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
  • C22B34/1209—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 dry processes, e.g. with selective chlorination of iron or with formation of a titanium bearing slag

Definitions

• the present invention relates to a process for the preparation of titanium dioxide concentrates by removing the iron and optionally the manganese and vanadium from their oxide-containing titanium oxide-containing material with the aid of chlorine-containing gases without the addition of carbon in a chlorination zone at temperatures of over 900 ° C. with the release of Oxygen and volatile iron chlorides and optionally manganese chloride and vanadium chlorides.
• ZA-PS 83/0699 discloses a process for the production of titanium dioxide concentrates by removing the iron from titanium oxide-containing material without the addition of carbon with the aid of chlorine-containing gases.
• the titanium oxide-containing material is allowed to move in the direction of gravity through a reaction zone heated to 800 to 1300 ° C. and is reacted with the chlorine-containing gases which are conducted in countercurrent, during which iron-III-chloride is evaporated.
• a residue essentially consisting of titanium dioxide remains.
• US Pat. No. 3,865,920 discloses a process for producing rutile from ores containing titanium oxide, in which the ores containing titanium oxide are reacted with chlorine in a fluidized bed at elevated temperatures together with 10 to 30% by weight of coke.
• the volatile iron chloride is reacted with oxygen in a chamber above the fluidized bed at temperatures of 980 to 1100 ° C, iron oxide and chlorine being formed from part of the iron chloride, while the rest of the iron chloride is converted to iron in a cooled tube oxide and chlorine are oxidized. Finally, the chlorine is separated from the iron oxide and unreacted iron chloride.
• a disadvantage of the last-mentioned process is that the chlorine obtained has to be condensed in a complex manner before it can be reused in order to separate it from the carbon dioxide it contains.
• This is achieved in the chlorination of the titanium oxide-containing material without the addition of carbon according to the invention in that the gas phase flowing out of the chlorination zone in a downstream oxygenation zone at temperatures from 550 to 900 ° C, preferably from 650 to 850 ° C, with the formation of chlorine and Metal oxides can react and that the chlorine-containing gases are separated from the metal oxides contaminated with unreacted portions of the metal chlorides at temperatures of less than 300 ° C.
• the gases leaving the oxygenation zone are free of carbon monoxide and carbon dioxide in the process according to the invention, they can be returned to the chlorination zone immediately after removal of the metal oxides from them - if appropriate after adding fresh chlorine.
• the reducing atmosphere when the titanium oxide-containing material is heated before it is used in the chlorination zone is obtained in the process according to the invention by treating the titanium oxide-containing material with hydrogen, carbon monoxide or natural gas.
• Ilmenite main constituents: FeTiO 3 , Fe 2 O 3 , TiO 2
• leukoxene weathering product of ilmenite
• titanium magnetite main constituents: Fe 3 0 4 , Fe 2 O 3 , Ti0 2
• TiO 2 titanium oxide-containing material
• the loss of Ti0 2 due to volatilization of titanium IV chloride formed was less than 1%, based on the Ti0 2 contained in the ilmenite.
• a vertical,. 300 cm long quartz tube was used, into which a D1 frit was melted 20 cm from its lower end. 10 cm above the D1 frit, the quartz tube was provided with an upward-facing nozzle for the introduction of ilmenite and on the opposite side with a downward-pointing nozzle for discharging the synthetic rutile. Above the connecting pieces, the quartz tube was lined with Al 2 O 3 ceramic tubes ( ⁇ 50 mm) in order to protect the quartz tube from being attacked by the aggressive gaseous metal chlorides. The chlorine was introduced into the quartz tube from below. The lower part of the quartz tube forming the chlorination zone and reaching to the nozzle was surrounded by a heating coil. The oxygenation zone (inner ⁇ 42 mm; 260 cm long; reaction volume: 3570 cm 3 ), which is lined with the Al 2 O 3 ceramic tubes and adjoins the chlorination zone at the top, is surrounded by electrically heated tube furnaces.
• the gas phase flowing out of the chlorination zone consisting essentially of iron chlorides, chlorine and oxygen, was passed through the oxygenation zone, which was kept in a temperature range from 735 to 810 ° C., with a residence time of 7 s based on chlorine.
• the iron oxide dust formed and unreacted iron chlorides were at a temperature of about 70 ° C, downstream dust separators.
• the chlorine mainly contained in the exhaust gas flow from the dust separator was condensed in a cold trap kept at -70 ° C, while the remaining chlorine gas was washed out with sodium hydroxide solution.
• the remaining oxygen was passed through a gas meter. Ilmenite dosing was carried out for 2 hours; During this time, 3.04 kg of chlorine gas were introduced.
• the synthetic rutile discharged from the chlorination zone through the downward-pointing nozzle contained 94.6% TiO 2 .
• the dust separators contained 740 g of iron oxide.
• the cold trap contained 2.38 kg of chlorine, while an additional 98 g of chlorine gas were washed out with sodium hydroxide solution, ie 81% of the chlorine introduced was recovered.
• Example 2 was repeated with the change that the oxygenation zone was kept in the temperature range from 590 to 631 ° C. Ilmenite dosing was carried out for 1.5 hours; 1.98 kg of chlorine gas were introduced during this time. The synthetic rutile discharged from the chlorination zone contained 95.2% Ti0 2 . After separating iron oxide and iron chlorides from the waste gas stream of the oxygenation zone, 1.09 kg of chlorine were recovered by condensation and washing with sodium hydroxide solution; this corresponds to 55% of the chlorine gas introduced.
• Example 2 was repeated with the change that the oxygenation zone was kept in the temperature range from 839 to 888 ° C.
• Ilmenite dosing was carried out for 2 hours; 2.90 kg of chlorine gas were introduced during this time.
• the synthetic rutile discharged from the chlorination zone contained 95.0% Ti0 2 .
• the dust separators contained 660 g of iron oxide with a content of 0.01% Mn0 and ⁇ 0.001% V 2 0 5 .
• the total of the chlorine condensed in the cold trap and washed out with sodium hydroxide solution was 2.01 kg, ie 69% of the chlorine introduced was recovered.
• Example 2 was repeated with the changes that 20 l / h of oxygen were added to the chlorine gas before it was introduced into the chlorination zone and that the oxygenation zone was kept in the temperature range from 731 to 795 ° C. Ilmenite dosing was carried out for 2 hours; 3.10 kg of chlorine gas were introduced during this time.
• the synthetic rutile discharged from the chlorination zone contained 94.8% Ti0 2 .
• the dust separators contained 730 g of iron oxide after washing out the soluble fractions present in them.
• the total of the chlorine condensed in the cold trap and washed out with sodium hydroxide solution was 2.60 kg, ie 84% of the chlorine introduced was recovered.
• Example 5 was repeated with the changes that 30 l / h of oxygen were added to the chlorine gas before it was introduced into the chlorination zone and that the oxygenation zone was kept in the temperature range from 738 to 784 ° C.
• Ilmenite dosing was carried out for 2 hours; 3.20 kg of chlorine gas were introduced during this time.
• the synthetic rutile discharged from the chlorination zone held 95.2% Ti0 2 .
• the total of the chlorine condensed in the cold trap and washed out with sodium hydroxide solution was 2.60 kg, ie 81% of the chlorine introduced was recovered.
• Example 2 was repeated with the changes that 3.05 kg of chlorine gas had been introduced after two hours of ilmenite metering, that 40 l / h of oxygen were additionally introduced above the fluidized bed and that the oxygenation zone was kept in the temperature range from 730 to 789 ° C.
• the synthetic rutile discharged from the chlorination zone contained 95.3% Ti0 2 . After washing out the soluble fractions contained in them, the dust separators contained 780 g of iron oxide. The total of the chlorine condensed in the cold trap and washed out with sodium hydroxide solution was 2.50 kg, ie 82% of the chlorine introduced was recovered.
• Example 7 was repeated with the change that the oxygenation zone was kept in the temperature range from 740 to 781 ° C.
• Example 2 was repeated with the changes that the ilmenite throughput to 0.62 kg / h and the chlorine through were reduced to 200 1 / h and that the oxygenation zone was kept in the temperature range from 749 to 788 ° C.
• the gas phase flowing out of the chlorination zone was passed through the oxygenation zone with a residence time of 18 s based on chlorine.
• Ilmenite dosing was carried out for 3 hours; During this time, 1.78 kg of chlorine gas were introduced.
• the synthetic rutile discharged from the chlorination zone contained 96.6% Ti0 2 .
• the total of the chlorine condensed in the cold trap and washed out with sodium hydroxide solution was 1.57 kg, ie 88% of the chlorine introduced was recovered.
• Example 9 was repeated with the changes that the oxygenation zone had been extended from 260 to 460 cm, that the oxygenation zone was kept in the temperature range from 745 to 772 ° C. and that the gas phase flowing out of the chlorination zone had a residence time of 32 s based on chlorine passed through the oxygenation zone.
• Ilmenite dosing was carried out for 2 hours; During this time, 1.20 kg of chlorine were introduced.
• the synthetic rutile discharged from the chlorination zone contained 96.4% Ti0 2 .
• the total of the chlorine condensed in the cold trap and washed out with sodium hydroxide solution was 1.09 kg, ie 91% of the chlorine introduced was recovered.
• Example 2 was repeated with the changes that 3.9 kg / h with hydrogen at a temperature of 800 3 C pre-reduced, 8.1% metallic iron containing ilmenite were metered in and that the oxygenation zone in Temperature range from 692 to 763 ° C was kept.
• the chlorination zone was heated to 800 ° C before the start of chlorination; a few minutes after the start of chlorination, the temperature in the chlorination zone rose to 1000 to 1050 ° C.
• the Ilmenit metering was carried out for 1 hour.
• the ilmenite was whirled up with 1.2 m 3 / h of chlorine gas, while an additional 80 1 / h of oxygen were introduced above the fluidized bed. A total of 3.70 kg of chlorine gas was introduced.
• the synthetic rutile discharged from the chlorination zone contained 96.5% Ti0 2 .
• the total of the chlorine condensed in the cold trap and washed out with sodium hydroxide solution was 2.90 kg, ie 78% of
• Example 11 was repeated with the changes that an additional 120 l / h of oxygen were introduced above the fluidized bed, that 1 kg / h of dust-like iron oxide (grain diameter: ⁇ 80 pm) was metered in as catalyst together with the ilmenite and that the temperature in the oxygenation zone was kept between 698 and 741 ° C.
• the ilmenit dosage was carried out for 1 hour; 3.55 kg of chlorine gas were introduced during this time.
• the synthetic rutile released from the chlorination zone contained 95.8% Ti0 2 .
• the total of the chlorine condensed in the cold trap and washed out with sodium hydroxide solution was 3.20 kg, ie 90% of the chlorine introduced was recovered.
• Example 2 was repeated with the modification that 27.1% Ti0 2 , 52.9% Fe and 0.4% V 2 0 5 was metered in instead of ilmenite titanium magnetite.
• Titanomagnetite dosingong was carried out for 1 hour; 1.5 kg of chlorine gas were introduced during this time.
• the oxygenation zone was kept in the temperature range from 895 to 748 ° C.
• the synthetic rutile discharged from the chlorination zone contained 93.8% Ti0 2 , 1.8% Fe and 0.01% V 2 O 5 . After washing out the soluble fractions contained in them, the dust separators contained 520 g of iron oxide. The total of the chlorine condensed in the cold trap and washed out with sodium hydroxide solution was 1.29 kg, ie 86% of the chlorine introduced was recovered.

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• Chemical & Material Sciences (AREA)
• Environmental & Geological Engineering (AREA)
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Citations (10)

• 1985
  • 1985-05-08 DE DE19853516549 patent/DE3516549A1/de not_active Withdrawn
• 1986
  • 1986-04-17 EP EP86105350A patent/EP0201752A3/fr not_active Withdrawn
  • 1986-05-07 AU AU57230/86A patent/AU5723086A/en not_active Abandoned
  • 1986-05-07 ZA ZA863398A patent/ZA863398B/xx unknown
  • 1986-05-07 BR BR8602047A patent/BR8602047A/pt unknown

Patent Citations (10)

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