US3903239A
Expired / Lapsed
US
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Recovery of titanium dioxide from ores
Assignee: Ortech Corp
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Filing: 1974-04-01
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Granted: 1975-09-02
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Expires: 1994-04-01
Abstract
Abstract Titanium dioxide is recovered from ilmenite in high purity and high yield. The ore is leached with concentrated hydrochloric acid at room temperature to dissolve at least 80% of the titanium and iron values of the ore and to leave gangue material substantially undissolved. After separation from solid gangue material and conversion of ferric iron to ferrous iron, the titanium chlorides are hydrolyzed and titanium oxyhydrate is precipitated. A substantial proportion of the ferrous chloride may be removed from the solution by crystallization prior to the hydrolysis of the titanium chlorides. The titanium oxyhydrate, after separation from the mother liquor, and purified, if necessary to remove traces of ferric materials, is dried and converted into substantially pure pigment grade titanium dioxide. The iron values may be recovered from the mother liquor and a closed hydrochloric acid cycle may be established.
Inventors
- 👤 Serge A Berkovich
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 13:42
CPC Classifications
C; C22; C22B; C22B34/00; C22B34/10; C22B34/12; C22B34/1236; C22B34/124; C22B34/1245; C01; C01G; C01G23/00; C01G23/04; C01G23/047; C01G23/053; C01G23/0536; C01G23/0538; Y; Y10; Y10S; Y10S423/00; Y10S423/01
Claims Analysis
Total Claims: 24
Claim 1
Independent Claim
176 words
A PROCESS FOR THE RECOVERY OF ITANIUM DIOXIDE FROM 2 ILMENITE OR WHICH COMPRISES CONTACTING SAID ORE OR CONCENTRATE THEREOF IN PARTICULATE FORM WITH CONCENTRATED HYDROCHLORIC ACID AT A TEMPERATURE OF FROM ABOUT 15* TO ABOUT 30*C TO SOLUBILIZE AND LEACH FROM SAID ORE OR CONCENTRATE AT LEAST 80% OF THE TITANIUM AND IRON VALUES THEREOF, SAID HYDROCHLORIC ACID BEING PRESENT IN SUCH A QUANTITY AS TO PROVIDE AT LEAST 2 MOLES OF HCI PER MOLE OF FERROUS IRON, AT LEAST 3 MOLES OF HCI PER MOLE OF FERRIC IRON AND AT LEAST 4 MOLES OF HCI PER MOLE OF TITANIUM IN THE ORE OR CONCENTRATE, SEPARATING THE RESULTING LEACH LIQUOR FROM RESIDUAL SOLID MATERIAL, CONVERTING SUBSTANTIALLY ANY FERRIC IRON PRESENT IN SAID LIQUOR TO FERROUS IRON TO PROVIDE AN AQUEOUS SOLUTION OF TITANIUM CHLORIDES AND FERROUS CHLORIDE, HYDROLYZING SAID TITANIUM CHLORIDES AND DEPOSITING FROM SAI AQUEOUS SOLUTION TITANIUM OXYHYDRATE WHILE INHIBITING THE DESPOSITION OF OTHER METAL HYDROXID S, SEPARATING SAID DEPOSITED TITANIUM OXYHYDRATE FRM THE MOTHER LIQUOR, WASHING SAID SEPARATED MATERIAL FREE FROM ENTRAINED MOTHER
Claim 2
Dependent Claim
176 words
A PROCESS FOR THE RECOVERY OF ITANIUM DIOXIDE FROM 2 ILMENITE OR WHICH COMPRISES CONTACTING SAID ORE OR CONCENTRATE THEREOF IN PARTICULATE FORM WITH CONCENTRATED HYDROCHLORIC ACID AT A TEMPERATURE OF FROM ABOUT 15* TO ABOUT 30*C TO SOLUBILIZE AND LEACH FROM SAID ORE OR CONCENTRATE AT LEAST 80% OF THE TITANIUM AND IRON VALUES THEREOF, SAID HYDROCHLORIC ACID BEING PRESENT IN SUCH A QUANTITY AS TO PROVIDE AT LEAST 2 MOLES OF HCI PER MOLE OF FERROUS IRON, AT LEAST 3 MOLES OF HCI PER MOLE OF FERRIC IRON AND AT LEAST 4 MOLES OF HCI PER MOLE OF TITANIUM IN THE ORE OR CONCENTRATE, SEPARATING THE RESULTING LEACH LIQUOR FROM RESIDUAL SOLID MATERIAL, CONVERTING SUBSTANTIALLY ANY FERRIC IRON PRESENT IN SAID LIQUOR TO FERROUS IRON TO PROVIDE AN AQUEOUS SOLUTION OF TITANIUM CHLORIDES AND FERROUS CHLORIDE, HYDROLYZING SAID TITANIUM CHLORIDES AND DEPOSITING FROM SAI AQUEOUS SOLUTION TITANIUM OXYHYDRATE WHILE INHIBITING THE DESPOSITION OF OTHER METAL HYDROXID S, SEPARATING SAID DEPOSITED TITANIUM OXYHYDRATE FRM THE MOTHER LIQUOR, WASHING SAID SEPARATED MATERIAL FREE FROM ENTRAINED MOTHER
Claim 3
Dependent Claim
30 words
The process of claim 1 wherein said ore is contacted with said acid to solubilize and leach from said ore at least 95% of the titanium and iron values thereof.
Claim 4
Dependent Claim
16 words
The process of claim 1 wherein said ore is contacted with said acid in countercurrent manner.
Claim 5
Dependent Claim
18 words
The process of claim 1 wherein said ore is leached at a temperature of about 20* to 25*C.
Claim 6
Dependent Claim
26 words
The process of claim 1 wherein said ferric iron values of said leach liquor are converted to ferrous iron values by the use of sulphur dioxide.
Claim 7
Dependent Claim
60 words
The process of claim 1 wherein said titanium chlorides are hydrolyzed and said titanium oxyhydrate is precipitated by mixing with said aqueous solution from 1 to 3 volumes of water for each volume of aqueous solution, including a seeding amount of titanium oxyhydrate in the resulting mixture and heating the seeded mixture to a temperature of from 80* to 100*C.
Claim 8
Dependent Claim
21 words
The process of claim 6 wherein said seeding amount of titanium oxyhydrate is added with said water to said aqueous solution.
Claim 9
Dependent Claim
14 words
The process of claim 7 wherein said seeding amount is about 1 to 2%.
Claim 10
Dependent Claim
25 words
The process of claim 1 wherein said ore has a particle size distribution of 90 to 95% -100 mesh and less than 50% -325 mesh.
Claim 11
Dependent Claim
53 words
The process of claim 1 including the further steps of recovering iron values from said mother liquor and providing thereby hydrochloric acid, recovering substantially all of the hydrogen chloride values of the latter hydrochloric acid and utilizing said recovered hydrogen chloride values in concentrated hydrochloric acid used to contact further ore or concentrate.
Claim 12
Dependent Claim
27 words
The process of claim 1 wherein said dried titanium oxyhydrate is converted to titanium dioxide by heating the titanium oxyhydrate to a temperature from 700* to 1000*C.
Claim 13
Dependent Claim
16 words
The process of claim 1 wherein said dried titanium oxyhydrate is converted to pigment grade anatase.
Claim 14
Dependent Claim
16 words
The process of claim 1 wherein said dried titanium oxyhydrate is converted to pigment grade rutile.
Claim 15
Dependent Claim
155 words
The process of claim 1 wherein said conversion of ferric iron to ferrous iron and said hydrolysis of titanium chlorides are achieved by heating said leach liquor at a temperature of about 60* to 75*C in the presence of sulphur dioxide for a time sufficient to convert substantially all of the ferric iron content of the leach liquor to ferrous iron, heating water containing a seeding amount of titanium oxyhydrate to a temperature of about 60* to 75*C, mixing said heated leach liquor after said conversion of ferric iron to ferrous iron with said water with said heated water in the proportion of from 1 to 3 volumes of water for each volume of liquor to provide a seeded mixture and heating said seeded mixture at a temperature of about 80* to 100*C while maintaining a sulphur dioxide atmosphere until substantially all of the titanium values of the leach liquor have precipitated as titanium oxyhydrate.
Claim 16
Dependent Claim
21 words
The process of claim 14 wherein said seeded mixture is heated at a temperature of about 95*C for about 1 hour.
Claim 17
Dependent Claim
75 words
The process of claim 1 wherein said ferric iron values of the leach liquor are converted to ferrous iron values by adding powdered metallic iron to the leach liquor in a quantity at least stoichiometrically sufficient to convert the ferric iron to ferrous iron in accordance with the equation: 2FeCl3 + Fe -> 3FeCl2 and reacting said ferric iron with the powdered iron at an elevated temperature below the boiling point of the leach liquor.
Claim 18
Dependent Claim
14 words
The process of claim 16, wherein said elevated temperature is about 50* to 95*C.
Claim 19
Dependent Claim
22 words
The process Of claim 17, wherein said elevated temperature is about 60*C and said reaction is carried out for about 1 hour.
Claim 20
Dependent Claim
35 words
The process of claim 16, wherein said powdered iron is used in a quantity sufficient to convert all said ferric iron to ferrous iron and up to 1% of the quatravalent titanium to trivalent titanium.
Claim 21
Dependent Claim
48 words
The process of claim 16, wherein said leach liquor after the substantial conversion of ferric iron to ferrous iron and before the hydrolysis is cooled to cause crystallization of ferrous chloride dihydrate from said leach liquor, and said ferrous chloride dihydrate is separated from the resulting mother liquor.
Claim 22
Dependent Claim
79 words
The process of claim 20, including the further steps of recovering iron values from the mother liquor from the separation of titanium oxyhydrate and providing thereby hydrochloric acid, recovering substantially all of the hydrogen chloride values of the latter hydrochloric acid, converting the separated ferrous chloride dihydrate into iron oxide and hydrogen chloride and utilzing the latter hydrogen chloride and the hydrogen chloride recovered from said hydrochloric acid to form concentrated hydrochloric acid for contacting further ore or concentrate.
Claim 23
Dependent Claim
77 words
The process of claim 21, wherein said quantity of hydrogen chloride obtained from the ferrous chloride dihydrate and from said hydrochloric acid and used to form recycled concentrated hydrochloric acid is substantially the same quantity as is present in the concentrated hydrochloric acid used to contact the ore or concentrate and any hydrogen chloride values lost from the system are replenished by mixing the appropriate amount of further concentrated hydrochloric acid with the recycle concentrated hydrochloric acid.
Claim 24
Dependent Claim
53 words
The process of claim 1 wherein said hydrolysis of said titanium chlorides, deposition of titanium oxyhydrate and inhibition of deposition of other metal hydroxides is achieved by mixing said aqueous solution of titanium chlorides and ferrous chloride with water to dilute the aqueous solution to a pH of about 0 to about 0.5.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-09-01 | 1979-03-03 | 1979-09-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-09-01 | 1983-03-03 | 1983-09-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-09-01 | 1987-03-03 | 1987-09-02 | $7700.00 | Window Closed / Lapsed |