IL25249A - Process for the preparation of hydrated iron oxides - Google Patents
Process for the preparation of hydrated iron oxidesInfo
- Publication number
- IL25249A IL25249A IL2524966A IL2524966A IL25249A IL 25249 A IL25249 A IL 25249A IL 2524966 A IL2524966 A IL 2524966A IL 2524966 A IL2524966 A IL 2524966A IL 25249 A IL25249 A IL 25249A
- Authority
- IL
- Israel
- Prior art keywords
- ferric
- ferrous
- salt
- hydrated
- solution
- Prior art date
Links
- 238000000034 method Methods 0.000 title claims description 30
- 238000002360 preparation method Methods 0.000 title claims description 13
- UQSXHKLRYXJYBZ-UHFFFAOYSA-N iron oxide Inorganic materials [Fe]=O UQSXHKLRYXJYBZ-UHFFFAOYSA-N 0.000 title description 9
- 235000013980 iron oxide Nutrition 0.000 title description 3
- VBMVTYDPPZVILR-UHFFFAOYSA-N iron(2+);oxygen(2-) Chemical class [O-2].[Fe+2] VBMVTYDPPZVILR-UHFFFAOYSA-N 0.000 title description 2
- LDHBWEYLDHLIBQ-UHFFFAOYSA-M iron(3+);oxygen(2-);hydroxide;hydrate Chemical compound O.[OH-].[O-2].[Fe+3] LDHBWEYLDHLIBQ-UHFFFAOYSA-M 0.000 claims description 23
- 239000000243 solution Substances 0.000 claims description 23
- HEMHJVSKTPXQMS-UHFFFAOYSA-M Sodium hydroxide Chemical compound [OH-].[Na+] HEMHJVSKTPXQMS-UHFFFAOYSA-M 0.000 claims description 18
- 150000003839 salts Chemical class 0.000 claims description 15
- CWYNVVGOOAEACU-UHFFFAOYSA-N Fe2+ Chemical compound [Fe+2] CWYNVVGOOAEACU-UHFFFAOYSA-N 0.000 claims description 11
- 239000000126 substance Substances 0.000 claims description 9
- 239000001052 yellow pigment Substances 0.000 claims description 9
- 238000001556 precipitation Methods 0.000 claims description 7
- QAOWNCQODCNURD-UHFFFAOYSA-N Sulfuric acid Chemical compound OS(O)(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-N 0.000 claims description 6
- 239000007864 aqueous solution Substances 0.000 claims description 6
- BAUYGSIQEAFULO-UHFFFAOYSA-L iron(2+) sulfate (anhydrous) Chemical compound [Fe+2].[O-]S([O-])(=O)=O BAUYGSIQEAFULO-UHFFFAOYSA-L 0.000 claims description 6
- 239000001117 sulphuric acid Substances 0.000 claims description 6
- 235000011149 sulphuric acid Nutrition 0.000 claims description 6
- 239000011790 ferrous sulphate Substances 0.000 claims description 5
- 235000003891 ferrous sulphate Nutrition 0.000 claims description 5
- 239000000203 mixture Substances 0.000 claims description 5
- 239000002667 nucleating agent Substances 0.000 claims description 5
- VTLYFUHAOXGGBS-UHFFFAOYSA-N Fe3+ Chemical compound [Fe+3] VTLYFUHAOXGGBS-UHFFFAOYSA-N 0.000 claims description 3
- XLYOFNOQVPJJNP-UHFFFAOYSA-M hydroxide Chemical compound [OH-] XLYOFNOQVPJJNP-UHFFFAOYSA-M 0.000 claims description 3
- 239000012429 reaction media Substances 0.000 claims description 3
- 229910021578 Iron(III) chloride Inorganic materials 0.000 claims description 2
- 238000001354 calcination Methods 0.000 claims description 2
- 229910001447 ferric ion Inorganic materials 0.000 claims description 2
- IMBKASBLAKCLEM-UHFFFAOYSA-L ferrous ammonium sulfate (anhydrous) Chemical compound [NH4+].[NH4+].[Fe+2].[O-]S([O-])(=O)=O.[O-]S([O-])(=O)=O IMBKASBLAKCLEM-UHFFFAOYSA-L 0.000 claims description 2
- 229960002089 ferrous chloride Drugs 0.000 claims description 2
- 238000001914 filtration Methods 0.000 claims description 2
- NMCUIPGRVMDVDB-UHFFFAOYSA-L iron dichloride Chemical compound Cl[Fe]Cl NMCUIPGRVMDVDB-UHFFFAOYSA-L 0.000 claims description 2
- RBTARNINKXHZNM-UHFFFAOYSA-K iron trichloride Chemical compound Cl[Fe](Cl)Cl RBTARNINKXHZNM-UHFFFAOYSA-K 0.000 claims description 2
- 239000007800 oxidant agent Substances 0.000 claims description 2
- 230000003647 oxidation Effects 0.000 claims description 2
- 238000007254 oxidation reaction Methods 0.000 claims description 2
- 230000001376 precipitating effect Effects 0.000 claims description 2
- 239000001054 red pigment Substances 0.000 claims description 2
- QAOWNCQODCNURD-UHFFFAOYSA-L Sulfate Chemical compound [O-]S([O-])(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-L 0.000 claims 1
- 239000002253 acid Substances 0.000 claims 1
- 229940037003 alum Drugs 0.000 claims 1
- 229910001448 ferrous ion Inorganic materials 0.000 claims 1
- 239000012266 salt solution Substances 0.000 claims 1
- 229910021653 sulphate ion Inorganic materials 0.000 claims 1
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 14
- 239000000725 suspension Substances 0.000 description 12
- 238000006243 chemical reaction Methods 0.000 description 9
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 9
- 229910052742 iron Inorganic materials 0.000 description 6
- 239000002244 precipitate Substances 0.000 description 6
- 239000000049 pigment Substances 0.000 description 5
- VEXZGXHMUGYJMC-UHFFFAOYSA-N Hydrochloric acid Chemical compound Cl VEXZGXHMUGYJMC-UHFFFAOYSA-N 0.000 description 4
- 230000005587 bubbling Effects 0.000 description 4
- NCNCGGDMXMBVIA-UHFFFAOYSA-L iron(ii) hydroxide Chemical compound [OH-].[OH-].[Fe+2] NCNCGGDMXMBVIA-UHFFFAOYSA-L 0.000 description 4
- NDLPOXTZKUMGOV-UHFFFAOYSA-N oxo(oxoferriooxy)iron hydrate Chemical compound O.O=[Fe]O[Fe]=O NDLPOXTZKUMGOV-UHFFFAOYSA-N 0.000 description 4
- 239000000047 product Substances 0.000 description 4
- 229910021506 iron(II) hydroxide Inorganic materials 0.000 description 3
- 238000005406 washing Methods 0.000 description 3
- PAYRUJLWNCNPSJ-UHFFFAOYSA-N Aniline Chemical compound NC1=CC=CC=C1 PAYRUJLWNCNPSJ-UHFFFAOYSA-N 0.000 description 2
- HCHKCACWOHOZIP-UHFFFAOYSA-N Zinc Chemical compound [Zn] HCHKCACWOHOZIP-UHFFFAOYSA-N 0.000 description 2
- 239000002585 base Substances 0.000 description 2
- 230000015572 biosynthetic process Effects 0.000 description 2
- 150000001875 compounds Chemical class 0.000 description 2
- 238000004519 manufacturing process Methods 0.000 description 2
- LQNUZADURLCDLV-UHFFFAOYSA-N nitrobenzene Chemical compound [O-][N+](=O)C1=CC=CC=C1 LQNUZADURLCDLV-UHFFFAOYSA-N 0.000 description 2
- 230000001105 regulatory effect Effects 0.000 description 2
- 229910052725 zinc Inorganic materials 0.000 description 2
- 239000011701 zinc Substances 0.000 description 2
- BVKZGUZCCUSVTD-UHFFFAOYSA-L Carbonate Chemical compound [O-]C([O-])=O BVKZGUZCCUSVTD-UHFFFAOYSA-L 0.000 description 1
- 235000002918 Fraxinus excelsior Nutrition 0.000 description 1
- 241000243251 Hydra Species 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
- 239000003513 alkali 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
- 239000002956 ash Substances 0.000 description 1
- 239000000872 buffer Substances 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
- 229910001861 calcium hydroxide Inorganic materials 0.000 description 1
- 239000003795 chemical substances by application Substances 0.000 description 1
- 238000004140 cleaning Methods 0.000 description 1
- 238000005238 degreasing Methods 0.000 description 1
- 238000007865 diluting Methods 0.000 description 1
- 238000001035 drying Methods 0.000 description 1
- 239000007789 gas Substances 0.000 description 1
- 229910052598 goethite Inorganic materials 0.000 description 1
- 230000007062 hydrolysis Effects 0.000 description 1
- 238000006460 hydrolysis reaction Methods 0.000 description 1
- AEIXRCIKZIZYPM-UHFFFAOYSA-M hydroxy(oxo)iron Chemical compound [O][Fe]O AEIXRCIKZIZYPM-UHFFFAOYSA-M 0.000 description 1
- 235000014413 iron hydroxide Nutrition 0.000 description 1
- JEIPFZHSYJVQDO-UHFFFAOYSA-N iron(III) oxide Inorganic materials O=[Fe]O[Fe]=O JEIPFZHSYJVQDO-UHFFFAOYSA-N 0.000 description 1
- QRXWMOHMRWLFEY-UHFFFAOYSA-N isoniazide Chemical compound NNC(=O)C1=CC=NC=C1 QRXWMOHMRWLFEY-UHFFFAOYSA-N 0.000 description 1
- 239000002184 metal Substances 0.000 description 1
- 229910052751 metal Inorganic materials 0.000 description 1
- 229910000000 metal hydroxide Inorganic materials 0.000 description 1
- 150000004692 metal hydroxides Chemical class 0.000 description 1
- 239000002994 raw material Substances 0.000 description 1
- 230000035484 reaction time Effects 0.000 description 1
- 239000002002 slurry Substances 0.000 description 1
- 229910052708 sodium Inorganic materials 0.000 description 1
- 239000011734 sodium Substances 0.000 description 1
- 239000007787 solid Substances 0.000 description 1
- 239000007858 starting material Substances 0.000 description 1
- 238000003756 stirring Methods 0.000 description 1
Classifications
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
- H01F1/00—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties
- H01F1/01—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials
- H01F1/03—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials characterised by their coercivity
- H01F1/0302—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials characterised by their coercivity characterised by unspecified or heterogeneous hardness or specially adapted for magnetic hardness transitions
- H01F1/0311—Compounds
- H01F1/0313—Oxidic compounds
- H01F1/0315—Ferrites
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01G—COMPOUNDS CONTAINING METALS NOT COVERED BY SUBCLASSES C01D OR C01F
- C01G49/00—Compounds of iron
- C01G49/02—Oxides; Hydroxides
- C01G49/06—Ferric oxide [Fe2O3]
-
- G—PHYSICS
- G11—INFORMATION STORAGE
- G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
- G11B5/00—Recording by magnetisation or demagnetisation of a record carrier; Reproducing by magnetic means; Record carriers therefor
- G11B5/62—Record carriers characterised by the selection of the material
- G11B5/68—Record carriers characterised by the selection of the material comprising one or more layers of magnetisable material homogeneously mixed with a bonding agent
- G11B5/70—Record carriers characterised by the selection of the material comprising one or more layers of magnetisable material homogeneously mixed with a bonding agent on a base layer
- G11B5/706—Record carriers characterised by the selection of the material comprising one or more layers of magnetisable material homogeneously mixed with a bonding agent on a base layer characterised by the composition of the magnetic material
- G11B5/70626—Record carriers characterised by the selection of the material comprising one or more layers of magnetisable material homogeneously mixed with a bonding agent on a base layer characterised by the composition of the magnetic material containing non-metallic substances
- G11B5/70642—Record carriers characterised by the selection of the material comprising one or more layers of magnetisable material homogeneously mixed with a bonding agent on a base layer characterised by the composition of the magnetic material containing non-metallic substances iron oxides
- G11B5/70647—Record carriers characterised by the selection of the material comprising one or more layers of magnetisable material homogeneously mixed with a bonding agent on a base layer characterised by the composition of the magnetic material containing non-metallic substances iron oxides with a skin
-
- G—PHYSICS
- G11—INFORMATION STORAGE
- G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
- G11B5/00—Recording by magnetisation or demagnetisation of a record carrier; Reproducing by magnetic means; Record carriers therefor
- G11B5/62—Record carriers characterised by the selection of the material
- G11B5/68—Record carriers characterised by the selection of the material comprising one or more layers of magnetisable material homogeneously mixed with a bonding agent
- G11B5/70—Record carriers characterised by the selection of the material comprising one or more layers of magnetisable material homogeneously mixed with a bonding agent on a base layer
- G11B5/706—Record carriers characterised by the selection of the material comprising one or more layers of magnetisable material homogeneously mixed with a bonding agent on a base layer characterised by the composition of the magnetic material
- G11B5/70626—Record carriers characterised by the selection of the material comprising one or more layers of magnetisable material homogeneously mixed with a bonding agent on a base layer characterised by the composition of the magnetic material containing non-metallic substances
- G11B5/70642—Record carriers characterised by the selection of the material comprising one or more layers of magnetisable material homogeneously mixed with a bonding agent on a base layer characterised by the composition of the magnetic material containing non-metallic substances iron oxides
- G11B5/70652—Record carriers characterised by the selection of the material comprising one or more layers of magnetisable material homogeneously mixed with a bonding agent on a base layer characterised by the composition of the magnetic material containing non-metallic substances iron oxides gamma - Fe2 O3
Landscapes
- Chemical & Material Sciences (AREA)
- Organic Chemistry (AREA)
- Health & Medical Sciences (AREA)
- Dermatology (AREA)
- General Health & Medical Sciences (AREA)
- Engineering & Computer Science (AREA)
- Power Engineering (AREA)
- Inorganic Chemistry (AREA)
- Compounds Of Iron (AREA)
- Pigments, Carbon Blacks, Or Wood Stains (AREA)
Description
n A process for the preparation of hydrated iron oxides 24096 This invention relates to a process for the preparation of hydrated iron oxide which has the chemical constitution whose structural formula can he ted as or PeOOH and which is known as This finds application various industrial It for be used advantageously as a yellow pigment of good quality as well as a raw material for the production of synthetic Many methods of preparation of such ferric compounds are already According to one of these an aqueous solution of ferrous sulphate is treated with sodium hydroxide to give a ferrous hydroxide which is then oxidised with air or other oxidising agents in suitable conditions of temperature and of pH of the solution to give hydrated ferric oxide According to another of these rather pure scrap iron is suspended in a solution of ferrous a small quantity of hydrated ferric oxide is then introduced as a nucleus and air is bubbled through the mixture which is heated to 70 to In this way oxidation of the ferrous iron into ferric iron is brought about at the pH tained by the ferrous precipitates as ferric oxide in the form of a yellow precipitate on the small quantity of the already present hydrated ferric oxide which acts as a The sulphuric acid which is formed from the ferrous sulphate under the reaction attacks the metallic iron present and restores the starting These methods of although leading to hydrated ferric oxides suitable for use as yellow ments of good general are not free from conveniences and These processes are particularly in only at the 2 to 4g per hour per litre of solution of precipitate can be excluding of course the quantity of ferric oxide which is introduced as a In the second mentioned process it is also of fundamental importance to use scrap iron of high such as for example soft iron in the form of in turns out to be rather Also a careful cleaning and degreasing of the metal is necessary and attacked iron residues must be systematically eliminated from the reaction It an object of the present invention to prepare hydrated ferric oxide which is particularly suited for use as yellow by a process in which these disadvan tages and drawbacks are eliminated or at least According to the invention there is provided a cess for the preparation of hydrated ferric oxide having the chemical constitution in which an aqueous solution of a ferric salt is added to an aqueous solution of a ferrous salt which contains hydrated ferric oxide having the chemical constitution as a nucleating agent for precipitating the hydrated ferric the mixture is maintained at a ture of 50 to and its is maintained at from 2 to 5 so that the ferric salt is and the hydrated ferric oxide formed is The process according to the invention haa the advantage that the formation of the hydrated ferric oxide occurs with a reaction velocity as the quantity of ferric oxide formed hour and per litre of solution of ferrous which is very much higher than the one obtained according to the It is possible to obtain the formation of 10 to of hydrated ferric oxide per litre of excluding of course any quantity of hydrated ferric oxide which may be used as the nucleating The pH is kept at from 2 to 5 preferably at tially By operating in accordance with the invention the ferric salt is hydrolysed to hydrated ferric in the form of a yellow deposits itself on the nucleating The chemical composition of this hydrated ferric oxide is The oxide has a fine yellow colour and can be represented by the formula or PeOOH The solid compound thus obtained is separated from the solution by hot filtration and the precipitate is then washed and dried in an oven at a temperature below to A particularly suitable hydrated ferric oxide ing agent is the suspension prepared by precipitation of ferrous hydroxide by adding to a solution of ferrous sulphate and then oxidising the hydroxide with an oxidising agen Suitable starting salts include the ferrous salts of sulphuric acid and of strong such as for example ferrous ferrous ammonium sulphate and ferrous example the product which obtained in the of iron or the product can be obtained by the treatment of by sulphuric Also ferrous chloride is particularly Similarly useful is the obtained in the reduction of nitrobenzene to aniline and hydrochloric The process acoording the invention is preferably effected with solutions of ferrous containing from 10 to 500 of ferrous per litre of Suitable as the ferric salts which are added in solution to the solution are the ferric salts of sulphuric acid and such as for ferric chloride and ferric iJarticularly suitable are the products obtained by treatment sulphuric or hydrochloric acid of pyrites ashes or the red slurries obtained in the preparation of alumina according to the Bayer and the product obtained by treatment with hydrochloric or sulphuric acid of the residue obtained during the preparation of electrolytic zinc starting from zinc According to the by roasting the sine blende one obtains besides ZnO a residue of ferric The mixture of the two oxides is attacked with and iron is separated by precip as process according to the invention is preferably effected with solutions of ferric containing from 50 to 600 of ferric salt per litre of The adjustment of the pH of the reaction medium to the values required to cause the hydrolysis of the ferric salt responsible for the precipitation of the hydra ed ferric is to add a base to the medium simultaneously with ferric In this way the acidity formed within the reactio medium by the precipitation of the ferric in of drated Oxide is immediately neutralised by the addition of the Operating in this the conditions ing the ferric ion as that is with a pH around remain The base which is added to adjust the pH can be a solution of an alkali or hydroxide or carbonate or a suspension of an earth metal hydroxide or ate or an organic It is preferable to ad a solution or suspension of a which is concentrated to avoid diluting the reaction but on the other hand the solution or suspension should not be too concentrated so to avoid any precipitation of iron hydroxides which will not redissolve and which are formed as a result of a great change in the region in drops of the solution or suspension of the baseare added to the aqueous reaction It is also possible to operate in the presence of buffers capable of maintaining the pH of the reaction medium to values very near to The colour and the covering power of the pigments obtained from the hydrated ferric oxide prepared according to the process of the present invention depend directly on a number of such the pH of the precipitation 2 to the reaction temperature 50 to the reaction time from 2 to 8 the ratio of the of from 1 to 0 the stirring A suitable choice of these variables allows the according to of the required type of yellow Another remarkable advantage connected with the process of the present invention is unlike the known the preparation of hydrated ferric oxide according to the invention can be carried out continuously in aa much while the solution of ferric salt is continuously the hydrated ferric which forms c n be separated continuously from the reaction A further advantage lies in the fact unlike some known it is not necessary to blow air or other oxidising gases into zone during the reaction according to the thus avoiding the use of complex and expensive Thanks to their structure the yellow pigments tained from the hydrated ferric oxide prepared according to the invention do not present any tendency to which is a considerable advantage in their use in the production of These yellow pigments are easily converted into red pigments with excellent eharaeteristics by simple calcination at temperatures of 400 to The invention will now be described by the following Examples to which it is not Example 1 Preparation of the of 25 to A suspension of the presence of excess sodium was Air was bubbled through this suspension until the mass passed from the colour of the ferrous hydroxide to the yellow colour of the goethite Preparation of the pigment 28 g of were dissolved in 250 ml of water and then 10 ml of the nucleus suspension prepared as above were added to the Part of the precipitated as while the pH rose to Air was bubbled through the mass which was kept at 20 to until the pH fell to and the colour became The bubbling of air through the mass was then At the same time the mass was heated to 70 to At this point a solution of 28 g of in 100 ml of water and a 2N solution of sodium hydroxide were added regulating the addition in such a way that the pH always remained around to the temperature being around 70 to The reaction was practically complete in about 5 hours and then the precipitate was washed and dried in an oven at g of a yellow pigment of excellent properties were Example 2 g of Fe were dissolved in 250 ml of water and 10 ml of the nucleating agent suspension prepared as previously described were The pH to with the precipitation of a small quantity of Air was bubbled through the mass which was simultaneously heated to 70 to The then fell to and the mass changed colour from green to bubbling of air through the mass was then At this point 29 g of dissolved in 100 ml of water and a solution of 2N sodium hydroxide were dripped into the the addition being regulated in such a way that the pH was kept between and The precipitate was washed dried at and g of a yellow pigment having excellent characteristics were Example 3 The process of the preceding Example was repeated except after the bubbling of air through the mass had been 29 g of dissolved in 100 ml of water and a suspension of calcium hydroxide in water were introduced taking care to keep the pH between and After washing and 10 g of a pigment of excellent characteristics were Example 4 14 of were in 250 ml of and 10 ml the previously prepared nucleating agent suspension were Air was bubbled through and the mass was simultaneously heated up to 70 to The bubbling of air was stopped and then 29 g of dissolved in 100 ml of water and a solution of sodium hydroxide were added in such a way as to keep the pH of the suspension between and After washing and g of a yellow pigment with excellent characteristics were Example The process was affected as in the preceding Example except of a pigment identical to the one previously Example 6 The process was effected as in Example 4 except that only g of were The yield was g of a yellow a little darker than the one obtained Example 7 Into a flask containing 250 ml of water at a temperature of 70 to 2g of the dry yellow pigment obtained from Example 1 and 14 g of were Then 15 g of in 50 ml of water and sodium hydroxide were added taking care that the pH was kept between and After washing and drying g of an pigment were When this procedure was repeated using as starting material the dry yellow pigment from any of Examples 2 to similar results were insufficientOCRQuality
Claims (1)
- - 11 - 2524*/2 CLAIMS ^ 1$ A process for the preparation of hydrated ferric oxide having the chemical constitution FeOgH in which an aqueous solution of a ferric salt is added to an aqueous solution of a ferrous salt which also contains hydrated ferric oxide having the chemical constitution eOgH as a nucleating agent for precipitating the hydrated ferric oxide, the mixture is maintained at a temperature of 50 to 100°C, and its pH is maintained at from 2 to 5 so that the ferric salt is hydro-lysed and the hydrated ferric oxide formed is precipitated,, 2* A process as claimed in claim 1 in which the precipitated oxide is separated by filtration and dried at a temperature below 300°C. 3· A process as claimed in claim 1 or claim 2 in which the pH is kept at substantially 3* 4e A process as claimed in any preceding claimSatt which the a .queous solution of the ferrous salt contains from 10 to 500 g of ferrous salt per litre of solution* 5· A process as claimed in any preceding claim in which the aqueous solution of the ferric salt contains from 50 to 600 g of ferric salt per litre of solution* 6« A process as claimed in any preceding claim in which the molecular ratio of the concentrations of ferrous ions to ferric ions is from 1 to 30, 7· A process as claimed in any preceding claim in which the ferrous salt is a salt of sulphuric acid or of a strong non-oxidising acid* 8* A process as claimed in any preceding claim in which the ferrous salt is ferrous sulphate, ferrous ammonium sulphate, or ferrous chloride* 25249/2 - 12 -ferric salt is ferric sulphate, ferric chloride or ferric alum. W 10, A process as claimed in any preceding elaim in which the pH is adjusted by the addition of a base to the reaction medium at the same time as the addition of the ferric salt solution, 11, A process as claimed in any preceding claim in which the hydrated ferric oxide nucleating agent has been prepared by precipitation of ferrous ihydroxide with NaOH from a solution of ferrous sulphate and oxidation of the hydroxide with an oxidising agent, 12, A process for the preparation of hydrated fer ic oxide having the chemical constitution FeOgH in accordance with claim 1 and substantially as herein described, 13, A process for the preparation of hydrated ferric oxide having the chemical constitution PeOgH, substantially as herein described with reference to the Examples· 14» Hydrated ferric oxide having the chemical constitution FeOgH prepared by a process as claimed in any preceding claim, 15", Yellow pigments prepared from the hydrated ferric oxide as claimed in Claim 14· 16, Red pigments prepared by calcination of the hydrated ferric oxide as claimed in claim 14 at a temperature of from 400
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
IT456265 | 1965-03-03 |
Publications (1)
Publication Number | Publication Date |
---|---|
IL25249A true IL25249A (en) | 1969-12-31 |
Family
ID=11112748
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
IL2524966A IL25249A (en) | 1965-03-03 | 1966-02-24 | Process for the preparation of hydrated iron oxides |
Country Status (6)
Country | Link |
---|---|
BE (1) | BE676970A (en) |
CH (1) | CH468308A (en) |
GB (1) | GB1133863A (en) |
IL (1) | IL25249A (en) |
LU (1) | LU50554A1 (en) |
NL (1) | NL6602319A (en) |
Families Citing this family (7)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS5116917B1 (en) * | 1971-02-08 | 1976-05-28 | ||
IT1008298B (en) * | 1974-02-25 | 1976-11-10 | Montedison Spa | METHOD FOR OBTAINING CONTROLLED GRANULOMETRY MAGNETITE STARTING FROM FERROUS SULPHATE SOLUTIONS |
DE3026686A1 (en) * | 1980-07-15 | 1982-02-11 | Basf Farben + Fasern Ag, 2000 Hamburg | Yellow iron oxide pigment synthesis - by pptn. aeration and heating without aeration to form rhombic seed suspension to increase growth rate |
EP1733058B8 (en) | 2004-03-16 | 2012-10-24 | Navinta LLC | Iron sucrose complexes and method of manufacture thereof |
WO2005094203A2 (en) | 2004-03-16 | 2005-10-13 | Navinta, Llc | Sodium ferric gluconate complexes and method of manufacture thereof |
CN102604435A (en) * | 2012-02-21 | 2012-07-25 | 升华集团德清华源颜料有限公司 | Nano transparent iron oxide yellow pigment |
CN102674471A (en) * | 2012-04-16 | 2012-09-19 | 北京航空航天大学 | Preparation method of flower-like mesoporous ferric oxide nano-material |
-
1966
- 1966-02-23 NL NL6602319A patent/NL6602319A/xx unknown
- 1966-02-24 IL IL2524966A patent/IL25249A/en unknown
- 1966-02-24 BE BE676970D patent/BE676970A/xx unknown
- 1966-02-28 GB GB877266A patent/GB1133863A/en not_active Expired
- 1966-02-28 CH CH283366A patent/CH468308A/en unknown
- 1966-03-02 LU LU50554A patent/LU50554A1/xx unknown
Also Published As
Publication number | Publication date |
---|---|
GB1133863A (en) | 1968-11-20 |
CH468308A (en) | 1969-02-15 |
NL6602319A (en) | 1966-09-05 |
BE676970A (en) | 1966-07-18 |
LU50554A1 (en) | 1966-05-03 |
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