... 2% SO4. e. . . . . . . 0 0. ... 0.05% F ............................................. .0.07% Mn ............................................ 0.001% Cu ............................................ 0.001% Fe ............................................ 0.03% BET values 50 - 180 m2 / g Particle size: 30 millimicrons Die by deposition Filtrates of SiO2 that have arisen and rinsing combine and are used for recovery exploited by Kriolit.

Die Kriolitsuspension mit einem Trockenstoffinhalt von 8 56 wird filtriert und in der Folge kalziniert. Das erhaltene Kriolit ist von einer Standard-Qualität.The criolite suspension with a dry matter content of 8 56 is filtered and subsequently calcined. The Kriolit obtained is of a standard quality.

Beispiel 2 Silikofluorwasserstoffsäure von maximal 30 % wird unter Mischung mit streng gleichmaßig dosiertem Ammoniakwasser von 30 g NH3/100 ml Konzentration, bei einer Temperatur von 70° C, im Verlauf von 120 Min., bis zur Erreichung eines pH-Wertes 10, intensiv neutralisiert. Hierbei beträgt die Suspensionskonzentration ca. 7 %. Die so erhaltene Suspension wird in der Folge mit einem Nutsche-Filter unter Vakuum von 380 mm Hg filtriert und der entstandene Kuchen von etwa 4 cm Stärke und 85 56 Feuchtigkeitsgehalt mit einer äquivalenten Menge Ammoniumfluoridlösung von 8 g NH4F/100 ml aus-und mit erweichtem Wasser nachgespült. Das Ende der Auswaschung wird durch Analyse auf NH4, dessen Konzentration 0,1 g/100 ml unterschreiten soll, bestifimt. Das weitere Verfahren ist dasselbe wie im Beispiel 1, mit der Ausnahme, daß der in der Kriolitsuspension enthaltene Trockenstoff 14 56 beträgt.Example 2 Hydrofluoric acid of a maximum of 30% is used under Mixture with strictly evenly dosed ammonia water of 30 g NH3 / 100 ml concentration, at a temperature of 70 ° C, in the course of 120 minutes, up to Achieving a pH value of 10, intensively neutralized. The suspension concentration is here approx. 7%. The suspension obtained in this way is subsequently filtered through a Nutsche filter filtered under vacuum of 380 mm Hg and the resulting cake of about 4 cm thick and 85 56 moisture content with an equivalent amount of ammonium fluoride solution of 8 g NH4F / 100 ml and rinsed with softened water. The end of the washout is determined by analysis for NH4, the concentration of which should fall below 0.1 g / 100 ml, determined. The rest of the procedure is the same as in Example 1, with the exception that the dry matter contained in the Kriolite suspension is 14 56.

Claims (2)

Patentansprüche 1. Verfahren zur Gewinnung von Na3AlF6 und aktivem SiO2, dadurch g e k e n n z e i c h n e t , daß eine 10 56 -30 56 Silikofluorwasserstoffsäure-Lösung unter intensiver Mischung mit streng gleichmäßig dosiertem Ammonlakwasser von 13 bis 30 g NH3/100 ml Konzentration, bei einer Temperatur von 10 bis 700 C und im Verlauf von 10 bis 120 Minuten, neutralisiert wird, worauf die erhaltene Suspension unter Vakuum von 380 mm Hg filtriert-und der entstandene Kuchen von etwa 3 - 4 cm Stärke und 85 % Ammoniumfluoridgehalt mit einer äquivalenten Lösungsmenge Ammoniumfluorid von 4 bis 8 g NH4F/100 ml Konzentration ausgespült und mit erweichtem Wasser nachgespült und auf 800 C getrocknet wird; die unter Vakuumfiltrierung und durch Aus spülung erhaltenen Lösungen des NH4 verbinden sich und werden zur Gewinnung von Kriolit ausgenützt, derart, daß eine Kriolitsuspension mit 8 - 14 56 Trockenstoffinhalt gebildet, filtriert und kalziniert wird um zur Gewinnung des Krdolits zu gelangen. Claims 1. Process for the production of Na3AlF6 and active SiO2, indicated that a 10 56 -30 56 hydrofluoric acid solution with intensive mixing with strictly evenly dosed ammonia water of 13 up to 30 g NH3 / 100 ml concentration, at a temperature of 10 to 700 C and im The course of 10 to 120 minutes, is neutralized, whereupon the suspension obtained Filtered under a vacuum of 380 mm Hg-and the resulting cake of about 3 - 4 cm Starch and 85% ammonium fluoride content with an equivalent amount of ammonium fluoride solution from 4 to 8 g NH4F / 100 ml concentration and rinsed with softened water and is dried to 800 C; those under vacuum filtration and by flushing The resulting solutions of the NH4 combine and are used to obtain Kriolit exploited in such a way that a criolite suspension with 8-14 56 dry matter content is formed, filtered and calcined in order to get to the recovery of the crdolite. 2. Verfahren nach Anspruch 1, dadurch gekennzeichnet, daß die Neutralisierung des H2SiF6 durch Ammoniakwasser bis zur Erreichung eines pE-Wertes von 8 - 10 erfolgt, wobe die Konzentration der Suspension 2 - 7 % beträgt.2. The method according to claim 1, characterized in that the neutralization of the H2SiF6 is carried out with ammonia water until a pE value of 8 - 10 is reached, whereby the concentration of the suspension is 2-7%.
DE19712121152 1971-04-29 1971-04-29 PROCESS FOR THE RECOVERY OF ACTIVE SILICON DIOXIDE Ceased DE2121152B2 (en)

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DE19712121152 DE2121152B2 (en) 1971-04-29 1971-04-29 PROCESS FOR THE RECOVERY OF ACTIVE SILICON DIOXIDE

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Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0094138A1 (en) * 1982-05-11 1983-11-16 Stamicarbon B.V. Process for preparing pure silicon dioxide having high mechanical strength, as well as silicon dioxide obtained by applying this process
EP0113137A1 (en) * 1982-12-04 1984-07-11 Stamicarbon B.V. Process for the preparation of pure silica

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0094138A1 (en) * 1982-05-11 1983-11-16 Stamicarbon B.V. Process for preparing pure silicon dioxide having high mechanical strength, as well as silicon dioxide obtained by applying this process
EP0113137A1 (en) * 1982-12-04 1984-07-11 Stamicarbon B.V. Process for the preparation of pure silica

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DE2121152B2 (en) 1977-03-17

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