Patent US3764651A successfully refreshed from Google Patents.
US3764651A
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Production of titanium dioxide concentrates from materials containing ilmenite
Assignee: Bayer AG
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Filing: 1971-04-20
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Granted: 1973-10-09
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Expires: 1991-04-20
Abstract
Abstract In the production of a titanium dioxide concentrate from an ilmenite-containing material the ilmenite-containing material is pretreated at about 600* to 900*C. with its Fe(II) : Fe(III) ratio in the range of about 5 : 1 to 1 : 18. An oxidizing atmosphere may be used to bring such ratio within the desired range and further heating may be effected in an inert atmosphere. The ratio may be monitored by measuring the magnetic properties or the X-ray lattice constants during pretreatment and discontinuing such treatment when the magnetic properties or lattice constants reach predetermined values. The pretreated material is than acid leached to dissolve away undesired materials and leave concentrated titanium dioxide.
Inventors
- 👤 H Henkel
- 👤 H Zirngibl
- 👤 J Rademachers
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 19:27
CPC Classifications
C; C22; C22B; C22B34/00; C22B34/10; C22B34/12; C22B34/1204; Y; Y02; Y02P; Y02P10/00; Y02P10/20
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
24 words
Process according to claim 1, wherein the Fe(II) : Fe(III) ratio is in the range of about 1 : 1 to 1 : 10.
Claim 2
Dependent Claim
24 words
Process according to claim 1, wherein the Fe(II) : Fe(III) ratio is in the range of about 1 : 1.5 to 1 : 4.
Claim 3
Dependent Claim
38 words
Processs according to claim 1, wherein the Fe(II) : Fe(III) ratio is brought within the desired range from an initial value outside said range by tempering in an atmosphere containing about 0.1% to 10% by volume of oxygen.
Claim 4
Dependent Claim
21 words
Process according to claim 1, wherein said tempering is effected in an atmosphere saturated with steam at a temperature above 40*C.
Claim 5
Dependent Claim
42 words
Process according to claim 1, wherein leaching is effected with hydrochloric acid of about 10 to 37% concentration, at a positive pressure up to about 5 atmospheres and at a temperature ranging from about 40*C. to the boiling point of hydrochloric acid.
Claim 6
Dependent Claim
28 words
Process according to claim 1, wherein the ilmenite-containing material has a grain size of about 75 to 350 microns and a magnesium content up to about 7 %.
Claim 7
Dependent Claim
38 words
Process according to claim 1, wherein the Fe(II) : Fe(III) ratio is brought within the desired range from an initial value outside said range by tempering in an oxidizing atmosphere at a temperature of about 600* to 900*C.
Claim 8
Dependent Claim
16 words
Process according to claim 8, wherein the pretreatment includes tempering is effected, in an inert atmosphere.
Claim 9
Dependent Claim
38 words
Process according to claim 8, wherein the Fe(II) : Fe(III) ratio is monitored during the course of the tempering by measuring the lattice constants of the product, the tempering being terminated when the lattice constants reach predetermined value.
Claim 10
Dependent Claim
44 words
Process according to claim 8, wherein the Fe(II) : Fe(III) ratio is monitored during the course of the tempering by measuring the magnetic properties of the product, as determined by X-ray photography, the tempering being terminated when the magnetic properties reach a predetermined values.
Claim 11
Dependent Claim
129 words
Process according to claim 9, wherein the ilmenite-containing material has a grain size of about 75 to 160 microns and a magnesium content up to about 7 %, wherein the Fe(II) : Fe(III) ratio is initially outside the range of 1:1.5 to 1:4 and is monitored during tempering in an oxidizing atmosphere containing steam and about 0.1 to 10% by volume of oxygen at a temperature of about 600* to 800*C, the tempering being discontinued when the monitor indicates a ratio within said range, the product being chilled with water or air after the final tempering, and being leached with azeotropic hydrochloric acid at a positive pressure of about 0.5 to 2 atmospheres and at a temperature ranging from about 40*C to the boiling point of the hydrochloric acid.
References Cited (Backward Citations)
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-10-08 | 1977-04-09 | 1977-10-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-10-08 | 1981-04-09 | 1981-10-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-10-08 | 1985-04-09 | 1985-10-09 | $7700.00 | Window Closed / Lapsed |