Classifications

• • C—CHEMISTRY; METALLURGY
  • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
  • C22B—PRODUCTION AND REFINING OF METALS; PRETREATMENT OF RAW MATERIALS
  • C22B34/00—Obtaining refractory metals
  • C22B34/10—Obtaining titanium, zirconium or hafnium
  • C22B34/12—Obtaining titanium or titanium compounds from ores or scrap by metallurgical processing; preparation of titanium compounds from other titanium compounds see C01G23/00 - C01G23/08
  • C22B34/1204—Obtaining titanium or titanium compounds from ores or scrap by metallurgical processing; preparation of titanium compounds from other titanium compounds see C01G23/00 - C01G23/08 preliminary treatment of ores or scrap to eliminate non- titanium constituents, e.g. iron, without attacking the titanium constituent
• • C—CHEMISTRY; METALLURGY
  • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
  • C22B—PRODUCTION AND REFINING OF METALS; PRETREATMENT OF RAW MATERIALS
  • C22B3/00—Extraction of metal compounds from ores or concentrates by wet processes
  • C22B3/04—Extraction of metal compounds from ores or concentrates by wet processes by leaching
  • C22B3/16—Extraction of metal compounds from ores or concentrates by wet processes by leaching in organic solutions
• • C—CHEMISTRY; METALLURGY
  • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
  • C22B—PRODUCTION AND REFINING OF METALS; PRETREATMENT OF RAW MATERIALS
  • C22B3/00—Extraction of metal compounds from ores or concentrates by wet processes
  • C22B3/04—Extraction of metal compounds from ores or concentrates by wet processes by leaching
  • C22B3/16—Extraction of metal compounds from ores or concentrates by wet processes by leaching in organic solutions
  • C22B3/1666—Leaching with heterocyclic compounds
• • C—CHEMISTRY; METALLURGY
  • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
  • C22B—PRODUCTION AND REFINING OF METALS; PRETREATMENT OF RAW MATERIALS
  • C22B34/00—Obtaining refractory metals
  • C22B34/10—Obtaining titanium, zirconium or hafnium
  • C22B34/12—Obtaining titanium or titanium compounds from ores or scrap by metallurgical processing; preparation of titanium compounds from other titanium compounds see C01G23/00 - C01G23/08
  • C22B34/1204—Obtaining titanium or titanium compounds from ores or scrap by metallurgical processing; preparation of titanium compounds from other titanium compounds see C01G23/00 - C01G23/08 preliminary treatment of ores or scrap to eliminate non- titanium constituents, e.g. iron, without attacking the titanium constituent
  • C22B34/1213—Obtaining titanium or titanium compounds from ores or scrap by metallurgical processing; preparation of titanium compounds from other titanium compounds see C01G23/00 - C01G23/08 preliminary treatment of ores or scrap to eliminate non- titanium constituents, e.g. iron, without attacking the titanium constituent by wet processes, e.g. using leaching methods or flotation techniques
• • 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
  • Y02P10/00—Technologies related to metal processing
  • Y02P10/20—Recycling

Definitions

• Titanium metal and certain titanium compounds possess properties which make them useful in certain applications.
• titanium dioxide, Ti0 2 which accounts for over 95% of world-wide use of titanium [1] is a compound which is non-toxic, has a high refractive index, and is white when pure, which makes it an ideal filler and pigment for many paint, paper, plastic, and rubber products.
• titanium metal and alloys of titanium are commonly used in the aerospace and related industries because they are light, strong and very corrosion resistant. Other titanium compounds are used as fluxes and in the manufacture of ceramics.
• a significant quantity of the world's titanium products is obtained from synthetic rutile (TiO 2 ), a material which is manufactured from the mineral ilmenite (FeTiO 3 ) via the Becher process. This process is based on a two-step procedure developed by the Western Australian Government Chemical Laboratories in 1961 [2,3], see Fig. 1 , and is currently used in commercial operations in Western Australia.
• the aqueous oxidation step reduced ilmenite particles are suspended in a dilute solution of ammonium chloride which is then stirred and aerated for circa 14 to 16 hours.
• the metallic iron is oxidised to soluble Fe 2+ which diffuses out of the reduced ilmenite particles, eventually precipitating as various iron oxides.
• the ammonium chloride solution contains a mixture of synthetic rutile particles and even finer particles of iron oxide. Because the particles of iron oxide are generally between 1 ⁇ m and 10 ⁇ m in diameter they are easily separated by washing from the larger particles of synthetic rutile, which are generally between 75 ⁇ m and 850 ⁇ m in diameter.
• the electrochemical half-reaction driving the oxidation of the metallic iron is the reduction of oxygen which is supplied by the air bubbling through the solution.
• the present invention provides a method of oxidising and removing metallic iron from a titanium-containing material which method includes oxidising the metallic iron in the presence of an additive that accelerates the rate of oxidation of the metallic iron.
• the titanium-containing material may be selected from ilmenite, reduced ilmenite, rutile, pseudorutile, leucoxene, pseudobrookite and other iron titanate phases or combinations thereof.
• the titanium- containing material is reduced ilmenite.
• the reduced ilmenite may be for example, that produced in the first step of the Becher process but is not limited to this source of reduced ilmenite.
• the metallic iron may be oxidised to soluble Fe + which may diffuse out of the reduced titanium-containing material and precipitate as iron oxide leaving behind a titanium product with diminished metallic iron content.
• the precipitated iron oxide is magnetite.
• the method includes a further step of separating the iron oxide from the titanium product.
• the titanium product is subject to acid leaching.
• the titanium product is synthetic rutile.
• the synthetic rutile is produced by the Becher process.
• the additive may consist of, or include, any redox couple, or mixture of redox couples. Both the reduced and oxidised forms may be soluble in the oxidation solution. The reduced form or forms may be capable of being oxidised by oxygen, and the oxidised form or forms may be capable of being reduced by metallic iron.
• the redox couple may be selected from chemical compounds of the quinone family, quinonimines, diimines, indigo derivatives, diketones, and thiazines, or Diels-Alder adducts of any of the foregoing.
• the oxidation is carried out in the presence of a halide salt.
• the halide salt is a chloride. More preferably the halide salt is ammonium chloride.
• the halide salt is present in an amount in the range of about .01 to 10%.
• the aqueous oxidation of metallic iron is carried out in the presence of a source of oxygen.
• the source of oxygen is air.
• Fig. 1 Schematic representation of the Becher process.
• REDUCTION STEP Ilmenite is mixed with coal and/or coal char and is reduced in a kiln to form Reduced ilmenite.
• OXIDATION STEP Reduced ilmenite is added to a solution of ammonium chloride and the metallic iron is dissolved away by an accelerated corrosion process. The product is Synthetic Rutile.
• Fig. 2 Metallic iron content of samples of standard reduced ilmenite withdrawn at intervals from the aeration reactor. Top curve: 250 grams reduced ilmenite in 500 mis 2% (w/v) NH 4 CI. Lower curves: various concentrations of AQ-2,6.
• Fig. 4 Metallic iron content of samples of standard reduced ilmenite withdrawn at intervals from the aeration reactor. Top curve: 250 grams reduced ilmenite in 500 mis 2% (w/v) NH 4 CI. Lower curves: 0.2% AQ-1 and AQ-2.
• the standard reduced ilmenite was characterised by the following measures.
• the metallic iron content of the fractions of the standard reduced ilmenite recovered by dry screening were measured using a Saturation Magnetisation Analyser, and the results are given in Table 2.
• the metallic iron content is not uniform with average particle size but increases from 26% to just over 30% as the particle size increases, which is believed to reflect a variation in the composition of the native ore, not variations introduced by processing.
• the stirring rate was 750-770 rpm. Air flow into the reactor was measured by a precision bore flow meter and the flow rate was accurately controlled using a fine- adjustment teflon valve. The air flow rate was 2.3-2.6 litres per minute. Before commencing aeration tests 250 g samples of standard reduced ilmenite were rigorously split from the fully-characterised stockpile using a commercial sample divider, and the metallic iron content of the samples was measured. A 500 ml solution of 2% (w/v) AR grade ammonium chloride was made up using deionised water. At the beginning of each run the solution, the standard reduced ilmenite, and the additive were added to the reactor, the air flow was started, and the heating mantle was switched on.
• the reactor reached temperature within 15 min of switching on. Samples of standard reduced ilmenite were recovered every hour by stopping the stirrer and drawing 5 millilitres of the settled contents of the reactor into a glass tube, transferring them to a beaker and washing away any iron oxides present. The remaining solids (typically 5 grams) were dried in an evacuable oven at 50°C and the metallic iron content was measured using a Saturation Magnetisation Analyser. The solids were then returned to the reactor. At the end of the experiment the synthetic rutile product was washed free of iron oxides and dried at 50°C under vacuum. Samples of the iron oxides were collected, and the crystal phases present were identified by X- ray diffraction. The elemental composition of the synthetic rutile was also confirmed by X-ray fluorescence.
• Table 4 Compositions of the synthetic rutile products determined by X-ray fluorescence. The figures are weight percentages, and the elements are reported as oxides because the method used oxidises the samples before analysis.
• compositions of the synthetic rutile products were determined by X-ray fluorescence. As is evident from Table 4, no significant differences in composition were observed in the runs with and without the additive.

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• Engineering & Computer Science (AREA)
• Chemical & Material Sciences (AREA)
• Geology (AREA)
• Life Sciences & Earth Sciences (AREA)
• General Life Sciences & Earth Sciences (AREA)
• Environmental & Geological Engineering (AREA)
• Manufacturing & Machinery (AREA)
• Materials Engineering (AREA)
• Mechanical Engineering (AREA)
• Metallurgy (AREA)
• Organic Chemistry (AREA)
• Geochemistry & Mineralogy (AREA)
• Inorganic Compounds Of Heavy Metals (AREA)
• Catalysts (AREA)
• Compounds Of Iron (AREA)

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• 1995
  • 1995-02-10 AU AUPN1051A patent/AUPN105195A0/en not_active Abandoned
• 1996
  • 1996-02-09 ZA ZA961060A patent/ZA961060B/xx unknown
  • 1996-02-09 WO PCT/AU1996/000059 patent/WO1996024699A1/en not_active Application Discontinuation
  • 1996-02-09 EP EP96901641A patent/EP0808377A4/de not_active Withdrawn

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