AT157695B - Process for cleaning alkali hydroxide solutions. - Google Patents
Process for cleaning alkali hydroxide solutions.Info
- Publication number
- AT157695B AT157695B AT157695DA AT157695B AT 157695 B AT157695 B AT 157695B AT 157695D A AT157695D A AT 157695DA AT 157695 B AT157695 B AT 157695B
- Authority
- AT
- Austria
- Prior art keywords
- alkali hydroxide
- hydroxide solutions
- cleaning alkali
- cleaning
- compounds
- Prior art date
Links
- 238000000034 method Methods 0.000 title claims description 5
- 238000004140 cleaning Methods 0.000 title description 4
- 229910001854 alkali hydroxide Inorganic materials 0.000 title description 3
- 150000008044 alkali metal hydroxides Chemical class 0.000 title description 3
- 150000001875 compounds Chemical class 0.000 claims description 5
- 239000003513 alkali Substances 0.000 claims description 3
- 238000009993 causticizing Methods 0.000 claims 1
- 239000010802 sludge Substances 0.000 claims 1
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 6
- 239000000377 silicon dioxide Substances 0.000 description 3
- 239000000243 solution Substances 0.000 description 3
- 235000008733 Citrus aurantifolia Nutrition 0.000 description 2
- 235000011941 Tilia x europaea Nutrition 0.000 description 2
- 239000003518 caustics Substances 0.000 description 2
- 239000004571 lime Substances 0.000 description 2
- RMAQACBXLXPBSY-UHFFFAOYSA-N silicic acid Chemical compound O[Si](O)(O)O RMAQACBXLXPBSY-UHFFFAOYSA-N 0.000 description 2
- 235000012239 silicon dioxide Nutrition 0.000 description 2
- BPQQTUXANYXVAA-UHFFFAOYSA-N Orthosilicate Chemical compound [O-][Si]([O-])([O-])[O-] BPQQTUXANYXVAA-UHFFFAOYSA-N 0.000 description 1
- 150000001447 alkali salts Chemical class 0.000 description 1
- 239000012670 alkaline solution Substances 0.000 description 1
- PNEYBMLMFCGWSK-UHFFFAOYSA-N aluminium oxide Inorganic materials [O-2].[O-2].[O-2].[Al+3].[Al+3] PNEYBMLMFCGWSK-UHFFFAOYSA-N 0.000 description 1
- 229910000323 aluminium silicate Inorganic materials 0.000 description 1
- 229910000171 calcio olivine Inorganic materials 0.000 description 1
- 235000012241 calcium silicate Nutrition 0.000 description 1
- 229910052918 calcium silicate Inorganic materials 0.000 description 1
- 239000001913 cellulose Substances 0.000 description 1
- 229920002678 cellulose Polymers 0.000 description 1
- 239000007795 chemical reaction product Substances 0.000 description 1
- 239000004927 clay Substances 0.000 description 1
- 239000012535 impurity Substances 0.000 description 1
- 238000011835 investigation Methods 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 238000001556 precipitation Methods 0.000 description 1
Landscapes
- Paper (AREA)
Description
<Desc/Clms Page number 1>
Verfahren zur Reinigung von Alkalihydroxydlösungen.
Bei Durchführung von Verfahren, nach welchen Lösungen kaustischer Alkalien aus AlkaJisalzen oder Alkaliverbindungen gewonnen werden, enthält das als Endprodukt erhaltene Alkalihydroxyd für gewöhnlich Verunreinigungen, wie z. B. Kieselsäure, welche für gewisse Verwendungszwecke so nachteilig sind, dass eine sehr weitgetriebene Reinigung gerechtfertigt ist.
Es ist bekannt, dass die Kieselsäure, welche in den Alkalilaugen, die zur Herstellung von Zellulose- brei verwendet werden, enthalten ist, durch Kalk in Form von Metasilikat CaSiOg oder von Orthosilikat Ca2Si04 oder auch durch Kalk und Tonerde in Form von Aluminosilikaten der Formel CaO.Al2O3.2SiO2 ausgefällt werden kann. Durch diese Mittel wird jedoch keine vollständige Ausfällung der Kieselsäure gewährleistet, von weleher ein kleiner Anteil, in der Grössenordnung von 0-5 bis 1 g pro Liter, in Lösung verbleibt. Es ist deshalb noch eine weitgehendere Reinigung erforderlieh.
Die vorliegende Erfindung, die sich auf eingehende Untersuchungen über die Lösliehkeit der Tonerde und der Kieselsäure in kaustischen Alkalilaugen gründet, betrifft ein Ver-
EMI1.1
EMI1.2
EMI1.3
EMI1.4
EMI1.5
EMI1.6
EMI1.7
EMI1.8
EMI1.9
EMI1.10
EMI1.11
verbindungen 25- bis 50mal geringer als die der Silikoaluminate der Formel CaO. Al2O3.2SiO2.
Das Verfahren gemäss der Erfindung wird vorzugsweise bei erhöhter Temperatur, z. B. bei 95 C, durchgeführt.
Die auf diese Weise in Form komplexer, unlöslicher Erdalkalisilikoaluminate ausgefällte Kieselsäure wird gleichzeitig mit dem Überschuss der Erdalkaliverbindungen abgetrennt.
<Desc/Clms Page number 2>
EMI2.1
EMI2.2
EMI2.3
<Desc / Clms Page number 1>
Process for cleaning alkali hydroxide solutions.
When carrying out processes according to which solutions of caustic alkalis are obtained from alkali salts or alkali compounds, the alkali hydroxide obtained as the end product usually contains impurities such as e.g. B. silica, which are so disadvantageous for certain uses that a very extensive cleaning is justified.
It is known that the silicic acid, which is contained in the alkali lye used for the production of cellulose pulp, is obtained from lime in the form of metasilicate CaSiOg or from orthosilicate Ca2SiO4 or also from lime and clay in the form of aluminosilicates of the formula CaO .Al2O3.2SiO2 can be precipitated. However, these means do not guarantee complete precipitation of the silica, of which a small proportion, in the order of magnitude of 0-5 to 1 g per liter, remains in solution. A more extensive cleaning is therefore necessary.
The present invention, which is based on detailed investigations into the solubility of alumina and silicic acid in caustic alkaline solutions, relates to a
EMI1.1
EMI1.2
EMI1.3
EMI1.4
EMI1.5
EMI1.6
EMI1.7
EMI1.8
EMI1.9
EMI1.10
EMI1.11
Compounds 25 to 50 times lower than those of the silicoaluminates of the formula CaO. Al2O3.2SiO2.
The method according to the invention is preferably carried out at an elevated temperature, e.g. B. at 95 C carried out.
The silica precipitated in this way in the form of complex, insoluble alkaline earth silicoaluminates is separated off at the same time as the excess of alkaline earth compounds.
<Desc / Clms Page number 2>
EMI2.1
EMI2.2
EMI2.3
Claims (1)
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| NL157695X | 1937-04-16 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| AT157695B true AT157695B (en) | 1940-01-10 |
Family
ID=19776503
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| AT157695D AT157695B (en) | 1937-04-16 | 1938-03-28 | Process for cleaning alkali hydroxide solutions. |
Country Status (1)
| Country | Link |
|---|---|
| AT (1) | AT157695B (en) |
-
1938
- 1938-03-28 AT AT157695D patent/AT157695B/en active
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| AT157695B (en) | Process for cleaning alkali hydroxide solutions. | |
| DE710349C (en) | Process for separating pure calcium aluminates from solutions | |
| AT149663B (en) | Process for the production of low-silica alumina from alkaline earth aluminates. | |
| DE946433C (en) | Process for the production of silica in highly active, voluminous powder form | |
| DE620901C (en) | Production of alumina hydrate alongside trialkali phosphate | |
| DE415897C (en) | Process for the production of barium hydroxide from raw sulfur barium | |
| AT102939B (en) | Process for the production of opacifiers. | |
| DE375308C (en) | Process for the digestion of boron atrocalcite | |
| DE380322C (en) | Process for breaking down potash-containing silicates, clay and the like like | |
| DE938965C (en) | Process for the processing of the sodium hydroxide and potassium hydroxide solutions that arise in the manufacture of water glass | |
| CH191007A (en) | Process for the production of a practically silica-free clay from alkaline earth aluminates. | |
| DE398105C (en) | Process for the production of sodium decaborate | |
| AT243761B (en) | Process for the production of a pure cryolite | |
| DE704293C (en) | Process for cleaning alkaline solutions containing silica | |
| AT136373B (en) | Process for the production of low-silica alumina from alkaline earth aluminates. | |
| DE570589C (en) | Separation of trialkali phosphate from this and alkaline hydrolytically cleaved salts, e.g. B. sodium aluminate containing solutions | |
| DE403135C (en) | Process for cleaning raw oils | |
| DE920789C (en) | Process for the purification of adipic dinitrile | |
| AT96802B (en) | Process for opening up boron ores. | |
| AT128847B (en) | Opacifiers for enamels, glasses, etc. like | |
| AT148123B (en) | Process for the production of powdered potassium metasilicate. | |
| DE752692C (en) | Process for the production of protein degradation products | |
| AT106692B (en) | Process for the production of alumina from alumina-containing materials of all kinds. | |
| DE407475C (en) | Process for the production of sodium decaborate | |
| DE394130C (en) | Process for the production of Blanc-fixe |