Classifications

• • C—CHEMISTRY; METALLURGY
  • C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
  • C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
  • C02F1/00—Treatment of water, waste water, or sewage
  • C02F1/52—Treatment of water, waste water, or sewage by flocculation or precipitation of suspended impurities
  • C02F1/5236—Treatment of water, waste water, or sewage by flocculation or precipitation of suspended impurities using inorganic agents
  • C02F1/5245—Treatment of water, waste water, or sewage by flocculation or precipitation of suspended impurities using inorganic agents using basic salts, e.g. of aluminium and iron
• • C—CHEMISTRY; METALLURGY
  • C01—INORGANIC CHEMISTRY
  • C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
  • C01B15/00—Peroxides; Peroxyhydrates; Peroxyacids or salts thereof; Superoxides; Ozonides
  • C01B15/01—Hydrogen peroxide
  • C01B15/022—Preparation from organic compounds
  • C01B15/023—Preparation from organic compounds by the alkyl-anthraquinone 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
  • C01F7/56—Chlorides
• • 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
  • C01F7/68—Aluminium compounds containing sulfur
  • C01F7/74—Sulfates

Definitions

• US patent specification 3 814 701 sets out removal of orgamc matter from spent alumimum oxide deriving from an anthraquinone working solution by calcinating sduminium oxide at a temperature of 300-400 °C.
• the organic matter adsorbed into aluminium oxide will be removed by combustion during calcination.
• the calcinated alumimum oxide is then subjected to caustic treatment and recalculation. Nonetheless, treated in this way, aluminium oxide is highly dusting if recycled in the H2O2 process.
• the invention relates to a new method for purifying impure aluminium oxide, which has been used in hydrogen peroxide preparation for the adsorption of organic components.
• the method of the invention makes it possible to obtain a perfectly pure aluminium salt, such as aluminium sulphate or aluminium chloride, which is even purer than commercially available products.
• aluminium salts prepared with this method are well suited to be used as raw materials in industrial applications, particularly the alruninium salts are suitable to be employed as water purification and retention chemicals.
• the impure aluminium oxide can be prewashed with an organic hydrocarbon solvent before thermal treatment.
• the washing solvent may consist of any organic hydrocarbon capable of dissolving the organic component forming an impurity in aluminium oxide.
• a preferred embodiment uses Shellsol AB as a solvent, which is a commercially available product containing mainly CJO-CI J aromatic hydrocarbons. Prewashing allows those organic useful components to be extracted from aliiminium oxide which are recyclable directly to the hydrogen peroxide process. Moreover, prewashing allows the amount of burnt organic matter to be reduced and simultaneously the organic compounds to be recirculated in the hydrogen peroxide process.
• the acid dissolving-extraction step comprises dissolving ground _d__minium oxide in a concentrated acid solution. Any concentrated mineral acid is appropriate for dissolving, however, sulphuric and hydrochloric acid are recommended. Sulphuric acid used in a 50-60% by weight concentration is considered particularly suitable.
• the dissolving is appropriately enhanced by heating. To ensure nearly complete dissolving of aluminium oxide it is recommended to heat the mixture to a temperature of about 100-160 °C, while stirring for several hours. In the course of dissolving, the organic component contained in aluminium oxide is separated into a separate phase on the surface of the aqueous phase. The reaction mixture is diluted with water to prevent aluminium salts from crystallising. Separation of organic components is enhanced by extracting by means of either entirely pure or entirely recycled, or partly recycled and partly pure organic solvent.
• the extraction solvent may consist of any organic hydrocarbon capable of dissolving organic components from aluminium oxide.
• a preferred embodiment uses Shellsol AB as a solvent, which is a commercially available product containing mainly Cjo-Cn aromatic hydrocarbons.
• Toluene is a particularly advantageous solvent, which after the phase separation can be easily distillated from the organic phase and returned to the step following dissolution.
• the recycled organic solvent to be returned to the extraction step can, if desired, be purified after the phase separation, and if necessary, enhanced with a pure solvent.
• the phases are allowed to separate. Impurities in the organic phase settled on the surface mainly contain organic components deriving from the apatinium oxide and possibly also organic solvents used in extraction.
• the organic phase is partly returned to the extraction step and partly conducted to a combustion plant. If desired, the portion returned to the extraction step can be purified, for instance by distillation.
• impure aluminium oxide is ground and subsequently dissolved in an acid.
• Organic impurities are separated as an organic phase.
• the mixture is diluted with water, and the separation of organic impurities is enhanced with extraction by using recycled and/or pure organic solvents.
• After the phase separation a portion of the organic phase is conducted to a combustion plant and another portion is recycled to the extraction step.
• the aqueous phase is filtered or centrifugated. Undissolved components from the aquoeus phase are returned to the dissolving step and the filtrate is used as such or is further purified.
• the insoluble precipitate was separated from the aqueous phase deriving from the extraction step either by filtering or by centrifugating.

Landscapes

• Chemical & Material Sciences (AREA)
• Organic Chemistry (AREA)
• Inorganic Chemistry (AREA)
• Life Sciences & Earth Sciences (AREA)
• Geology (AREA)
• Hydrology & Water Resources (AREA)
• Engineering & Computer Science (AREA)
• Environmental & Geological Engineering (AREA)
• Water Supply & Treatment (AREA)
• Extraction Or Liquid Replacement (AREA)
• Compounds Of Alkaline-Earth Elements, Aluminum Or Rare-Earth Metals (AREA)

Applications Claiming Priority (3)

Publications (1)

Family

ID=8540737

Family Applications (1)

Country Status (4)

Families Citing this family (2)

Family Cites Families (2)

• 1994
  • 1994-05-20 FI FI942338A patent/FI98508C/fi active
• 1995
  • 1995-05-19 WO PCT/FI1995/000272 patent/WO1995032152A1/en not_active Application Discontinuation
  • 1995-05-19 JP JP7530075A patent/JPH10500931A/ja active Pending
  • 1995-05-19 EP EP95918629A patent/EP0796224A1/de not_active Withdrawn

Non-Patent Citations (1)

Also Published As

Similar Documents

Legal Events