Patent US3875285A successfully refreshed from Google Patents.
US3875285A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for selective extraction of ferric iron from trivalent chromium by alkyl-phosphorous compounds
Assignee: Outokumpu Oyj
•
Filing: 1973-08-30
•
Granted: 1975-04-01
•
Expires: 1993-08-30
Abstract
Abstract A process for a selective extraction of iron (III) from an electrolyte-containing aqueous solution in which chromium (III) and iron (III) are present, comprising extracting iron (III) at an elevated temperature with an extraction solution containing acid organic alkyl-substituted phosphorus compound and with a high extraction agent content from a chromium (III) sulphate solution containing over 50 g H2SO4/1, and then regenerating the separated extraction agent before it is recycled to the extraction process.
Inventors
- 👤 Bror Goran Nyman
- 👤 Stig-Erik Hultholm
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 03:26
CPC Classifications
C; C01; C01G; C01G49/00; C01G49/0009
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
57 words
A PROCESS FOR SELECTIVE EXTRACTION OF IRON (III) FROM AN ACID AQUEOUS SOLUTION CONTAINING IRON (III) AND CHRONIUM (III) WHICH COMPRISES EXTRACTING IRON (III) FROM AN AQUEOUS SULPHATE SOLUTION CONTAINING MORE THAN 50 G/H2S04 AT AN ELEVATED TEMPERATURE WITH A HYDROCARBON SOLUTION OF A SUBSTANTIALLY WATER IMMISCIBLE ORGANIC EXTRACTANT, SAID EXTRACTANT BEING AN ACID ALKYL-SUBSTITUTED PHOSPHORIC COMPOUND.
Claim 2
Dependent Claim
57 words
A PROCESS FOR SELECTIVE EXTRACTION OF IRON (III) FROM AN ACID AQUEOUS SOLUTION CONTAINING IRON (III) AND CHRONIUM (III) WHICH COMPRISES EXTRACTING IRON (III) FROM AN AQUEOUS SULPHATE SOLUTION CONTAINING MORE THAN 50 G/H2S04 AT AN ELEVATED TEMPERATURE WITH A HYDROCARBON SOLUTION OF A SUBSTANTIALLY WATER IMMISCIBLE ORGANIC EXTRACTANT, SAID EXTRACTANT BEING AN ACID ALKYL-SUBSTITUTED PHOSPHORIC COMPOUND.
Claim 3
Dependent Claim
37 words
The process of claim 1 wherein after the iron is extracted the hydrocarbon solution is separated from the acid aqueous solution, the extraction solution is regenerated, and the regenerated extraction solution is recycled to the extraction process.
Claim 4
Dependent Claim
12 words
The process of claim 1 wherein the extractant is di-(2-ethylhexyl) phosphoric acid.
Claim 5
Dependent Claim
22 words
The process of claim 1 wherein the hydrocarbon solution is a solution of 1.3 - 1.8 M di-(2-ethylhexyl) phosphoric acid in kerosene.
Claim 6
Dependent Claim
18 words
The process of claim 1 wherein extraction is carried out at a temperature of from 50*C to 70*C.
Claim 7
Dependent Claim
22 words
The process of claim 1 wherein said aqueous sulphate solution contains from 100 to 200 g/l H2SO4 and also contains ammonium sulphate.
Claim 8
Dependent Claim
76 words
The process of claim 1 and including the steps of separating iron in the form of a ferriferous solution containing said extractant, regenerating said extractant by contacting said ferriferous solution with an aqueous hydrochloric solution to obtain a ferriferous hydrochloric solution, removing iron from said ferriferous hydrochloric solution with a mixed extracting agent consisting of about 40% tributylphosphate, about 35% isodecanol and about 25% kerosene by volume, and then regenerating said mixed extraction agent with water.
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) | 1978-03-31 | 1978-09-30 | 1979-04-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-03-31 | 1982-09-30 | 1983-04-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-03-31 | 1986-09-30 | 1987-04-01 | $7700.00 | Window Closed / Lapsed |